From e5211a44c0e93aad1d2527ed75cd77b6aedfed7f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:02:38 +0100
Subject: [PATCH 001/277] Issue #16: added a Python script stub for checking
 multi-threading reliability

---
 .../multithreading_reliability_check.py       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100755 src/tests/pipeline/multithreading_reliability_check.py

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
new file mode 100755
index 00000000..c6729066
--- /dev/null
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from pygiftgrab import (VideoSourceFactory,
+                        ColourSpace,
+                        IObservableObserver)
+
+"""
+This script provides a multi-threading reliability check.
+The background is issue #16. It looks like in applications
+where multiple Python threads are involved, occasionally
+the acquisition of the Global Interpreter Lock leads to a
+deadlocks, which crashes the whole application with a
+non-specific segmentation fault.
+
+In this script we run a number of multi-threaded GIFT-Grab
+pipelines, which should serve as a validation that this
+problem is fixed.
+"""
+
+if __name__ == '__main__':
+    print('multithreading reliability check script')

From 30d63ee4b3a5c05966aea868784450269f886cc7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:03:41 +0100
Subject: [PATCH 002/277] Issue #16: added a Bash script for building GIFT-Grab
 and subsequently running the multi-threading reliability check script

---
 .gitignore                                    |  1 +
 .../check_multithreading_reliability.sh       | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100755 src/tests/pipeline/check_multithreading_reliability.sh

diff --git a/.gitignore b/.gitignore
index 08b31459..d7eb0905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ src/build
 src/dist
 src/*.egg-info
 *.swp
+src/tests/pipeline/mtr-build
diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
new file mode 100755
index 00000000..b974bfa8
--- /dev/null
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8 -*-
+
+# Build a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python
+# and NumPy support. Subsequently run the multi-threading
+# reliability check script.
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$CURRENT_DIR/mtr-build
+SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+CMAKE_OPTS="-D USE_FILES=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+
+mkdir -p $BUILD_DIR
+rm -rf $BUILD_DIR/*
+cd $BUILD_DIR
+cmake $CMAKE_OPTS $SOURCE_DIR
+make -j4
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT

From d40566a6eb418212720c041dc09763e1dff6c020 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:06:21 +0100
Subject: [PATCH 003/277] Issue #16: added a 'Dyer' processing node to
 multi-threading reliability checker

---
 .../pipeline/multithreading_reliability_check.py  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c6729066..7aa1fc0d 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -18,5 +18,20 @@
 problem is fixed.
 """
 
+
+class Dyer(IObservableObserver):
+
+    def __init__(self, channel, value):
+        super(Dyer, self).__init__()
+        assert 0 <= channel < 3
+        assert 0 <= value < 256
+        self.channel = channel
+        self.value = value
+
+    def update(self, frame):
+        data = frame.data(True)
+        data[:, :, self.channel] = self.value
+
+
 if __name__ == '__main__':
     print('multithreading reliability check script')

From 974a5f81ff2cd7b64db08b428c82cb7e44ec7860 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:28:08 +0100
Subject: [PATCH 004/277] Issue #16: Python script now uses CLI argument for
 input file

---
 .../pipeline/check_multithreading_reliability.sh   |  2 +-
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index b974bfa8..efae4d95 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -20,4 +20,4 @@ rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7aa1fc0d..02982cf7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+import argparse
+import os.path
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace,
                         IObservableObserver)
@@ -34,4 +36,14 @@ def update(self, frame):
 
 
 if __name__ == '__main__':
-    print('multithreading reliability check script')
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-i', '--input', type=str, required=True,
+                        metavar='VIDEO_FILE',
+                        help='Input video file (HEVC-encoded MP4)')
+    args = parser.parse_args()
+    in_file = args.input
+
+    filename = os.path.basename(in_file)
+    filename, ext = os.path.splitext(filename)
+    assert filename
+    assert ext == '.mp4'

From 88f76a12839c100a138597b54801237b3ff367a3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:32:30 +0100
Subject: [PATCH 005/277] Issue #16: added multi-node pipeline producing red-
 and yellow-dyed output

---
 .../multithreading_reliability_check.py       | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 02982cf7..01c4ead3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from time import sleep
 import argparse
 import os.path
 from pygiftgrab import (VideoSourceFactory,
-                        ColourSpace,
-                        IObservableObserver)
+                        ColourSpace, IObservableObserver,
+                        VideoTargetFactory, Codec)
 
 """
 This script provides a multi-threading reliability check.
@@ -47,3 +48,29 @@ def update(self, frame):
     filename, ext = os.path.splitext(filename)
     assert filename
     assert ext == '.mp4'
+
+    sfac = VideoSourceFactory.get_instance()
+    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    tfac = VideoTargetFactory.get_instance()
+    frame_rate = reader.get_frame_rate()
+
+    red = Dyer(2, 127)
+    green = Dyer(1, 191)
+
+    red_file = os.path.join('.', ''.join([filename, '-red', ext]))
+    red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
+    yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
+    yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
+
+    reader.attach(red)
+    red.attach(red_writer)
+    red.attach(green)
+    green.attach(yellow_writer)
+
+    sleep(20)  # operate pipeline for 20 sec
+
+    reader.detach(red)
+    red.detach(red_writer)
+    red.detach(green)
+    green.detach(yellow_writer)

From bc4eda524d42853c967b87457b8c96337e30d859 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:09:08 +0100
Subject: [PATCH 006/277] Issue #16: added a threaded Histogrammer class stub

---
 .../multithreading_reliability_check.py       | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 01c4ead3..c1ba3b48 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -4,6 +4,7 @@
 from time import sleep
 import argparse
 import os.path
+import threading
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -22,6 +23,30 @@
 """
 
 
+buffer = None
+lock = threading.Lock()
+
+
+class Histogrammer(threading.Thread, IObservableObserver):
+
+    def __init__(self, channel):
+        super(Histogrammer, self).__init__()
+        assert 0 <= channel < 3
+        self.channel = channel
+        self.running = False
+
+    def run(self):
+        if self.running:
+            return
+
+        pass
+
+    def stop(self):
+        self.running = False
+
+    def update(self, frame):
+        pass
+
 class Dyer(IObservableObserver):
 
     def __init__(self, channel, value):
@@ -57,6 +82,8 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
+    hist = Histogrammer(0)
+    hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
@@ -69,6 +96,7 @@ def update(self, frame):
     green.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
+    hist.stop()
 
     reader.detach(red)
     red.detach(red_writer)

From 178bfbdcd116b84e0e61e218e2e6c9efc040eff2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:12:38 +0100
Subject: [PATCH 007/277] Issue #16: added dummy print statement to see
 Histogrammer is alive

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c1ba3b48..4dd459a1 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,6 +40,10 @@ def run(self):
             return
 
         pass
+        self.running = True
+        while self.running:
+            print('Running')
+            sleep(0.100)
 
     def stop(self):
         self.running = False

From b1f5865d0419eca5302c7cd1ae7e0e93a71ec21b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:57:57 +0100
Subject: [PATCH 008/277] Issue #16: factored Histogrammer stub out to
 HistogrammerRed and BuffererRed

---
 .../multithreading_reliability_check.py       | 27 ++++++++++++-------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4dd459a1..12a467bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -23,33 +23,40 @@
 """
 
 
-buffer = None
+buffer_red = None
 lock = threading.Lock()
 
 
-class Histogrammer(threading.Thread, IObservableObserver):
+class BuffererRed(IObservableObserver):
 
-    def __init__(self, channel):
-        super(Histogrammer, self).__init__()
-        assert 0 <= channel < 3
-        self.channel = channel
+    def __init__(self):
+        super(BuffererRed, self).__init__()
+
+    def update(self, frame):
+        global buffer_red
+        # TODO
+
+
+class HistogrammerRed(threading.Thread):
+
+    def __init__(self):
+        super(HistogrammerRed, self).__init__()
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        pass
+        # TODO
         self.running = True
         while self.running:
             print('Running')
+            # TODO
             sleep(0.100)
 
     def stop(self):
         self.running = False
 
-    def update(self, frame):
-        pass
 
 class Dyer(IObservableObserver):
 
@@ -86,7 +93,7 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
-    hist = Histogrammer(0)
+    hist = HistogrammerRed()
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From efcff6293bca733d5609f4d7ce1eda1da407fedd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:59:41 +0100
Subject: [PATCH 009/277] Issue #16: implemented update of BuffererRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 12a467bb..aa8eb0dd 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -5,6 +5,7 @@
 import argparse
 import os.path
 import threading
+import numpy as np
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -34,7 +35,12 @@ def __init__(self):
 
     def update(self, frame):
         global buffer_red
-        # TODO
+        with lock:
+            data = frame.data(True)
+            if buffer_red is None:
+                buffer_red = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
 
 
 class HistogrammerRed(threading.Thread):

From 6e639edaa3bb7fd380376c0fb076a7c3ce91dc08 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:06:55 +0100
Subject: [PATCH 010/277] Issue #16: implemented run of HistogrammerRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index aa8eb0dd..54ceb230 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -53,11 +53,15 @@ def run(self):
         if self.running:
             return
 
-        # TODO
+        global buffer_red
+        histogram = None
         self.running = True
         while self.running:
-            print('Running')
-            # TODO
+            with lock:
+                if buffer_red is not None:
+                    histogram = np.histogram(buffer_red[:, :, 2],
+                                             bins=8, range=(0, 256))
+            print(histogram)
             sleep(0.100)
 
     def stop(self):

From 963bfc0b3fed82d858d37686f514cdd1e8d556c3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:11:05 +0100
Subject: [PATCH 011/277] Issue #16: renamed Dyer vars for clarity

---
 .../multithreading_reliability_check.py       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54ceb230..ff1fda67 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -101,8 +101,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red = Dyer(2, 127)
-    green = Dyer(1, 191)
+    red_dyer = Dyer(2, 127)
+    green_dyer = Dyer(1, 191)
     hist = HistogrammerRed()
     hist.start()
 
@@ -111,15 +111,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red)
-    red.attach(red_writer)
-    red.attach(green)
-    green.attach(yellow_writer)
+    reader.attach(red_dyer)
+    red_dyer.attach(red_writer)
+    red_dyer.attach(green_dyer)
+    green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
     hist.stop()
 
-    reader.detach(red)
-    red.detach(red_writer)
-    red.detach(green)
-    green.detach(yellow_writer)
+    reader.detach(red_dyer)
+    red_dyer.detach(red_writer)
+    red_dyer.detach(green_dyer)
+    green_dyer.detach(yellow_writer)

From f7988744d96ef17b1d290dbdf49ce4079790ac7d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:19:12 +0100
Subject: [PATCH 012/277] Issue #16: Dyer.update uses lock

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ff1fda67..ee40fea7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -78,8 +78,9 @@ def __init__(self, channel, value):
         self.value = value
 
     def update(self, frame):
-        data = frame.data(True)
-        data[:, :, self.channel] = self.value
+        with lock:
+            data = frame.data(True)
+            data[:, :, self.channel] = self.value
 
 
 if __name__ == '__main__':

From 87660df5a1e43f6272f678357bee12d57225e076 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:20:32 +0100
Subject: [PATCH 013/277] Issue #16: inserted a red bufferer into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ee40fea7..dd0f0dcf 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -104,6 +104,9 @@ def update(self, frame):
 
     red_dyer = Dyer(2, 127)
     green_dyer = Dyer(1, 191)
+
+    bufferer_red = BuffererRed()
+
     hist = HistogrammerRed()
     hist.start()
 
@@ -114,6 +117,7 @@ def update(self, frame):
 
     reader.attach(red_dyer)
     red_dyer.attach(red_writer)
+    red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
@@ -122,5 +126,6 @@ def update(self, frame):
 
     reader.detach(red_dyer)
     red_dyer.detach(red_writer)
+    red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)

From 0512cc2963a64b6422d730b315a1a8b3699c35d2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:22:03 +0100
Subject: [PATCH 014/277] Issue #16: fixed call to histogram function

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index dd0f0dcf..0987129b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,8 +59,9 @@ def run(self):
         while self.running:
             with lock:
                 if buffer_red is not None:
-                    histogram = np.histogram(buffer_red[:, :, 2],
-                                             bins=8, range=(0, 256))
+                    histogram, _ = np.histogram(
+                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                    )
             print(histogram)
             sleep(0.100)
 

From 5de7d2ccce9fd3fa56d825de305710b2f9aa41f6 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:32:24 +0100
Subject: [PATCH 015/277] Issue #16: Dyer now really dyes instead of fixing
 color to a value

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0987129b..54802904 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -71,17 +71,18 @@ def stop(self):
 
 class Dyer(IObservableObserver):
 
-    def __init__(self, channel, value):
+    def __init__(self, channel, increment):
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
-        assert 0 <= value < 256
+        assert 0 <= increment < 256
         self.channel = channel
-        self.value = value
+        self.increment = increment
 
     def update(self, frame):
         with lock:
             data = frame.data(True)
-            data[:, :, self.channel] = self.value
+            channel_data = data[:, :, self.channel]
+            channel_data[channel_data < 255 - self.increment] += self.increment
 
 
 if __name__ == '__main__':

From 9416804cd28a21b523c7544d04a90a8f5bef950c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:53:49 +0100
Subject: [PATCH 016/277] Issue #16: histogrammer now displays a redness score
 instead of histogram

---
 .../pipeline/multithreading_reliability_check.py     | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54802904..d8bf97ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -54,15 +54,21 @@ def run(self):
             return
 
         global buffer_red
-        histogram = None
+        histogram, num_bins = None, 10
+        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
                 if buffer_red is not None:
                     histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
                     )
-            print(histogram)
+            if histogram is not None:
+                redness = np.sum(histogram * redness_scale)
+                redness /= np.sum(histogram)
+                redness /= num_bins
+                redness *= 100
+                print('Redness: {} %'.format(int(round(redness))))
             sleep(0.100)
 
     def stop(self):

From 81929f74abc49ab4197037a11cf91d604716658d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:54:11 +0100
Subject: [PATCH 017/277] Issue #16: using more sensible values for dyeing

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index d8bf97ed..a024030b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -110,8 +110,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 127)
-    green_dyer = Dyer(1, 191)
+    red_dyer = Dyer(2, 64)
+    green_dyer = Dyer(1, 64)
 
     bufferer_red = BuffererRed()
 

From 053f499ae6554460df9a755067e1ff5ec817a247 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:59:42 +0100
Subject: [PATCH 018/277] Issue #16: added a BuffererOrig class, a virtual
 replica of BuffererRed

---
 .../multithreading_reliability_check.py         | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a024030b..7b497725 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -43,6 +43,21 @@ def update(self, frame):
                 buffer_red[:, :, :] = data[:, :, :]
 
 
+class BuffererOrig(IObservableObserver):
+
+    def __init__(self):
+        super(BuffererOrig, self).__init__()
+
+    def update(self, frame):
+        global buffer_orig
+        with lock:
+            data = frame.data(True)
+            if buffer_orig is None:
+                buffer_orig = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
+
+
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From 90de48b6c4bc3f06750598427aed8e00c9184bf1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:03:50 +0100
Subject: [PATCH 019/277] Issue #16: BuffererRed now takes buffer as parameter
 to constructor instead of using global var

---
 .../multithreading_reliability_check.py         | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7b497725..0ca024bc 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,7 +6,7 @@
 import os.path
 import threading
 import numpy as np
-from pygiftgrab import (VideoSourceFactory,
+from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
 
@@ -30,17 +30,14 @@
 
 class BuffererRed(IObservableObserver):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(BuffererRed, self).__init__()
+        self.buffer = buffer
 
     def update(self, frame):
-        global buffer_red
         with lock:
             data = frame.data(True)
-            if buffer_red is None:
-                buffer_red = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
+            self.buffer[:, :, :] = data[:, :, :]
 
 
 class BuffererOrig(IObservableObserver):
@@ -121,6 +118,9 @@ def update(self, frame):
 
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+    frame = VideoFrame(ColourSpace.BGRA, False)
+    reader.get_frame(frame)
+    frame_shape = (frame.rows(), frame.cols(), 4)
 
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
@@ -128,7 +128,8 @@ def update(self, frame):
     red_dyer = Dyer(2, 64)
     green_dyer = Dyer(1, 64)
 
-    bufferer_red = BuffererRed()
+    buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = BuffererRed(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 97f8d27931fac817888405fdbad6c6d96f97fb3c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:10:43 +0100
Subject: [PATCH 020/277] Revert "Issue #16: added a BuffererOrig class, a
 virtual replica of BuffererRed"

This reverts commit 053f499ae6554460df9a755067e1ff5ec817a247.
---
 .../multithreading_reliability_check.py         | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0ca024bc..8aed9c85 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+buffer_red = None
 lock = threading.Lock()
 
 
@@ -40,21 +40,6 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class BuffererOrig(IObservableObserver):
-
-    def __init__(self):
-        super(BuffererOrig, self).__init__()
-
-    def update(self, frame):
-        global buffer_orig
-        with lock:
-            data = frame.data(True)
-            if buffer_orig is None:
-                buffer_orig = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
-
-
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From 97e9e65ff42958005dd069c4db9ecbf84cd755a1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:12:15 +0100
Subject: [PATCH 021/277] Issue #16: renamed BuffererRed => Bufferer

---
 src/tests/pipeline/multithreading_reliability_check.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8aed9c85..a345dfd6 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -28,10 +28,10 @@
 lock = threading.Lock()
 
 
-class BuffererRed(IObservableObserver):
+class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):
-        super(BuffererRed, self).__init__()
+        super(Bufferer, self).__init__()
         self.buffer = buffer
 
     def update(self, frame):
@@ -114,7 +114,7 @@ def update(self, frame):
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = BuffererRed(buffer_red)
+    bufferer_red = Bufferer(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 7dacc271d3d662ed794cb90b3d0847b52bf1add9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:15:02 +0100
Subject: [PATCH 022/277] Issue #16: HistogrammerRed now takes buffer as a
 constructor argument rather than using global var

---
 .../pipeline/multithreading_reliability_check.py    | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a345dfd6..4a58d7bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -42,24 +42,23 @@ def update(self, frame):
 
 class HistogrammerRed(threading.Thread):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(HistogrammerRed, self).__init__()
+        self.buffer = buffer
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        global buffer_red
         histogram, num_bins = None, 10
         redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
-                if buffer_red is not None:
-                    histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
-                    )
+                histogram, _ = np.histogram(
+                    self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
+                )
             if histogram is not None:
                 redness = np.sum(histogram * redness_scale)
                 redness /= np.sum(histogram)
@@ -116,7 +115,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed()
+    hist = HistogrammerRed(buffer_red)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 051e36c55386d570a09e8af6bf05b053fa770d31 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:22:12 +0100
Subject: [PATCH 023/277] Issue #16: HistogrammerRed is now generic
 Histogrammer

---
 .../multithreading_reliability_check.py       | 26 ++++++++++++-------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4a58d7bb..0de913ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,10 +40,14 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class HistogrammerRed(threading.Thread):
+class Histogrammer(threading.Thread):
 
-    def __init__(self, buffer):
-        super(HistogrammerRed, self).__init__()
+    channels = ('Blue', 'Green', 'Red', 'Alpha')
+
+    def __init__(self, buffer, channel):
+        super(Histogrammer, self).__init__()
+        assert channel in range(3)
+        self.channel = channel
         self.buffer = buffer
         self.running = False
 
@@ -52,7 +56,7 @@ def run(self):
             return
 
         histogram, num_bins = None, 10
-        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
+        scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
@@ -60,11 +64,13 @@ def run(self):
                     self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
                 )
             if histogram is not None:
-                redness = np.sum(histogram * redness_scale)
-                redness /= np.sum(histogram)
-                redness /= num_bins
-                redness *= 100
-                print('Redness: {} %'.format(int(round(redness))))
+                coloredness = np.sum(histogram * scale)
+                coloredness /= np.sum(histogram)
+                coloredness /= num_bins
+                coloredness *= 100
+                print('{}ness of dyed image: {} %'.format(
+                    Histogrammer.channels[self.channel], int(round(coloredness))
+                ))
             sleep(0.100)
 
     def stop(self):
@@ -115,7 +121,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed(buffer_red)
+    hist = Histogrammer(buffer_red, 2)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 6d1c02b253e6d480d2344ae16eae310c1d166c24 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:27:00 +0100
Subject: [PATCH 024/277] Issue #16: Histogrammer now accepts a tag for
 generically printing what the image is

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0de913ed..168b6b9f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,11 +44,12 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel):
+    def __init__(self, buffer, channel, tag):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         self.channel = channel
         self.buffer = buffer
+        self.tag = tag
         self.running = False
 
     def run(self):
@@ -68,8 +69,8 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of dyed image: {} %'.format(
-                    Histogrammer.channels[self.channel], int(round(coloredness))
+                print('{}ness of {} image: {} %'.format(
+                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
                 ))
             sleep(0.100)
 
@@ -121,7 +122,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = Histogrammer(buffer_red, 2)
+    hist = Histogrammer(buffer_red, 2, 'red-dyed')
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 712da535ef3165f93fc9a8ed4134903a9041ff4f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:34:30 +0100
Subject: [PATCH 025/277] Issue #16: inserted an original image histogrammer
 into the pipeline

---
 .../multithreading_reliability_check.py       | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 168b6b9f..971e94b2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -121,25 +121,32 @@ def update(self, frame):
 
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
+    buffer_orig = np.zeros_like(buffer_red)
+    bufferer_orig = Bufferer(buffer_orig)
 
-    hist = Histogrammer(buffer_red, 2, 'red-dyed')
-    hist.start()
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red.start()
+    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red_dyer)
+    reader.attach(bufferer_orig)
+    bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
-    hist.stop()
+    hist_red.stop()
+    hist_orig.stop()
 
-    reader.detach(red_dyer)
+    reader.detach(bufferer_orig)
+    bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)

From 7707bb26bc9b16cc38a27d9fcb925b5ff8d1a6e2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:39:33 +0100
Subject: [PATCH 026/277] Issue #16: Histogrammer now accepts a frame rate and
 flag for displaying coloredness

---
 .../multithreading_reliability_check.py       | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 971e94b2..df093c13 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,12 +44,15 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag):
+    def __init__(self, buffer, channel, tag, frame_rate, show=True):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
+        assert 0 < frame_rate <= 60
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
+        self.show = show
+        self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
     def run(self):
@@ -69,10 +72,12 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of {} image: {} %'.format(
-                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
-                ))
-            sleep(0.100)
+                if self.show:
+                    print('{}ness of {} image: {} %'.format(
+                        Histogrammer.channels[self.channel],
+                        self.tag, int(round(coloredness))
+                    ))
+            sleep(self.sleep_interval)
 
     def stop(self):
         self.running = False
@@ -124,9 +129,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 63f2fcd47eb6e6cad73614c6dae072d0fe1f05d9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:45:12 +0100
Subject: [PATCH 027/277] Issue #16: now can specify the frequency of
 coloredness prints

---
 .../pipeline/multithreading_reliability_check.py  | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index df093c13..43e82a19 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,14 +44,16 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, show=True):
+    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
+        assert 0 <= display_freq
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
-        self.show = show
+        self.display_freq = display_freq
+        self.num_skipped = 0
         self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
@@ -72,11 +74,14 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                if self.show:
+                if self.num_skipped >= self.display_freq:
                     print('{}ness of {} image: {} %'.format(
                         Histogrammer.channels[self.channel],
                         self.tag, int(round(coloredness))
                     ))
+                    self.num_skipped = 0
+                else:
+                    self.num_skipped += 1
             sleep(self.sleep_interval)
 
     def stop(self):
@@ -129,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From c8c22be3dc83e00833485d867e596acc5aa16190 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:47:38 +0100
Subject: [PATCH 028/277] Issue #16: dyeing red more prominently

---
 src/tests/pipeline/multithreading_reliability_check.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 43e82a19..72ab94d2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -126,7 +126,7 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 64)
+    red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)

From e0076d9a2b9c5062d33bb010de6735fe37bbc734 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:53:47 +0100
Subject: [PATCH 029/277] Issue #16: frame rate values that reproduced the
 problem

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 72ab94d2..42cc36e3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -134,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 125b11eec9d3c4a8838f9b39f3f98b02a797afdb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:54:25 +0100
Subject: [PATCH 030/277] Issue #16: using Debug CMake type in build script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index efae4d95..7ea874b2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -13,6 +13,7 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR

From 20fb19e7601806e790797f1d037051ec0e5fc72b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 08:28:50 +0100
Subject: [PATCH 031/277] Issue #16: renamed variable for clarity in run script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 7ea874b2..2be8fea2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,15 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
-BUILD_DIR=$CURRENT_DIR/mtr-build
-SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$ROOT_DIR/mtr-build
+SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*

From 7dac7e6e36afbb2028073edc6af37b6d10619836 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:00:44 +0100
Subject: [PATCH 032/277] Issue #16: setting ulimit to dump cores when running
 check

---
 src/tests/pipeline/check_multithreading_reliability.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 2be8fea2..4519cb84 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+ulimit -c unlimited
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
@@ -22,3 +23,5 @@ cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+ulimit -c 0

From 470cfc842c43de888f3c85e810940ce78ad13ea2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:02:44 +0100
Subject: [PATCH 033/277] Issue #16: saving all output in a hierarchical
 session directory

---
 .../pipeline/check_multithreading_reliability.sh    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 4519cb84..f3cc6910 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,13 +15,26 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
+mkdir $SESSION_DIR
 ulimit -c unlimited
 
+BUILD_LOG=$SESSION_DIR/build.log
+{
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
+} > $BUILD_LOG 2>&1
+
+run_no=1
+WORKING_DIR=$SESSION_DIR/$run_no
+mkdir $WORKING_DIR
+cd $WORKING_DIR
+RUN_LOG=$WORKING_DIR/run.log
+{
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+} > $RUN_LOG 2>&1
 
 ulimit -c 0

From 5e89c911da13ee50ac533200436e0bacefb46f38 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:05:12 +0100
Subject: [PATCH 034/277] Issue #16: added indentation for readability

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f3cc6910..71e9efc0 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -21,11 +21,11 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
-mkdir -p $BUILD_DIR
-rm -rf $BUILD_DIR/*
-cd $BUILD_DIR
-cmake $CMAKE_OPTS $SOURCE_DIR
-make -j4
+    mkdir -p $BUILD_DIR
+    rm -rf $BUILD_DIR/*
+    cd $BUILD_DIR
+    cmake $CMAKE_OPTS $SOURCE_DIR
+    make -j4
 } > $BUILD_LOG 2>&1
 
 run_no=1
@@ -34,7 +34,7 @@ mkdir $WORKING_DIR
 cd $WORKING_DIR
 RUN_LOG=$WORKING_DIR/run.log
 {
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
 } > $RUN_LOG 2>&1
 
 ulimit -c 0

From bc2a2d935666bc5abc478541f485ff6fb654571f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:14:47 +0100
Subject: [PATCH 035/277] Issue #16: can now specify number of reps in check
 script

---
 .../check_multithreading_reliability.sh       | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e9efc0..52eed368 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,13 +28,20 @@ BUILD_LOG=$SESSION_DIR/build.log
     make -j4
 } > $BUILD_LOG 2>&1
 
-run_no=1
-WORKING_DIR=$SESSION_DIR/$run_no
-mkdir $WORKING_DIR
-cd $WORKING_DIR
-RUN_LOG=$WORKING_DIR/run.log
-{
-    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
-} > $RUN_LOG 2>&1
+num_reps=1
+if [ $# -ge 2 ];
+then
+    num_reps=$2
+fi
+for run_no in `seq 1 $num_reps`;
+do
+    WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
+    mkdir $WORKING_DIR
+    cd $WORKING_DIR
+    RUN_LOG=$WORKING_DIR/run.log
+    {
+        PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    } > $RUN_LOG 2>&1
+done
 
 ulimit -c 0

From 435b302d28e8312efe9b86ea2e0d944adcf6f7f5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:38:52 +0100
Subject: [PATCH 036/277] Issue #16: can now optionally specify root output dir
 (e.g. not to fill up disk space)

---
 .../pipeline/check_multithreading_reliability.sh    | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 52eed368..1a90362e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,22 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+if [ $# -ge 3 ];
+then
+    ROOT_DIR=$3
+else
+    ROOT_DIR=$CALL_DIR
+fi
+
 BUILD_DIR=$ROOT_DIR/mtr-build
-SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
 ulimit -c unlimited

From d69aee7b3ce66917e3c41c42cb089cccd931c993 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:48:37 +0100
Subject: [PATCH 037/277] Issue #16: logging frequency of exit codes as well

---
 .../pipeline/check_multithreading_reliability.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 1a90362e..f7fbb5fe 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -40,6 +40,8 @@ if [ $# -ge 2 ];
 then
     num_reps=$2
 fi
+
+declare -a exit_code_freqs
 for run_no in `seq 1 $num_reps`;
 do
     WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
@@ -48,7 +50,21 @@ do
     RUN_LOG=$WORKING_DIR/run.log
     {
         PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+        exit_code=$?
+        echo "Exit code was: $exit_code"
+        freq=${exit_code_freqs[$exit_code]}
+        let freq=$freq+1
+        exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
+
+    sleep 5
+done
+
+EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+for exit_code in "${!exit_code_freqs[@]}";
+do
+    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From dfab9e4050c937ba2bc654a64c77ff05aa809c65 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:59:58 +0100
Subject: [PATCH 038/277] Issue #16: nicer formatting of exit code frequencies
 log

---
 src/tests/pipeline/check_multithreading_reliability.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f7fbb5fe..419b7c08 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -62,9 +62,14 @@ do
 done
 
 EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+printf "%10s" "frequency" >> $EXIT_CODES_LOG
+printf "\n" >> $EXIT_CODES_LOG
 for exit_code in "${!exit_code_freqs[@]}";
 do
-    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
+    printf "%10d" $exit_code >> $EXIT_CODES_LOG
+    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+    printf "\n" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From b74aeb5552c78401d7a2e9d91c307cbca389a3f3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:02:37 +0100
Subject: [PATCH 039/277] Issue #16: ignoring output folder to avoid an
 accidental commit of big files

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index d7eb0905..35b7a77b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ src/dist
 src/*.egg-info
 *.swp
 src/tests/pipeline/mtr-build
+gg-iss-16

From 099903ae87d26e8d6cbeff2467cf5ab73d5d0ddf Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:06:29 +0100
Subject: [PATCH 040/277] Issue #16: using absolute path expansion if root-dir
 passed as a CLI param

---
 src/tests/pipeline/check_multithreading_reliability.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 419b7c08..18b9133e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -11,7 +11,7 @@ SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
 if [ $# -ge 3 ];
 then
-    ROOT_DIR=$3
+    ROOT_DIR="$( cd "$3" >/dev/null && pwd )"
 else
     ROOT_DIR=$CALL_DIR
 fi

From a0cc695e749fe2372c7364923c832b0744c354e1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:56:45 +0100
Subject: [PATCH 041/277] Issue #16: intermediately writing exit codes every 10
 iterations

---
 .../check_multithreading_reliability.sh       | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 18b9133e..64b58250 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -58,18 +58,21 @@ do
         exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
 
