[ros_speech_recognition] Use installed vosk model

ros_speech_recognition/README.md

@@ -223,8 +223,11 @@ roslaunch ros_speech_recognition parrotry.launch language:=ja-JP
 
 * `~vosk_model_path` (`String`, default: `None`)
 
-  Path to model for Vosk API that can be downloaded from [Model list](https://alphacephei.com/vosk/models).
+  Path to trainded model for Vosk API.
   This is valid only if `~engine` is `Vosk`.
+
+  If `en-US` or `ja` is selected as `~language`, you do not need to specify the path.
+  To load other models, please download them from [Model list](https://alphacephei.com/vosk/models).
 
 ## Author
 

ros_speech_recognition/src/ros_speech_recognition/recognize_vosk.py

@@ -5,18 +5,28 @@
 from ros_speech_recognition.recognize_google_cloud import RecognizerEx
 from vosk import Model, KaldiRecognizer
 import json
+import os.path as osp
+import rospkg
+import rospy
 
-def recognize_vosk(self, audio_data, model_path=None, language='en'):
+def recognize_vosk(self, audio_data, model_path=None, language='en-US'):
 
     assert isinstance(audio_data, AudioData), "Data must be audio data"
 
     if not hasattr(self, 'vosk_model'):
-        if model_path is not None:
-            self.vosk_model = Model(model_path)
-        else:
-            print("Please download the model from https://alphacephei.com/vosk/models and specify its path as 'vosk_model_path'.")
-            exit (1)
-
+        if model_path is None:
+            PKG = 'ros_speech_recognition'
+            rp = rospkg.RosPack()
+            data_path = osp.join(rp.get_path(PKG), 'trained_data')
+            if language == 'en-US':
+                model_path = osp.join(data_path, 'vosk-model-small-en-us-0.15')
+            elif language == 'ja':
+                model_path = osp.join(data_path, 'vosk-model-small-ja-0.22')
+            else:
+                rospy.logerr("Unsupported language: {0}.\n Please download the model from https://alphacephei.com/vosk/models and specify its path as 'vosk_model_path'.".format(language))
+                exit (1)
+    rospy.loginfo("Loading model from {}".format(model_path))
+    self.vosk_model = Model(model_path)
     rec = KaldiRecognizer(self.vosk_model, 16000);
 
     rec.AcceptWaveform(audio_data.get_raw_data(convert_rate=16000, convert_width=2));