prefer gstreamer as audio player as it works better on raspberry pi

README.md

@@ -14,7 +14,7 @@ Python Alexa Voice Service App
 
 Choose a player from `mpv`, `mpg123` and gstreamer.
 `SpeechSynthesizer` and `Alerts` prefer `mpg123` as it is more responsive.
-`AudioPlayer` likes `mpv` > gstreamer > `mpg123` as `mpv` and gstreamer support more audio format. We can also specify the player of `AudioPlayer` using the environment variable `PLAYER`.
+`AudioPlayer` likes gstreamer > `mpv` > `mpg123`. Gstreamer supports more audio format and works well on raspberry pi. We can also specify the player of `AudioPlayer` using the environment variable `PLAYER`.
 
 * one of mpg123, mpv and gstreamer 1.0
 * python-pyaudio

avs/player/__init__.py

@@ -2,7 +2,7 @@
 
 """Player
 support mpv, mpg123 and gstreamer 1.0
-It prefers mpv if it is available, otherwise use gstreamer 1.0
+It likes gstreamer 1.0 > mpv > mpg123
 We can specify a player using environment variable PLAYER (mpv, mpg123, gstreamer, single_gstreamer)
 """
 
@@ -19,10 +19,15 @@
 elif player_option.find('gstreamer') >= 0:
     from gstreamer_player import Player
 else:
-    if os.system('which mpv') == 0:
-        from mpv_player import Player
-    else:
+    try:
         from gstreamer_player import Player
+    except ImportError:
+        if os.system('which mpv') == 0:
+            from mpv_player import Player
+        elif os.system('which mpg123') == 0:
+            from mpg123_player import Player
+        else:
+            raise ImportError('No player available, install gstreamer, mpv or mpg123 first')
 
 
 __all__ = ['Player']