-    sleep 5
-done
+    if [ $(($run_no % 10)) -eq 0 ] || [ $run_no -eq $num_reps ];
+    then
+        EXIT_CODES_LOG=$SESSION_DIR/exit-codes-$run_no.csv
+        printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+        printf "%10s" "frequency" >> $EXIT_CODES_LOG
+        printf "\n" >> $EXIT_CODES_LOG
+        for exit_code in "${!exit_code_freqs[@]}";
+        do
+            printf "%10d" $exit_code >> $EXIT_CODES_LOG
+            printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+            printf "\n" >> $EXIT_CODES_LOG
+        done
+    fi
 
-EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
-printf "%10s" "exit-code" >> $EXIT_CODES_LOG
-printf "%10s" "frequency" >> $EXIT_CODES_LOG
-printf "\n" >> $EXIT_CODES_LOG
-for exit_code in "${!exit_code_freqs[@]}";
-do
-    printf "%10d" $exit_code >> $EXIT_CODES_LOG
-    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
-    printf "\n" >> $EXIT_CODES_LOG
+    sleep 5
 done
 
 ulimit -c 0

From 2ee8a52b8806fb9c76f351aff6b1a16f5aad2797 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:19:39 +0100
Subject: [PATCH 042/277] Issue #16: using git-describe to tag the output with
 the version used

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 64b58250..71e2bb62 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,6 +28,7 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
+    git describe --dirty
     mkdir -p $BUILD_DIR
     rm -rf $BUILD_DIR/*
     cd $BUILD_DIR

From e319205c580a484bf665b00cd50f513e8bd79495 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:47:45 +0100
Subject: [PATCH 043/277] Issue #16: querying for update override after the
 acquisition of GIL

---
 src/python/wrapper.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index ba34c646..a82018bc 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -332,11 +332,13 @@ class IObservableObserverWrapper : public gg::IObservable
 
     void update(gg::VideoFrame & frame)
     {
-        if (override f = this->get_override("update"))
         {
-            VideoFrameNumPyWrapper wrapped_frame(&frame);
             gg::ScopedPythonGILLock gil_lock;
-            f(boost::ref(wrapped_frame));
+            if (override f = this->get_override("update"))
+            {
+                VideoFrameNumPyWrapper wrapped_frame(&frame);
+                f(boost::ref(wrapped_frame));
+            }
         }
         notify(frame);
     }

From 40777b605d5dd4caa599543d70b5ce6281346218 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 13:35:54 +0100
Subject: [PATCH 044/277] Issue #16: checking update method overridden in
 Python before actually calling it from within IObserverWrapper

---
 src/python/wrapper.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index a82018bc..83c4f11a 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -268,7 +268,8 @@ class IObserverWrapper : public gg::IObserver, public wrapper<gg::IObserver>
     {
         gg::ScopedPythonGILLock gil_lock;
         VideoFrameNumPyWrapper wrapped_frame(&frame);
-        this->get_override("update")(boost::ref(wrapped_frame));
+        if (override f = this->get_override("update"))
+            f(boost::ref(wrapped_frame));
     }
 };
 

From f47b76ed396d64b4720bc2b3128ad0ae91a3453e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:06:14 +0100
Subject: [PATCH 045/277] Issue #16: using Pythonic percentage formatting

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 42cc36e3..e1c50e30 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -73,11 +73,10 @@ def run(self):
                 coloredness = np.sum(histogram * scale)
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
-                coloredness *= 100
                 if self.num_skipped >= self.display_freq:
-                    print('{}ness of {} image: {} %'.format(
+                    print('{}ness of {} image: {:.0%}'.format(
                         Histogrammer.channels[self.channel],
-                        self.tag, int(round(coloredness))
+                        self.tag, coloredness
                     ))
                     self.num_skipped = 0
                 else:

From ed3a02ade578786a4fe13a2a2de1d11a2cf22780 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:24:39 +0100
Subject: [PATCH 046/277] Issue #16: added a SnapshotSaver class that
 implements IObserver directly

---
 .../multithreading_reliability_check.py       | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index e1c50e30..a880b355 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,9 +6,10 @@
 import os.path
 import threading
 import numpy as np
+import scipy.misc
 from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
-                        VideoTargetFactory, Codec)
+                        VideoTargetFactory, Codec, IObserver)
 
 """
 This script provides a multi-threading reliability check.
@@ -28,6 +29,32 @@
 lock = threading.Lock()
 
 
+class SnapshotSaver(IObserver):
+    """A snapshot saver for saving incoming frames to PNG files."""
+
+    def __init__(self, root_dir, frame_rate=0.2):
+        """
+        Initialise a snapshot saver with a saving frequency.
+
+        :param root_dir: the folder where to save the snapshots
+        :param frame_rate: saving frequency. The default value tells
+        the saver to save a frame every 5 sec.
+        """
+        super(SnapshotSaver, self).__init__()
+        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
+        self.save_freq = 1.0 / frame_rate
+        self.root_dir = root_dir
+        self.num_called = 0
+
+    def update(self, frame):
+        """Implement ``IObserver.update``."""
+        self.num_called += 1
+        if self.num_called % self.save_freq == 1:
+            out_file = os.path.join(self.root_dir,
+                                    'frame-{:010d}.png'.format(self.num_called))
+            scipy.misc.imsave(out_file, frame.data(True))
+
+
 class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):

From f87c8ff63dafe2a3f50df67cb90b0f630c906126 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:25:08 +0100
Subject: [PATCH 047/277] Issue #16: inserted snapshot saver into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a880b355..f1a1697f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -170,12 +170,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    yellow_snapshots = SnapshotSaver('.')
+
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
+    green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
     hist_red.stop()
@@ -187,3 +190,4 @@ def update(self, frame):
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)
+    green_dyer.detach(yellow_snapshots)

From 9be73e9e497502e8f033498b16d31962a2fdbea0 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:47:20 +0100
Subject: [PATCH 048/277] Issue #16: fixed timed saving of snapshots

---
 .../multithreading_reliability_check.py       | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index f1a1697f..7eca3382 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from time import sleep
+from time import (sleep, time)
 import argparse
 import os.path
 import threading
@@ -32,27 +32,29 @@
 class SnapshotSaver(IObserver):
     """A snapshot saver for saving incoming frames to PNG files."""
 
-    def __init__(self, root_dir, frame_rate=0.2):
+    def __init__(self, root_dir, save_freq=5):
         """
         Initialise a snapshot saver with a saving frequency.
 
         :param root_dir: the folder where to save the snapshots
-        :param frame_rate: saving frequency. The default value tells
-        the saver to save a frame every 5 sec.
+        :param save_freq: saving frequency. The default value tells
+        the saver to save every 5 seconds.
         """
         super(SnapshotSaver, self).__init__()
-        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
-        self.save_freq = 1.0 / frame_rate
+        assert 5 <= save_freq  # to avoid flooding disk with images
+        self.save_freq = save_freq
         self.root_dir = root_dir
-        self.num_called = 0
+        self.last_saved = time()
+        self.num_saved = 0
 
     def update(self, frame):
         """Implement ``IObserver.update``."""
-        self.num_called += 1
-        if self.num_called % self.save_freq == 1:
+        if time() - self.last_saved >= self.save_freq:
+            self.num_saved += 1
             out_file = os.path.join(self.root_dir,
-                                    'frame-{:010d}.png'.format(self.num_called))
+                                    'frame-{:010d}.png'.format(self.num_saved))
             scipy.misc.imsave(out_file, frame.data(True))
+            self.last_saved = time()
 
 
 class Bufferer(IObservableObserver):

From e4c17d0bae912678e40f9cb55c50036409d47ed5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:10:24 +0100
Subject: [PATCH 049/277] Issue #16: renamed buffer => np_buffer as buffer is
 built-in type

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7eca3382..0091b993 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,9 +59,9 @@ def update(self, frame):
 
 class Bufferer(IObservableObserver):
 
-    def __init__(self, buffer):
+    def __init__(self, np_buffer):
         super(Bufferer, self).__init__()
-        self.buffer = buffer
+        self.buffer = np_buffer
 
     def update(self, frame):
         with lock:
@@ -73,13 +73,13 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
+    def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
         assert 0 <= display_freq
         self.channel = channel
-        self.buffer = buffer
+        self.buffer = np_buffer
         self.tag = tag
         self.display_freq = display_freq
         self.num_skipped = 0

From 93a6cc7dd22c8fb933cdffbabc5875dc8097f408 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:17:51 +0100
Subject: [PATCH 050/277] Issue #16: renamed global buffers for clarity

---
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0091b993..8d3d4b89 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+np_buffer_red, np_buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -157,14 +157,14 @@ def update(self, frame):
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
-    buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = Bufferer(buffer_red)
-    buffer_orig = np.zeros_like(buffer_red)
-    bufferer_orig = Bufferer(buffer_orig)
+    np_buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = Bufferer(np_buffer_red)
+    np_buffer_orig = np.zeros_like(np_buffer_red)
+    bufferer_orig = Bufferer(np_buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
+    hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
+    hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 782c8a17e04a1b9c230106ad6012cfcc769c880a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:20:01 +0100
Subject: [PATCH 051/277] Issue #16: commented checker script

---
 .../multithreading_reliability_check.py       | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8d3d4b89..b4d21c9c 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,11 @@
 """
 
 
+# global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None
+
+# mutex protecting frame data passed from node to node
+# in the GIFT-Grab processing pipeline
 lock = threading.Lock()
 
 
@@ -58,22 +62,41 @@ def update(self, frame):
 
 
 class Bufferer(IObservableObserver):
+    """GIFT-Grab processing node that updates a frame buffer."""
 
     def __init__(self, np_buffer):
+        """Initialise a bufferer that will update given buffer."""
         super(Bufferer, self).__init__()
         self.buffer = np_buffer
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             self.buffer[:, :, :] = data[:, :, :]
 
 
 class Histogrammer(threading.Thread):
+    """
+    GIFT-Grab processing node that computes the histogram of
+    an image channel and prints how "colored" that channel is.
+    """
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
     def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
+        """
+        :param np_buffer: image buffer to use
+        :param channel: image channel to compute coloredness for
+        :param tag: a tag describing what this image is, e.g.
+        how it's been processed within a GIFT-Grab pipeline
+        :param frame_rate: the rate at which to compute the
+        coloredness (unit: frames-per-second)
+        :param display_freq: how many times to skip the display
+        of computed coloredness, e.g. if 5 is provided, the
+        coloredness of every 5th frame will be printed to the
+        console
+        """
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
@@ -87,6 +110,7 @@ def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         self.running = False
 
     def run(self):
+        """Override ``Thread.run``."""
         if self.running:
             return
 
@@ -113,12 +137,18 @@ def run(self):
             sleep(self.sleep_interval)
 
     def stop(self):
+        """Stop the thread."""
         self.running = False
 
 
 class Dyer(IObservableObserver):
+    """Dyes specified channel of an incoming video frame."""
 
     def __init__(self, channel, increment):
+        """
+        :param channel: image channel to dye
+        :param increment: how much to dye the image channel
+        """
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
         assert 0 <= increment < 256
@@ -126,6 +156,7 @@ def __init__(self, channel, increment):
         self.increment = increment
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             channel_data = data[:, :, self.channel]
@@ -145,35 +176,46 @@ def update(self, frame):
     assert filename
     assert ext == '.mp4'
 
+    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
+    # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
+    # create a red and green Dyer
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
+    # create the bufferer for the red and green Dyers
     np_buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(np_buffer_red)
     np_buffer_orig = np.zeros_like(np_buffer_red)
     bufferer_orig = Bufferer(np_buffer_orig)
 
+    # create the histogrammers for the red-dyed and
+    # the original video frames, and start them
     hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
     hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
+    # create encoders for the red-dyed and yellow-dyed (as green
+    # is applied on top of red) video streams
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    # create a SnapshotSavers for saving a number of yellow-dyed
+    # video frames
     yellow_snapshots = SnapshotSaver('.')
 
+    # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
@@ -183,9 +225,12 @@ def update(self, frame):
     green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
+
+    # stop the histogrammers
     hist_red.stop()
     hist_orig.stop()
 
+    # disassemble the GIFT-Grab pipeline
     reader.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)

From b6261c57d99e2cb25ba46f897cb09fa633e0d4e7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:24 +0100
Subject: [PATCH 052/277] Issue #16: moved issue-specific comments to shell
 script

---
 .../check_multithreading_reliability.sh        | 17 +++++++++++++----
 .../multithreading_reliability_check.py        | 18 +++++-------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e2bb62..ceafc345 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -1,10 +1,19 @@
 #!/usr/bin/env bash
 # -*- coding: utf-8 -*-
 
-# Build a basic GIFT-Grab capable of reading a video file,
-# and encoding to a video file in real time, with Python
-# and NumPy support. Subsequently run the multi-threading
-# reliability check script.
+# This script provides a multi-threading reliability check.
+# The background is issue #16. It looks like in applications
+# where multiple Python threads are involved, occasionally
+# the acquisition of the Global Interpreter Lock leads to a
+# deadlocks, which crashes the whole application with a
+# non-specific segmentation fault.
+#
+# It builds a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python and
+# NumPy support. It subsequently runs a multi-threaded
+# GIFT-Grab pipeline a number of times, recording the exit
+# status each time. This is essentially a stress-test that
+# should serve as a validation that issue #16 is fixed.
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index b4d21c9c..3fdad38b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,11 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+"""
+Example showing a complex GIFT-Grab pipeline with
+multiple intermediate processing nodes.
+"""
+
 from time import (sleep, time)
 import argparse
 import os.path
@@ -11,19 +16,6 @@
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
-"""
-This script provides a multi-threading reliability check.
-The background is issue #16. It looks like in applications
-where multiple Python threads are involved, occasionally
-the acquisition of the Global Interpreter Lock leads to a
-deadlocks, which crashes the whole application with a
-non-specific segmentation fault.
-
-In this script we run a number of multi-threaded GIFT-Grab
-pipelines, which should serve as a validation that this
-problem is fixed.
-"""
-
 
 # global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None

From fdfbde5942972c6845e1a8542ebd3f9a95bc9cd2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:45 +0100
Subject: [PATCH 053/277] Issue #16: added synopsis display to shell script

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index ceafc345..c6419403 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,18 @@
 # status each time. This is essentially a stress-test that
 # should serve as a validation that issue #16 is fixed.
 
+if [ $# -lt 1 ] || [ $# -gt 3 ];
+then
+    THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
+    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tnum_reps:   how many times to run the Python script "
+    printf "(default: once)\n"
+    printf "\toutput_dir: where to save all the generated output "
+    printf "(default: current directory)\n"
+    exit 1
+fi
+
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py

From 9108bdd280f1c21a5995424f64ef9988a144b827 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:57:52 +0100
Subject: [PATCH 054/277] Issue #16: shell script now shows the current session
 directory before starting

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index c6419403..39df9537 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -45,6 +45,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
+echo "Session directory: $SESSION_DIR"
 ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log

From 345aa97c3092eccf95ee25a88d716def8b8eae3d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:01:37 +0100
Subject: [PATCH 055/277] Issue #16: shorter name for Python script

---
 .../{multithreading_reliability_check.py => complex_pipeline.py}  | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{multithreading_reliability_check.py => complex_pipeline.py} (100%)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/complex_pipeline.py
similarity index 100%
rename from src/tests/pipeline/multithreading_reliability_check.py
rename to src/tests/pipeline/complex_pipeline.py

From 1a88e0b6db4c8802b10a2e14b4f504ee7c25edf9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:02:26 +0100
Subject: [PATCH 056/277] Issue #16: shorter name for Bash script

---
 ...heck_multithreading_reliability.sh => run-complex-pipeline.sh} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{check_multithreading_reliability.sh => run-complex-pipeline.sh} (100%)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/run-complex-pipeline.sh
similarity index 100%
rename from src/tests/pipeline/check_multithreading_reliability.sh
rename to src/tests/pipeline/run-complex-pipeline.sh

From 5db2dcc64da2ba52367f95718a5279bf56c97327 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:37 +0100
Subject: [PATCH 057/277] Issue #16: fixed typos

---
 src/tests/pipeline/complex_pipeline.py     | 2 +-
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 3fdad38b..1d9d7346 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -203,7 +203,7 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    # create a SnapshotSavers for saving a number of yellow-dyed
+    # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
     yellow_snapshots = SnapshotSaver('.')
 
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 39df9537..5166507b 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -5,7 +5,7 @@
 # The background is issue #16. It looks like in applications
 # where multiple Python threads are involved, occasionally
 # the acquisition of the Global Interpreter Lock leads to a
-# deadlocks, which crashes the whole application with a
+# deadlock, which crashes the whole application with a
 # non-specific segmentation fault.
 #
 # It builds a basic GIFT-Grab capable of reading a video file,

From 37ff47d70ea5a1f3a59086ff769963642d488448 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:55 +0100
Subject: [PATCH 058/277] Issue #16: reduced snapshot output

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1d9d7346..66686f1e 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -205,7 +205,7 @@ def update(self, frame):
 
     # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
-    yellow_snapshots = SnapshotSaver('.')
+    yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)

From 67ee662300a3f795933d9747b7f73a39126a0dae Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:09:55 +0100
Subject: [PATCH 059/277] Issue #16: fixed calling of Python script from Bash
 script

---
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5166507b..3ed9e038 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -29,7 +29,7 @@ fi
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/complex_pipeline.py
 if [ $# -ge 3 ];
 then
     ROOT_DIR="$( cd "$3" >/dev/null && pwd )"

From 4f5a726f0b31f1546d03f55846fa99eb41cb4676 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:33 +0100
Subject: [PATCH 060/277] Issue #16: added an RTD page linking to the complex
 pipeline example

---
 doc/source/complex.rst | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 doc/source/complex.rst

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
new file mode 100644
index 00000000..3982fb7f
--- /dev/null
+++ b/doc/source/complex.rst
@@ -0,0 +1,20 @@
+.. _Complex:
+
+Multi-threaded processing pipelines
+===================================
+
+This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
+processing nodes and threads.
+The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
+
+.. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
+.. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
+.. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
+
+Below is the commented full source code:
+
+.. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
+   :language: python
+   :linenos:
+

From aae78a2e148bf1892bb15cd178b26ea5d3403afc Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:59 +0100
Subject: [PATCH 061/277] Issue #16: added the new RTD page to the index

---
 doc/source/index.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/index.rst b/doc/source/index.rst
index 2c8fddc2..8e9af514 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -51,6 +51,7 @@ Examples
    network
    scipy
    encoding
+   complex
 
 Citing GIFT-Grab
 ^^^^^^^^^^^^^^^^

From 291fc3fdbc1a196cb3da74090b20242a1b09a5f3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:59:27 +0100
Subject: [PATCH 062/277] Issue #16: fixed cross-reference to NumPy example
 from new RTD page

---
 doc/source/complex.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 3982fb7f..6e0c8a60 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -5,7 +5,7 @@ Multi-threaded processing pipelines
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files

From 153175848d7881f7295780aef2f9d95afb0aaee7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 12:00:34 +0100
Subject: [PATCH 063/277] Issue #16: added link from new RTD page to example
 source code on GitHub

---
 doc/source/complex.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 6e0c8a60..060bce72 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -12,9 +12,11 @@ Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code:
+Below is the commented full source code, which is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
    :linenos:
 
+.. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
+

From a7c65355514be06a3c02e8ca33d5ed3475164974 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:47:20 +0100
Subject: [PATCH 064/277] Issue #16: made the title of the new RTD page more
 descriptive

---
 doc/source/complex.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 060bce72..98fc12ce 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -1,7 +1,7 @@
 .. _Complex:
 
-Multi-threaded processing pipelines
-===================================
+Multi-threaded complex processing pipelines
+===========================================
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.

From e78af6fb6f192be5d81c462e0a24bc8cebd0b092 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:51:26 +0100
Subject: [PATCH 065/277] Issue #16: revised the RTD page wording for clarity

---
 doc/source/complex.rst | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 98fc12ce..0d231ccb 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -3,16 +3,19 @@
 Multi-threaded complex processing pipelines
 ===========================================
 
-This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
-processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
+The example below shows how GIFT-Grab can be used for running complex pipelines with multiple
+intermediate processing nodes and threads.
+The intermediate processing nodes in this example are built on the same principles as in the
+:ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code, which is also available on GitHub_:
+The full source code of the example is below.
+Please follow the comments and the flow of code.
+This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python

From 2e07b9af9477f884e24c04c9f861168793761f0a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:53:21 +0100
Subject: [PATCH 066/277] Issue #16: removed line numbers from example on new
 RTD page

---
 doc/source/complex.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 0d231ccb..eba60359 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -19,7 +19,6 @@ This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
-   :linenos:
 
 .. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
 

From 3657e010bbc2ca054ceed1e7730398618ca8ffff Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:02:38 +0100
Subject: [PATCH 067/277] Issue #16: added a Python script stub for checking
 multi-threading reliability

---
 .../multithreading_reliability_check.py       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100755 src/tests/pipeline/multithreading_reliability_check.py

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
new file mode 100755
index 00000000..c6729066
--- /dev/null
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from pygiftgrab import (VideoSourceFactory,
+                        ColourSpace,
+                        IObservableObserver)
+
+"""
+This script provides a multi-threading reliability check.
+The background is issue #16. It looks like in applications
+where multiple Python threads are involved, occasionally
+the acquisition of the Global Interpreter Lock leads to a
+deadlocks, which crashes the whole application with a
+non-specific segmentation fault.
+
+In this script we run a number of multi-threaded GIFT-Grab
+pipelines, which should serve as a validation that this
+problem is fixed.
+"""
+
+if __name__ == '__main__':
+    print('multithreading reliability check script')

From 559b95508d017daac15445daa24443cfed5dbb79 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:03:41 +0100
Subject: [PATCH 068/277] Issue #16: added a Bash script for building GIFT-Grab
 and subsequently running the multi-threading reliability check script

---
 .gitignore                                    |  1 +
 .../check_multithreading_reliability.sh       | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100755 src/tests/pipeline/check_multithreading_reliability.sh

diff --git a/.gitignore b/.gitignore
index 08b31459..d7eb0905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ src/build
 src/dist
 src/*.egg-info
 *.swp
+src/tests/pipeline/mtr-build
diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
new file mode 100755
index 00000000..b974bfa8
--- /dev/null
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8 -*-
+
+# Build a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python
+# and NumPy support. Subsequently run the multi-threading
+# reliability check script.
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$CURRENT_DIR/mtr-build
+SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+CMAKE_OPTS="-D USE_FILES=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+
+mkdir -p $BUILD_DIR
+rm -rf $BUILD_DIR/*
+cd $BUILD_DIR
+cmake $CMAKE_OPTS $SOURCE_DIR
+make -j4
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT

From 21bd7c0f1b4f0f49e5e4222d3b22ccb734aac746 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:06:21 +0100
Subject: [PATCH 069/277] Issue #16: added a 'Dyer' processing node to
 multi-threading reliability checker

---
 .../pipeline/multithreading_reliability_check.py  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c6729066..7aa1fc0d 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -18,5 +18,20 @@
 problem is fixed.
 """
 
+
+class Dyer(IObservableObserver):
+
+    def __init__(self, channel, value):
+        super(Dyer, self).__init__()
+        assert 0 <= channel < 3
+        assert 0 <= value < 256
+        self.channel = channel
+        self.value = value
+
+    def update(self, frame):
+        data = frame.data(True)
+        data[:, :, self.channel] = self.value
+
+
 if __name__ == '__main__':
     print('multithreading reliability check script')

From 7b7e8ced9678d5933d1efac9902c8fdfa5c41c31 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:28:08 +0100
Subject: [PATCH 070/277] Issue #16: Python script now uses CLI argument for
 input file

---
 .../pipeline/check_multithreading_reliability.sh   |  2 +-
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index b974bfa8..efae4d95 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -20,4 +20,4 @@ rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7aa1fc0d..02982cf7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+import argparse
+import os.path
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace,
                         IObservableObserver)
@@ -34,4 +36,14 @@ def update(self, frame):
 
 
 if __name__ == '__main__':
-    print('multithreading reliability check script')
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-i', '--input', type=str, required=True,
+                        metavar='VIDEO_FILE',
+                        help='Input video file (HEVC-encoded MP4)')
+    args = parser.parse_args()
+    in_file = args.input
+
+    filename = os.path.basename(in_file)
+    filename, ext = os.path.splitext(filename)
+    assert filename
+    assert ext == '.mp4'

From da1a82d98eaaed478f9f084df91a09a5edc33d1a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:32:30 +0100
Subject: [PATCH 071/277] Issue #16: added multi-node pipeline producing red-
 and yellow-dyed output

---
 .../multithreading_reliability_check.py       | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 02982cf7..01c4ead3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from time import sleep
 import argparse
 import os.path
 from pygiftgrab import (VideoSourceFactory,
-                        ColourSpace,
-                        IObservableObserver)
+                        ColourSpace, IObservableObserver,
+                        VideoTargetFactory, Codec)
 
 """
 This script provides a multi-threading reliability check.
@@ -47,3 +48,29 @@ def update(self, frame):
     filename, ext = os.path.splitext(filename)
     assert filename
     assert ext == '.mp4'
+
+    sfac = VideoSourceFactory.get_instance()
+    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    tfac = VideoTargetFactory.get_instance()
+    frame_rate = reader.get_frame_rate()
+
+    red = Dyer(2, 127)
+    green = Dyer(1, 191)
+
+    red_file = os.path.join('.', ''.join([filename, '-red', ext]))
+    red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
+    yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
+    yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
+
+    reader.attach(red)
+    red.attach(red_writer)
+    red.attach(green)
+    green.attach(yellow_writer)
+
+    sleep(20)  # operate pipeline for 20 sec
+
+    reader.detach(red)
+    red.detach(red_writer)
+    red.detach(green)
+    green.detach(yellow_writer)

From e63d5e3f7b4efaa7fd977954fefc376a5f7a583a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:09:08 +0100
Subject: [PATCH 072/277] Issue #16: added a threaded Histogrammer class stub

---
 .../multithreading_reliability_check.py       | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 01c4ead3..c1ba3b48 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -4,6 +4,7 @@
 from time import sleep
 import argparse
 import os.path
+import threading
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -22,6 +23,30 @@
 """
 
 
+buffer = None
+lock = threading.Lock()
+
+
+class Histogrammer(threading.Thread, IObservableObserver):
+
+    def __init__(self, channel):
+        super(Histogrammer, self).__init__()
+        assert 0 <= channel < 3
+        self.channel = channel
+        self.running = False
+
+    def run(self):
+        if self.running:
+            return
+
+        pass
+
+    def stop(self):
+        self.running = False
+
+    def update(self, frame):
+        pass
+
 class Dyer(IObservableObserver):
 
     def __init__(self, channel, value):
@@ -57,6 +82,8 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
+    hist = Histogrammer(0)
+    hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
@@ -69,6 +96,7 @@ def update(self, frame):
     green.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
+    hist.stop()
 
     reader.detach(red)
     red.detach(red_writer)

From e9bebfc5b1a08ea3b61da395fefe830c48bf4937 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:12:38 +0100
Subject: [PATCH 073/277] Issue #16: added dummy print statement to see
 Histogrammer is alive

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c1ba3b48..4dd459a1 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,6 +40,10 @@ def run(self):
             return
 
         pass
+        self.running = True
+        while self.running:
+            print('Running')
+            sleep(0.100)
 
     def stop(self):
         self.running = False

From 7395cbd13722c582f195bc7b34124eef29ebc1f9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:57:57 +0100
Subject: [PATCH 074/277] Issue #16: factored Histogrammer stub out to
 HistogrammerRed and BuffererRed

---
 .../multithreading_reliability_check.py       | 27 ++++++++++++-------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4dd459a1..12a467bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -23,33 +23,40 @@
 """
 
 
-buffer = None
+buffer_red = None
 lock = threading.Lock()
 
 
-class Histogrammer(threading.Thread, IObservableObserver):
+class BuffererRed(IObservableObserver):
 
-    def __init__(self, channel):
-        super(Histogrammer, self).__init__()
-        assert 0 <= channel < 3
-        self.channel = channel
+    def __init__(self):
+        super(BuffererRed, self).__init__()
+
+    def update(self, frame):
+        global buffer_red
+        # TODO
+
+
+class HistogrammerRed(threading.Thread):
+
+    def __init__(self):
+        super(HistogrammerRed, self).__init__()
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        pass
+        # TODO
         self.running = True
         while self.running:
             print('Running')
+            # TODO
             sleep(0.100)
 
     def stop(self):
         self.running = False
 
-    def update(self, frame):
-        pass
 
 class Dyer(IObservableObserver):
 
@@ -86,7 +93,7 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
-    hist = Histogrammer(0)
+    hist = HistogrammerRed()
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From e54ed8906f01e61d6b6f25763b186bdc6e747fe1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:59:41 +0100
Subject: [PATCH 075/277] Issue #16: implemented update of BuffererRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 12a467bb..aa8eb0dd 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -5,6 +5,7 @@
 import argparse
 import os.path
 import threading
+import numpy as np
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -34,7 +35,12 @@ def __init__(self):
 
     def update(self, frame):
         global buffer_red
-        # TODO
+        with lock:
+            data = frame.data(True)
+            if buffer_red is None:
+                buffer_red = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
 
 
 class HistogrammerRed(threading.Thread):

From 0851be6d1cdbc52a599c6c06b32b342e31f5afe2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:06:55 +0100
Subject: [PATCH 076/277] Issue #16: implemented run of HistogrammerRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index aa8eb0dd..54ceb230 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -53,11 +53,15 @@ def run(self):
         if self.running:
             return
 
-        # TODO
+        global buffer_red
+        histogram = None
         self.running = True
         while self.running:
-            print('Running')
-            # TODO
+            with lock:
+                if buffer_red is not None:
+                    histogram = np.histogram(buffer_red[:, :, 2],
+                                             bins=8, range=(0, 256))
+            print(histogram)
             sleep(0.100)
 
     def stop(self):

From 3b40ef0808d1d4777420488e949f981e2e417019 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:11:05 +0100
Subject: [PATCH 077/277] Issue #16: renamed Dyer vars for clarity

---
 .../multithreading_reliability_check.py       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54ceb230..ff1fda67 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -101,8 +101,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red = Dyer(2, 127)
-    green = Dyer(1, 191)
+    red_dyer = Dyer(2, 127)
+    green_dyer = Dyer(1, 191)
     hist = HistogrammerRed()
     hist.start()
 
@@ -111,15 +111,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red)
-    red.attach(red_writer)
-    red.attach(green)
-    green.attach(yellow_writer)
+    reader.attach(red_dyer)
+    red_dyer.attach(red_writer)
+    red_dyer.attach(green_dyer)
+    green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
     hist.stop()
 
-    reader.detach(red)
-    red.detach(red_writer)
-    red.detach(green)
-    green.detach(yellow_writer)
+    reader.detach(red_dyer)
+    red_dyer.detach(red_writer)
+    red_dyer.detach(green_dyer)
+    green_dyer.detach(yellow_writer)

