test for clicking sound at the end of signal

reported in spatialaudio/python-sounddevice#482

beep_buffer_underrun.py

@@ -0,0 +1,56 @@
+import numpy as np
+import sounddevice as sd
+import time
+import matplotlib.pyplot as plt
+plt.rcParams["figure.dpi"] = 150
+
+class SoundEngine():
+    def __init__(self):
+        self.FS = sd.query_devices(
+            device=sd.default.device,
+            kind='output',
+            )["default_samplerate"]
+        self.start_stream()
+        self.test_beep()
+
+    def start_stream(self):
+        self.stream = sd.OutputStream(samplerate=self.FS, channels=2, latency='high')
+        self.stream.start()
+
+    def beep(self, T, freq):
+        t = np.arange(T * self.FS) / self.FS
+        y = 0.1 * np.sin(t * 2 * np.pi * freq)
+
+        # pad = np.zeros(100)
+        # y = np.concatenate([pad, y, pad])
+
+        y = np.tile(y, self.stream.channels)
+        y = y.reshape((len(y) // self.stream.channels, self.stream.channels), order='F')
+        y = np.ascontiguousarray(y, self.stream.dtype)
+        plt.plot(y[-1000:, :]); plt.grid()
+        self.stream.write(y)
+
+    def test_beep(self):
+        self.beep(1, 200)
+
+sound_engine = SoundEngine()
+time.sleep(1)
+
+# %%
+
+def beep(T, freq):
+    channels = 2
+
+    FS = sd.query_devices(
+        device=sd.default.device,
+        kind='output',
+        )["default_samplerate"]
+
+    t = np.arange(T * FS) / FS
+    y = np.tile(0.1 * np.sin(t * 2 * np.pi * freq), channels)
+    y = y.reshape((len(y) // channels, channels), order='F')
+    y = y.astype(sd.default.dtype[0])
+    plt.plot(y[-100:, :]); plt.grid()  # what the signal looks like at the end
+    sd.play(y, latency='high')
+
+# beep(1, 200)