[Cast] Clean-up: Merge RtpReceiver+AudioReceiver+VideoReceiver-->FrameReceiver.

media/cast/receiver/cast_receiver_impl.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.
 
-#ifndef MEDIA_CAST_CAST_RECEIVER_IMPL_H_
-#define MEDIA_CAST_CAST_RECEIVER_IMPL_H_
+#ifndef MEDIA_CAST_RECEIVER_CAST_RECEIVER_IMPL_H_
+#define MEDIA_CAST_RECEIVER_CAST_RECEIVER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "media/cast/audio_receiver/audio_receiver.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/cast_environment.h"
 #include "media/cast/cast_receiver.h"
+#include "media/cast/receiver/frame_receiver.h"
 #include "media/cast/transport/pacing/paced_sender.h"
-#include "media/cast/video_receiver/video_receiver.h"
 
 namespace media {
 namespace cast {
-// This calls is a pure owner class that group all required receive objects
-// together such as pacer, packet receiver, frame receiver, audio and video
-// receivers.
+
+class AudioDecoder;
+class VideoDecoder;
+
+// This is a pure owner class that groups all required receiver-related objects
+// together, such as the paced packet sender, audio/video RTP frame receivers,
+// and software decoders (created on-demand).
 class CastReceiverImpl : public CastReceiver {
  public:
   CastReceiverImpl(scoped_refptr<CastEnvironment> cast_environment,
                    const FrameReceiverConfig& audio_config,
                    const FrameReceiverConfig& video_config,
                    transport::PacketSender* const packet_sender);
 
   virtual ~CastReceiverImpl();
 
-  // All received RTP and RTCP packets for the call should be sent to this
-  // PacketReceiver;
+  // CastReceiver implementation.
   virtual transport::PacketReceiverCallback packet_receiver() OVERRIDE;
-
-  // Interface to get audio and video frames from the CastReceiver.
-  virtual scoped_refptr<FrameReceiver> frame_receiver() OVERRIDE;
+  virtual void RequestDecodedAudioFrame(
+      const AudioFrameDecodedCallback& callback) OVERRIDE;
+  virtual void RequestEncodedAudioFrame(
+      const ReceiveEncodedFrameCallback& callback) OVERRIDE;
+  virtual void RequestDecodedVideoFrame(
+      const VideoFrameDecodedCallback& callback) OVERRIDE;
+  virtual void RequestEncodedVideoFrame(
+      const ReceiveEncodedFrameCallback& callback) OVERRIDE;
 
  private:
-  void ReceivedPacket(scoped_ptr<Packet> packet);
+  // Forwards |packet| to a specific RTP frame receiver, or drops it if SSRC
+  // does not map to one of the receivers.
+  void DispatchReceivedPacket(scoped_ptr<Packet> packet);
 
+  // Feeds an EncodedFrame into |audio_decoder_|.  RequestDecodedAudioFrame()
+  // uses this as a callback for RequestEncodedAudioFrame().
+  void DecodeEncodedAudioFrame(
+      const AudioFrameDecodedCallback& callback,
+      scoped_ptr<transport::EncodedFrame> encoded_frame);
+
+  // Feeds an EncodedFrame into |video_decoder_|.  RequestDecodedVideoFrame()
+  // uses this as a callback for RequestEncodedVideoFrame().
+  void DecodeEncodedVideoFrame(
+      const VideoFrameDecodedCallback& callback,
+      scoped_ptr<transport::EncodedFrame> encoded_frame);
+
+  // Receives an AudioBus from |audio_decoder_|, logs the event, and passes the
+  // data on by running the given |callback|.  This method is static to ensure
+  // it can be called after a CastReceiverImpl instance is destroyed.
+  // DecodeEncodedAudioFrame() uses this as a callback for
+  // AudioDecoder::DecodeFrame().
+  static void EmitDecodedAudioFrame(
+      const scoped_refptr<CastEnvironment>& cast_environment,
+      const AudioFrameDecodedCallback& callback,
+      uint32 frame_id,
+      uint32 rtp_timestamp,
+      const base::TimeTicks& playout_time,
+      scoped_ptr<AudioBus> audio_bus,
+      bool is_continuous);
+
+  // Receives a VideoFrame from |video_decoder_|, logs the event, and passes the
+  // data on by running the given |callback|.  This method is static to ensure
+  // it can be called after a CastReceiverImpl instance is destroyed.
+  // DecodeEncodedVideoFrame() uses this as a callback for
+  // VideoDecoder::DecodeFrame().
+  static void EmitDecodedVideoFrame(
+      const scoped_refptr<CastEnvironment>& cast_environment,
+      const VideoFrameDecodedCallback& callback,
+      uint32 frame_id,
+      uint32 rtp_timestamp,
+      const base::TimeTicks& playout_time,
+      const scoped_refptr<VideoFrame>& video_frame,
+      bool is_continuous);
+
+  const scoped_refptr<CastEnvironment> cast_environment_;
   transport::PacedSender pacer_;
-  AudioReceiver audio_receiver_;
-  VideoReceiver video_receiver_;
-  scoped_refptr<FrameReceiver> frame_receiver_;
-  scoped_refptr<CastEnvironment> cast_environment_;
+  FrameReceiver audio_receiver_;
+  FrameReceiver video_receiver_;
+
+  // Used by DispatchReceivedPacket() to direct packets to the appropriate frame
+  // receiver.
   const uint32 ssrc_of_audio_sender_;
   const uint32 ssrc_of_video_sender_;
 
+  // Parameters for the decoders that are created on-demand.  The values here
+  // might be nonsense if the client of CastReceiverImpl never intends to use
+  // the internal software-based decoders.
+  const int num_audio_channels_;
+  const int audio_sampling_rate_;
+  const transport::AudioCodec audio_codec_;
+  const transport::VideoCodec video_codec_;
+
+  // Created on-demand to decode frames from |audio_receiver_| into AudioBuses
+  // for playback.
+  scoped_ptr<AudioDecoder> audio_decoder_;
+
+  // Created on-demand to decode frames from |video_receiver_| into VideoFrame
+  // images for playback.
+  scoped_ptr<VideoDecoder> video_decoder_;
+
   DISALLOW_COPY_AND_ASSIGN(CastReceiverImpl);
 };
 
 }  // namespace cast
 }  // namespace media
 
-#endif  // MEDIA_CAST_CAST_RECEIVER_IMPL_
+#endif  // MEDIA_CAST_RECEIVER_CAST_RECEIVER_IMPL_