From a05de379b64dfd03b80a1da11fb77f1bdd141b1a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:19:12 +0100
Subject: [PATCH 078/277] Issue #16: Dyer.update uses lock

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ff1fda67..ee40fea7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -78,8 +78,9 @@ def __init__(self, channel, value):
         self.value = value
 
     def update(self, frame):
-        data = frame.data(True)
-        data[:, :, self.channel] = self.value
+        with lock:
+            data = frame.data(True)
+            data[:, :, self.channel] = self.value
 
 
 if __name__ == '__main__':

From 41bb484d3ebcc4f9d0f8dcb4c247735de3c705e2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:20:32 +0100
Subject: [PATCH 079/277] Issue #16: inserted a red bufferer into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ee40fea7..dd0f0dcf 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -104,6 +104,9 @@ def update(self, frame):
 
     red_dyer = Dyer(2, 127)
     green_dyer = Dyer(1, 191)
+
+    bufferer_red = BuffererRed()
+
     hist = HistogrammerRed()
     hist.start()
 
@@ -114,6 +117,7 @@ def update(self, frame):
 
     reader.attach(red_dyer)
     red_dyer.attach(red_writer)
+    red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
@@ -122,5 +126,6 @@ def update(self, frame):
 
     reader.detach(red_dyer)
     red_dyer.detach(red_writer)
+    red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)

From 1855e357912539e5f81db019940cafc8fdf6384c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:22:03 +0100
Subject: [PATCH 080/277] Issue #16: fixed call to histogram function

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index dd0f0dcf..0987129b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,8 +59,9 @@ def run(self):
         while self.running:
             with lock:
                 if buffer_red is not None:
-                    histogram = np.histogram(buffer_red[:, :, 2],
-                                             bins=8, range=(0, 256))
+                    histogram, _ = np.histogram(
+                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                    )
             print(histogram)
             sleep(0.100)
 

From 6c468c9b064e72ac0b8327ef47e14d51bf5150e2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:32:24 +0100
Subject: [PATCH 081/277] Issue #16: Dyer now really dyes instead of fixing
 color to a value

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0987129b..54802904 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -71,17 +71,18 @@ def stop(self):
 
 class Dyer(IObservableObserver):
 
-    def __init__(self, channel, value):
+    def __init__(self, channel, increment):
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
-        assert 0 <= value < 256
+        assert 0 <= increment < 256
         self.channel = channel
-        self.value = value
+        self.increment = increment
 
     def update(self, frame):
         with lock:
             data = frame.data(True)
-            data[:, :, self.channel] = self.value
+            channel_data = data[:, :, self.channel]
+            channel_data[channel_data < 255 - self.increment] += self.increment
 
 
 if __name__ == '__main__':

From ae82811e40d7d89a459fb938312fa30b2adefbcf Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:53:49 +0100
Subject: [PATCH 082/277] Issue #16: histogrammer now displays a redness score
 instead of histogram

---
 .../pipeline/multithreading_reliability_check.py     | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54802904..d8bf97ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -54,15 +54,21 @@ def run(self):
             return
 
         global buffer_red
-        histogram = None
+        histogram, num_bins = None, 10
+        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
                 if buffer_red is not None:
                     histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
                     )
-            print(histogram)
+            if histogram is not None:
+                redness = np.sum(histogram * redness_scale)
+                redness /= np.sum(histogram)
+                redness /= num_bins
+                redness *= 100
+                print('Redness: {} %'.format(int(round(redness))))
             sleep(0.100)
 
     def stop(self):

From a571512e53c8d29ead300c3364f8305ce2776028 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:54:11 +0100
Subject: [PATCH 083/277] Issue #16: using more sensible values for dyeing

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index d8bf97ed..a024030b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -110,8 +110,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 127)
-    green_dyer = Dyer(1, 191)
+    red_dyer = Dyer(2, 64)
+    green_dyer = Dyer(1, 64)
 
     bufferer_red = BuffererRed()
 

From 42544f9809936b41838406947bcc8e39f22dc81e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:59:42 +0100
Subject: [PATCH 084/277] Issue #16: added a BuffererOrig class, a virtual
 replica of BuffererRed

---
 .../multithreading_reliability_check.py         | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a024030b..7b497725 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -43,6 +43,21 @@ def update(self, frame):
                 buffer_red[:, :, :] = data[:, :, :]
 
 
+class BuffererOrig(IObservableObserver):
+
+    def __init__(self):
+        super(BuffererOrig, self).__init__()
+
+    def update(self, frame):
+        global buffer_orig
+        with lock:
+            data = frame.data(True)
+            if buffer_orig is None:
+                buffer_orig = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
+
+
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From 59bf5b2eeb9e9635bca79e444989f795d0b73c38 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:03:50 +0100
Subject: [PATCH 085/277] Issue #16: BuffererRed now takes buffer as parameter
 to constructor instead of using global var

---
 .../multithreading_reliability_check.py         | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7b497725..0ca024bc 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,7 +6,7 @@
 import os.path
 import threading
 import numpy as np
-from pygiftgrab import (VideoSourceFactory,
+from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
 
@@ -30,17 +30,14 @@
 
 class BuffererRed(IObservableObserver):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(BuffererRed, self).__init__()
+        self.buffer = buffer
 
     def update(self, frame):
-        global buffer_red
         with lock:
             data = frame.data(True)
-            if buffer_red is None:
-                buffer_red = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
+            self.buffer[:, :, :] = data[:, :, :]
 
 
 class BuffererOrig(IObservableObserver):
@@ -121,6 +118,9 @@ def update(self, frame):
 
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+    frame = VideoFrame(ColourSpace.BGRA, False)
+    reader.get_frame(frame)
+    frame_shape = (frame.rows(), frame.cols(), 4)
 
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
@@ -128,7 +128,8 @@ def update(self, frame):
     red_dyer = Dyer(2, 64)
     green_dyer = Dyer(1, 64)
 
-    bufferer_red = BuffererRed()
+    buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = BuffererRed(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From f436ed71a9c94735ffae8a3fa21f015d4e7cb80a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:10:43 +0100
Subject: [PATCH 086/277] Revert "Issue #16: added a BuffererOrig class, a
 virtual replica of BuffererRed"

This reverts commit 053f499ae6554460df9a755067e1ff5ec817a247.
---
 .../multithreading_reliability_check.py         | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0ca024bc..8aed9c85 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+buffer_red = None
 lock = threading.Lock()
 
 
@@ -40,21 +40,6 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class BuffererOrig(IObservableObserver):
-
-    def __init__(self):
-        super(BuffererOrig, self).__init__()
-
-    def update(self, frame):
-        global buffer_orig
-        with lock:
-            data = frame.data(True)
-            if buffer_orig is None:
-                buffer_orig = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
-
-
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From db0527fa773b561176ea4ee634915ed81396d2ed Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:12:15 +0100
Subject: [PATCH 087/277] Issue #16: renamed BuffererRed => Bufferer

---
 src/tests/pipeline/multithreading_reliability_check.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8aed9c85..a345dfd6 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -28,10 +28,10 @@
 lock = threading.Lock()
 
 
-class BuffererRed(IObservableObserver):
+class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):
-        super(BuffererRed, self).__init__()
+        super(Bufferer, self).__init__()
         self.buffer = buffer
 
     def update(self, frame):
@@ -114,7 +114,7 @@ def update(self, frame):
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = BuffererRed(buffer_red)
+    bufferer_red = Bufferer(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 85db3b3a91520b8ecbb21289149828b054e1ea4c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:15:02 +0100
Subject: [PATCH 088/277] Issue #16: HistogrammerRed now takes buffer as a
 constructor argument rather than using global var

---
 .../pipeline/multithreading_reliability_check.py    | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a345dfd6..4a58d7bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -42,24 +42,23 @@ def update(self, frame):
 
 class HistogrammerRed(threading.Thread):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(HistogrammerRed, self).__init__()
+        self.buffer = buffer
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        global buffer_red
         histogram, num_bins = None, 10
         redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
-                if buffer_red is not None:
-                    histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
-                    )
+                histogram, _ = np.histogram(
+                    self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
+                )
             if histogram is not None:
                 redness = np.sum(histogram * redness_scale)
                 redness /= np.sum(histogram)
@@ -116,7 +115,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed()
+    hist = HistogrammerRed(buffer_red)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 1105daacf93b3564840845a527ebcb76a7f58cad Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:22:12 +0100
Subject: [PATCH 089/277] Issue #16: HistogrammerRed is now generic
 Histogrammer

---
 .../multithreading_reliability_check.py       | 26 ++++++++++++-------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4a58d7bb..0de913ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,10 +40,14 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class HistogrammerRed(threading.Thread):
+class Histogrammer(threading.Thread):
 
-    def __init__(self, buffer):
-        super(HistogrammerRed, self).__init__()
+    channels = ('Blue', 'Green', 'Red', 'Alpha')
+
+    def __init__(self, buffer, channel):
+        super(Histogrammer, self).__init__()
+        assert channel in range(3)
+        self.channel = channel
         self.buffer = buffer
         self.running = False
 
@@ -52,7 +56,7 @@ def run(self):
             return
 
         histogram, num_bins = None, 10
-        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
+        scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
@@ -60,11 +64,13 @@ def run(self):
                     self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
                 )
             if histogram is not None:
-                redness = np.sum(histogram * redness_scale)
-                redness /= np.sum(histogram)
-                redness /= num_bins
-                redness *= 100
-                print('Redness: {} %'.format(int(round(redness))))
+                coloredness = np.sum(histogram * scale)
+                coloredness /= np.sum(histogram)
+                coloredness /= num_bins
+                coloredness *= 100
+                print('{}ness of dyed image: {} %'.format(
+                    Histogrammer.channels[self.channel], int(round(coloredness))
+                ))
             sleep(0.100)
 
     def stop(self):
@@ -115,7 +121,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed(buffer_red)
+    hist = Histogrammer(buffer_red, 2)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 0b9296a1f449017f3bce1a41c4a222799f7c5e63 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:27:00 +0100
Subject: [PATCH 090/277] Issue #16: Histogrammer now accepts a tag for
 generically printing what the image is

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0de913ed..168b6b9f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,11 +44,12 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel):
+    def __init__(self, buffer, channel, tag):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         self.channel = channel
         self.buffer = buffer
+        self.tag = tag
         self.running = False
 
     def run(self):
@@ -68,8 +69,8 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of dyed image: {} %'.format(
-                    Histogrammer.channels[self.channel], int(round(coloredness))
+                print('{}ness of {} image: {} %'.format(
+                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
                 ))
             sleep(0.100)
 
@@ -121,7 +122,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = Histogrammer(buffer_red, 2)
+    hist = Histogrammer(buffer_red, 2, 'red-dyed')
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 5b0e52117dca89d46a99b8adeae450c2e4f52881 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:34:30 +0100
Subject: [PATCH 091/277] Issue #16: inserted an original image histogrammer
 into the pipeline

---
 .../multithreading_reliability_check.py       | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 168b6b9f..971e94b2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -121,25 +121,32 @@ def update(self, frame):
 
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
+    buffer_orig = np.zeros_like(buffer_red)
+    bufferer_orig = Bufferer(buffer_orig)
 
-    hist = Histogrammer(buffer_red, 2, 'red-dyed')
-    hist.start()
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red.start()
+    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red_dyer)
+    reader.attach(bufferer_orig)
+    bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
-    hist.stop()
+    hist_red.stop()
+    hist_orig.stop()
 
-    reader.detach(red_dyer)
+    reader.detach(bufferer_orig)
+    bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)

From 682dae16daafce89efce95e62569bed75d462529 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:39:33 +0100
Subject: [PATCH 092/277] Issue #16: Histogrammer now accepts a frame rate and
 flag for displaying coloredness

---
 .../multithreading_reliability_check.py       | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 971e94b2..df093c13 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,12 +44,15 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag):
+    def __init__(self, buffer, channel, tag, frame_rate, show=True):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
+        assert 0 < frame_rate <= 60
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
+        self.show = show
+        self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
     def run(self):
@@ -69,10 +72,12 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of {} image: {} %'.format(
-                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
-                ))
-            sleep(0.100)
+                if self.show:
+                    print('{}ness of {} image: {} %'.format(
+                        Histogrammer.channels[self.channel],
+                        self.tag, int(round(coloredness))
+                    ))
+            sleep(self.sleep_interval)
 
     def stop(self):
         self.running = False
@@ -124,9 +129,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From decbde60935fa97c079bf77912c3136448465f3d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:45:12 +0100
Subject: [PATCH 093/277] Issue #16: now can specify the frequency of
 coloredness prints

---
 .../pipeline/multithreading_reliability_check.py  | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index df093c13..43e82a19 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,14 +44,16 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, show=True):
+    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
+        assert 0 <= display_freq
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
-        self.show = show
+        self.display_freq = display_freq
+        self.num_skipped = 0
         self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
@@ -72,11 +74,14 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                if self.show:
+                if self.num_skipped >= self.display_freq:
                     print('{}ness of {} image: {} %'.format(
                         Histogrammer.channels[self.channel],
                         self.tag, int(round(coloredness))
                     ))
+                    self.num_skipped = 0
+                else:
+                    self.num_skipped += 1
             sleep(self.sleep_interval)
 
     def stop(self):
@@ -129,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From a6e4c34bd3ea95cfeae3eddd853e93dc9d4db96b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:47:38 +0100
Subject: [PATCH 094/277] Issue #16: dyeing red more prominently

---
 src/tests/pipeline/multithreading_reliability_check.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 43e82a19..72ab94d2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -126,7 +126,7 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 64)
+    red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)

From e544b48f9ff4d26be36430439a88e7fa71728931 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:53:47 +0100
Subject: [PATCH 095/277] Issue #16: frame rate values that reproduced the
 problem

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 72ab94d2..42cc36e3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -134,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 1446b97a43296c4899fff458a067ee22881e4957 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:54:25 +0100
Subject: [PATCH 096/277] Issue #16: using Debug CMake type in build script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index efae4d95..7ea874b2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -13,6 +13,7 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR

From 0b0398b5d517b5b922f43eb8c664cfb9924f9b48 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 08:28:50 +0100
Subject: [PATCH 097/277] Issue #16: renamed variable for clarity in run script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 7ea874b2..2be8fea2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,15 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
-BUILD_DIR=$CURRENT_DIR/mtr-build
-SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$ROOT_DIR/mtr-build
+SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*

From 171ed86de698e1a84babe41b0f443047de0853a5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:00:44 +0100
Subject: [PATCH 098/277] Issue #16: setting ulimit to dump cores when running
 check

---
 src/tests/pipeline/check_multithreading_reliability.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 2be8fea2..4519cb84 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+ulimit -c unlimited
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
@@ -22,3 +23,5 @@ cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+ulimit -c 0

From 382c77a257b1084b31da4a7423c1d1759fe2044f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:02:44 +0100
Subject: [PATCH 099/277] Issue #16: saving all output in a hierarchical
 session directory

---
 .../pipeline/check_multithreading_reliability.sh    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 4519cb84..f3cc6910 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,13 +15,26 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
+mkdir $SESSION_DIR
 ulimit -c unlimited
 
+BUILD_LOG=$SESSION_DIR/build.log
+{
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
+} > $BUILD_LOG 2>&1
+
+run_no=1
+WORKING_DIR=$SESSION_DIR/$run_no
+mkdir $WORKING_DIR
+cd $WORKING_DIR
+RUN_LOG=$WORKING_DIR/run.log
+{
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+} > $RUN_LOG 2>&1
 
 ulimit -c 0

From 84b4757129ebf3aa38fcab1d3eb52d847e7c01a9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:05:12 +0100
Subject: [PATCH 100/277] Issue #16: added indentation for readability

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f3cc6910..71e9efc0 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -21,11 +21,11 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
-mkdir -p $BUILD_DIR
-rm -rf $BUILD_DIR/*
-cd $BUILD_DIR
-cmake $CMAKE_OPTS $SOURCE_DIR
-make -j4
+    mkdir -p $BUILD_DIR
+    rm -rf $BUILD_DIR/*
+    cd $BUILD_DIR
+    cmake $CMAKE_OPTS $SOURCE_DIR
+    make -j4
 } > $BUILD_LOG 2>&1
 
 run_no=1
@@ -34,7 +34,7 @@ mkdir $WORKING_DIR
 cd $WORKING_DIR
 RUN_LOG=$WORKING_DIR/run.log
 {
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
 } > $RUN_LOG 2>&1
 
 ulimit -c 0

From 6736a2412736d391a3738edbebd7a8cefe50cb8c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:14:47 +0100
Subject: [PATCH 101/277] Issue #16: can now specify number of reps in check
 script

---
 .../check_multithreading_reliability.sh       | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e9efc0..52eed368 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,13 +28,20 @@ BUILD_LOG=$SESSION_DIR/build.log
     make -j4
 } > $BUILD_LOG 2>&1
 
-run_no=1
-WORKING_DIR=$SESSION_DIR/$run_no
-mkdir $WORKING_DIR
-cd $WORKING_DIR
-RUN_LOG=$WORKING_DIR/run.log
-{
-    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
-} > $RUN_LOG 2>&1
+num_reps=1
+if [ $# -ge 2 ];
+then
+    num_reps=$2
+fi
+for run_no in `seq 1 $num_reps`;
+do
+    WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
+    mkdir $WORKING_DIR
+    cd $WORKING_DIR
+    RUN_LOG=$WORKING_DIR/run.log
+    {
+        PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    } > $RUN_LOG 2>&1
+done
 
 ulimit -c 0

From f1c5d657ecb6a8afb91b16a12ff7dea358cd4fd7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:38:52 +0100
Subject: [PATCH 102/277] Issue #16: can now optionally specify root output dir
 (e.g. not to fill up disk space)

---
 .../pipeline/check_multithreading_reliability.sh    | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 52eed368..1a90362e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,22 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+if [ $# -ge 3 ];
+then
+    ROOT_DIR=$3
+else
+    ROOT_DIR=$CALL_DIR
+fi
+
 BUILD_DIR=$ROOT_DIR/mtr-build
-SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
 ulimit -c unlimited

From bdd466b7955990ef3639dd73b7f95508a89ff8e1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:48:37 +0100
Subject: [PATCH 103/277] Issue #16: logging frequency of exit codes as well

---
 .../pipeline/check_multithreading_reliability.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 1a90362e..f7fbb5fe 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -40,6 +40,8 @@ if [ $# -ge 2 ];
 then
     num_reps=$2
 fi
+
+declare -a exit_code_freqs
 for run_no in `seq 1 $num_reps`;
 do
     WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
@@ -48,7 +50,21 @@ do
     RUN_LOG=$WORKING_DIR/run.log
     {
         PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+        exit_code=$?
+        echo "Exit code was: $exit_code"
+        freq=${exit_code_freqs[$exit_code]}
+        let freq=$freq+1
+        exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
+
+    sleep 5
+done
+
+EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+for exit_code in "${!exit_code_freqs[@]}";
+do
+    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From 4f06fa905474b795a9a92627301aa5a275b30404 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:59:58 +0100
Subject: [PATCH 104/277] Issue #16: nicer formatting of exit code frequencies
 log

---
 src/tests/pipeline/check_multithreading_reliability.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f7fbb5fe..419b7c08 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -62,9 +62,14 @@ do
 done
 
 EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+printf "%10s" "frequency" >> $EXIT_CODES_LOG
+printf "\n" >> $EXIT_CODES_LOG
 for exit_code in "${!exit_code_freqs[@]}";
 do
-    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
+    printf "%10d" $exit_code >> $EXIT_CODES_LOG
+    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+    printf "\n" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From 90d10ac9df2cfb64db6ba39abbb9dd6566764bb5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:02:37 +0100
Subject: [PATCH 105/277] Issue #16: ignoring output folder to avoid an
 accidental commit of big files

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index d7eb0905..35b7a77b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ src/dist
 src/*.egg-info
 *.swp
 src/tests/pipeline/mtr-build
+gg-iss-16

From ba7731be46a6dd976ef73deb64875e48d0051aae Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:06:29 +0100
Subject: [PATCH 106/277] Issue #16: using absolute path expansion if root-dir
 passed as a CLI param

---
 src/tests/pipeline/check_multithreading_reliability.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 419b7c08..18b9133e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -11,7 +11,7 @@ SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
 if [ $# -ge 3 ];
 then
-    ROOT_DIR=$3
+    ROOT_DIR="$( cd "$3" >/dev/null && pwd )"
 else
     ROOT_DIR=$CALL_DIR
 fi

From 4f5dec2b908b89911b682ba83f8388cd724def1c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:56:45 +0100
Subject: [PATCH 107/277] Issue #16: intermediately writing exit codes every 10
 iterations

---
 .../check_multithreading_reliability.sh       | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 18b9133e..64b58250 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -58,18 +58,21 @@ do
         exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
 
-    sleep 5
-done
+    if [ $(($run_no % 10)) -eq 0 ] || [ $run_no -eq $num_reps ];
+    then
+        EXIT_CODES_LOG=$SESSION_DIR/exit-codes-$run_no.csv
+        printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+        printf "%10s" "frequency" >> $EXIT_CODES_LOG
+        printf "\n" >> $EXIT_CODES_LOG
+        for exit_code in "${!exit_code_freqs[@]}";
+        do
+            printf "%10d" $exit_code >> $EXIT_CODES_LOG
+            printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+            printf "\n" >> $EXIT_CODES_LOG
+        done
+    fi
 
-EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
-printf "%10s" "exit-code" >> $EXIT_CODES_LOG
-printf "%10s" "frequency" >> $EXIT_CODES_LOG
-printf "\n" >> $EXIT_CODES_LOG
-for exit_code in "${!exit_code_freqs[@]}";
-do
-    printf "%10d" $exit_code >> $EXIT_CODES_LOG
-    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
-    printf "\n" >> $EXIT_CODES_LOG
+    sleep 5
 done
 
 ulimit -c 0

From 46f2e79b496f13dda960dc5657b82206413d12e2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:19:39 +0100
Subject: [PATCH 108/277] Issue #16: using git-describe to tag the output with
 the version used

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 64b58250..71e2bb62 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,6 +28,7 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
+    git describe --dirty
     mkdir -p $BUILD_DIR
     rm -rf $BUILD_DIR/*
     cd $BUILD_DIR

From 8096d0ae921c62feeed76bc446a55710e8076ce1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:47:45 +0100
Subject: [PATCH 109/277] Issue #16: querying for update override after the
 acquisition of GIL

---
 src/python/wrapper.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index ae1125de..f6651d9a 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -332,11 +332,13 @@ class IObservableObserverWrapper : public gg::IObservable
 
     void update(gg::VideoFrame & frame)
     {
-        if (override f = this->get_override("update"))
         {
-            VideoFrameNumPyWrapper wrapped_frame(&frame);
             gg::ScopedPythonGILLock gil_lock;
-            f(boost::ref(wrapped_frame));
+            if (override f = this->get_override("update"))
+            {
+                VideoFrameNumPyWrapper wrapped_frame(&frame);
+                f(boost::ref(wrapped_frame));
+            }
         }
         notify(frame);
     }

From bddf3a9e0a741b11568c784ca37ef5df9dd58508 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 13:35:54 +0100
Subject: [PATCH 110/277] Issue #16: checking update method overridden in
 Python before actually calling it from within IObserverWrapper

---
 src/python/wrapper.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index f6651d9a..11f7e72f 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -268,7 +268,8 @@ class IObserverWrapper : public gg::IObserver, public wrapper<gg::IObserver>
     {
         gg::ScopedPythonGILLock gil_lock;
         VideoFrameNumPyWrapper wrapped_frame(&frame);
-        this->get_override("update")(boost::ref(wrapped_frame));
+        if (override f = this->get_override("update"))
+            f(boost::ref(wrapped_frame));
     }
 };
 

From 27c2dc169e57656b1d64175f0d4007296b575205 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:06:14 +0100
Subject: [PATCH 111/277] Issue #16: using Pythonic percentage formatting

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 42cc36e3..e1c50e30 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -73,11 +73,10 @@ def run(self):
                 coloredness = np.sum(histogram * scale)
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
-                coloredness *= 100
                 if self.num_skipped >= self.display_freq:
-                    print('{}ness of {} image: {} %'.format(
+                    print('{}ness of {} image: {:.0%}'.format(
                         Histogrammer.channels[self.channel],
-                        self.tag, int(round(coloredness))
+                        self.tag, coloredness
                     ))
                     self.num_skipped = 0
                 else:

From ab70a44e944a15936b4a45a7ab2eb024217c1192 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:24:39 +0100
Subject: [PATCH 112/277] Issue #16: added a SnapshotSaver class that
 implements IObserver directly

---
 .../multithreading_reliability_check.py       | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index e1c50e30..a880b355 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,9 +6,10 @@
 import os.path
 import threading
 import numpy as np
+import scipy.misc
 from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
-                        VideoTargetFactory, Codec)
+                        VideoTargetFactory, Codec, IObserver)
 
 """
 This script provides a multi-threading reliability check.
@@ -28,6 +29,32 @@
 lock = threading.Lock()
 
 
+class SnapshotSaver(IObserver):
+    """A snapshot saver for saving incoming frames to PNG files."""
+
+    def __init__(self, root_dir, frame_rate=0.2):
+        """
+        Initialise a snapshot saver with a saving frequency.
+
+        :param root_dir: the folder where to save the snapshots
+        :param frame_rate: saving frequency. The default value tells
+        the saver to save a frame every 5 sec.
+        """
+        super(SnapshotSaver, self).__init__()
+        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
+        self.save_freq = 1.0 / frame_rate
+        self.root_dir = root_dir
+        self.num_called = 0
+
+    def update(self, frame):
+        """Implement ``IObserver.update``."""
+        self.num_called += 1
+        if self.num_called % self.save_freq == 1:
+            out_file = os.path.join(self.root_dir,
+                                    'frame-{:010d}.png'.format(self.num_called))
+            scipy.misc.imsave(out_file, frame.data(True))
+
+
 class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):

From 4009f1518e0780487ab8e0a383d44ecbf700247b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:25:08 +0100
Subject: [PATCH 113/277] Issue #16: inserted snapshot saver into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a880b355..f1a1697f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -170,12 +170,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    yellow_snapshots = SnapshotSaver('.')
+
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
+    green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
     hist_red.stop()
@@ -187,3 +190,4 @@ def update(self, frame):
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)
+    green_dyer.detach(yellow_snapshots)

From d318f78e9ca2c6c217f065bc6143a5816588cc43 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:47:20 +0100
Subject: [PATCH 114/277] Issue #16: fixed timed saving of snapshots

---
 .../multithreading_reliability_check.py       | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index f1a1697f..7eca3382 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from time import sleep
+from time import (sleep, time)
 import argparse
 import os.path
 import threading
@@ -32,27 +32,29 @@
 class SnapshotSaver(IObserver):
     """A snapshot saver for saving incoming frames to PNG files."""
 
-    def __init__(self, root_dir, frame_rate=0.2):
+    def __init__(self, root_dir, save_freq=5):
         """
         Initialise a snapshot saver with a saving frequency.
 
         :param root_dir: the folder where to save the snapshots
-        :param frame_rate: saving frequency. The default value tells
-        the saver to save a frame every 5 sec.
+        :param save_freq: saving frequency. The default value tells
+        the saver to save every 5 seconds.
         """
         super(SnapshotSaver, self).__init__()
-        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
-        self.save_freq = 1.0 / frame_rate
+        assert 5 <= save_freq  # to avoid flooding disk with images
+        self.save_freq = save_freq
         self.root_dir = root_dir
-        self.num_called = 0
+        self.last_saved = time()
+        self.num_saved = 0
 
     def update(self, frame):
         """Implement ``IObserver.update``."""
-        self.num_called += 1
-        if self.num_called % self.save_freq == 1:
+        if time() - self.last_saved >= self.save_freq:
+            self.num_saved += 1
             out_file = os.path.join(self.root_dir,
-                                    'frame-{:010d}.png'.format(self.num_called))
+                                    'frame-{:010d}.png'.format(self.num_saved))
             scipy.misc.imsave(out_file, frame.data(True))
+            self.last_saved = time()
 
 
 class Bufferer(IObservableObserver):

From 9b57f8881ea497ffaa7eb81d005a128b32e54d65 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:10:24 +0100
Subject: [PATCH 115/277] Issue #16: renamed buffer => np_buffer as buffer is
 built-in type

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7eca3382..0091b993 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,9 +59,9 @@ def update(self, frame):
 
 class Bufferer(IObservableObserver):
 
-    def __init__(self, buffer):
+    def __init__(self, np_buffer):
         super(Bufferer, self).__init__()
-        self.buffer = buffer
+        self.buffer = np_buffer
 
     def update(self, frame):
         with lock:
@@ -73,13 +73,13 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
+    def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
         assert 0 <= display_freq
         self.channel = channel
-        self.buffer = buffer
+        self.buffer = np_buffer
         self.tag = tag
         self.display_freq = display_freq
         self.num_skipped = 0

From 1b119b048f01ef82094d5f8d6ed532b06ad1873c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:17:51 +0100
Subject: [PATCH 116/277] Issue #16: renamed global buffers for clarity

---
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0091b993..8d3d4b89 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+np_buffer_red, np_buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -157,14 +157,14 @@ def update(self, frame):
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
-    buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = Bufferer(buffer_red)
-    buffer_orig = np.zeros_like(buffer_red)
-    bufferer_orig = Bufferer(buffer_orig)
+    np_buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = Bufferer(np_buffer_red)
+    np_buffer_orig = np.zeros_like(np_buffer_red)
+    bufferer_orig = Bufferer(np_buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
+    hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
+    hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From d1b7ece3d84597afd51688a13e8ae90674604484 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:20:01 +0100
Subject: [PATCH 117/277] Issue #16: commented checker script

---
 .../multithreading_reliability_check.py       | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8d3d4b89..b4d21c9c 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,11 @@
 """
 
 
+# global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None
+
+# mutex protecting frame data passed from node to node
+# in the GIFT-Grab processing pipeline
 lock = threading.Lock()
 
 
@@ -58,22 +62,41 @@ def update(self, frame):
 
 
 class Bufferer(IObservableObserver):
+    """GIFT-Grab processing node that updates a frame buffer."""
 
     def __init__(self, np_buffer):
+        """Initialise a bufferer that will update given buffer."""
         super(Bufferer, self).__init__()
         self.buffer = np_buffer
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             self.buffer[:, :, :] = data[:, :, :]
 
 
 class Histogrammer(threading.Thread):
+    """
+    GIFT-Grab processing node that computes the histogram of
+    an image channel and prints how "colored" that channel is.
+    """
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
     def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
+        """
+        :param np_buffer: image buffer to use
+        :param channel: image channel to compute coloredness for
+        :param tag: a tag describing what this image is, e.g.
+        how it's been processed within a GIFT-Grab pipeline
+        :param frame_rate: the rate at which to compute the
+        coloredness (unit: frames-per-second)
+        :param display_freq: how many times to skip the display
+        of computed coloredness, e.g. if 5 is provided, the
+        coloredness of every 5th frame will be printed to the
+        console
+        """
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
@@ -87,6 +110,7 @@ def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         self.running = False
 
     def run(self):
+        """Override ``Thread.run``."""
         if self.running:
             return
 
@@ -113,12 +137,18 @@ def run(self):
             sleep(self.sleep_interval)
 
     def stop(self):
+        """Stop the thread."""
         self.running = False
 
 
 class Dyer(IObservableObserver):
+    """Dyes specified channel of an incoming video frame."""
 
     def __init__(self, channel, increment):
+        """
+        :param channel: image channel to dye
+        :param increment: how much to dye the image channel
+        """
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
         assert 0 <= increment < 256
@@ -126,6 +156,7 @@ def __init__(self, channel, increment):
         self.increment = increment
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             channel_data = data[:, :, self.channel]
@@ -145,35 +176,46 @@ def update(self, frame):
     assert filename
     assert ext == '.mp4'
 
+    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
+    # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
+    # create a red and green Dyer
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
+    # create the bufferer for the red and green Dyers
     np_buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(np_buffer_red)
     np_buffer_orig = np.zeros_like(np_buffer_red)
     bufferer_orig = Bufferer(np_buffer_orig)
 
+    # create the histogrammers for the red-dyed and
+    # the original video frames, and start them
     hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
     hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
+    # create encoders for the red-dyed and yellow-dyed (as green
+    # is applied on top of red) video streams
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    # create a SnapshotSavers for saving a number of yellow-dyed
+    # video frames
     yellow_snapshots = SnapshotSaver('.')
 
