[Cast] Remove AudioDecoder's dependency on WebRTC, and refactor/clean-up AudioReceiver.

media/cast/cast_receiver.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This is the main interface for the cast receiver. All configuration are done
 // at creation.
 
 #ifndef MEDIA_CAST_CAST_RECEIVER_H_
 #define MEDIA_CAST_CAST_RECEIVER_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
+#include "media/base/audio_bus.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/cast_environment.h"
 
 namespace media {
 class VideoFrame;
 
 namespace cast {
 
 namespace transport {
 class PacketSender;
 }
 
-// Callback in which the raw audio frame and play-out time will be returned
-// once decoding is complete.
-typedef base::Callback<void(scoped_ptr<PcmAudioFrame>, const base::TimeTicks&)>
-    AudioFrameDecodedCallback;
+// Callback in which the raw audio frame, play-out time, and a continuity flag
+// will be returned.  |is_continuous| will be false to indicate the loss of
+// audio data due to a loss of frames (or decoding errors).  This allows the
+// client to take steps to smooth discontinuities for playback.  Note: A NULL
+// AudioBus can be returned when data is not available (e.g., bad packet or when
+// flushing callbacks during shutdown).
+typedef base::Callback<void(scoped_ptr<AudioBus> audio_bus,
+                            const base::TimeTicks& playout_time,
+                            bool is_continuous)> AudioFrameDecodedCallback;
 
-// Callback in which the encoded audio frame and play-out time will be returned.
+// Callback in which the encoded audio frame and play-out time will be
+// returned.  The client should examine the EncodedAudioFrame::frame_id field to
+// determine whether any frames have been dropped (i.e., frame_id should be
+// incrementing by one each time).  Note: A NULL EncodedAudioFrame can be
+// returned on error/shutdown.
 typedef base::Callback<void(scoped_ptr<transport::EncodedAudioFrame>,
                             const base::TimeTicks&)> AudioFrameEncodedCallback;
 
 // Callback in which the raw frame and render time will be returned once
 // decoding is complete.
 typedef base::Callback<void(const scoped_refptr<media::VideoFrame>& video_frame,
                             const base::TimeTicks&)> VideoFrameDecodedCallback;
 
 // Callback in which the encoded video frame and render time will be returned.
 typedef base::Callback<void(scoped_ptr<transport::EncodedVideoFrame>,
                             const base::TimeTicks&)> VideoFrameEncodedCallback;
 
 // This Class is thread safe.
 class FrameReceiver : public base::RefCountedThreadSafe<FrameReceiver> {
  public:
-  virtual void GetRawAudioFrame(int number_of_10ms_blocks,
-                                int desired_frequency,
-                                const AudioFrameDecodedCallback& callback) = 0;
+  virtual void GetRawAudioFrame(const AudioFrameDecodedCallback& callback) = 0;
 
   virtual void GetCodedAudioFrame(
       const AudioFrameEncodedCallback& callback) = 0;
 
   virtual void GetRawVideoFrame(const VideoFrameDecodedCallback& callback) = 0;
 
   virtual void GetEncodedVideoFrame(
       const VideoFrameEncodedCallback& callback) = 0;
 
  protected:
@@ skipping 21 matching lines @@
   // Polling interface to get audio and video frames from the CastReceiver.
   virtual scoped_refptr<FrameReceiver> frame_receiver() = 0;
 
   virtual ~CastReceiver() {}
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_CAST_RECEIVER_H_