Add new GStreamer-based software mixer and make it the default on all platforms

docs/api/mixers.rst

@@ -67,6 +67,16 @@ methods as described below.
 .. inheritance-diagram:: mopidy.mixers.dummy
 
 
+:mod:`mopidy.mixers.gstreamer_software` -- Software mixer for all platforms
+===========================================================================
+
+.. automodule:: mopidy.mixers.gstreamer_software
+    :synopsis: Software mixer for all platforms
+    :members:
+
+.. inheritance-diagram:: mopidy.mixers.gstreamer_software
+
+
 :mod:`mopidy.mixers.osa` -- Osa mixer for OS X
 ==============================================
 

docs/changes.rst

@@ -25,6 +25,8 @@ Another great release.
 - :mod:`mopidy.backends.libspotify` is now the default backend.
 - A Spotify application key is now bundled with the source. The
   ``SPOTIFY_LIB_APPKEY`` setting is thus removed.
+- Added new :mod:`mopidy.mixers.GStreamerSoftwareMixer` which now is the
+  default mixer on all platforms.
 - MPD frontend:
 
   - Relocate from :mod:`mopidy.mpd` to :mod:`mopidy.frontends.mpd`.

mopidy/mixers/gstreamer.py

@@ -1,14 +0,0 @@
-from mopidy.mixers import BaseMixer
-
-class GStreamerMixer(BaseMixer):
-    """Mixer which uses GStreamer to control volume."""
-
-    def __init__(self, *args, **kwargs):
-        super(GStreamerMixer, self).__init__(*args, **kwargs)
-
-    def _get_volume(self):
-        pass # TODO Get volume from GStreamerProcess
-
-    def _set_volume(self, volume):
-        pass # TODO Send volume to GStreamerProcess
-

mopidy/mixers/gstreamer_software.py

@@ -0,0 +1,25 @@
+import multiprocessing
+
+from mopidy.mixers import BaseMixer
+from mopidy.process import pickle_connection
+
+class GStreamerSoftwareMixer(BaseMixer):
+    """Mixer which uses GStreamer to control volume in software."""
+
+    def __init__(self, *args, **kwargs):
+        super(GStreamerSoftwareMixer, self).__init__(*args, **kwargs)
+
+    def _get_volume(self):
+        my_end, other_end = multiprocessing.Pipe()
+        self.backend.output_queue.put({
+            'command': 'get_volume',
+            'reply_to': pickle_connection(other_end),
+        })
+        my_end.poll(None)
+        return my_end.recv()
+
+    def _set_volume(self, volume):
+        self.backend.output_queue.put({
+            'command': 'set_volume',
+            'volume': volume,
+        })

mopidy/outputs/gstreamer.py

@@ -93,6 +93,12 @@ class GStreamerProcess(BaseProcess):
             response = self.set_state(message['state'])
             connection = unpickle_connection(message['reply_to'])
             connection.send(response)
+        elif message['command'] == 'get_volume':
+            volume = self.get_volume()
+            connection = unpickle_connection(message['reply_to'])
+            connection.send(volume)
+        elif message['command'] == 'set_volume':
+            self.set_volume(message['volume'])
         else:
             logger.warning(u'Cannot handle message: %s', message)
 

mopidy/settings.py

@@ -82,22 +82,10 @@ LOCAL_TAG_CACHE = u'~/.mopidy/tag_cache'
 
 #: Sound mixer to use. See :mod:`mopidy.mixers` for all available mixers.
 #:
-#: Default on Linux::
+#: Default::
 #:
-#:     MIXER = u'mopidy.mixers.alsa.AlsaMixer'
-#:
-#: Default on OS X::
-#:
-#:     MIXER = u'mopidy.mixers.osa.OsaMixer'
-#:
-#: Default on other operating systems::
-#:
-#:     MIXER = u'mopidy.mixers.dummy.DummyMixer'
-MIXER = u'mopidy.mixers.dummy.DummyMixer'
-if sys.platform == 'linux2':
-    MIXER = u'mopidy.mixers.alsa.AlsaMixer'
-elif sys.platform == 'darwin':
-    MIXER = u'mopidy.mixers.osa.OsaMixer'
+#:     MIXER = u'mopidy.mixers.gstreamer_software.GStreamerSoftwareMixer'
+MIXER = u'mopidy.mixers.gstreamer_software.GStreamerSoftwareMixer'
 
 #: ALSA mixer only. What mixer control to use. If set to :class:`False`, first
 #: ``Master`` and then ``PCM`` will be tried.