+    # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
@@ -183,9 +225,12 @@ def update(self, frame):
     green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
+
+    # stop the histogrammers
     hist_red.stop()
     hist_orig.stop()
 
+    # disassemble the GIFT-Grab pipeline
     reader.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)

From e3368a19864d307a878d195be26f5dbd996cb39e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:24 +0100
Subject: [PATCH 118/277] Issue #16: moved issue-specific comments to shell
 script

---
 .../check_multithreading_reliability.sh        | 17 +++++++++++++----
 .../multithreading_reliability_check.py        | 18 +++++-------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e2bb62..ceafc345 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -1,10 +1,19 @@
 #!/usr/bin/env bash
 # -*- coding: utf-8 -*-
 
-# Build a basic GIFT-Grab capable of reading a video file,
-# and encoding to a video file in real time, with Python
-# and NumPy support. Subsequently run the multi-threading
-# reliability check script.
+# This script provides a multi-threading reliability check.
+# The background is issue #16. It looks like in applications
+# where multiple Python threads are involved, occasionally
+# the acquisition of the Global Interpreter Lock leads to a
+# deadlocks, which crashes the whole application with a
+# non-specific segmentation fault.
+#
+# It builds a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python and
+# NumPy support. It subsequently runs a multi-threaded
+# GIFT-Grab pipeline a number of times, recording the exit
+# status each time. This is essentially a stress-test that
+# should serve as a validation that issue #16 is fixed.
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index b4d21c9c..3fdad38b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,11 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+"""
+Example showing a complex GIFT-Grab pipeline with
+multiple intermediate processing nodes.
+"""
+
 from time import (sleep, time)
 import argparse
 import os.path
@@ -11,19 +16,6 @@
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
-"""
-This script provides a multi-threading reliability check.
-The background is issue #16. It looks like in applications
-where multiple Python threads are involved, occasionally
-the acquisition of the Global Interpreter Lock leads to a
-deadlocks, which crashes the whole application with a
-non-specific segmentation fault.
-
-In this script we run a number of multi-threaded GIFT-Grab
-pipelines, which should serve as a validation that this
-problem is fixed.
-"""
-
 
 # global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None

From 5298af2919ec179d0e441b398a634935179aea9d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:45 +0100
Subject: [PATCH 119/277] Issue #16: added synopsis display to shell script

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index ceafc345..c6419403 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,18 @@
 # status each time. This is essentially a stress-test that
 # should serve as a validation that issue #16 is fixed.
 
+if [ $# -lt 1 ] || [ $# -gt 3 ];
+then
+    THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
+    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tnum_reps:   how many times to run the Python script "
+    printf "(default: once)\n"
+    printf "\toutput_dir: where to save all the generated output "
+    printf "(default: current directory)\n"
+    exit 1
+fi
+
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py

From 075eeacdd0386365593c0dcc72b10f00d5143422 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:57:52 +0100
Subject: [PATCH 120/277] Issue #16: shell script now shows the current session
 directory before starting

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index c6419403..39df9537 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -45,6 +45,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
+echo "Session directory: $SESSION_DIR"
 ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log

From 70e8fde6e24fe142a26392b8b547c75521a04ff3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:01:37 +0100
Subject: [PATCH 121/277] Issue #16: shorter name for Python script

---
 .../{multithreading_reliability_check.py => complex_pipeline.py}  | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{multithreading_reliability_check.py => complex_pipeline.py} (100%)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/complex_pipeline.py
similarity index 100%
rename from src/tests/pipeline/multithreading_reliability_check.py
rename to src/tests/pipeline/complex_pipeline.py

From 18ef69b7810261e8158791aa321cdb2a942aa843 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:02:26 +0100
Subject: [PATCH 122/277] Issue #16: shorter name for Bash script

---
 ...heck_multithreading_reliability.sh => run-complex-pipeline.sh} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{check_multithreading_reliability.sh => run-complex-pipeline.sh} (100%)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/run-complex-pipeline.sh
similarity index 100%
rename from src/tests/pipeline/check_multithreading_reliability.sh
rename to src/tests/pipeline/run-complex-pipeline.sh

From cf3c85ed23f8b81d5768786b19faa447ea1d2966 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:37 +0100
Subject: [PATCH 123/277] Issue #16: fixed typos

---
 src/tests/pipeline/complex_pipeline.py     | 2 +-
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 3fdad38b..1d9d7346 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -203,7 +203,7 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    # create a SnapshotSavers for saving a number of yellow-dyed
+    # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
     yellow_snapshots = SnapshotSaver('.')
 
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 39df9537..5166507b 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -5,7 +5,7 @@
 # The background is issue #16. It looks like in applications
 # where multiple Python threads are involved, occasionally
 # the acquisition of the Global Interpreter Lock leads to a
-# deadlocks, which crashes the whole application with a
+# deadlock, which crashes the whole application with a
 # non-specific segmentation fault.
 #
 # It builds a basic GIFT-Grab capable of reading a video file,

From 38e62cef86fada9719ac18b748a11428760cddbc Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:55 +0100
Subject: [PATCH 124/277] Issue #16: reduced snapshot output

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1d9d7346..66686f1e 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -205,7 +205,7 @@ def update(self, frame):
 
     # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
-    yellow_snapshots = SnapshotSaver('.')
+    yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)

From 124e100908450a0f4b47216ac54dcbdb53aa9af5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:09:55 +0100
Subject: [PATCH 125/277] Issue #16: fixed calling of Python script from Bash
 script

---
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5166507b..3ed9e038 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -29,7 +29,7 @@ fi
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/complex_pipeline.py
 if [ $# -ge 3 ];
 then
     ROOT_DIR="$( cd "$3" >/dev/null && pwd )"

From b194ba8076f98da010f05fb2c8fcec6915e03257 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:33 +0100
Subject: [PATCH 126/277] Issue #16: added an RTD page linking to the complex
 pipeline example

---
 doc/source/complex.rst | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 doc/source/complex.rst

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
new file mode 100644
index 00000000..3982fb7f
--- /dev/null
+++ b/doc/source/complex.rst
@@ -0,0 +1,20 @@
+.. _Complex:
+
+Multi-threaded processing pipelines
+===================================
+
+This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
+processing nodes and threads.
+The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
+
+.. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
+.. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
+.. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
+
+Below is the commented full source code:
+
+.. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
+   :language: python
+   :linenos:
+

From 791a83c98d07bfe7148287d92b269602d1954493 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:59 +0100
Subject: [PATCH 127/277] Issue #16: added the new RTD page to the index

---
 doc/source/index.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/index.rst b/doc/source/index.rst
index 2c8fddc2..8e9af514 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -51,6 +51,7 @@ Examples
    network
    scipy
    encoding
+   complex
 
 Citing GIFT-Grab
 ^^^^^^^^^^^^^^^^

From 7ea7c47fe8c2d93cb876c1c105241269d7d9e6b5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:59:27 +0100
Subject: [PATCH 128/277] Issue #16: fixed cross-reference to NumPy example
 from new RTD page

---
 doc/source/complex.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 3982fb7f..6e0c8a60 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -5,7 +5,7 @@ Multi-threaded processing pipelines
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files

From 75fb5bd839100f4f77ff22501cef44cb70ac78dd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 12:00:34 +0100
Subject: [PATCH 129/277] Issue #16: added link from new RTD page to example
 source code on GitHub

---
 doc/source/complex.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 6e0c8a60..060bce72 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -12,9 +12,11 @@ Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code:
+Below is the commented full source code, which is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
    :linenos:
 
+.. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
+

From 2ec3b25364f9f83a2da61223446297d2dab074e1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:47:20 +0100
Subject: [PATCH 130/277] Issue #16: made the title of the new RTD page more
 descriptive

---
 doc/source/complex.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 060bce72..98fc12ce 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -1,7 +1,7 @@
 .. _Complex:
 
-Multi-threaded processing pipelines
-===================================
+Multi-threaded complex processing pipelines
+===========================================
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.

From 8ca5d2021cfc6545216d369cd22368a1087b9c0a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:51:26 +0100
Subject: [PATCH 131/277] Issue #16: revised the RTD page wording for clarity

---
 doc/source/complex.rst | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 98fc12ce..0d231ccb 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -3,16 +3,19 @@
 Multi-threaded complex processing pipelines
 ===========================================
 
-This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
-processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
+The example below shows how GIFT-Grab can be used for running complex pipelines with multiple
+intermediate processing nodes and threads.
+The intermediate processing nodes in this example are built on the same principles as in the
+:ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code, which is also available on GitHub_:
+The full source code of the example is below.
+Please follow the comments and the flow of code.
+This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python

From b7cd7b92ee72a76a5473692a675121f04750c957 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:53:21 +0100
Subject: [PATCH 132/277] Issue #16: removed line numbers from example on new
 RTD page

---
 doc/source/complex.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 0d231ccb..eba60359 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -19,7 +19,6 @@ This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
-   :linenos:
 
 .. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
 

From be5620a685af687b70232b46167b82ebb72e2d8e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 14:57:13 +0100
Subject: [PATCH 133/277] Issue #16: checker script now supports Blackmagic
 DeckLink 4K Extreme 12G

---
 src/tests/pipeline/complex_pipeline.py     | 27 ++++++++++++++--------
 src/tests/pipeline/run-complex-pipeline.sh | 10 +++++++-
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 66686f1e..e3738d9b 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -12,7 +12,7 @@
 import threading
 import numpy as np
 import scipy.misc
-from pygiftgrab import (VideoSourceFactory, VideoFrame,
+from pygiftgrab import (VideoSourceFactory, VideoFrame, Device,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
@@ -158,19 +158,26 @@ def update(self, frame):
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
-                        metavar='VIDEO_FILE',
-                        help='Input video file (HEVC-encoded MP4)')
+                        metavar='VIDEO_INPUT',
+                        help='"decklink" (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                             ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
     in_file = args.input
 
-    filename = os.path.basename(in_file)
-    filename, ext = os.path.splitext(filename)
-    assert filename
-    assert ext == '.mp4'
-
-    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
-    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    if in_file == 'decklink':
+        reader = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+        reader.set_sub_frame(640, 300, 640, 480)
+    else:
+        filename = os.path.basename(in_file)
+        filename, ext = os.path.splitext(filename)
+        assert filename
+        assert ext == '.mp4'
+
+        # initialise reading of passed file
+        reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 3ed9e038..5dfb083a 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -18,8 +18,9 @@
 if [ $# -lt 1 ] || [ $# -gt 3 ];
 then
     THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
-    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "Usage: $THIS_SCRIPT video_file|decklink [ num_reps [ output_dir ] ]\n"
     printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tdecklink: Blackmagic DeckLink 4K Extreme 12G frame grabber\n"
     printf "\tnum_reps:   how many times to run the Python script "
     printf "(default: once)\n"
     printf "\toutput_dir: where to save all the generated output "
@@ -42,6 +43,13 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+if [ "$1" = "decklink" ]; then
+    if [[ -z "${BlackmagicSDK_DIR}" ]]; then
+        echo "Please set BlackmagicSDK_DIR to the path of the Blackmagic SDK"
+        exit 1
+    fi
+    CMAKE_OPTS="$CMAKE_OPTS -D USE_BLACKMAGIC_DECKLINK_4K_EXTREME_12G=ON -D ENABLE_NONFREE=ON"
+fi
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR

From 32921fc439c0175a06f1fa83aae5845b0a43590f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 14:59:14 +0100
Subject: [PATCH 134/277] Issue #16: revised checker script for more generic
 variable names

---
 src/tests/pipeline/complex_pipeline.py | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index e3738d9b..1968c33a 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -159,32 +159,33 @@ def update(self, frame):
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
                         metavar='VIDEO_INPUT',
-                        help='"decklink" (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
                              ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
-    in_file = args.input
+    video_input = args.input
 
     sfac = VideoSourceFactory.get_instance()
 
-    if in_file == 'decklink':
-        reader = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
-        reader.set_sub_frame(640, 300, 640, 480)
+    if video_input == 'decklink':
+        # start acquiring frames from a DeckLink 4K Extreme 12G
+        source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+        source.set_sub_frame(640, 300, 640, 480)
     else:
-        filename = os.path.basename(in_file)
+        filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)
         assert filename
         assert ext == '.mp4'
 
         # initialise reading of passed file
-        reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+        source = sfac.create_file_reader(video_input, ColourSpace.BGRA)
 
     frame = VideoFrame(ColourSpace.BGRA, False)
-    reader.get_frame(frame)
+    source.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
     # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
-    frame_rate = reader.get_frame_rate()
+    frame_rate = source.get_frame_rate()
 
     # create a red and green Dyer
     red_dyer = Dyer(2, 128)
@@ -215,7 +216,7 @@ def update(self, frame):
     yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
-    reader.attach(bufferer_orig)
+    source.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
@@ -230,7 +231,7 @@ def update(self, frame):
     hist_orig.stop()
 
     # disassemble the GIFT-Grab pipeline
-    reader.detach(bufferer_orig)
+    source.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)

From 3f003c90991ea2553314ad5c43ef4e7fa41d034f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 15:21:23 +0100
Subject: [PATCH 135/277] Issue #16: added missing variable and removed
 cropping in checker script BM part

---
 src/tests/pipeline/complex_pipeline.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1968c33a..fbdf3196 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -167,9 +167,10 @@ def update(self, frame):
     sfac = VideoSourceFactory.get_instance()
 
     if video_input == 'decklink':
+        filename = 'decklink'
+
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
-        source.set_sub_frame(640, 300, 640, 480)
     else:
         filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)

From af2157c01933191b07e71b653dc8466c098f1b57 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 15:44:04 +0100
Subject: [PATCH 136/277] Issue #16: added missing file extension specification
 when using DeckLink device

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index fbdf3196..b61e8f1c 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -167,7 +167,7 @@ def update(self, frame):
     sfac = VideoSourceFactory.get_instance()
 
     if video_input == 'decklink':
-        filename = 'decklink'
+        filename, ext = 'decklink', '.mp4'
 
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)

From a327c37a95351c56fcb73725b818ba799adba9ab Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 21 Oct 2018 11:48:02 +0100
Subject: [PATCH 137/277] Issue #16: multi-threading reliability checker now
 supports Epiphan DVI2PCIe Duo DVI port

---
 src/tests/pipeline/complex_pipeline.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index b61e8f1c..9383db13 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -159,7 +159,8 @@ def update(self, frame):
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
                         metavar='VIDEO_INPUT',
-                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G),\n'
+                             'dvi2pcie (for grabbing frames from an Epiphan DVI2PCIe Duo DVI port\n'
                              ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
     video_input = args.input
@@ -171,6 +172,11 @@ def update(self, frame):
 
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+    elif video_input == 'dvi2pcie':
+        filename, ext = 'dvi2pcie', '.mp4'
+
+        # start acquirigin frames from an Epiphan DVI2PCIe Duo DVI port
+        source = sfac.get_device(Device.DVI2PCIeDuo_DVI, ColourSpace.BGRA)
     else:
         filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)

From f1179d0d1d85723b6b54bd96ecef5e6439cfa6dd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 21 Oct 2018 11:48:42 +0100
Subject: [PATCH 138/277] Issue #16: multi-threading reliability launch script
 now supports Epiphan DVI2PCIe Duo as well

---
 src/tests/pipeline/run-complex-pipeline.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5dfb083a..8a016785 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -18,9 +18,10 @@
 if [ $# -lt 1 ] || [ $# -gt 3 ];
 then
     THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
-    printf "Usage: $THIS_SCRIPT video_file|decklink [ num_reps [ output_dir ] ]\n"
+    printf "Usage: $THIS_SCRIPT video_file|decklink|dvi2pcie [ num_reps [ output_dir ] ]\n"
     printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
     printf "\tdecklink: Blackmagic DeckLink 4K Extreme 12G frame grabber\n"
+    printf "\tdvi2pcie: Epiphan DVI2PCIe Duo frame grabber\n"
     printf "\tnum_reps:   how many times to run the Python script "
     printf "(default: once)\n"
     printf "\toutput_dir: where to save all the generated output "
@@ -49,6 +50,8 @@ if [ "$1" = "decklink" ]; then
         exit 1
     fi
     CMAKE_OPTS="$CMAKE_OPTS -D USE_BLACKMAGIC_DECKLINK_4K_EXTREME_12G=ON -D ENABLE_NONFREE=ON"
+elif [ "$1" = "dvi2pcie" ]; then
+    CMAKE_OPTS="$CMAKE_OPTS -D USE_EPIPHAN_DVI2PCIE_DUO=ON -D USE_I420=OFF"
 fi
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")

From 5cdd60a32b674544f7ee0bf71d3cb112723268c1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:02:38 +0100
Subject: [PATCH 139/277] Issue #16: added a Python script stub for checking
 multi-threading reliability

---
 .../multithreading_reliability_check.py       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100755 src/tests/pipeline/multithreading_reliability_check.py

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
new file mode 100755
index 00000000..c6729066
--- /dev/null
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from pygiftgrab import (VideoSourceFactory,
+                        ColourSpace,
+                        IObservableObserver)
+
+"""
+This script provides a multi-threading reliability check.
+The background is issue #16. It looks like in applications
+where multiple Python threads are involved, occasionally
+the acquisition of the Global Interpreter Lock leads to a
+deadlocks, which crashes the whole application with a
+non-specific segmentation fault.
+
+In this script we run a number of multi-threaded GIFT-Grab
+pipelines, which should serve as a validation that this
+problem is fixed.
+"""
+
+if __name__ == '__main__':
+    print('multithreading reliability check script')

From 28a40bf8739c12c8a3f01fedbe0636fccc0a2279 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:03:41 +0100
Subject: [PATCH 140/277] Issue #16: added a Bash script for building GIFT-Grab
 and subsequently running the multi-threading reliability check script

---
 .gitignore                                    |  1 +
 .../check_multithreading_reliability.sh       | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100755 src/tests/pipeline/check_multithreading_reliability.sh

diff --git a/.gitignore b/.gitignore
index 08b31459..d7eb0905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ src/build
 src/dist
 src/*.egg-info
 *.swp
+src/tests/pipeline/mtr-build
diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
new file mode 100755
index 00000000..b974bfa8
--- /dev/null
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8 -*-
+
+# Build a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python
+# and NumPy support. Subsequently run the multi-threading
+# reliability check script.
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$CURRENT_DIR/mtr-build
+SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+CMAKE_OPTS="-D USE_FILES=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+
+mkdir -p $BUILD_DIR
+rm -rf $BUILD_DIR/*
+cd $BUILD_DIR
+cmake $CMAKE_OPTS $SOURCE_DIR
+make -j4
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT

From b4ab05be343a6aa84746d3e28fb9697ddb4e57df Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:06:21 +0100
Subject: [PATCH 141/277] Issue #16: added a 'Dyer' processing node to
 multi-threading reliability checker

---
 .../pipeline/multithreading_reliability_check.py  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c6729066..7aa1fc0d 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -18,5 +18,20 @@
 problem is fixed.
 """
 
+
+class Dyer(IObservableObserver):
+
+    def __init__(self, channel, value):
+        super(Dyer, self).__init__()
+        assert 0 <= channel < 3
+        assert 0 <= value < 256
+        self.channel = channel
+        self.value = value
+
+    def update(self, frame):
+        data = frame.data(True)
+        data[:, :, self.channel] = self.value
+
+
 if __name__ == '__main__':
     print('multithreading reliability check script')

From 5a59a172553d975d4671441a4e4d3c4ee6c95b45 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:28:08 +0100
Subject: [PATCH 142/277] Issue #16: Python script now uses CLI argument for
 input file

---
 .../pipeline/check_multithreading_reliability.sh   |  2 +-
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index b974bfa8..efae4d95 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -20,4 +20,4 @@ rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7aa1fc0d..02982cf7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+import argparse
+import os.path
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace,
                         IObservableObserver)
@@ -34,4 +36,14 @@ def update(self, frame):
 
 
 if __name__ == '__main__':
-    print('multithreading reliability check script')
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-i', '--input', type=str, required=True,
+                        metavar='VIDEO_FILE',
+                        help='Input video file (HEVC-encoded MP4)')
+    args = parser.parse_args()
+    in_file = args.input
+
+    filename = os.path.basename(in_file)
+    filename, ext = os.path.splitext(filename)
+    assert filename
+    assert ext == '.mp4'

From 10c748f8179323cb0620bf4462a68bd9970d7f1a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:32:30 +0100
Subject: [PATCH 143/277] Issue #16: added multi-node pipeline producing red-
 and yellow-dyed output

---
 .../multithreading_reliability_check.py       | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 02982cf7..01c4ead3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from time import sleep
 import argparse
 import os.path
 from pygiftgrab import (VideoSourceFactory,
-                        ColourSpace,
-                        IObservableObserver)
+                        ColourSpace, IObservableObserver,
+                        VideoTargetFactory, Codec)
 
 """
 This script provides a multi-threading reliability check.
@@ -47,3 +48,29 @@ def update(self, frame):
     filename, ext = os.path.splitext(filename)
     assert filename
     assert ext == '.mp4'
+
+    sfac = VideoSourceFactory.get_instance()
+    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    tfac = VideoTargetFactory.get_instance()
+    frame_rate = reader.get_frame_rate()
+
+    red = Dyer(2, 127)
+    green = Dyer(1, 191)
+
+    red_file = os.path.join('.', ''.join([filename, '-red', ext]))
+    red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
+    yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
+    yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
+
+    reader.attach(red)
+    red.attach(red_writer)
+    red.attach(green)
+    green.attach(yellow_writer)
+
+    sleep(20)  # operate pipeline for 20 sec
+
+    reader.detach(red)
+    red.detach(red_writer)
+    red.detach(green)
+    green.detach(yellow_writer)

From b7078b33b634e369a54fe7b462f42cc8202c7536 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:09:08 +0100
Subject: [PATCH 144/277] Issue #16: added a threaded Histogrammer class stub

---
 .../multithreading_reliability_check.py       | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 01c4ead3..c1ba3b48 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -4,6 +4,7 @@
 from time import sleep
 import argparse
 import os.path
+import threading
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -22,6 +23,30 @@
 """
 
 
+buffer = None
+lock = threading.Lock()
+
+
+class Histogrammer(threading.Thread, IObservableObserver):
+
+    def __init__(self, channel):
+        super(Histogrammer, self).__init__()
+        assert 0 <= channel < 3
+        self.channel = channel
+        self.running = False
+
+    def run(self):
+        if self.running:
+            return
+
+        pass
+
+    def stop(self):
+        self.running = False
+
+    def update(self, frame):
+        pass
+
 class Dyer(IObservableObserver):
 
     def __init__(self, channel, value):
@@ -57,6 +82,8 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
+    hist = Histogrammer(0)
+    hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
@@ -69,6 +96,7 @@ def update(self, frame):
     green.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
+    hist.stop()
 
     reader.detach(red)
     red.detach(red_writer)

From 836abb05370e071ab75268f73551e99b3b4ad9f2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:12:38 +0100
Subject: [PATCH 145/277] Issue #16: added dummy print statement to see
 Histogrammer is alive

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c1ba3b48..4dd459a1 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,6 +40,10 @@ def run(self):
             return
 
         pass
+        self.running = True
+        while self.running:
+            print('Running')
+            sleep(0.100)
 
     def stop(self):
         self.running = False

From 79ae44518aa6275c51cece824d37207abc2529d3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:57:57 +0100
Subject: [PATCH 146/277] Issue #16: factored Histogrammer stub out to
 HistogrammerRed and BuffererRed

---
 .../multithreading_reliability_check.py       | 27 ++++++++++++-------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4dd459a1..12a467bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -23,33 +23,40 @@
 """
 
 
-buffer = None
+buffer_red = None
 lock = threading.Lock()
 
 
-class Histogrammer(threading.Thread, IObservableObserver):
+class BuffererRed(IObservableObserver):
 
-    def __init__(self, channel):
-        super(Histogrammer, self).__init__()
-        assert 0 <= channel < 3
-        self.channel = channel
+    def __init__(self):
+        super(BuffererRed, self).__init__()
+
+    def update(self, frame):
+        global buffer_red
+        # TODO
+
+
+class HistogrammerRed(threading.Thread):
+
+    def __init__(self):
+        super(HistogrammerRed, self).__init__()
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        pass
+        # TODO
         self.running = True
         while self.running:
             print('Running')
+            # TODO
             sleep(0.100)
 
     def stop(self):
         self.running = False
 
-    def update(self, frame):
-        pass
 
 class Dyer(IObservableObserver):
 
@@ -86,7 +93,7 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
-    hist = Histogrammer(0)
+    hist = HistogrammerRed()
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From f6b9a61fd57a100c9be193f7ceb24ccaa139649e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:59:41 +0100
Subject: [PATCH 147/277] Issue #16: implemented update of BuffererRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 12a467bb..aa8eb0dd 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -5,6 +5,7 @@
 import argparse
 import os.path
 import threading
+import numpy as np
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -34,7 +35,12 @@ def __init__(self):
 
     def update(self, frame):
         global buffer_red
-        # TODO
+        with lock:
+            data = frame.data(True)
+            if buffer_red is None:
+                buffer_red = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
 
 
 class HistogrammerRed(threading.Thread):

From 57e85b004f37dd3614b90c70942b3ad5c1e34dcd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:06:55 +0100
Subject: [PATCH 148/277] Issue #16: implemented run of HistogrammerRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index aa8eb0dd..54ceb230 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -53,11 +53,15 @@ def run(self):
         if self.running:
             return
 
-        # TODO
+        global buffer_red
+        histogram = None
         self.running = True
         while self.running:
-            print('Running')
-            # TODO
+            with lock:
+                if buffer_red is not None:
+                    histogram = np.histogram(buffer_red[:, :, 2],
+                                             bins=8, range=(0, 256))
+            print(histogram)
             sleep(0.100)
 
     def stop(self):

From ea8e80921e740a014e9f7a03269a71b613bc2553 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:11:05 +0100
Subject: [PATCH 149/277] Issue #16: renamed Dyer vars for clarity

---
 .../multithreading_reliability_check.py       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54ceb230..ff1fda67 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -101,8 +101,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red = Dyer(2, 127)
-    green = Dyer(1, 191)
+    red_dyer = Dyer(2, 127)
+    green_dyer = Dyer(1, 191)
     hist = HistogrammerRed()
     hist.start()
 
@@ -111,15 +111,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red)
-    red.attach(red_writer)
-    red.attach(green)
-    green.attach(yellow_writer)
+    reader.attach(red_dyer)
+    red_dyer.attach(red_writer)
+    red_dyer.attach(green_dyer)
+    green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
     hist.stop()
 
-    reader.detach(red)
-    red.detach(red_writer)
-    red.detach(green)
-    green.detach(yellow_writer)
+    reader.detach(red_dyer)
+    red_dyer.detach(red_writer)
+    red_dyer.detach(green_dyer)
+    green_dyer.detach(yellow_writer)

From 1a8d91ca86853dc430db532492da19fd25210b79 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:19:12 +0100
Subject: [PATCH 150/277] Issue #16: Dyer.update uses lock

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ff1fda67..ee40fea7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -78,8 +78,9 @@ def __init__(self, channel, value):
         self.value = value
 
     def update(self, frame):
-        data = frame.data(True)
-        data[:, :, self.channel] = self.value
+        with lock:
+            data = frame.data(True)
+            data[:, :, self.channel] = self.value
 
 
 if __name__ == '__main__':

From 6d1ede03d4843925ef3e25251e9951275bb611dd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:20:32 +0100
Subject: [PATCH 151/277] Issue #16: inserted a red bufferer into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ee40fea7..dd0f0dcf 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -104,6 +104,9 @@ def update(self, frame):
 
     red_dyer = Dyer(2, 127)
     green_dyer = Dyer(1, 191)
+
+    bufferer_red = BuffererRed()
+
     hist = HistogrammerRed()
     hist.start()
 
@@ -114,6 +117,7 @@ def update(self, frame):
 
     reader.attach(red_dyer)
     red_dyer.attach(red_writer)
+    red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
@@ -122,5 +126,6 @@ def update(self, frame):
 
     reader.detach(red_dyer)
     red_dyer.detach(red_writer)
+    red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)

From b1b52468075342e84cdff7279aa08357361e085f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:22:03 +0100
Subject: [PATCH 152/277] Issue #16: fixed call to histogram function

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index dd0f0dcf..0987129b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,8 +59,9 @@ def run(self):
         while self.running:
             with lock:
                 if buffer_red is not None:
-                    histogram = np.histogram(buffer_red[:, :, 2],
-                                             bins=8, range=(0, 256))
+                    histogram, _ = np.histogram(
+                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                    )
             print(histogram)
             sleep(0.100)
 

From 4cc919c0af2906e1452189b1fd51061472cf8d8a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:32:24 +0100
Subject: [PATCH 153/277] Issue #16: Dyer now really dyes instead of fixing
 color to a value

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0987129b..54802904 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -71,17 +71,18 @@ def stop(self):
 
 class Dyer(IObservableObserver):
 
-    def __init__(self, channel, value):
+    def __init__(self, channel, increment):
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
-        assert 0 <= value < 256
+        assert 0 <= increment < 256
         self.channel = channel
-        self.value = value
+        self.increment = increment
 
     def update(self, frame):
         with lock:
             data = frame.data(True)
-            data[:, :, self.channel] = self.value
+            channel_data = data[:, :, self.channel]
+            channel_data[channel_data < 255 - self.increment] += self.increment
 
 
 if __name__ == '__main__':

From 36ba5c443f9760ca6bd5293a0f1484ef52d7a309 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:53:49 +0100
Subject: [PATCH 154/277] Issue #16: histogrammer now displays a redness score
 instead of histogram

