Update emit_data to take buffers.

Simplify emit data method to take Gstreamer buffers. This allows us to more
concisely give it buffers with duration, timestamp and other relevant data set.

mopidy/audio/actor.py

@@ -225,22 +225,16 @@ class Audio(pykka.ThreadingActor):
         """
         self._playbin.set_property('uri', uri)
 
-    def emit_data(self, capabilities, data):
+    def emit_data(self, buffer_):
         """
         Call this to deliver raw audio data to be played.
 
         Note that the uri must be set to ``appsrc://`` for this to work.
 
-        :param capabilities: a GStreamer capabilities string
-        :type capabilities: string
-        :param data: raw audio data to be played
+        :param buffer_: buffer to pass to appsrc
+        :type buffer_: :class:`gst.Buffer`
         """
-        caps = gst.caps_from_string(capabilities)
-        buffer_ = gst.Buffer(buffer(data))
-        buffer_.set_caps(caps)
-
         source = self._playbin.get_property('source')
-        source.set_property('caps', caps)
         source.emit('push-buffer', buffer_)
 
     def emit_end_of_stream(self):

mopidy/backends/spotify/session_manager.py

@@ -1,5 +1,9 @@
 from __future__ import unicode_literals
 
+import pygst
+pygst.require('0.10')
+import gst
+
 import logging
 import os
 import threading
@@ -108,7 +112,10 @@ class SpotifySessionManager(process.BaseThread, PyspotifySessionManager):
             'sample_rate': sample_rate,
             'channels': channels,
         }
-        self.audio.emit_data(capabilites, bytes(frames))
+        buffer_ = gst.Buffer(bytes(frames))
+        buffer_.set_caps(gst.caps_from_string(capabilites))
+
+        self.audio.emit_data(buffer_)
         return num_frames
 
     def play_token_lost(self, session):