---
 .../pipeline/multithreading_reliability_check.py     | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54802904..d8bf97ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -54,15 +54,21 @@ def run(self):
             return
 
         global buffer_red
-        histogram = None
+        histogram, num_bins = None, 10
+        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
                 if buffer_red is not None:
                     histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
                     )
-            print(histogram)
+            if histogram is not None:
+                redness = np.sum(histogram * redness_scale)
+                redness /= np.sum(histogram)
+                redness /= num_bins
+                redness *= 100
+                print('Redness: {} %'.format(int(round(redness))))
             sleep(0.100)
 
     def stop(self):

From 1c247f2b87c4139bd127c96e4a33e862b170bca8 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:54:11 +0100
Subject: [PATCH 155/277] Issue #16: using more sensible values for dyeing

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index d8bf97ed..a024030b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -110,8 +110,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 127)
-    green_dyer = Dyer(1, 191)
+    red_dyer = Dyer(2, 64)
+    green_dyer = Dyer(1, 64)
 
     bufferer_red = BuffererRed()
 

From d001d8f9d5ccaa103bb229859067bc2a660ede89 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:59:42 +0100
Subject: [PATCH 156/277] Issue #16: added a BuffererOrig class, a virtual
 replica of BuffererRed

---
 .../multithreading_reliability_check.py         | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a024030b..7b497725 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -43,6 +43,21 @@ def update(self, frame):
                 buffer_red[:, :, :] = data[:, :, :]
 
 
+class BuffererOrig(IObservableObserver):
+
+    def __init__(self):
+        super(BuffererOrig, self).__init__()
+
+    def update(self, frame):
+        global buffer_orig
+        with lock:
+            data = frame.data(True)
+            if buffer_orig is None:
+                buffer_orig = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
+
+
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From b1d83109864e527ec940497c849b3856ba102dfb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:03:50 +0100
Subject: [PATCH 157/277] Issue #16: BuffererRed now takes buffer as parameter
 to constructor instead of using global var

---
 .../multithreading_reliability_check.py         | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7b497725..0ca024bc 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,7 +6,7 @@
 import os.path
 import threading
 import numpy as np
-from pygiftgrab import (VideoSourceFactory,
+from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
 
@@ -30,17 +30,14 @@
 
 class BuffererRed(IObservableObserver):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(BuffererRed, self).__init__()
+        self.buffer = buffer
 
     def update(self, frame):
-        global buffer_red
         with lock:
             data = frame.data(True)
-            if buffer_red is None:
-                buffer_red = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
+            self.buffer[:, :, :] = data[:, :, :]
 
 
 class BuffererOrig(IObservableObserver):
@@ -121,6 +118,9 @@ def update(self, frame):
 
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+    frame = VideoFrame(ColourSpace.BGRA, False)
+    reader.get_frame(frame)
+    frame_shape = (frame.rows(), frame.cols(), 4)
 
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
@@ -128,7 +128,8 @@ def update(self, frame):
     red_dyer = Dyer(2, 64)
     green_dyer = Dyer(1, 64)
 
-    bufferer_red = BuffererRed()
+    buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = BuffererRed(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 1290fad47f8e953ec290fa5979466ff301c05e9c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:10:43 +0100
Subject: [PATCH 158/277] Revert "Issue #16: added a BuffererOrig class, a
 virtual replica of BuffererRed"

This reverts commit 053f499ae6554460df9a755067e1ff5ec817a247.
---
 .../multithreading_reliability_check.py         | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0ca024bc..8aed9c85 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+buffer_red = None
 lock = threading.Lock()
 
 
@@ -40,21 +40,6 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class BuffererOrig(IObservableObserver):
-
-    def __init__(self):
-        super(BuffererOrig, self).__init__()
-
-    def update(self, frame):
-        global buffer_orig
-        with lock:
-            data = frame.data(True)
-            if buffer_orig is None:
-                buffer_orig = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
-
-
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From 6fcf20a134ba3c453460d868a3fef0067cdc1f56 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:12:15 +0100
Subject: [PATCH 159/277] Issue #16: renamed BuffererRed => Bufferer

---
 src/tests/pipeline/multithreading_reliability_check.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8aed9c85..a345dfd6 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -28,10 +28,10 @@
 lock = threading.Lock()
 
 
-class BuffererRed(IObservableObserver):
+class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):
-        super(BuffererRed, self).__init__()
+        super(Bufferer, self).__init__()
         self.buffer = buffer
 
     def update(self, frame):
@@ -114,7 +114,7 @@ def update(self, frame):
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = BuffererRed(buffer_red)
+    bufferer_red = Bufferer(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 66dd339f02970fe13cd16df3f0243948a08072dd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:15:02 +0100
Subject: [PATCH 160/277] Issue #16: HistogrammerRed now takes buffer as a
 constructor argument rather than using global var

---
 .../pipeline/multithreading_reliability_check.py    | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a345dfd6..4a58d7bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -42,24 +42,23 @@ def update(self, frame):
 
 class HistogrammerRed(threading.Thread):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(HistogrammerRed, self).__init__()
+        self.buffer = buffer
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        global buffer_red
         histogram, num_bins = None, 10
         redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
-                if buffer_red is not None:
-                    histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
-                    )
+                histogram, _ = np.histogram(
+                    self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
+                )
             if histogram is not None:
                 redness = np.sum(histogram * redness_scale)
                 redness /= np.sum(histogram)
@@ -116,7 +115,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed()
+    hist = HistogrammerRed(buffer_red)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 60d44a59863738b28a1996772d82baddee0cfb7c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:22:12 +0100
Subject: [PATCH 161/277] Issue #16: HistogrammerRed is now generic
 Histogrammer

---
 .../multithreading_reliability_check.py       | 26 ++++++++++++-------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4a58d7bb..0de913ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,10 +40,14 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class HistogrammerRed(threading.Thread):
+class Histogrammer(threading.Thread):
 
-    def __init__(self, buffer):
-        super(HistogrammerRed, self).__init__()
+    channels = ('Blue', 'Green', 'Red', 'Alpha')
+
+    def __init__(self, buffer, channel):
+        super(Histogrammer, self).__init__()
+        assert channel in range(3)
+        self.channel = channel
         self.buffer = buffer
         self.running = False
 
@@ -52,7 +56,7 @@ def run(self):
             return
 
         histogram, num_bins = None, 10
-        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
+        scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
@@ -60,11 +64,13 @@ def run(self):
                     self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
                 )
             if histogram is not None:
-                redness = np.sum(histogram * redness_scale)
-                redness /= np.sum(histogram)
-                redness /= num_bins
-                redness *= 100
-                print('Redness: {} %'.format(int(round(redness))))
+                coloredness = np.sum(histogram * scale)
+                coloredness /= np.sum(histogram)
+                coloredness /= num_bins
+                coloredness *= 100
+                print('{}ness of dyed image: {} %'.format(
+                    Histogrammer.channels[self.channel], int(round(coloredness))
+                ))
             sleep(0.100)
 
     def stop(self):
@@ -115,7 +121,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed(buffer_red)
+    hist = Histogrammer(buffer_red, 2)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 07d9ca9c1c1dfca3c61d75238e2a539dad5bc312 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:27:00 +0100
Subject: [PATCH 162/277] Issue #16: Histogrammer now accepts a tag for
 generically printing what the image is

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0de913ed..168b6b9f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,11 +44,12 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel):
+    def __init__(self, buffer, channel, tag):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         self.channel = channel
         self.buffer = buffer
+        self.tag = tag
         self.running = False
 
     def run(self):
@@ -68,8 +69,8 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of dyed image: {} %'.format(
-                    Histogrammer.channels[self.channel], int(round(coloredness))
+                print('{}ness of {} image: {} %'.format(
+                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
                 ))
             sleep(0.100)
 
@@ -121,7 +122,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = Histogrammer(buffer_red, 2)
+    hist = Histogrammer(buffer_red, 2, 'red-dyed')
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 2347e43170d54276224abe67359e022e0a7afd22 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:34:30 +0100
Subject: [PATCH 163/277] Issue #16: inserted an original image histogrammer
 into the pipeline

---
 .../multithreading_reliability_check.py       | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 168b6b9f..971e94b2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -121,25 +121,32 @@ def update(self, frame):
 
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
+    buffer_orig = np.zeros_like(buffer_red)
+    bufferer_orig = Bufferer(buffer_orig)
 
-    hist = Histogrammer(buffer_red, 2, 'red-dyed')
-    hist.start()
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red.start()
+    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red_dyer)
+    reader.attach(bufferer_orig)
+    bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
-    hist.stop()
+    hist_red.stop()
+    hist_orig.stop()
 
-    reader.detach(red_dyer)
+    reader.detach(bufferer_orig)
+    bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)

From a947f5bcfe8d015191a066842a5076e7e648d292 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:39:33 +0100
Subject: [PATCH 164/277] Issue #16: Histogrammer now accepts a frame rate and
 flag for displaying coloredness

---
 .../multithreading_reliability_check.py       | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 971e94b2..df093c13 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,12 +44,15 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag):
+    def __init__(self, buffer, channel, tag, frame_rate, show=True):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
+        assert 0 < frame_rate <= 60
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
+        self.show = show
+        self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
     def run(self):
@@ -69,10 +72,12 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of {} image: {} %'.format(
-                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
-                ))
-            sleep(0.100)
+                if self.show:
+                    print('{}ness of {} image: {} %'.format(
+                        Histogrammer.channels[self.channel],
+                        self.tag, int(round(coloredness))
+                    ))
+            sleep(self.sleep_interval)
 
     def stop(self):
         self.running = False
@@ -124,9 +129,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 7e4bfe4145c9b0570a206b05a9edeb997e1b33f7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:45:12 +0100
Subject: [PATCH 165/277] Issue #16: now can specify the frequency of
 coloredness prints

---
 .../pipeline/multithreading_reliability_check.py  | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index df093c13..43e82a19 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,14 +44,16 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, show=True):
+    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
+        assert 0 <= display_freq
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
-        self.show = show
+        self.display_freq = display_freq
+        self.num_skipped = 0
         self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
@@ -72,11 +74,14 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                if self.show:
+                if self.num_skipped >= self.display_freq:
                     print('{}ness of {} image: {} %'.format(
                         Histogrammer.channels[self.channel],
                         self.tag, int(round(coloredness))
                     ))
+                    self.num_skipped = 0
+                else:
+                    self.num_skipped += 1
             sleep(self.sleep_interval)
 
     def stop(self):
@@ -129,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 805e6592dfc54b73aa6152a36eae5387c6e3a079 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:47:38 +0100
Subject: [PATCH 166/277] Issue #16: dyeing red more prominently

---
 src/tests/pipeline/multithreading_reliability_check.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 43e82a19..72ab94d2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -126,7 +126,7 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 64)
+    red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)

From faf96f7d82ecbd1bb1638319e28813d276c4af59 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:53:47 +0100
Subject: [PATCH 167/277] Issue #16: frame rate values that reproduced the
 problem

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 72ab94d2..42cc36e3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -134,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 36746d2217db89d30cc7d52c95530d4ee402f278 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:54:25 +0100
Subject: [PATCH 168/277] Issue #16: using Debug CMake type in build script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index efae4d95..7ea874b2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -13,6 +13,7 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR

From 1ef3c353aa9a5c2812c40c4e6fa7549471048d65 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 08:28:50 +0100
Subject: [PATCH 169/277] Issue #16: renamed variable for clarity in run script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 7ea874b2..2be8fea2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,15 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
-BUILD_DIR=$CURRENT_DIR/mtr-build
-SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$ROOT_DIR/mtr-build
+SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*

From 5483be9c7188c6b5bce94dc06f50492b493892fb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:00:44 +0100
Subject: [PATCH 170/277] Issue #16: setting ulimit to dump cores when running
 check

---
 src/tests/pipeline/check_multithreading_reliability.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 2be8fea2..4519cb84 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+ulimit -c unlimited
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
@@ -22,3 +23,5 @@ cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+ulimit -c 0

From fe2930011eafdb962fca98486078767d4d27589b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:02:44 +0100
Subject: [PATCH 171/277] Issue #16: saving all output in a hierarchical
 session directory

---
 .../pipeline/check_multithreading_reliability.sh    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 4519cb84..f3cc6910 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,13 +15,26 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
+mkdir $SESSION_DIR
 ulimit -c unlimited
 
+BUILD_LOG=$SESSION_DIR/build.log
+{
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
+} > $BUILD_LOG 2>&1
+
+run_no=1
+WORKING_DIR=$SESSION_DIR/$run_no
+mkdir $WORKING_DIR
+cd $WORKING_DIR
+RUN_LOG=$WORKING_DIR/run.log
+{
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+} > $RUN_LOG 2>&1
 
 ulimit -c 0

From 620f0f4b97147755ed580aec000ac8fc72c6dd69 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:05:12 +0100
Subject: [PATCH 172/277] Issue #16: added indentation for readability

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f3cc6910..71e9efc0 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -21,11 +21,11 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
-mkdir -p $BUILD_DIR
-rm -rf $BUILD_DIR/*
-cd $BUILD_DIR
-cmake $CMAKE_OPTS $SOURCE_DIR
-make -j4
+    mkdir -p $BUILD_DIR
+    rm -rf $BUILD_DIR/*
+    cd $BUILD_DIR
+    cmake $CMAKE_OPTS $SOURCE_DIR
+    make -j4
 } > $BUILD_LOG 2>&1
 
 run_no=1
@@ -34,7 +34,7 @@ mkdir $WORKING_DIR
 cd $WORKING_DIR
 RUN_LOG=$WORKING_DIR/run.log
 {
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
 } > $RUN_LOG 2>&1
 
 ulimit -c 0

From ee7aa5fdeaced44d5ed64eb4efc790ed10376bbb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:14:47 +0100
Subject: [PATCH 173/277] Issue #16: can now specify number of reps in check
 script

---
 .../check_multithreading_reliability.sh       | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e9efc0..52eed368 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,13 +28,20 @@ BUILD_LOG=$SESSION_DIR/build.log
     make -j4
 } > $BUILD_LOG 2>&1
 
-run_no=1
-WORKING_DIR=$SESSION_DIR/$run_no
-mkdir $WORKING_DIR
-cd $WORKING_DIR
-RUN_LOG=$WORKING_DIR/run.log
-{
-    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
-} > $RUN_LOG 2>&1
+num_reps=1
+if [ $# -ge 2 ];
+then
+    num_reps=$2
+fi
+for run_no in `seq 1 $num_reps`;
+do
+    WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
+    mkdir $WORKING_DIR
+    cd $WORKING_DIR
+    RUN_LOG=$WORKING_DIR/run.log
+    {
+        PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    } > $RUN_LOG 2>&1
+done
 
 ulimit -c 0

From 94ffd82f97b25afe4030608be8493234e953cef2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:38:52 +0100
Subject: [PATCH 174/277] Issue #16: can now optionally specify root output dir
 (e.g. not to fill up disk space)

---
 .../pipeline/check_multithreading_reliability.sh    | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 52eed368..1a90362e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,22 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+if [ $# -ge 3 ];
+then
+    ROOT_DIR=$3
+else
+    ROOT_DIR=$CALL_DIR
+fi
+
 BUILD_DIR=$ROOT_DIR/mtr-build
-SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
 ulimit -c unlimited

From f77c463803bac067cee347b1fdbb990248520a4a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:48:37 +0100
Subject: [PATCH 175/277] Issue #16: logging frequency of exit codes as well

---
 .../pipeline/check_multithreading_reliability.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 1a90362e..f7fbb5fe 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -40,6 +40,8 @@ if [ $# -ge 2 ];
 then
     num_reps=$2
 fi
+
+declare -a exit_code_freqs
 for run_no in `seq 1 $num_reps`;
 do
     WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
@@ -48,7 +50,21 @@ do
     RUN_LOG=$WORKING_DIR/run.log
     {
         PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+        exit_code=$?
+        echo "Exit code was: $exit_code"
+        freq=${exit_code_freqs[$exit_code]}
+        let freq=$freq+1
+        exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
+
+    sleep 5
+done
+
+EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+for exit_code in "${!exit_code_freqs[@]}";
+do
+    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From c3ce578fd59b56842e30c1224556787da1d126f4 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:59:58 +0100
Subject: [PATCH 176/277] Issue #16: nicer formatting of exit code frequencies
 log

---
 src/tests/pipeline/check_multithreading_reliability.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f7fbb5fe..419b7c08 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -62,9 +62,14 @@ do
 done
 
 EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+printf "%10s" "frequency" >> $EXIT_CODES_LOG
+printf "\n" >> $EXIT_CODES_LOG
 for exit_code in "${!exit_code_freqs[@]}";
 do
-    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
+    printf "%10d" $exit_code >> $EXIT_CODES_LOG
+    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+    printf "\n" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From 5072e59398690250201454064882b997ddb83cac Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:02:37 +0100
Subject: [PATCH 177/277] Issue #16: ignoring output folder to avoid an
 accidental commit of big files

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index d7eb0905..35b7a77b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ src/dist
 src/*.egg-info
 *.swp
 src/tests/pipeline/mtr-build
+gg-iss-16

From 8d884351255cfb3946c6f1a769d4266866860de8 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:06:29 +0100
Subject: [PATCH 178/277] Issue #16: using absolute path expansion if root-dir
 passed as a CLI param

---
 src/tests/pipeline/check_multithreading_reliability.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 419b7c08..18b9133e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -11,7 +11,7 @@ SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
 if [ $# -ge 3 ];
 then
-    ROOT_DIR=$3
+    ROOT_DIR="$( cd "$3" >/dev/null && pwd )"
 else
     ROOT_DIR=$CALL_DIR
 fi

From 43e9512f10c3f530f98253505a8cc0ccc43ce08a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:56:45 +0100
Subject: [PATCH 179/277] Issue #16: intermediately writing exit codes every 10
 iterations

---
 .../check_multithreading_reliability.sh       | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 18b9133e..64b58250 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -58,18 +58,21 @@ do
         exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
 
-    sleep 5
-done
+    if [ $(($run_no % 10)) -eq 0 ] || [ $run_no -eq $num_reps ];
+    then
+        EXIT_CODES_LOG=$SESSION_DIR/exit-codes-$run_no.csv
+        printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+        printf "%10s" "frequency" >> $EXIT_CODES_LOG
+        printf "\n" >> $EXIT_CODES_LOG
+        for exit_code in "${!exit_code_freqs[@]}";
+        do
+            printf "%10d" $exit_code >> $EXIT_CODES_LOG
+            printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+            printf "\n" >> $EXIT_CODES_LOG
+        done
+    fi
 
-EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
-printf "%10s" "exit-code" >> $EXIT_CODES_LOG
-printf "%10s" "frequency" >> $EXIT_CODES_LOG
-printf "\n" >> $EXIT_CODES_LOG
-for exit_code in "${!exit_code_freqs[@]}";
-do
-    printf "%10d" $exit_code >> $EXIT_CODES_LOG
-    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
-    printf "\n" >> $EXIT_CODES_LOG
+    sleep 5
 done
 
 ulimit -c 0

From 8e0704296e7e685574edc46e311c4557cb90dc12 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:19:39 +0100
Subject: [PATCH 180/277] Issue #16: using git-describe to tag the output with
 the version used

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 64b58250..71e2bb62 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,6 +28,7 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
+    git describe --dirty
     mkdir -p $BUILD_DIR
     rm -rf $BUILD_DIR/*
     cd $BUILD_DIR

From f0f7bb533b4cf600e245789c78454958f248024d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:47:45 +0100
Subject: [PATCH 181/277] Issue #16: querying for update override after the
 acquisition of GIL

---
 src/python/wrapper.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index ae1125de..f6651d9a 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -332,11 +332,13 @@ class IObservableObserverWrapper : public gg::IObservable
 
     void update(gg::VideoFrame & frame)
     {
-        if (override f = this->get_override("update"))
         {
-            VideoFrameNumPyWrapper wrapped_frame(&frame);
             gg::ScopedPythonGILLock gil_lock;
-            f(boost::ref(wrapped_frame));
+            if (override f = this->get_override("update"))
+            {
+                VideoFrameNumPyWrapper wrapped_frame(&frame);
+                f(boost::ref(wrapped_frame));
+            }
         }
         notify(frame);
     }

From 3b96e7219b79e84a3cb5816823602b57f2cd6a59 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 13:35:54 +0100
Subject: [PATCH 182/277] Issue #16: checking update method overridden in
 Python before actually calling it from within IObserverWrapper

---
 src/python/wrapper.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/python/wrapper.cpp b/src/python/wrapper.cpp
index f6651d9a..11f7e72f 100644
--- a/src/python/wrapper.cpp
+++ b/src/python/wrapper.cpp
@@ -268,7 +268,8 @@ class IObserverWrapper : public gg::IObserver, public wrapper<gg::IObserver>
     {
         gg::ScopedPythonGILLock gil_lock;
         VideoFrameNumPyWrapper wrapped_frame(&frame);
-        this->get_override("update")(boost::ref(wrapped_frame));
+        if (override f = this->get_override("update"))
+            f(boost::ref(wrapped_frame));
     }
 };
 

From 8a41daef1a61a9db3339a92f4d43c68b0c3055ad Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:06:14 +0100
Subject: [PATCH 183/277] Issue #16: using Pythonic percentage formatting

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 42cc36e3..e1c50e30 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -73,11 +73,10 @@ def run(self):
                 coloredness = np.sum(histogram * scale)
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
-                coloredness *= 100
                 if self.num_skipped >= self.display_freq:
-                    print('{}ness of {} image: {} %'.format(
+                    print('{}ness of {} image: {:.0%}'.format(
                         Histogrammer.channels[self.channel],
-                        self.tag, int(round(coloredness))
+                        self.tag, coloredness
                     ))
                     self.num_skipped = 0
                 else:

From 3ac735d9326a15dcf0327ca78e4f72510b7d220f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:24:39 +0100
Subject: [PATCH 184/277] Issue #16: added a SnapshotSaver class that
 implements IObserver directly

---
 .../multithreading_reliability_check.py       | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index e1c50e30..a880b355 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,9 +6,10 @@
 import os.path
 import threading
 import numpy as np
+import scipy.misc
 from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
-                        VideoTargetFactory, Codec)
+                        VideoTargetFactory, Codec, IObserver)
 
 """
 This script provides a multi-threading reliability check.
@@ -28,6 +29,32 @@
 lock = threading.Lock()
 
 
+class SnapshotSaver(IObserver):
+    """A snapshot saver for saving incoming frames to PNG files."""
+
+    def __init__(self, root_dir, frame_rate=0.2):
+        """
+        Initialise a snapshot saver with a saving frequency.
+
+        :param root_dir: the folder where to save the snapshots
+        :param frame_rate: saving frequency. The default value tells
+        the saver to save a frame every 5 sec.
+        """
+        super(SnapshotSaver, self).__init__()
+        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
+        self.save_freq = 1.0 / frame_rate
+        self.root_dir = root_dir
+        self.num_called = 0
+
+    def update(self, frame):
+        """Implement ``IObserver.update``."""
+        self.num_called += 1
+        if self.num_called % self.save_freq == 1:
+            out_file = os.path.join(self.root_dir,
+                                    'frame-{:010d}.png'.format(self.num_called))
+            scipy.misc.imsave(out_file, frame.data(True))
+
+
 class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):

From 74ee1c808368ee5bd6fca0e7699c7bf2c0478402 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:25:08 +0100
Subject: [PATCH 185/277] Issue #16: inserted snapshot saver into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a880b355..f1a1697f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -170,12 +170,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    yellow_snapshots = SnapshotSaver('.')
+
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
+    green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
     hist_red.stop()
@@ -187,3 +190,4 @@ def update(self, frame):
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)
+    green_dyer.detach(yellow_snapshots)

From 4b10f04db7133a75ec8d8375f967ae929c8c0e80 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:47:20 +0100
Subject: [PATCH 186/277] Issue #16: fixed timed saving of snapshots

---
 .../multithreading_reliability_check.py       | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index f1a1697f..7eca3382 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from time import sleep
+from time import (sleep, time)
 import argparse
 import os.path
 import threading
@@ -32,27 +32,29 @@
 class SnapshotSaver(IObserver):
     """A snapshot saver for saving incoming frames to PNG files."""
 
-    def __init__(self, root_dir, frame_rate=0.2):
+    def __init__(self, root_dir, save_freq=5):
         """
         Initialise a snapshot saver with a saving frequency.
 
         :param root_dir: the folder where to save the snapshots
-        :param frame_rate: saving frequency. The default value tells
-        the saver to save a frame every 5 sec.
+        :param save_freq: saving frequency. The default value tells
+        the saver to save every 5 seconds.
         """
         super(SnapshotSaver, self).__init__()
-        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
-        self.save_freq = 1.0 / frame_rate
+        assert 5 <= save_freq  # to avoid flooding disk with images
+        self.save_freq = save_freq
         self.root_dir = root_dir
-        self.num_called = 0
+        self.last_saved = time()
+        self.num_saved = 0
 
     def update(self, frame):
         """Implement ``IObserver.update``."""
-        self.num_called += 1
-        if self.num_called % self.save_freq == 1:
+        if time() - self.last_saved >= self.save_freq:
+            self.num_saved += 1
             out_file = os.path.join(self.root_dir,
-                                    'frame-{:010d}.png'.format(self.num_called))
+                                    'frame-{:010d}.png'.format(self.num_saved))
             scipy.misc.imsave(out_file, frame.data(True))
+            self.last_saved = time()
 
 
 class Bufferer(IObservableObserver):

From 5e03e8376d990f1ed4d2ef98002af892d7ba286c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:10:24 +0100
Subject: [PATCH 187/277] Issue #16: renamed buffer => np_buffer as buffer is
 built-in type

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7eca3382..0091b993 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,9 +59,9 @@ def update(self, frame):
 
 class Bufferer(IObservableObserver):
 
-    def __init__(self, buffer):
+    def __init__(self, np_buffer):
         super(Bufferer, self).__init__()
-        self.buffer = buffer
+        self.buffer = np_buffer
 
     def update(self, frame):
         with lock:
@@ -73,13 +73,13 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
+    def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
         assert 0 <= display_freq
         self.channel = channel
-        self.buffer = buffer
+        self.buffer = np_buffer
         self.tag = tag
         self.display_freq = display_freq
         self.num_skipped = 0

From 67e384c351b5a4d182bce16f0bc1f8ec6be1f656 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:17:51 +0100
Subject: [PATCH 188/277] Issue #16: renamed global buffers for clarity

---
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0091b993..8d3d4b89 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+np_buffer_red, np_buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -157,14 +157,14 @@ def update(self, frame):
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
-    buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = Bufferer(buffer_red)
-    buffer_orig = np.zeros_like(buffer_red)
-    bufferer_orig = Bufferer(buffer_orig)
+    np_buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = Bufferer(np_buffer_red)
+    np_buffer_orig = np.zeros_like(np_buffer_red)
+    bufferer_orig = Bufferer(np_buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
+    hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
+    hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 3ed391a422af29a178200748bd9b22e866075771 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:20:01 +0100
Subject: [PATCH 189/277] Issue #16: commented checker script

---
 .../multithreading_reliability_check.py       | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8d3d4b89..b4d21c9c 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,11 @@
 """
 
 
+# global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None
+
+# mutex protecting frame data passed from node to node
+# in the GIFT-Grab processing pipeline
 lock = threading.Lock()
 
 
@@ -58,22 +62,41 @@ def update(self, frame):
 
 
 class Bufferer(IObservableObserver):
+    """GIFT-Grab processing node that updates a frame buffer."""
 
     def __init__(self, np_buffer):
+        """Initialise a bufferer that will update given buffer."""
         super(Bufferer, self).__init__()
         self.buffer = np_buffer
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             self.buffer[:, :, :] = data[:, :, :]
 
 
 class Histogrammer(threading.Thread):
+    """
+    GIFT-Grab processing node that computes the histogram of
+    an image channel and prints how "colored" that channel is.
+    """
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
     def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
+        """
+        :param np_buffer: image buffer to use
+        :param channel: image channel to compute coloredness for
+        :param tag: a tag describing what this image is, e.g.
+        how it's been processed within a GIFT-Grab pipeline
+        :param frame_rate: the rate at which to compute the
+        coloredness (unit: frames-per-second)
+        :param display_freq: how many times to skip the display
+        of computed coloredness, e.g. if 5 is provided, the
+        coloredness of every 5th frame will be printed to the
+        console
+        """
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
@@ -87,6 +110,7 @@ def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         self.running = False
 
     def run(self):
+        """Override ``Thread.run``."""
         if self.running:
             return
 
@@ -113,12 +137,18 @@ def run(self):
             sleep(self.sleep_interval)
 
     def stop(self):
+        """Stop the thread."""
         self.running = False
 
 
 class Dyer(IObservableObserver):
+    """Dyes specified channel of an incoming video frame."""
 
     def __init__(self, channel, increment):
+        """
+        :param channel: image channel to dye
+        :param increment: how much to dye the image channel
+        """
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
         assert 0 <= increment < 256
@@ -126,6 +156,7 @@ def __init__(self, channel, increment):
         self.increment = increment
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             channel_data = data[:, :, self.channel]
@@ -145,35 +176,46 @@ def update(self, frame):
     assert filename
     assert ext == '.mp4'
 
+    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
+    # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
+    # create a red and green Dyer
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
+    # create the bufferer for the red and green Dyers
     np_buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(np_buffer_red)
     np_buffer_orig = np.zeros_like(np_buffer_red)
     bufferer_orig = Bufferer(np_buffer_orig)
 
+    # create the histogrammers for the red-dyed and
+    # the original video frames, and start them
     hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
     hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
+    # create encoders for the red-dyed and yellow-dyed (as green
+    # is applied on top of red) video streams
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    # create a SnapshotSavers for saving a number of yellow-dyed
+    # video frames
     yellow_snapshots = SnapshotSaver('.')
 
+    # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
@@ -183,9 +225,12 @@ def update(self, frame):
     green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
+
+    # stop the histogrammers
     hist_red.stop()
     hist_orig.stop()
 
+    # disassemble the GIFT-Grab pipeline
     reader.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)

From c66665c5d984a98f4275affe2f6e5f165aebaf9a Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:24 +0100
Subject: [PATCH 190/277] Issue #16: moved issue-specific comments to shell
 script

---
 .../check_multithreading_reliability.sh        | 17 +++++++++++++----
 .../multithreading_reliability_check.py        | 18 +++++-------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e2bb62..ceafc345 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -1,10 +1,19 @@
 #!/usr/bin/env bash
 # -*- coding: utf-8 -*-
 
-# Build a basic GIFT-Grab capable of reading a video file,
-# and encoding to a video file in real time, with Python
-# and NumPy support. Subsequently run the multi-threading
-# reliability check script.
+# This script provides a multi-threading reliability check.
+# The background is issue #16. It looks like in applications
+# where multiple Python threads are involved, occasionally
+# the acquisition of the Global Interpreter Lock leads to a
+# deadlocks, which crashes the whole application with a
+# non-specific segmentation fault.
+#
+# It builds a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python and
+# NumPy support. It subsequently runs a multi-threaded
+# GIFT-Grab pipeline a number of times, recording the exit
+# status each time. This is essentially a stress-test that
+# should serve as a validation that issue #16 is fixed.
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index b4d21c9c..3fdad38b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,11 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+"""
+Example showing a complex GIFT-Grab pipeline with
+multiple intermediate processing nodes.
+"""
+
 from time import (sleep, time)
 import argparse
 import os.path
@@ -11,19 +16,6 @@
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
-"""
-This script provides a multi-threading reliability check.
-The background is issue #16. It looks like in applications
-where multiple Python threads are involved, occasionally
-the acquisition of the Global Interpreter Lock leads to a
-deadlocks, which crashes the whole application with a
-non-specific segmentation fault.
-
-In this script we run a number of multi-threaded GIFT-Grab
-pipelines, which should serve as a validation that this
-problem is fixed.
-"""
-
 
 # global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None

From c9eb7dd115c0be11e6d3e643b0dd93f4484b13ed Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:45 +0100
Subject: [PATCH 191/277] Issue #16: added synopsis display to shell script

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index ceafc345..c6419403 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,18 @@
 # status each time. This is essentially a stress-test that
 # should serve as a validation that issue #16 is fixed.
 
+if [ $# -lt 1 ] || [ $# -gt 3 ];
+then
+    THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
+    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tnum_reps:   how many times to run the Python script "
+    printf "(default: once)\n"
+    printf "\toutput_dir: where to save all the generated output "
+    printf "(default: current directory)\n"
+    exit 1
+fi
+
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py

From f76c706e49ebe090ed98fe95453ae8e09f4102ef Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:57:52 +0100
Subject: [PATCH 192/277] Issue #16: shell script now shows the current session
 directory before starting

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index c6419403..39df9537 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -45,6 +45,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
+echo "Session directory: $SESSION_DIR"
 ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log

From a1968280b4d46ecd982f7649b3aff0c170d141e9 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:01:37 +0100
Subject: [PATCH 193/277] Issue #16: shorter name for Python script

---
 .../{multithreading_reliability_check.py => complex_pipeline.py}  | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{multithreading_reliability_check.py => complex_pipeline.py} (100%)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/complex_pipeline.py
similarity index 100%
rename from src/tests/pipeline/multithreading_reliability_check.py
rename to src/tests/pipeline/complex_pipeline.py

From 9289a48c7883b7c95811277191e926d6fd376343 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:02:26 +0100
Subject: [PATCH 194/277] Issue #16: shorter name for Bash script

---
 ...heck_multithreading_reliability.sh => run-complex-pipeline.sh} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename src/tests/pipeline/{check_multithreading_reliability.sh => run-complex-pipeline.sh} (100%)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/run-complex-pipeline.sh
similarity index 100%
rename from src/tests/pipeline/check_multithreading_reliability.sh
rename to src/tests/pipeline/run-complex-pipeline.sh

From 206efc2f07d11c5693c7d530fc284bdf08a84141 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:37 +0100
Subject: [PATCH 195/277] Issue #16: fixed typos

---
 src/tests/pipeline/complex_pipeline.py     | 2 +-
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 3fdad38b..1d9d7346 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -203,7 +203,7 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    # create a SnapshotSavers for saving a number of yellow-dyed
+    # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
     yellow_snapshots = SnapshotSaver('.')
 
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 39df9537..5166507b 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -5,7 +5,7 @@
 # The background is issue #16. It looks like in applications
 # where multiple Python threads are involved, occasionally
 # the acquisition of the Global Interpreter Lock leads to a
-# deadlocks, which crashes the whole application with a
+# deadlock, which crashes the whole application with a
 # non-specific segmentation fault.
 #
 # It builds a basic GIFT-Grab capable of reading a video file,

From db276e82f7498d1a422072b754206084a31e1be1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:55 +0100
Subject: [PATCH 196/277] Issue #16: reduced snapshot output

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1d9d7346..66686f1e 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -205,7 +205,7 @@ def update(self, frame):
 
     # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
-    yellow_snapshots = SnapshotSaver('.')
+    yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)

From b1bad2e07cd7ebcd5ac835289026eca00d37ea3e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:09:55 +0100
Subject: [PATCH 197/277] Issue #16: fixed calling of Python script from Bash
 script

---
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5166507b..3ed9e038 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -29,7 +29,7 @@ fi
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/complex_pipeline.py
 if [ $# -ge 3 ];
 then
     ROOT_DIR="$( cd "$3" >/dev/null && pwd )"

From 209e918e10cb9ebc0f2a95f5919b27845cb3089e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:33 +0100
Subject: [PATCH 198/277] Issue #16: added an RTD page linking to the complex
 pipeline example

---
 doc/source/complex.rst | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 doc/source/complex.rst

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
new file mode 100644
index 00000000..3982fb7f
--- /dev/null
+++ b/doc/source/complex.rst
@@ -0,0 +1,20 @@
+.. _Complex:
+
+Multi-threaded processing pipelines
+===================================
+
+This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
+processing nodes and threads.
+The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
+
+.. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
+.. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
+.. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
+
+Below is the commented full source code:
+
+.. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
+   :language: python
+   :linenos:
+

From 7aa547eb59b9e64a47274d50e9ff76ffe3248ad3 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:59 +0100
Subject: [PATCH 199/277] Issue #16: added the new RTD page to the index

---
 doc/source/index.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/index.rst b/doc/source/index.rst
index 2c8fddc2..8e9af514 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -51,6 +51,7 @@ Examples
    network
    scipy
    encoding
+   complex
 
 Citing GIFT-Grab
 ^^^^^^^^^^^^^^^^

From 3da6eea48c0072c612589d8e64a96aa95429c3b0 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:59:27 +0100
Subject: [PATCH 200/277] Issue #16: fixed cross-reference to NumPy example
 from new RTD page

---
 doc/source/complex.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 3982fb7f..6e0c8a60 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -5,7 +5,7 @@ Multi-threaded processing pipelines
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files

From 7ead125bca62efb3d7a4b1b30c1993aa0e1159ee Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 12:00:34 +0100
Subject: [PATCH 201/277] Issue #16: added link from new RTD page to example
 source code on GitHub

---
 doc/source/complex.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 6e0c8a60..060bce72 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -12,9 +12,11 @@ Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code:
+Below is the commented full source code, which is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
    :linenos:
 
+.. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
+

From 83dd35d7448f96444aa8b347482a776dd965d729 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:47:20 +0100
Subject: [PATCH 202/277] Issue #16: made the title of the new RTD page more
 descriptive

---
 doc/source/complex.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 060bce72..98fc12ce 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -1,7 +1,7 @@
 .. _Complex:
 
-Multi-threaded processing pipelines
-===================================
+Multi-threaded complex processing pipelines
+===========================================
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.

From 1b4e3eb77dd6b37666020fb88c99f21f67d9ec00 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:51:26 +0100
Subject: [PATCH 203/277] Issue #16: revised the RTD page wording for clarity

---
 doc/source/complex.rst | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 98fc12ce..0d231ccb 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -3,16 +3,19 @@
 Multi-threaded complex processing pipelines
 ===========================================
 
-This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
-processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
+The example below shows how GIFT-Grab can be used for running complex pipelines with multiple
+intermediate processing nodes and threads.
+The intermediate processing nodes in this example are built on the same principles as in the
+:ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code, which is also available on GitHub_:
+The full source code of the example is below.
+Please follow the comments and the flow of code.
+This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python

From 5a15bc00cffe555651dd0fc420f4e9d30851a0e8 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:53:21 +0100
Subject: [PATCH 204/277] Issue #16: removed line numbers from example on new
 RTD page

---
 doc/source/complex.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 0d231ccb..eba60359 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -19,7 +19,6 @@ This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
-   :linenos:
 
 .. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
 

From eee97b95cec66288e570bff7c647475d441f083b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:02:38 +0100
Subject: [PATCH 205/277] Issue #16: added a Python script stub for checking
 multi-threading reliability

---
 .../multithreading_reliability_check.py       | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100755 src/tests/pipeline/multithreading_reliability_check.py

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
new file mode 100755
index 00000000..c6729066
--- /dev/null
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from pygiftgrab import (VideoSourceFactory,
+                        ColourSpace,
+                        IObservableObserver)
+
+"""
+This script provides a multi-threading reliability check.
+The background is issue #16. It looks like in applications
+where multiple Python threads are involved, occasionally
+the acquisition of the Global Interpreter Lock leads to a
+deadlocks, which crashes the whole application with a
+non-specific segmentation fault.
+
+In this script we run a number of multi-threaded GIFT-Grab
+pipelines, which should serve as a validation that this
+problem is fixed.
+"""
+
+if __name__ == '__main__':
+    print('multithreading reliability check script')

From 170f789a7955f75ba4a2dc8ee70d61706d8d9a6d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Thu, 11 Oct 2018 09:03:41 +0100
Subject: [PATCH 206/277] Issue #16: added a Bash script for building GIFT-Grab
 and subsequently running the multi-threading reliability check script

---
 .gitignore                                    |  1 -
 .../check_multithreading_reliability.sh       | 23 +++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100755 src/tests/pipeline/check_multithreading_reliability.sh

diff --git a/.gitignore b/.gitignore
index 35b7a77b..d7eb0905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,4 +17,3 @@ src/dist
 src/*.egg-info
 *.swp
 src/tests/pipeline/mtr-build
-gg-iss-16
diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
new file mode 100755
index 00000000..b974bfa8
--- /dev/null
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8 -*-
+
+# Build a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python
+# and NumPy support. Subsequently run the multi-threading
+# reliability check script.
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$CURRENT_DIR/mtr-build
+SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+CMAKE_OPTS="-D USE_FILES=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+
+mkdir -p $BUILD_DIR
+rm -rf $BUILD_DIR/*
+cd $BUILD_DIR
+cmake $CMAKE_OPTS $SOURCE_DIR
+make -j4
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT

From 455cc681a3dc552439bd899945b3a490cd50d06d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:06:21 +0100
Subject: [PATCH 207/277] Issue #16: added a 'Dyer' processing node to
 multi-threading reliability checker

---
 .../pipeline/multithreading_reliability_check.py  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c6729066..7aa1fc0d 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -18,5 +18,20 @@
 problem is fixed.
 """
 
+
+class Dyer(IObservableObserver):
+
+    def __init__(self, channel, value):
+        super(Dyer, self).__init__()
+        assert 0 <= channel < 3
+        assert 0 <= value < 256
+        self.channel = channel
+        self.value = value
+
+    def update(self, frame):
+        data = frame.data(True)
+        data[:, :, self.channel] = self.value
+
+
 if __name__ == '__main__':
     print('multithreading reliability check script')

From 9488646b539e01557ef23e09e35d63ec082d6533 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:28:08 +0100
Subject: [PATCH 208/277] Issue #16: Python script now uses CLI argument for
 input file

---
 .../pipeline/check_multithreading_reliability.sh   |  2 +-
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index b974bfa8..efae4d95 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -20,4 +20,4 @@ rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT
+PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7aa1fc0d..02982cf7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+import argparse
+import os.path
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace,
                         IObservableObserver)
@@ -34,4 +36,14 @@ def update(self, frame):
 
 
 if __name__ == '__main__':
-    print('multithreading reliability check script')
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-i', '--input', type=str, required=True,
+                        metavar='VIDEO_FILE',
+                        help='Input video file (HEVC-encoded MP4)')
+    args = parser.parse_args()
+    in_file = args.input
+
+    filename = os.path.basename(in_file)
+    filename, ext = os.path.splitext(filename)
+    assert filename
+    assert ext == '.mp4'

From 20343bb1840eb7e21f9e5e935e01d3bc2be6effa Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 08:32:30 +0100
Subject: [PATCH 209/277] Issue #16: added multi-node pipeline producing red-
 and yellow-dyed output

---
 .../multithreading_reliability_check.py       | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 02982cf7..01c4ead3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from time import sleep
 import argparse
 import os.path
 from pygiftgrab import (VideoSourceFactory,
-                        ColourSpace,
-                        IObservableObserver)
+                        ColourSpace, IObservableObserver,
+                        VideoTargetFactory, Codec)
 
 """
 This script provides a multi-threading reliability check.
@@ -47,3 +48,29 @@ def update(self, frame):
     filename, ext = os.path.splitext(filename)
     assert filename
     assert ext == '.mp4'
+
+    sfac = VideoSourceFactory.get_instance()
+    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    tfac = VideoTargetFactory.get_instance()
+    frame_rate = reader.get_frame_rate()
+
+    red = Dyer(2, 127)
+    green = Dyer(1, 191)
+
+    red_file = os.path.join('.', ''.join([filename, '-red', ext]))
+    red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
+    yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
+    yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
+
+    reader.attach(red)
+    red.attach(red_writer)
+    red.attach(green)
+    green.attach(yellow_writer)
+
+    sleep(20)  # operate pipeline for 20 sec
+
+    reader.detach(red)
+    red.detach(red_writer)
+    red.detach(green)
+    green.detach(yellow_writer)

From 726bb377875dd0224bd8c6861af1bc8e6f602b5f Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:09:08 +0100
Subject: [PATCH 210/277] Issue #16: added a threaded Histogrammer class stub

---
 .../multithreading_reliability_check.py       | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 01c4ead3..c1ba3b48 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -4,6 +4,7 @@
 from time import sleep
 import argparse
 import os.path
+import threading
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -22,6 +23,30 @@
 """
 
 
+buffer = None
+lock = threading.Lock()
+
+
+class Histogrammer(threading.Thread, IObservableObserver):
+
+    def __init__(self, channel):
+        super(Histogrammer, self).__init__()
+        assert 0 <= channel < 3
+        self.channel = channel
+        self.running = False
+
+    def run(self):
+        if self.running:
+            return
+
+        pass
+
+    def stop(self):
+        self.running = False
+
+    def update(self, frame):
+        pass
+
 class Dyer(IObservableObserver):
 
     def __init__(self, channel, value):
@@ -57,6 +82,8 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
+    hist = Histogrammer(0)
+    hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
@@ -69,6 +96,7 @@ def update(self, frame):
     green.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
+    hist.stop()
 
     reader.detach(red)
     red.detach(red_writer)

From 9fda3965b01b2616e42824fbda4d9f522ad3077c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:12:38 +0100
Subject: [PATCH 211/277] Issue #16: added dummy print statement to see
 Histogrammer is alive

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index c1ba3b48..4dd459a1 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,6 +40,10 @@ def run(self):
             return
 
         pass
+        self.running = True
+        while self.running:
+            print('Running')
+            sleep(0.100)
 
     def stop(self):
         self.running = False

From 9b551611b873d83267d296e0a1a8724a216c55cd Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:57:57 +0100
Subject: [PATCH 212/277] Issue #16: factored Histogrammer stub out to
 HistogrammerRed and BuffererRed

---
 .../multithreading_reliability_check.py       | 27 ++++++++++++-------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4dd459a1..12a467bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -23,33 +23,40 @@
 """
 
 
-buffer = None
+buffer_red = None
 lock = threading.Lock()
 
 
-class Histogrammer(threading.Thread, IObservableObserver):
+class BuffererRed(IObservableObserver):
 
-    def __init__(self, channel):
-        super(Histogrammer, self).__init__()
-        assert 0 <= channel < 3
-        self.channel = channel
+    def __init__(self):
+        super(BuffererRed, self).__init__()
+
+    def update(self, frame):
+        global buffer_red
+        # TODO
+
+
+class HistogrammerRed(threading.Thread):
+
+    def __init__(self):
+        super(HistogrammerRed, self).__init__()
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        pass
+        # TODO
         self.running = True
         while self.running:
             print('Running')
+            # TODO
             sleep(0.100)
 
     def stop(self):
         self.running = False
 
-    def update(self, frame):
-        pass
 
 class Dyer(IObservableObserver):
 
@@ -86,7 +93,7 @@ def update(self, frame):
 
     red = Dyer(2, 127)
     green = Dyer(1, 191)
-    hist = Histogrammer(0)
+    hist = HistogrammerRed()
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From c820adbe163da9f5531a4458e5b6f650e5eb6348 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 09:59:41 +0100
Subject: [PATCH 213/277] Issue #16: implemented update of BuffererRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 12a467bb..aa8eb0dd 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -5,6 +5,7 @@
 import argparse
 import os.path
 import threading
+import numpy as np
 from pygiftgrab import (VideoSourceFactory,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
@@ -34,7 +35,12 @@ def __init__(self):
 
     def update(self, frame):
         global buffer_red
-        # TODO
+        with lock:
+            data = frame.data(True)
+            if buffer_red is None:
+                buffer_red = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
 
 
 class HistogrammerRed(threading.Thread):

From 3d4dfce06d9dcd9697caed07d2e05c57e68d1af6 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:06:55 +0100
Subject: [PATCH 214/277] Issue #16: implemented run of HistogrammerRed

---
 src/tests/pipeline/multithreading_reliability_check.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index aa8eb0dd..54ceb230 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -53,11 +53,15 @@ def run(self):
         if self.running:
             return
 
-        # TODO
+        global buffer_red
+        histogram = None
         self.running = True
         while self.running:
-            print('Running')
-            # TODO
+            with lock:
+                if buffer_red is not None:
+                    histogram = np.histogram(buffer_red[:, :, 2],
+                                             bins=8, range=(0, 256))
+            print(histogram)
             sleep(0.100)
 
     def stop(self):

From beab3d0164eb139463ad8c24191f27d84906c95b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:11:05 +0100
Subject: [PATCH 215/277] Issue #16: renamed Dyer vars for clarity

---
 .../multithreading_reliability_check.py       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54ceb230..ff1fda67 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -101,8 +101,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red = Dyer(2, 127)
-    green = Dyer(1, 191)
+    red_dyer = Dyer(2, 127)
+    green_dyer = Dyer(1, 191)
     hist = HistogrammerRed()
     hist.start()
 
@@ -111,15 +111,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red)
-    red.attach(red_writer)
-    red.attach(green)
-    green.attach(yellow_writer)
+    reader.attach(red_dyer)
+    red_dyer.attach(red_writer)
+    red_dyer.attach(green_dyer)
+    green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
     hist.stop()
 
-    reader.detach(red)
-    red.detach(red_writer)
-    red.detach(green)
-    green.detach(yellow_writer)
+    reader.detach(red_dyer)
+    red_dyer.detach(red_writer)
+    red_dyer.detach(green_dyer)
+    green_dyer.detach(yellow_writer)

From 72e48309a4e8a27eed8479d3a3f9691e503f21e8 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:19:12 +0100
Subject: [PATCH 216/277] Issue #16: Dyer.update uses lock

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ff1fda67..ee40fea7 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -78,8 +78,9 @@ def __init__(self, channel, value):
         self.value = value
 
     def update(self, frame):
-        data = frame.data(True)
-        data[:, :, self.channel] = self.value
+        with lock:
+            data = frame.data(True)
+            data[:, :, self.channel] = self.value
 
 
 if __name__ == '__main__':

From b8f91ad33f63fdc8d515c1b514e1788ee4c3df56 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:20:32 +0100
Subject: [PATCH 217/277] Issue #16: inserted a red bufferer into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index ee40fea7..dd0f0dcf 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -104,6 +104,9 @@ def update(self, frame):
 
     red_dyer = Dyer(2, 127)
     green_dyer = Dyer(1, 191)
+
+    bufferer_red = BuffererRed()
+
     hist = HistogrammerRed()
     hist.start()
 
@@ -114,6 +117,7 @@ def update(self, frame):
 
     reader.attach(red_dyer)
     red_dyer.attach(red_writer)
+    red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
@@ -122,5 +126,6 @@ def update(self, frame):
 
     reader.detach(red_dyer)
     red_dyer.detach(red_writer)
+    red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)

From 2c8fc12c354a3d8a203a102b36682ef8211be671 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:22:03 +0100
Subject: [PATCH 218/277] Issue #16: fixed call to histogram function

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index dd0f0dcf..0987129b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,8 +59,9 @@ def run(self):
         while self.running:
             with lock:
                 if buffer_red is not None:
-                    histogram = np.histogram(buffer_red[:, :, 2],
-                                             bins=8, range=(0, 256))
+                    histogram, _ = np.histogram(
+                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                    )
             print(histogram)
             sleep(0.100)
 

From 67d370b62a2e79c6f519bfdfc5416575e53db0cb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:32:24 +0100
Subject: [PATCH 219/277] Issue #16: Dyer now really dyes instead of fixing
 color to a value

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0987129b..54802904 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -71,17 +71,18 @@ def stop(self):
 
 class Dyer(IObservableObserver):
 
-    def __init__(self, channel, value):
+    def __init__(self, channel, increment):
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
-        assert 0 <= value < 256
+        assert 0 <= increment < 256
         self.channel = channel
-        self.value = value
+        self.increment = increment
 
     def update(self, frame):
         with lock:
             data = frame.data(True)
-            data[:, :, self.channel] = self.value
+            channel_data = data[:, :, self.channel]
+            channel_data[channel_data < 255 - self.increment] += self.increment
 
 
 if __name__ == '__main__':

From f09e3048c47a2117630ee538ad865409141a03f7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:53:49 +0100
Subject: [PATCH 220/277] Issue #16: histogrammer now displays a redness score
 instead of histogram

---
 .../pipeline/multithreading_reliability_check.py     | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 54802904..d8bf97ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -54,15 +54,21 @@ def run(self):
             return
 
         global buffer_red
-        histogram = None
+        histogram, num_bins = None, 10
+        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
                 if buffer_red is not None:
                     histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=8, range=(0, 256)
+                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
                     )
-            print(histogram)
+            if histogram is not None:
+                redness = np.sum(histogram * redness_scale)
+                redness /= np.sum(histogram)
+                redness /= num_bins
+                redness *= 100
+                print('Redness: {} %'.format(int(round(redness))))
             sleep(0.100)
 
     def stop(self):

From 91ca884c12d961d15012e236004d5bf951911ae5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:54:11 +0100
Subject: [PATCH 221/277] Issue #16: using more sensible values for dyeing

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index d8bf97ed..a024030b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -110,8 +110,8 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 127)
-    green_dyer = Dyer(1, 191)
+    red_dyer = Dyer(2, 64)
+    green_dyer = Dyer(1, 64)
 
     bufferer_red = BuffererRed()
 

From 97910f88b0116bf7c105e53dd14bdfda1b7a5b9b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 10:59:42 +0100
Subject: [PATCH 222/277] Issue #16: added a BuffererOrig class, a virtual
 replica of BuffererRed

---
 .../multithreading_reliability_check.py         | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a024030b..7b497725 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -43,6 +43,21 @@ def update(self, frame):
                 buffer_red[:, :, :] = data[:, :, :]
 
 
+class BuffererOrig(IObservableObserver):
+
+    def __init__(self):
+        super(BuffererOrig, self).__init__()
+
+    def update(self, frame):
+        global buffer_orig
+        with lock:
+            data = frame.data(True)
+            if buffer_orig is None:
+                buffer_orig = np.copy(data)
+            else:
+                buffer_red[:, :, :] = data[:, :, :]
+
+
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From b5be85c0d5451b4936aab98d31c5ea24a1852b4e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:03:50 +0100
Subject: [PATCH 223/277] Issue #16: BuffererRed now takes buffer as parameter
 to constructor instead of using global var

---
 .../multithreading_reliability_check.py         | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7b497725..0ca024bc 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,7 +6,7 @@
 import os.path
 import threading
 import numpy as np
-from pygiftgrab import (VideoSourceFactory,
+from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec)
 
@@ -30,17 +30,14 @@
 
 class BuffererRed(IObservableObserver):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(BuffererRed, self).__init__()
+        self.buffer = buffer
 
     def update(self, frame):
-        global buffer_red
         with lock:
             data = frame.data(True)
-            if buffer_red is None:
-                buffer_red = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
+            self.buffer[:, :, :] = data[:, :, :]
 
 
 class BuffererOrig(IObservableObserver):
@@ -121,6 +118,9 @@ def update(self, frame):
 
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+    frame = VideoFrame(ColourSpace.BGRA, False)
+    reader.get_frame(frame)
+    frame_shape = (frame.rows(), frame.cols(), 4)
 
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
@@ -128,7 +128,8 @@ def update(self, frame):
     red_dyer = Dyer(2, 64)
     green_dyer = Dyer(1, 64)
 
-    bufferer_red = BuffererRed()
+    buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = BuffererRed(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From c64f86336689ad2854a6e34c02fa7598b769f431 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:10:43 +0100
Subject: [PATCH 224/277] Revert "Issue #16: added a BuffererOrig class, a
 virtual replica of BuffererRed"

This reverts commit 053f499ae6554460df9a755067e1ff5ec817a247.
---
 .../multithreading_reliability_check.py         | 17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0ca024bc..8aed9c85 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+buffer_red = None
 lock = threading.Lock()
 
 
@@ -40,21 +40,6 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class BuffererOrig(IObservableObserver):
-
-    def __init__(self):
-        super(BuffererOrig, self).__init__()
-
-    def update(self, frame):
-        global buffer_orig
-        with lock:
-            data = frame.data(True)
-            if buffer_orig is None:
-                buffer_orig = np.copy(data)
-            else:
-                buffer_red[:, :, :] = data[:, :, :]
-
-
 class HistogrammerRed(threading.Thread):
 
     def __init__(self):

From 8f7666144a0ef88a1cc843b4b71fd491c8a87e4c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:12:15 +0100
Subject: [PATCH 225/277] Issue #16: renamed BuffererRed => Bufferer

---
 src/tests/pipeline/multithreading_reliability_check.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8aed9c85..a345dfd6 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -28,10 +28,10 @@
 lock = threading.Lock()
 
 
-class BuffererRed(IObservableObserver):
+class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):
-        super(BuffererRed, self).__init__()
+        super(Bufferer, self).__init__()
         self.buffer = buffer
 
     def update(self, frame):
@@ -114,7 +114,7 @@ def update(self, frame):
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = BuffererRed(buffer_red)
+    bufferer_red = Bufferer(buffer_red)
 
     hist = HistogrammerRed()
     hist.start()

From 66559805268794d41060e2e23b07df9cd6a8f2d1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:15:02 +0100
Subject: [PATCH 226/277] Issue #16: HistogrammerRed now takes buffer as a
 constructor argument rather than using global var

---
 .../pipeline/multithreading_reliability_check.py    | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a345dfd6..4a58d7bb 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -42,24 +42,23 @@ def update(self, frame):
 
 class HistogrammerRed(threading.Thread):
 
-    def __init__(self):
+    def __init__(self, buffer):
         super(HistogrammerRed, self).__init__()
+        self.buffer = buffer
         self.running = False
 
     def run(self):
         if self.running:
             return
 
-        global buffer_red
         histogram, num_bins = None, 10
         redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
-                if buffer_red is not None:
-                    histogram, _ = np.histogram(
-                        buffer_red[:, :, 2], bins=num_bins, range=(0, 256)
-                    )
+                histogram, _ = np.histogram(
+                    self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
+                )
             if histogram is not None:
                 redness = np.sum(histogram * redness_scale)
                 redness /= np.sum(histogram)
@@ -116,7 +115,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed()
+    hist = HistogrammerRed(buffer_red)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From a8e95b61487034d006d48d4ef7debcd86f8e0aa7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:22:12 +0100
Subject: [PATCH 227/277] Issue #16: HistogrammerRed is now generic
 Histogrammer

---
 .../multithreading_reliability_check.py       | 26 ++++++++++++-------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 4a58d7bb..0de913ed 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -40,10 +40,14 @@ def update(self, frame):
             self.buffer[:, :, :] = data[:, :, :]
 
 
-class HistogrammerRed(threading.Thread):
+class Histogrammer(threading.Thread):
 
-    def __init__(self, buffer):
-        super(HistogrammerRed, self).__init__()
+    channels = ('Blue', 'Green', 'Red', 'Alpha')
+
+    def __init__(self, buffer, channel):
+        super(Histogrammer, self).__init__()
+        assert channel in range(3)
+        self.channel = channel
         self.buffer = buffer
         self.running = False
 
@@ -52,7 +56,7 @@ def run(self):
             return
 
         histogram, num_bins = None, 10
-        redness_scale = np.array([i for i in range(1, num_bins + 1)], np.float)
+        scale = np.array([i for i in range(1, num_bins + 1)], np.float)
         self.running = True
         while self.running:
             with lock:
@@ -60,11 +64,13 @@ def run(self):
                     self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
                 )
             if histogram is not None:
-                redness = np.sum(histogram * redness_scale)
-                redness /= np.sum(histogram)
-                redness /= num_bins
-                redness *= 100
-                print('Redness: {} %'.format(int(round(redness))))
+                coloredness = np.sum(histogram * scale)
+                coloredness /= np.sum(histogram)
+                coloredness /= num_bins
+                coloredness *= 100
+                print('{}ness of dyed image: {} %'.format(
+                    Histogrammer.channels[self.channel], int(round(coloredness))
+                ))
             sleep(0.100)
 
     def stop(self):
@@ -115,7 +121,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = HistogrammerRed(buffer_red)
+    hist = Histogrammer(buffer_red, 2)
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From a409400c2eaace4ded9f62a9c285c6bfa02ed255 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:27:00 +0100
Subject: [PATCH 228/277] Issue #16: Histogrammer now accepts a tag for
 generically printing what the image is

---
 src/tests/pipeline/multithreading_reliability_check.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0de913ed..168b6b9f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,11 +44,12 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel):
+    def __init__(self, buffer, channel, tag):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         self.channel = channel
         self.buffer = buffer
+        self.tag = tag
         self.running = False
 
     def run(self):
@@ -68,8 +69,8 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of dyed image: {} %'.format(
-                    Histogrammer.channels[self.channel], int(round(coloredness))
+                print('{}ness of {} image: {} %'.format(
+                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
                 ))
             sleep(0.100)
 
@@ -121,7 +122,7 @@ def update(self, frame):
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
 
-    hist = Histogrammer(buffer_red, 2)
+    hist = Histogrammer(buffer_red, 2, 'red-dyed')
     hist.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 5e4df492d32ffebbc32a1f2d80a3a18460ec9b61 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:34:30 +0100
Subject: [PATCH 229/277] Issue #16: inserted an original image histogrammer
 into the pipeline

---
 .../multithreading_reliability_check.py       | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 168b6b9f..971e94b2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -24,7 +24,7 @@
 """
 
 
-buffer_red = None
+buffer_red, buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -121,25 +121,32 @@ def update(self, frame):
 
     buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(buffer_red)
+    buffer_orig = np.zeros_like(buffer_red)
+    bufferer_orig = Bufferer(buffer_orig)
 
-    hist = Histogrammer(buffer_red, 2, 'red-dyed')
-    hist.start()
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red.start()
+    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    reader.attach(red_dyer)
+    reader.attach(bufferer_orig)
+    bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
 
     sleep(20)  # operate pipeline for 20 sec
-    hist.stop()
+    hist_red.stop()
+    hist_orig.stop()
 
-    reader.detach(red_dyer)
+    reader.detach(bufferer_orig)
+    bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)

From 492cfada88590dd39d46feef28ac62f0b82df056 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:39:33 +0100
Subject: [PATCH 230/277] Issue #16: Histogrammer now accepts a frame rate and
 flag for displaying coloredness

---
 .../multithreading_reliability_check.py       | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 971e94b2..df093c13 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,12 +44,15 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag):
+    def __init__(self, buffer, channel, tag, frame_rate, show=True):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
+        assert 0 < frame_rate <= 60
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
+        self.show = show
+        self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
     def run(self):
@@ -69,10 +72,12 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                print('{}ness of {} image: {} %'.format(
-                    Histogrammer.channels[self.channel], self.tag, int(round(coloredness))
-                ))
-            sleep(0.100)
+                if self.show:
+                    print('{}ness of {} image: {} %'.format(
+                        Histogrammer.channels[self.channel],
+                        self.tag, int(round(coloredness))
+                    ))
+            sleep(self.sleep_interval)
 
     def stop(self):
         self.running = False
@@ -124,9 +129,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed')
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original')
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 59e4a9a984ede40c47417d25f8d53b387c3fc492 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:45:12 +0100
Subject: [PATCH 231/277] Issue #16: now can specify the frequency of
 coloredness prints

---
 .../pipeline/multithreading_reliability_check.py  | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index df093c13..43e82a19 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -44,14 +44,16 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, show=True):
+    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
+        assert 0 <= display_freq
         self.channel = channel
         self.buffer = buffer
         self.tag = tag
-        self.show = show
+        self.display_freq = display_freq
+        self.num_skipped = 0
         self.sleep_interval = 1.0 / frame_rate
         self.running = False
 
@@ -72,11 +74,14 @@ def run(self):
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
                 coloredness *= 100
-                if self.show:
+                if self.num_skipped >= self.display_freq:
                     print('{}ness of {} image: {} %'.format(
                         Histogrammer.channels[self.channel],
                         self.tag, int(round(coloredness))
                     ))
+                    self.num_skipped = 0
+                else:
+                    self.num_skipped += 1
             sleep(self.sleep_interval)
 
     def stop(self):
@@ -129,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30, False)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30, False)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From a80a29ce71716f798fc3ee9072ebe1bec3a71182 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:47:38 +0100
Subject: [PATCH 232/277] Issue #16: dyeing red more prominently

---
 src/tests/pipeline/multithreading_reliability_check.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 43e82a19..72ab94d2 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -126,7 +126,7 @@ def update(self, frame):
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
-    red_dyer = Dyer(2, 64)
+    red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
     buffer_red = np.zeros(frame_shape, np.uint8)

From c032350532b563f61e218735634b4d54fa0521f5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:53:47 +0100
Subject: [PATCH 233/277] Issue #16: frame rate values that reproduced the
 problem

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 72ab94d2..42cc36e3 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -134,9 +134,9 @@ def update(self, frame):
     buffer_orig = np.zeros_like(buffer_red)
     bufferer_orig = Bufferer(buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 30.0, 10)
+    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 30.0, 10)
+    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 0f3d327aa74b48181a02e831778b78011272eba1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 12 Oct 2018 11:54:25 +0100
Subject: [PATCH 234/277] Issue #16: using Debug CMake type in build script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index efae4d95..7ea874b2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -13,6 +13,7 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR

From c13a24f7be4c5ccd34f8fe1ded260afffb1e6e25 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 08:28:50 +0100
Subject: [PATCH 235/277] Issue #16: renamed variable for clarity in run script

---
 src/tests/pipeline/check_multithreading_reliability.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 7ea874b2..2be8fea2 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,15 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
-BUILD_DIR=$CURRENT_DIR/mtr-build
-SOURCE_DIR="$( cd "$CURRENT_DIR/../.." >/dev/null && pwd )"
+ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+BUILD_DIR=$ROOT_DIR/mtr-build
+SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$CURRENT_DIR/multithreading_reliability_check.py
+MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*

From a15424a820c19b3080ef84f1378a7d1477691b3e Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:00:44 +0100
Subject: [PATCH 236/277] Issue #16: setting ulimit to dump cores when running
 check

---
 src/tests/pipeline/check_multithreading_reliability.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 2be8fea2..4519cb84 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+ulimit -c unlimited
 
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
@@ -22,3 +23,5 @@ cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+ulimit -c 0

From b864abec24d9e94c0c437b148db5da6f1b218a21 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:02:44 +0100
Subject: [PATCH 237/277] Issue #16: saving all output in a hierarchical
 session directory

---
 .../pipeline/check_multithreading_reliability.sh    | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 4519cb84..f3cc6910 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,13 +15,26 @@ CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
+SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
+mkdir $SESSION_DIR
 ulimit -c unlimited
 
+BUILD_LOG=$SESSION_DIR/build.log
+{
 mkdir -p $BUILD_DIR
 rm -rf $BUILD_DIR/*
 cd $BUILD_DIR
 cmake $CMAKE_OPTS $SOURCE_DIR
 make -j4
+} > $BUILD_LOG 2>&1
+
+run_no=1
+WORKING_DIR=$SESSION_DIR/$run_no
+mkdir $WORKING_DIR
+cd $WORKING_DIR
+RUN_LOG=$WORKING_DIR/run.log
+{
 PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+} > $RUN_LOG 2>&1
 
 ulimit -c 0

From 5c7bde3a6d4605262c10d0928540c1029c1304a2 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:05:12 +0100
Subject: [PATCH 238/277] Issue #16: added indentation for readability

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f3cc6910..71e9efc0 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -21,11 +21,11 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
-mkdir -p $BUILD_DIR
-rm -rf $BUILD_DIR/*
-cd $BUILD_DIR
-cmake $CMAKE_OPTS $SOURCE_DIR
-make -j4
+    mkdir -p $BUILD_DIR
+    rm -rf $BUILD_DIR/*
+    cd $BUILD_DIR
+    cmake $CMAKE_OPTS $SOURCE_DIR
+    make -j4
 } > $BUILD_LOG 2>&1
 
 run_no=1
@@ -34,7 +34,7 @@ mkdir $WORKING_DIR
 cd $WORKING_DIR
 RUN_LOG=$WORKING_DIR/run.log
 {
-PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
 } > $RUN_LOG 2>&1
 
 ulimit -c 0

From d3534e6a4fe0a02e9227bc2a0f20691dac4abb36 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 09:14:47 +0100
Subject: [PATCH 239/277] Issue #16: can now specify number of reps in check
 script

---
 .../check_multithreading_reliability.sh       | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e9efc0..52eed368 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,13 +28,20 @@ BUILD_LOG=$SESSION_DIR/build.log
     make -j4
 } > $BUILD_LOG 2>&1
 
-run_no=1
-WORKING_DIR=$SESSION_DIR/$run_no
-mkdir $WORKING_DIR
-cd $WORKING_DIR
-RUN_LOG=$WORKING_DIR/run.log
-{
-    PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
-} > $RUN_LOG 2>&1
+num_reps=1
+if [ $# -ge 2 ];
+then
+    num_reps=$2
+fi
+for run_no in `seq 1 $num_reps`;
+do
+    WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
+    mkdir $WORKING_DIR
+    cd $WORKING_DIR
+    RUN_LOG=$WORKING_DIR/run.log
+    {
+        PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+    } > $RUN_LOG 2>&1
+done
 
 ulimit -c 0

From 22c158b48424f3ff6754d47a74c4752febff7af7 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:38:52 +0100
Subject: [PATCH 240/277] Issue #16: can now optionally specify root output dir
 (e.g. not to fill up disk space)

---
 .../pipeline/check_multithreading_reliability.sh    | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 52eed368..1a90362e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -6,15 +6,22 @@
 # and NumPy support. Subsequently run the multi-threading
 # reliability check script.
 
-ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
+SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+if [ $# -ge 3 ];
+then
+    ROOT_DIR=$3
+else
+    ROOT_DIR=$CALL_DIR
+fi
+
 BUILD_DIR=$ROOT_DIR/mtr-build
-SOURCE_DIR="$( cd "$ROOT_DIR/../.." >/dev/null && pwd )"
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-MTR_SCRIPT=$ROOT_DIR/multithreading_reliability_check.py
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
 ulimit -c unlimited

From 5795b393c3bda3ab8d19a7046817cffb22e01af6 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:48:37 +0100
Subject: [PATCH 241/277] Issue #16: logging frequency of exit codes as well

---
 .../pipeline/check_multithreading_reliability.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 1a90362e..f7fbb5fe 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -40,6 +40,8 @@ if [ $# -ge 2 ];
 then
     num_reps=$2
 fi
+
+declare -a exit_code_freqs
 for run_no in `seq 1 $num_reps`;
 do
     WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
@@ -48,7 +50,21 @@ do
     RUN_LOG=$WORKING_DIR/run.log
     {
         PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
+
+        exit_code=$?
+        echo "Exit code was: $exit_code"
+        freq=${exit_code_freqs[$exit_code]}
+        let freq=$freq+1
+        exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
+
+    sleep 5
+done
+
+EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+for exit_code in "${!exit_code_freqs[@]}";
+do
+    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From 85f48387c74dad8b4590b3546349fb53f938becb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 10:59:58 +0100
Subject: [PATCH 242/277] Issue #16: nicer formatting of exit code frequencies
 log

---
 src/tests/pipeline/check_multithreading_reliability.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index f7fbb5fe..419b7c08 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -62,9 +62,14 @@ do
 done
 
 EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
+printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+printf "%10s" "frequency" >> $EXIT_CODES_LOG
+printf "\n" >> $EXIT_CODES_LOG
 for exit_code in "${!exit_code_freqs[@]}";
 do
-    echo "$exit_code ${exit_code_freqs[$exit_code]}" >> $EXIT_CODES_LOG
+    printf "%10d" $exit_code >> $EXIT_CODES_LOG
+    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+    printf "\n" >> $EXIT_CODES_LOG
 done
 
 ulimit -c 0

From d0a3c050b413807445200264f70c2c083877ad30 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:02:37 +0100
Subject: [PATCH 243/277] Issue #16: ignoring output folder to avoid an
 accidental commit of big files

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index d7eb0905..35b7a77b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@ src/dist
 src/*.egg-info
 *.swp
 src/tests/pipeline/mtr-build
+gg-iss-16

From 36f008692da887d70d8b976d743e613b3bc1bd80 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:06:29 +0100
Subject: [PATCH 244/277] Issue #16: using absolute path expansion if root-dir
 passed as a CLI param

---
 src/tests/pipeline/check_multithreading_reliability.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 419b7c08..18b9133e 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -11,7 +11,7 @@ SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
 if [ $# -ge 3 ];
 then
-    ROOT_DIR=$3
+    ROOT_DIR="$( cd "$3" >/dev/null && pwd )"
 else
     ROOT_DIR=$CALL_DIR
 fi

From c866810a6fda35d9f48a37add773bf1f96a86b9d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 11:56:45 +0100
Subject: [PATCH 245/277] Issue #16: intermediately writing exit codes every 10
 iterations

---
 .../check_multithreading_reliability.sh       | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 18b9133e..64b58250 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -58,18 +58,21 @@ do
         exit_code_freqs[$exit_code]=$freq
     } > $RUN_LOG 2>&1
 
-    sleep 5
-done
+    if [ $(($run_no % 10)) -eq 0 ] || [ $run_no -eq $num_reps ];
+    then
+        EXIT_CODES_LOG=$SESSION_DIR/exit-codes-$run_no.csv
+        printf "%10s" "exit-code" >> $EXIT_CODES_LOG
+        printf "%10s" "frequency" >> $EXIT_CODES_LOG
+        printf "\n" >> $EXIT_CODES_LOG
+        for exit_code in "${!exit_code_freqs[@]}";
+        do
+            printf "%10d" $exit_code >> $EXIT_CODES_LOG
+            printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
+            printf "\n" >> $EXIT_CODES_LOG
+        done
+    fi
 
-EXIT_CODES_LOG=$SESSION_DIR/exit-codes.csv
-printf "%10s" "exit-code" >> $EXIT_CODES_LOG
-printf "%10s" "frequency" >> $EXIT_CODES_LOG
-printf "\n" >> $EXIT_CODES_LOG
-for exit_code in "${!exit_code_freqs[@]}";
-do
-    printf "%10d" $exit_code >> $EXIT_CODES_LOG
-    printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
-    printf "\n" >> $EXIT_CODES_LOG
+    sleep 5
 done
 
 ulimit -c 0

From 5177b081c0e4af55b218798072e7bb8a5d609400 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sat, 13 Oct 2018 12:19:39 +0100
Subject: [PATCH 246/277] Issue #16: using git-describe to tag the output with
 the version used

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 64b58250..71e2bb62 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -28,6 +28,7 @@ ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log
 {
+    git describe --dirty
     mkdir -p $BUILD_DIR
     rm -rf $BUILD_DIR/*
     cd $BUILD_DIR

From 452b0f938bfc37bc0eee0441be138793c1c4aad6 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:06:14 +0100
Subject: [PATCH 247/277] Issue #16: using Pythonic percentage formatting

---
 src/tests/pipeline/multithreading_reliability_check.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 42cc36e3..e1c50e30 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -73,11 +73,10 @@ def run(self):
                 coloredness = np.sum(histogram * scale)
                 coloredness /= np.sum(histogram)
                 coloredness /= num_bins
-                coloredness *= 100
                 if self.num_skipped >= self.display_freq:
-                    print('{}ness of {} image: {} %'.format(
+                    print('{}ness of {} image: {:.0%}'.format(
                         Histogrammer.channels[self.channel],
-                        self.tag, int(round(coloredness))
+                        self.tag, coloredness
                     ))
                     self.num_skipped = 0
                 else:

From b2f649d1bc5f14a0fa9524577c3856ad811b34a1 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:24:39 +0100
Subject: [PATCH 248/277] Issue #16: added a SnapshotSaver class that
 implements IObserver directly

---
 .../multithreading_reliability_check.py       | 29 ++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index e1c50e30..a880b355 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -6,9 +6,10 @@
 import os.path
 import threading
 import numpy as np
+import scipy.misc
 from pygiftgrab import (VideoSourceFactory, VideoFrame,
                         ColourSpace, IObservableObserver,
-                        VideoTargetFactory, Codec)
+                        VideoTargetFactory, Codec, IObserver)
 
 """
 This script provides a multi-threading reliability check.
@@ -28,6 +29,32 @@
 lock = threading.Lock()
 
 
+class SnapshotSaver(IObserver):
+    """A snapshot saver for saving incoming frames to PNG files."""
+
+    def __init__(self, root_dir, frame_rate=0.2):
+        """
+        Initialise a snapshot saver with a saving frequency.
+
+        :param root_dir: the folder where to save the snapshots
+        :param frame_rate: saving frequency. The default value tells
+        the saver to save a frame every 5 sec.
+        """
+        super(SnapshotSaver, self).__init__()
+        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
+        self.save_freq = 1.0 / frame_rate
+        self.root_dir = root_dir
+        self.num_called = 0
+
+    def update(self, frame):
+        """Implement ``IObserver.update``."""
+        self.num_called += 1
+        if self.num_called % self.save_freq == 1:
+            out_file = os.path.join(self.root_dir,
+                                    'frame-{:010d}.png'.format(self.num_called))
+            scipy.misc.imsave(out_file, frame.data(True))
+
+
 class Bufferer(IObservableObserver):
 
     def __init__(self, buffer):

From ecd72865e44689f61127bbfaf77e3dfa8c467bec Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:25:08 +0100
Subject: [PATCH 249/277] Issue #16: inserted snapshot saver into the pipeline

---
 src/tests/pipeline/multithreading_reliability_check.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index a880b355..f1a1697f 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -170,12 +170,15 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    yellow_snapshots = SnapshotSaver('.')
+
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
     red_dyer.attach(green_dyer)
     green_dyer.attach(yellow_writer)
+    green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
     hist_red.stop()
@@ -187,3 +190,4 @@ def update(self, frame):
     red_dyer.detach(bufferer_red)
     red_dyer.detach(green_dyer)
     green_dyer.detach(yellow_writer)
+    green_dyer.detach(yellow_snapshots)

From 0b90bd701ea36d006d792577e9479b6b7b346807 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 09:47:20 +0100
Subject: [PATCH 250/277] Issue #16: fixed timed saving of snapshots

---
 .../multithreading_reliability_check.py       | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index f1a1697f..7eca3382 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from time import sleep
+from time import (sleep, time)
 import argparse
 import os.path
 import threading
@@ -32,27 +32,29 @@
 class SnapshotSaver(IObserver):
     """A snapshot saver for saving incoming frames to PNG files."""
 
-    def __init__(self, root_dir, frame_rate=0.2):
+    def __init__(self, root_dir, save_freq=5):
         """
         Initialise a snapshot saver with a saving frequency.
 
         :param root_dir: the folder where to save the snapshots
-        :param frame_rate: saving frequency. The default value tells
-        the saver to save a frame every 5 sec.
+        :param save_freq: saving frequency. The default value tells
+        the saver to save every 5 seconds.
         """
         super(SnapshotSaver, self).__init__()
-        assert 0 < frame_rate <= 1  # to avoid flooding disk with images
-        self.save_freq = 1.0 / frame_rate
+        assert 5 <= save_freq  # to avoid flooding disk with images
+        self.save_freq = save_freq
         self.root_dir = root_dir
-        self.num_called = 0
+        self.last_saved = time()
+        self.num_saved = 0
 
     def update(self, frame):
         """Implement ``IObserver.update``."""
-        self.num_called += 1
-        if self.num_called % self.save_freq == 1:
+        if time() - self.last_saved >= self.save_freq:
+            self.num_saved += 1
             out_file = os.path.join(self.root_dir,
-                                    'frame-{:010d}.png'.format(self.num_called))
+                                    'frame-{:010d}.png'.format(self.num_saved))
             scipy.misc.imsave(out_file, frame.data(True))
+            self.last_saved = time()
 
 
 class Bufferer(IObservableObserver):

From 3f5e56d49b20fd0b969927ec6e17d1228d88b00d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:10:24 +0100
Subject: [PATCH 251/277] Issue #16: renamed buffer => np_buffer as buffer is
 built-in type

---
 src/tests/pipeline/multithreading_reliability_check.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 7eca3382..0091b993 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -59,9 +59,9 @@ def update(self, frame):
 
 class Bufferer(IObservableObserver):
 
-    def __init__(self, buffer):
+    def __init__(self, np_buffer):
         super(Bufferer, self).__init__()
-        self.buffer = buffer
+        self.buffer = np_buffer
 
     def update(self, frame):
         with lock:
@@ -73,13 +73,13 @@ class Histogrammer(threading.Thread):
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
-    def __init__(self, buffer, channel, tag, frame_rate, display_freq):
+    def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
         assert 0 <= display_freq
         self.channel = channel
-        self.buffer = buffer
+        self.buffer = np_buffer
         self.tag = tag
         self.display_freq = display_freq
         self.num_skipped = 0

From 5099c9d03d160bd794244a34f49ecaec93b0ee98 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:17:51 +0100
Subject: [PATCH 252/277] Issue #16: renamed global buffers for clarity

---
 .../pipeline/multithreading_reliability_check.py   | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 0091b993..8d3d4b89 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,7 @@
 """
 
 
-buffer_red, buffer_orig = None, None
+np_buffer_red, np_buffer_orig = None, None
 lock = threading.Lock()
 
 
@@ -157,14 +157,14 @@ def update(self, frame):
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
-    buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = Bufferer(buffer_red)
-    buffer_orig = np.zeros_like(buffer_red)
-    bufferer_orig = Bufferer(buffer_orig)
+    np_buffer_red = np.zeros(frame_shape, np.uint8)
+    bufferer_red = Bufferer(np_buffer_red)
+    np_buffer_orig = np.zeros_like(np_buffer_red)
+    bufferer_orig = Bufferer(np_buffer_orig)
 
-    hist_red = Histogrammer(buffer_red, 2, 'red-dyed', 60.0, 10)
+    hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
-    hist_orig = Histogrammer(buffer_orig, 2, 'original', 50.0, 10)
+    hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))

From 58a2afef831d76f0a69b0c982681e464a81587b5 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:20:01 +0100
Subject: [PATCH 253/277] Issue #16: commented checker script

---
 .../multithreading_reliability_check.py       | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index 8d3d4b89..b4d21c9c 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -25,7 +25,11 @@
 """
 
 
+# global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None
+
+# mutex protecting frame data passed from node to node
+# in the GIFT-Grab processing pipeline
 lock = threading.Lock()
 
 
@@ -58,22 +62,41 @@ def update(self, frame):
 
 
 class Bufferer(IObservableObserver):
+    """GIFT-Grab processing node that updates a frame buffer."""
 
     def __init__(self, np_buffer):
+        """Initialise a bufferer that will update given buffer."""
         super(Bufferer, self).__init__()
         self.buffer = np_buffer
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             self.buffer[:, :, :] = data[:, :, :]
 
 
 class Histogrammer(threading.Thread):
+    """
+    GIFT-Grab processing node that computes the histogram of
+    an image channel and prints how "colored" that channel is.
+    """
 
     channels = ('Blue', 'Green', 'Red', 'Alpha')
 
     def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
+        """
+        :param np_buffer: image buffer to use
+        :param channel: image channel to compute coloredness for
+        :param tag: a tag describing what this image is, e.g.
+        how it's been processed within a GIFT-Grab pipeline
+        :param frame_rate: the rate at which to compute the
+        coloredness (unit: frames-per-second)
+        :param display_freq: how many times to skip the display
+        of computed coloredness, e.g. if 5 is provided, the
+        coloredness of every 5th frame will be printed to the
+        console
+        """
         super(Histogrammer, self).__init__()
         assert channel in range(3)
         assert 0 < frame_rate <= 60
@@ -87,6 +110,7 @@ def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
         self.running = False
 
     def run(self):
+        """Override ``Thread.run``."""
         if self.running:
             return
 
@@ -113,12 +137,18 @@ def run(self):
             sleep(self.sleep_interval)
 
     def stop(self):
+        """Stop the thread."""
         self.running = False
 
 
 class Dyer(IObservableObserver):
+    """Dyes specified channel of an incoming video frame."""
 
     def __init__(self, channel, increment):
+        """
+        :param channel: image channel to dye
+        :param increment: how much to dye the image channel
+        """
         super(Dyer, self).__init__()
         assert 0 <= channel < 3
         assert 0 <= increment < 256
@@ -126,6 +156,7 @@ def __init__(self, channel, increment):
         self.increment = increment
 
     def update(self, frame):
+        """Implement ``IObservableObserver.update``."""
         with lock:
             data = frame.data(True)
             channel_data = data[:, :, self.channel]
@@ -145,35 +176,46 @@ def update(self, frame):
     assert filename
     assert ext == '.mp4'
 
+    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
     reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
+    # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
     frame_rate = reader.get_frame_rate()
 
+    # create a red and green Dyer
     red_dyer = Dyer(2, 128)
     green_dyer = Dyer(1, 64)
 
+    # create the bufferer for the red and green Dyers
     np_buffer_red = np.zeros(frame_shape, np.uint8)
     bufferer_red = Bufferer(np_buffer_red)
     np_buffer_orig = np.zeros_like(np_buffer_red)
     bufferer_orig = Bufferer(np_buffer_orig)
 
+    # create the histogrammers for the red-dyed and
+    # the original video frames, and start them
     hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
     hist_red.start()
     hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
     hist_orig.start()
 
+    # create encoders for the red-dyed and yellow-dyed (as green
+    # is applied on top of red) video streams
     red_file = os.path.join('.', ''.join([filename, '-red', ext]))
     red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
+    # create a SnapshotSavers for saving a number of yellow-dyed
+    # video frames
     yellow_snapshots = SnapshotSaver('.')
 
+    # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
@@ -183,9 +225,12 @@ def update(self, frame):
     green_dyer.attach(yellow_snapshots)
 
     sleep(20)  # operate pipeline for 20 sec
+
+    # stop the histogrammers
     hist_red.stop()
     hist_orig.stop()
 
+    # disassemble the GIFT-Grab pipeline
     reader.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)

From a78214ce9091fcacc78a7af8d15f01fde60717ee Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:24 +0100
Subject: [PATCH 254/277] Issue #16: moved issue-specific comments to shell
 script

---
 .../check_multithreading_reliability.sh        | 17 +++++++++++++----
 .../multithreading_reliability_check.py        | 18 +++++-------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index 71e2bb62..ceafc345 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -1,10 +1,19 @@
 #!/usr/bin/env bash
 # -*- coding: utf-8 -*-
 
-# Build a basic GIFT-Grab capable of reading a video file,
-# and encoding to a video file in real time, with Python
-# and NumPy support. Subsequently run the multi-threading
-# reliability check script.
+# This script provides a multi-threading reliability check.
+# The background is issue #16. It looks like in applications
+# where multiple Python threads are involved, occasionally
+# the acquisition of the Global Interpreter Lock leads to a
+# deadlocks, which crashes the whole application with a
+# non-specific segmentation fault.
+#
+# It builds a basic GIFT-Grab capable of reading a video file,
+# and encoding to a video file in real time, with Python and
+# NumPy support. It subsequently runs a multi-threaded
+# GIFT-Grab pipeline a number of times, recording the exit
+# status each time. This is essentially a stress-test that
+# should serve as a validation that issue #16 is fixed.
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
index b4d21c9c..3fdad38b 100755
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ b/src/tests/pipeline/multithreading_reliability_check.py
@@ -1,6 +1,11 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+"""
+Example showing a complex GIFT-Grab pipeline with
+multiple intermediate processing nodes.
+"""
+
 from time import (sleep, time)
 import argparse
 import os.path
@@ -11,19 +16,6 @@
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
-"""
-This script provides a multi-threading reliability check.
-The background is issue #16. It looks like in applications
-where multiple Python threads are involved, occasionally
-the acquisition of the Global Interpreter Lock leads to a
-deadlocks, which crashes the whole application with a
-non-specific segmentation fault.
-
-In this script we run a number of multi-threaded GIFT-Grab
-pipelines, which should serve as a validation that this
-problem is fixed.
-"""
-
 
 # global NumPy buffers
 np_buffer_red, np_buffer_orig = None, None

From 1844626b5f3657d6a290605b652a4c1284931b13 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:54:45 +0100
Subject: [PATCH 255/277] Issue #16: added synopsis display to shell script

---
 .../pipeline/check_multithreading_reliability.sh     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index ceafc345..c6419403 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -15,6 +15,18 @@
 # status each time. This is essentially a stress-test that
 # should serve as a validation that issue #16 is fixed.
 
+if [ $# -lt 1 ] || [ $# -gt 3 ];
+then
+    THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
+    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tnum_reps:   how many times to run the Python script "
+    printf "(default: once)\n"
+    printf "\toutput_dir: where to save all the generated output "
+    printf "(default: current directory)\n"
+    exit 1
+fi
+
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
 MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py

From 8ef5a463a0fe819e9319d0d647c30b561733e3ed Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 10:57:52 +0100
Subject: [PATCH 256/277] Issue #16: shell script now shows the current session
 directory before starting

---
 src/tests/pipeline/check_multithreading_reliability.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
index c6419403..39df9537 100755
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ b/src/tests/pipeline/check_multithreading_reliability.sh
@@ -45,6 +45,7 @@ CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR
+echo "Session directory: $SESSION_DIR"
 ulimit -c unlimited
 
 BUILD_LOG=$SESSION_DIR/build.log

From ad142620e3bbbe40fd7f22a29a1e1924b3ddef1b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:01:37 +0100
Subject: [PATCH 257/277] Issue #16: shorter name for Python script

---
 src/tests/pipeline/complex_pipeline.py        |   4 +-
 .../multithreading_reliability_check.py       | 232 ------------------
 2 files changed, 2 insertions(+), 234 deletions(-)
 delete mode 100755 src/tests/pipeline/multithreading_reliability_check.py

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 66686f1e..3fdad38b 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -203,9 +203,9 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    # create a SnapshotSaver for saving a number of yellow-dyed
+    # create a SnapshotSavers for saving a number of yellow-dyed
     # video frames
-    yellow_snapshots = SnapshotSaver('.', 9)
+    yellow_snapshots = SnapshotSaver('.')
 
     # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)
diff --git a/src/tests/pipeline/multithreading_reliability_check.py b/src/tests/pipeline/multithreading_reliability_check.py
deleted file mode 100755
index 3fdad38b..00000000
--- a/src/tests/pipeline/multithreading_reliability_check.py
+++ /dev/null
@@ -1,232 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-"""
-Example showing a complex GIFT-Grab pipeline with
-multiple intermediate processing nodes.
-"""
-
-from time import (sleep, time)
-import argparse
-import os.path
-import threading
-import numpy as np
-import scipy.misc
-from pygiftgrab import (VideoSourceFactory, VideoFrame,
-                        ColourSpace, IObservableObserver,
-                        VideoTargetFactory, Codec, IObserver)
-
-
-# global NumPy buffers
-np_buffer_red, np_buffer_orig = None, None
-
-# mutex protecting frame data passed from node to node
-# in the GIFT-Grab processing pipeline
-lock = threading.Lock()
-
-
-class SnapshotSaver(IObserver):
-    """A snapshot saver for saving incoming frames to PNG files."""
-
-    def __init__(self, root_dir, save_freq=5):
-        """
-        Initialise a snapshot saver with a saving frequency.
-
-        :param root_dir: the folder where to save the snapshots
-        :param save_freq: saving frequency. The default value tells
-        the saver to save every 5 seconds.
-        """
-        super(SnapshotSaver, self).__init__()
-        assert 5 <= save_freq  # to avoid flooding disk with images
-        self.save_freq = save_freq
-        self.root_dir = root_dir
-        self.last_saved = time()
-        self.num_saved = 0
-
-    def update(self, frame):
-        """Implement ``IObserver.update``."""
-        if time() - self.last_saved >= self.save_freq:
-            self.num_saved += 1
-            out_file = os.path.join(self.root_dir,
-                                    'frame-{:010d}.png'.format(self.num_saved))
-            scipy.misc.imsave(out_file, frame.data(True))
-            self.last_saved = time()
-
-
-class Bufferer(IObservableObserver):
-    """GIFT-Grab processing node that updates a frame buffer."""
-
-    def __init__(self, np_buffer):
-        """Initialise a bufferer that will update given buffer."""
-        super(Bufferer, self).__init__()
-        self.buffer = np_buffer
-
-    def update(self, frame):
-        """Implement ``IObservableObserver.update``."""
-        with lock:
-            data = frame.data(True)
-            self.buffer[:, :, :] = data[:, :, :]
-
-
-class Histogrammer(threading.Thread):
-    """
-    GIFT-Grab processing node that computes the histogram of
-    an image channel and prints how "colored" that channel is.
-    """
-
-    channels = ('Blue', 'Green', 'Red', 'Alpha')
-
-    def __init__(self, np_buffer, channel, tag, frame_rate, display_freq):
-        """
-        :param np_buffer: image buffer to use
-        :param channel: image channel to compute coloredness for
-        :param tag: a tag describing what this image is, e.g.
-        how it's been processed within a GIFT-Grab pipeline
-        :param frame_rate: the rate at which to compute the
-        coloredness (unit: frames-per-second)
-        :param display_freq: how many times to skip the display
-        of computed coloredness, e.g. if 5 is provided, the
-        coloredness of every 5th frame will be printed to the
-        console
-        """
-        super(Histogrammer, self).__init__()
-        assert channel in range(3)
-        assert 0 < frame_rate <= 60
-        assert 0 <= display_freq
-        self.channel = channel
-        self.buffer = np_buffer
-        self.tag = tag
-        self.display_freq = display_freq
-        self.num_skipped = 0
-        self.sleep_interval = 1.0 / frame_rate
-        self.running = False
-
-    def run(self):
-        """Override ``Thread.run``."""
-        if self.running:
-            return
-
-        histogram, num_bins = None, 10
-        scale = np.array([i for i in range(1, num_bins + 1)], np.float)
-        self.running = True
-        while self.running:
-            with lock:
-                histogram, _ = np.histogram(
-                    self.buffer[:, :, 2], bins=num_bins, range=(0, 256)
-                )
-            if histogram is not None:
-                coloredness = np.sum(histogram * scale)
-                coloredness /= np.sum(histogram)
-                coloredness /= num_bins
-                if self.num_skipped >= self.display_freq:
-                    print('{}ness of {} image: {:.0%}'.format(
-                        Histogrammer.channels[self.channel],
-                        self.tag, coloredness
-                    ))
-                    self.num_skipped = 0
-                else:
-                    self.num_skipped += 1
-            sleep(self.sleep_interval)
-
-    def stop(self):
-        """Stop the thread."""
-        self.running = False
-
-
-class Dyer(IObservableObserver):
-    """Dyes specified channel of an incoming video frame."""
-
-    def __init__(self, channel, increment):
-        """
-        :param channel: image channel to dye
-        :param increment: how much to dye the image channel
-        """
-        super(Dyer, self).__init__()
-        assert 0 <= channel < 3
-        assert 0 <= increment < 256
-        self.channel = channel
-        self.increment = increment
-
-    def update(self, frame):
-        """Implement ``IObservableObserver.update``."""
-        with lock:
-            data = frame.data(True)
-            channel_data = data[:, :, self.channel]
-            channel_data[channel_data < 255 - self.increment] += self.increment
-
-
-if __name__ == '__main__':
-    parser = argparse.ArgumentParser()
-    parser.add_argument('-i', '--input', type=str, required=True,
-                        metavar='VIDEO_FILE',
-                        help='Input video file (HEVC-encoded MP4)')
-    args = parser.parse_args()
-    in_file = args.input
-
-    filename = os.path.basename(in_file)
-    filename, ext = os.path.splitext(filename)
-    assert filename
-    assert ext == '.mp4'
-
-    # initialise reading of passed file
-    sfac = VideoSourceFactory.get_instance()
-    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
-    frame = VideoFrame(ColourSpace.BGRA, False)
-    reader.get_frame(frame)
-    frame_shape = (frame.rows(), frame.cols(), 4)
-
-    # prepare for creating encoders (writers)
-    tfac = VideoTargetFactory.get_instance()
-    frame_rate = reader.get_frame_rate()
-
-    # create a red and green Dyer
-    red_dyer = Dyer(2, 128)
-    green_dyer = Dyer(1, 64)
-
-    # create the bufferer for the red and green Dyers
-    np_buffer_red = np.zeros(frame_shape, np.uint8)
-    bufferer_red = Bufferer(np_buffer_red)
-    np_buffer_orig = np.zeros_like(np_buffer_red)
-    bufferer_orig = Bufferer(np_buffer_orig)
-
-    # create the histogrammers for the red-dyed and
-    # the original video frames, and start them
-    hist_red = Histogrammer(np_buffer_red, 2, 'red-dyed', 60.0, 10)
-    hist_red.start()
-    hist_orig = Histogrammer(np_buffer_orig, 2, 'original', 50.0, 10)
-    hist_orig.start()
-
-    # create encoders for the red-dyed and yellow-dyed (as green
-    # is applied on top of red) video streams
-    red_file = os.path.join('.', ''.join([filename, '-red', ext]))
-    red_writer = tfac.create_file_writer(Codec.HEVC, red_file, frame_rate)
-    yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
-    yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
-
-    # create a SnapshotSavers for saving a number of yellow-dyed
-    # video frames
-    yellow_snapshots = SnapshotSaver('.')
-
-    # assemble the GIFT-Grab pipeline
-    reader.attach(bufferer_orig)
-    bufferer_orig.attach(red_dyer)
-    red_dyer.attach(red_writer)
-    red_dyer.attach(bufferer_red)
-    red_dyer.attach(green_dyer)
-    green_dyer.attach(yellow_writer)
-    green_dyer.attach(yellow_snapshots)
-
-    sleep(20)  # operate pipeline for 20 sec
-
-    # stop the histogrammers
-    hist_red.stop()
-    hist_orig.stop()
-
-    # disassemble the GIFT-Grab pipeline
-    reader.detach(bufferer_orig)
-    bufferer_orig.detach(red_dyer)
-    red_dyer.detach(red_writer)
-    red_dyer.detach(bufferer_red)
-    red_dyer.detach(green_dyer)
-    green_dyer.detach(yellow_writer)
-    green_dyer.detach(yellow_snapshots)

From 4a32b61af73d6788f5d9fc8d65e1527f61c48f4b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:02:26 +0100
Subject: [PATCH 258/277] Issue #16: shorter name for Bash script

---
 .../check_multithreading_reliability.sh       | 101 ------------------
 src/tests/pipeline/run-complex-pipeline.sh    |   4 +-
 2 files changed, 2 insertions(+), 103 deletions(-)
 delete mode 100755 src/tests/pipeline/check_multithreading_reliability.sh

diff --git a/src/tests/pipeline/check_multithreading_reliability.sh b/src/tests/pipeline/check_multithreading_reliability.sh
deleted file mode 100755
index 39df9537..00000000
--- a/src/tests/pipeline/check_multithreading_reliability.sh
+++ /dev/null
@@ -1,101 +0,0 @@
-#!/usr/bin/env bash
-# -*- coding: utf-8 -*-
-
-# This script provides a multi-threading reliability check.
-# The background is issue #16. It looks like in applications
-# where multiple Python threads are involved, occasionally
-# the acquisition of the Global Interpreter Lock leads to a
-# deadlocks, which crashes the whole application with a
-# non-specific segmentation fault.
-#
-# It builds a basic GIFT-Grab capable of reading a video file,
-# and encoding to a video file in real time, with Python and
-# NumPy support. It subsequently runs a multi-threaded
-# GIFT-Grab pipeline a number of times, recording the exit
-# status each time. This is essentially a stress-test that
-# should serve as a validation that issue #16 is fixed.
-
-if [ $# -lt 1 ] || [ $# -gt 3 ];
-then
-    THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
-    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
-    printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
-    printf "\tnum_reps:   how many times to run the Python script "
-    printf "(default: once)\n"
-    printf "\toutput_dir: where to save all the generated output "
-    printf "(default: current directory)\n"
-    exit 1
-fi
-
-CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
-SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
-if [ $# -ge 3 ];
-then
-    ROOT_DIR="$( cd "$3" >/dev/null && pwd )"
-else
-    ROOT_DIR=$CALL_DIR
-fi
-
-BUILD_DIR=$ROOT_DIR/mtr-build
-CMAKE_OPTS="-D USE_FILES=ON"
-CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
-CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
-CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
-CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
-SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
-mkdir $SESSION_DIR
-echo "Session directory: $SESSION_DIR"
-ulimit -c unlimited
-
-BUILD_LOG=$SESSION_DIR/build.log
-{
-    git describe --dirty
-    mkdir -p $BUILD_DIR
-    rm -rf $BUILD_DIR/*
-    cd $BUILD_DIR
-    cmake $CMAKE_OPTS $SOURCE_DIR
-    make -j4
-} > $BUILD_LOG 2>&1
-
-num_reps=1
-if [ $# -ge 2 ];
-then
-    num_reps=$2
-fi
-
-declare -a exit_code_freqs
-for run_no in `seq 1 $num_reps`;
-do
-    WORKING_DIR=$SESSION_DIR/$(printf "%03d" $run_no)
-    mkdir $WORKING_DIR
-    cd $WORKING_DIR
-    RUN_LOG=$WORKING_DIR/run.log
-    {
-        PYTHONPATH=$BUILD_DIR python $MTR_SCRIPT --input $1
-
-        exit_code=$?
-        echo "Exit code was: $exit_code"
-        freq=${exit_code_freqs[$exit_code]}
-        let freq=$freq+1
-        exit_code_freqs[$exit_code]=$freq
-    } > $RUN_LOG 2>&1
-
-    if [ $(($run_no % 10)) -eq 0 ] || [ $run_no -eq $num_reps ];
-    then
-        EXIT_CODES_LOG=$SESSION_DIR/exit-codes-$run_no.csv
-        printf "%10s" "exit-code" >> $EXIT_CODES_LOG
-        printf "%10s" "frequency" >> $EXIT_CODES_LOG
-        printf "\n" >> $EXIT_CODES_LOG
-        for exit_code in "${!exit_code_freqs[@]}";
-        do
-            printf "%10d" $exit_code >> $EXIT_CODES_LOG
-            printf "%10d" ${exit_code_freqs[$exit_code]} >> $EXIT_CODES_LOG
-            printf "\n" >> $EXIT_CODES_LOG
-        done
-    fi
-
-    sleep 5
-done
-
-ulimit -c 0
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 3ed9e038..39df9537 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -5,7 +5,7 @@
 # The background is issue #16. It looks like in applications
 # where multiple Python threads are involved, occasionally
 # the acquisition of the Global Interpreter Lock leads to a
-# deadlock, which crashes the whole application with a
+# deadlocks, which crashes the whole application with a
 # non-specific segmentation fault.
 #
 # It builds a basic GIFT-Grab capable of reading a video file,
@@ -29,7 +29,7 @@ fi
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/complex_pipeline.py
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
 if [ $# -ge 3 ];
 then
     ROOT_DIR="$( cd "$3" >/dev/null && pwd )"

From 0408f12662b1b5ee99d675efadb46803f7248a72 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:37 +0100
Subject: [PATCH 259/277] Issue #16: fixed typos

---
 src/tests/pipeline/complex_pipeline.py     | 2 +-
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 3fdad38b..1d9d7346 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -203,7 +203,7 @@ def update(self, frame):
     yellow_file = os.path.join('.', ''.join([filename, '-yellow', ext]))
     yellow_writer = tfac.create_file_writer(Codec.HEVC, yellow_file, frame_rate)
 
-    # create a SnapshotSavers for saving a number of yellow-dyed
+    # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
     yellow_snapshots = SnapshotSaver('.')
 
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 39df9537..5166507b 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -5,7 +5,7 @@
 # The background is issue #16. It looks like in applications
 # where multiple Python threads are involved, occasionally
 # the acquisition of the Global Interpreter Lock leads to a
-# deadlocks, which crashes the whole application with a
+# deadlock, which crashes the whole application with a
 # non-specific segmentation fault.
 #
 # It builds a basic GIFT-Grab capable of reading a video file,

From 66b0c337dcc065a517bfc1b2675e551f1a779071 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:04:55 +0100
Subject: [PATCH 260/277] Issue #16: reduced snapshot output

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1d9d7346..66686f1e 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -205,7 +205,7 @@ def update(self, frame):
 
     # create a SnapshotSaver for saving a number of yellow-dyed
     # video frames
-    yellow_snapshots = SnapshotSaver('.')
+    yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
     reader.attach(bufferer_orig)

From 6f3982d7f9fcc85bda346951d5f9cde19e1796ea Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:09:55 +0100
Subject: [PATCH 261/277] Issue #16: fixed calling of Python script from Bash
 script

---
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5166507b..3ed9e038 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -29,7 +29,7 @@ fi
 
 CALL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 SOURCE_DIR="$( cd "$CALL_DIR/../.." >/dev/null && pwd )"
-MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/multithreading_reliability_check.py
+MTR_SCRIPT=$SOURCE_DIR/tests/pipeline/complex_pipeline.py
 if [ $# -ge 3 ];
 then
     ROOT_DIR="$( cd "$3" >/dev/null && pwd )"

From f434c03423a1e8f4b3c9f64445d0b1e697c301bf Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:41:33 +0100
Subject: [PATCH 262/277] Issue #16: added an RTD page linking to the complex
 pipeline example

---
 doc/source/complex.rst | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index eba60359..443b8182 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -1,24 +1,19 @@
 .. _Complex:
 
-Multi-threaded complex processing pipelines
-===========================================
+Multi-threaded processing pipelines
+===================================
 
-The example below shows how GIFT-Grab can be used for running complex pipelines with multiple
-intermediate processing nodes and threads.
-The intermediate processing nodes in this example are built on the same principles as in the
-:ref:`SciPy` example.
+This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
+processing nodes and threads.
+The intermediate processing nodes are built on the same principles as in the SciPy_ example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-The full source code of the example is below.
-Please follow the comments and the flow of code.
-This example is also available on GitHub_:
+Below is the commented full source code:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
-
-.. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py
-
+   :linenos:

From 0bd666ac2b1197445766cf59f6ccc8bd9935a30c Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 11:59:27 +0100
Subject: [PATCH 263/277] Issue #16: fixed cross-reference to NumPy example
 from new RTD page

---
 doc/source/complex.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 443b8182..47104d65 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -5,7 +5,7 @@ Multi-threaded processing pipelines
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the SciPy_ example.
+The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files

From 144a5170f145e0c49f58bbddc52adbfa648e834b Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 12:00:34 +0100
Subject: [PATCH 264/277] Issue #16: added link from new RTD page to example
 source code on GitHub

---
 doc/source/complex.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 47104d65..61ef4427 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -12,8 +12,10 @@ Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code:
+Below is the commented full source code, which is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
    :linenos:
+
+.. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py

From c890e4d63a84e5ace2eca250caea85d5b2c9e4d4 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:47:20 +0100
Subject: [PATCH 265/277] Issue #16: made the title of the new RTD page more
 descriptive

---
 doc/source/complex.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index 61ef4427..e5702f99 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -1,7 +1,7 @@
 .. _Complex:
 
-Multi-threaded processing pipelines
-===================================
+Multi-threaded complex processing pipelines
+===========================================
 
 This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
 processing nodes and threads.

From 0bf6a100dc986c6f4f672f2079009cb5393009c4 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:51:26 +0100
Subject: [PATCH 266/277] Issue #16: revised the RTD page wording for clarity

---
 doc/source/complex.rst | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index e5702f99..de681cb6 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -3,16 +3,19 @@
 Multi-threaded complex processing pipelines
 ===========================================
 
-This example shows how GIFT-Grab can be used for running complex pipelines with multiple intermediate
-processing nodes and threads.
-The intermediate processing nodes are built on the same principles as in the :ref:`SciPy` example.
+The example below shows how GIFT-Grab can be used for running complex pipelines with multiple
+intermediate processing nodes and threads.
+The intermediate processing nodes in this example are built on the same principles as in the
+:ref:`SciPy` example.
 Running the example requires an `HEVC-encoded MP4 file`_, an `NVENC-capable GPU`_, and `NumPy support`_.
 
 .. _`HEVC-encoded MP4 file`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#reading-video-files
 .. _`NVENC-capable GPU`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#hevc
 .. _`NumPy support`: https://github.com/gift-surg/GIFT-Grab/blob/master/doc/build.md#python-api
 
-Below is the commented full source code, which is also available on GitHub_:
+The full source code of the example is below.
+Please follow the comments and the flow of code.
+This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python

From eaa67d46e88095815be554a92e568681689c1cd4 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 14 Oct 2018 18:53:21 +0100
Subject: [PATCH 267/277] Issue #16: removed line numbers from example on new
 RTD page

---
 doc/source/complex.rst | 1 -
 1 file changed, 1 deletion(-)

diff --git a/doc/source/complex.rst b/doc/source/complex.rst
index de681cb6..b6ac054b 100644
--- a/doc/source/complex.rst
+++ b/doc/source/complex.rst
@@ -19,6 +19,5 @@ This example is also available on GitHub_:
 
 .. literalinclude:: ../../src/tests/pipeline/complex_pipeline.py
    :language: python
-   :linenos:
 
 .. _GitHub: https://github.com/gift-surg/GIFT-Grab/blob/master/src/tests/pipeline/complex_pipeline.py

From c6d611ade7d832f26dbf4184a150fa21a7e82e31 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 14:57:13 +0100
Subject: [PATCH 268/277] Issue #16: checker script now supports Blackmagic
 DeckLink 4K Extreme 12G

---
 src/tests/pipeline/complex_pipeline.py     | 27 ++++++++++++++--------
 src/tests/pipeline/run-complex-pipeline.sh | 10 +++++++-
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 66686f1e..e3738d9b 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -12,7 +12,7 @@
 import threading
 import numpy as np
 import scipy.misc
-from pygiftgrab import (VideoSourceFactory, VideoFrame,
+from pygiftgrab import (VideoSourceFactory, VideoFrame, Device,
                         ColourSpace, IObservableObserver,
                         VideoTargetFactory, Codec, IObserver)
 
@@ -158,19 +158,26 @@ def update(self, frame):
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
-                        metavar='VIDEO_FILE',
-                        help='Input video file (HEVC-encoded MP4)')
+                        metavar='VIDEO_INPUT',
+                        help='"decklink" (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                             ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
     in_file = args.input
 
-    filename = os.path.basename(in_file)
-    filename, ext = os.path.splitext(filename)
-    assert filename
-    assert ext == '.mp4'
-
-    # initialise reading of passed file
     sfac = VideoSourceFactory.get_instance()
-    reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
+    if in_file == 'decklink':
+        reader = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+        reader.set_sub_frame(640, 300, 640, 480)
+    else:
+        filename = os.path.basename(in_file)
+        filename, ext = os.path.splitext(filename)
+        assert filename
+        assert ext == '.mp4'
+
+        # initialise reading of passed file
+        reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+
     frame = VideoFrame(ColourSpace.BGRA, False)
     reader.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 3ed9e038..5dfb083a 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -18,8 +18,9 @@
 if [ $# -lt 1 ] || [ $# -gt 3 ];
 then
     THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
-    printf "Usage: $THIS_SCRIPT video_file [ num_reps [ output_dir ] ]\n"
+    printf "Usage: $THIS_SCRIPT video_file|decklink [ num_reps [ output_dir ] ]\n"
     printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
+    printf "\tdecklink: Blackmagic DeckLink 4K Extreme 12G frame grabber\n"
     printf "\tnum_reps:   how many times to run the Python script "
     printf "(default: once)\n"
     printf "\toutput_dir: where to save all the generated output "
@@ -42,6 +43,13 @@ CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D BUILD_PYTHON=ON -D USE_NUMPY=ON"
+if [ "$1" = "decklink" ]; then
+    if [[ -z "${BlackmagicSDK_DIR}" ]]; then
+        echo "Please set BlackmagicSDK_DIR to the path of the Blackmagic SDK"
+        exit 1
+    fi
+    CMAKE_OPTS="$CMAKE_OPTS -D USE_BLACKMAGIC_DECKLINK_4K_EXTREME_12G=ON -D ENABLE_NONFREE=ON"
+fi
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")
 mkdir $SESSION_DIR

From 41db15f34503ae48931cceb698ab7d9c0ab07318 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 14:59:14 +0100
Subject: [PATCH 269/277] Issue #16: revised checker script for more generic
 variable names

---
 src/tests/pipeline/complex_pipeline.py | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index e3738d9b..1968c33a 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -159,32 +159,33 @@ def update(self, frame):
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
                         metavar='VIDEO_INPUT',
-                        help='"decklink" (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
                              ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
-    in_file = args.input
+    video_input = args.input
 
     sfac = VideoSourceFactory.get_instance()
 
-    if in_file == 'decklink':
-        reader = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
-        reader.set_sub_frame(640, 300, 640, 480)
+    if video_input == 'decklink':
+        # start acquiring frames from a DeckLink 4K Extreme 12G
+        source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+        source.set_sub_frame(640, 300, 640, 480)
     else:
-        filename = os.path.basename(in_file)
+        filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)
         assert filename
         assert ext == '.mp4'
 
         # initialise reading of passed file
-        reader = sfac.create_file_reader(in_file, ColourSpace.BGRA)
+        source = sfac.create_file_reader(video_input, ColourSpace.BGRA)
 
     frame = VideoFrame(ColourSpace.BGRA, False)
-    reader.get_frame(frame)
+    source.get_frame(frame)
     frame_shape = (frame.rows(), frame.cols(), 4)
 
     # prepare for creating encoders (writers)
     tfac = VideoTargetFactory.get_instance()
-    frame_rate = reader.get_frame_rate()
+    frame_rate = source.get_frame_rate()
 
     # create a red and green Dyer
     red_dyer = Dyer(2, 128)
@@ -215,7 +216,7 @@ def update(self, frame):
     yellow_snapshots = SnapshotSaver('.', 9)
 
     # assemble the GIFT-Grab pipeline
-    reader.attach(bufferer_orig)
+    source.attach(bufferer_orig)
     bufferer_orig.attach(red_dyer)
     red_dyer.attach(red_writer)
     red_dyer.attach(bufferer_red)
@@ -230,7 +231,7 @@ def update(self, frame):
     hist_orig.stop()
 
     # disassemble the GIFT-Grab pipeline
-    reader.detach(bufferer_orig)
+    source.detach(bufferer_orig)
     bufferer_orig.detach(red_dyer)
     red_dyer.detach(red_writer)
     red_dyer.detach(bufferer_red)

From 65b87240f431266d289b734e7b69499e8c177dbb Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 15:21:23 +0100
Subject: [PATCH 270/277] Issue #16: added missing variable and removed
 cropping in checker script BM part

---
 src/tests/pipeline/complex_pipeline.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 1968c33a..fbdf3196 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -167,9 +167,10 @@ def update(self, frame):
     sfac = VideoSourceFactory.get_instance()
 
     if video_input == 'decklink':
+        filename = 'decklink'
+
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
-        source.set_sub_frame(640, 300, 640, 480)
     else:
         filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)

From 9fa86408224a8e221c3ccf1300c3522db8792658 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Fri, 19 Oct 2018 15:44:04 +0100
Subject: [PATCH 271/277] Issue #16: added missing file extension specification
 when using DeckLink device

---
 src/tests/pipeline/complex_pipeline.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index fbdf3196..b61e8f1c 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -167,7 +167,7 @@ def update(self, frame):
     sfac = VideoSourceFactory.get_instance()
 
     if video_input == 'decklink':
-        filename = 'decklink'
+        filename, ext = 'decklink', '.mp4'
 
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)

From 64f1e8bfdcfa467bef9a754a0448c4d2a578b169 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 21 Oct 2018 11:48:02 +0100
Subject: [PATCH 272/277] Issue #16: multi-threading reliability checker now
 supports Epiphan DVI2PCIe Duo DVI port

---
 src/tests/pipeline/complex_pipeline.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index b61e8f1c..9383db13 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -159,7 +159,8 @@ def update(self, frame):
     parser = argparse.ArgumentParser()
     parser.add_argument('-i', '--input', type=str, required=True,
                         metavar='VIDEO_INPUT',
-                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G)'
+                        help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G),\n'
+                             'dvi2pcie (for grabbing frames from an Epiphan DVI2PCIe Duo DVI port\n'
                              ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
     video_input = args.input
@@ -171,6 +172,11 @@ def update(self, frame):
 
         # start acquiring frames from a DeckLink 4K Extreme 12G
         source = sfac.get_device(Device.DeckLink4KExtreme12G, ColourSpace.BGRA)
+    elif video_input == 'dvi2pcie':
+        filename, ext = 'dvi2pcie', '.mp4'
+
+        # start acquirigin frames from an Epiphan DVI2PCIe Duo DVI port
+        source = sfac.get_device(Device.DVI2PCIeDuo_DVI, ColourSpace.BGRA)
     else:
         filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)

From 30a2ed99d6c89c3d6d80b24dc4c63078002beb1d Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Sun, 21 Oct 2018 11:48:42 +0100
Subject: [PATCH 273/277] Issue #16: multi-threading reliability launch script
 now supports Epiphan DVI2PCIe Duo as well

---
 src/tests/pipeline/run-complex-pipeline.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 5dfb083a..8a016785 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -18,9 +18,10 @@
 if [ $# -lt 1 ] || [ $# -gt 3 ];
 then
     THIS_SCRIPT="$(basename "$(test -L "${BASH_SOURCE[0]}" && readlink "$0" || echo "$0")")"
-    printf "Usage: $THIS_SCRIPT video_file|decklink [ num_reps [ output_dir ] ]\n"
+    printf "Usage: $THIS_SCRIPT video_file|decklink|dvi2pcie [ num_reps [ output_dir ] ]\n"
     printf "\tvideo_file: path to an HEVC-encoded MP4 file\n"
     printf "\tdecklink: Blackmagic DeckLink 4K Extreme 12G frame grabber\n"
+    printf "\tdvi2pcie: Epiphan DVI2PCIe Duo frame grabber\n"
     printf "\tnum_reps:   how many times to run the Python script "
     printf "(default: once)\n"
     printf "\toutput_dir: where to save all the generated output "
@@ -49,6 +50,8 @@ if [ "$1" = "decklink" ]; then
         exit 1
     fi
     CMAKE_OPTS="$CMAKE_OPTS -D USE_BLACKMAGIC_DECKLINK_4K_EXTREME_12G=ON -D ENABLE_NONFREE=ON"
+elif [ "$1" = "dvi2pcie" ]; then
+    CMAKE_OPTS="$CMAKE_OPTS -D USE_EPIPHAN_DVI2PCIE_DUO=ON -D USE_I420=OFF"
 fi
 CMAKE_OPTS="$CMAKE_OPTS -D CMAKE_BUILD_TYPE=Debug"
 SESSION_DIR=$ROOT_DIR/$(date +"%Y-%m-%d-%H-%M-%S")

From 7e355c7dd641ddde91de15ce0f8030b901ff5082 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Mon, 22 Oct 2018 08:48:14 +0100
Subject: [PATCH 274/277] Issue #16: using the SDI port of Epiphan DVI2PCIe Duo
 instead of the DVI port in checker

---
 src/tests/pipeline/complex_pipeline.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/tests/pipeline/complex_pipeline.py b/src/tests/pipeline/complex_pipeline.py
index 9383db13..864a2e9d 100755
--- a/src/tests/pipeline/complex_pipeline.py
+++ b/src/tests/pipeline/complex_pipeline.py
@@ -160,7 +160,7 @@ def update(self, frame):
     parser.add_argument('-i', '--input', type=str, required=True,
                         metavar='VIDEO_INPUT',
                         help='decklink (for grabbing frames from a Blackmagic DeckLink 4K Extreme 12G),\n'
-                             'dvi2pcie (for grabbing frames from an Epiphan DVI2PCIe Duo DVI port\n'
+                             'dvi2pcie (for grabbing frames from an Epiphan DVI2PCIe Duo SDI port\n'
                              ' or a video file (HEVC-encoded MP4)')
     args = parser.parse_args()
     video_input = args.input
@@ -175,8 +175,8 @@ def update(self, frame):
     elif video_input == 'dvi2pcie':
         filename, ext = 'dvi2pcie', '.mp4'
 
-        # start acquirigin frames from an Epiphan DVI2PCIe Duo DVI port
-        source = sfac.get_device(Device.DVI2PCIeDuo_DVI, ColourSpace.BGRA)
+        # start acquirigin frames from an Epiphan DVI2PCIe Duo SDI port
+        source = sfac.get_device(Device.DVI2PCIeDuo_SDI, ColourSpace.BGRA)
     else:
         filename = os.path.basename(video_input)
         filename, ext = os.path.splitext(filename)

From c5f590facc919b7868e5ab06b59b49792f044341 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Tue, 23 Oct 2018 16:55:14 +0100
Subject: [PATCH 275/277] Issue #16: using default thread constructor with move
 semantics to ensure BroadcastDaemon thread does not start until it's safe to
 do so

---
 src/api/broadcastdaemon.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/api/broadcastdaemon.cpp b/src/api/broadcastdaemon.cpp
index df7f7486..666655eb 100644
--- a/src/api/broadcastdaemon.cpp
+++ b/src/api/broadcastdaemon.cpp
@@ -10,6 +10,7 @@ namespace gg
 BroadcastDaemon::BroadcastDaemon(IVideoSource * source)
         : _source(source)
         , _running(false)
+        , _thread()
 {
     if (_source == nullptr)
         throw VideoSourceError("Null pointer passed"

From 8bdc48c540a3edb2f4542e632dfa4b5a65c59d11 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Tue, 23 Oct 2018 19:09:40 +0100
Subject: [PATCH 276/277] Issue #35, #16: surrounded VideoSourceOpenCV colour
 conversion with a broad try-catch block

---
 src/opencv/opencv_video_source.cpp | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/opencv/opencv_video_source.cpp b/src/opencv/opencv_video_source.cpp
index d41ee42a..e4fe19d4 100644
--- a/src/opencv/opencv_video_source.cpp
+++ b/src/opencv/opencv_video_source.cpp
@@ -121,8 +121,24 @@ bool VideoSourceOpenCV::get_frame(gg::VideoFrame & frame)
             _buffer_bgra.cols != _buffer.cols) {
             _buffer_bgra = cv::Mat::zeros(_buffer.rows, _buffer.cols, CV_8UC4);
         }
-        // Convert to BGRA
-        cv::cvtColor(_buffer, _buffer_bgra, CV_BGR2BGRA);
+        /* This too broad try-catch block is a workaround to
+         * https://github.com/gift-surg/GIFT-Grab/issues/35
+         * as OpenCV seems to intermittently throw an assertion
+         * exception in the form:
+         * "Can't fetch data from terminated TLS container".
+         * To make things worse, this exception is unhandled in
+         * the accompanying BroadcastDaemon thread, and so leads
+         * to an unspecific abortion of the whole application.
+         */
+        try
+        {
+            // Convert to BGRA
+            cv::cvtColor(_buffer, _buffer_bgra, CV_BGR2BGRA);
+        }
+        catch (...)
+        {
+            return false;
+        }
         unsigned char * data = nullptr;
         size_t data_length = 0;
         size_t cols = 0, rows = 0;

From 03220341626cec23a8601e228b52886a02f85617 Mon Sep 17 00:00:00 2001
From: Dzhoshkun Ismail Shakir <dzhoshkun.shakir@gmail.com>
Date: Tue, 23 Oct 2018 19:24:03 +0100
Subject: [PATCH 277/277] Issue #16: build directory is now relative to calling
 directory, to prevent symlink problems

---
 src/tests/pipeline/run-complex-pipeline.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/pipeline/run-complex-pipeline.sh b/src/tests/pipeline/run-complex-pipeline.sh
index 8a016785..d9bd9406 100755
--- a/src/tests/pipeline/run-complex-pipeline.sh
+++ b/src/tests/pipeline/run-complex-pipeline.sh
@@ -39,7 +39,7 @@ else
     ROOT_DIR=$CALL_DIR
 fi
 
-BUILD_DIR=$ROOT_DIR/mtr-build
+BUILD_DIR=$CALL_DIR/mtr-build
 CMAKE_OPTS="-D USE_FILES=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D USE_HEVC=ON"
 CMAKE_OPTS="$CMAKE_OPTS -D ENABLE_NONFREE=ON -D USE_NVENC=ON"