[Cast] VideoFrameFactory interface to vend frames with encoder affinity.

media/cast/sender/video_sender.h

 // Copyright 2014 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_SENDER_VIDEO_SENDER_H_
 #define MEDIA_CAST_SENDER_VIDEO_SENDER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/sender/congestion_control.h"
 #include "media/cast/sender/frame_sender.h"
+#include "media/cast/sender/video_frame_factory.h"
 
 namespace media {
 
 class VideoFrame;
 
 namespace cast {
 
 class CastTransportSender;
 class VideoEncoder;
 
@@ skipping 21 matching lines @@
 
   // Note: It is not guaranteed that |video_frame| will actually be encoded and
   // sent, if VideoSender detects too many frames in flight.  Therefore, clients
   // should be careful about the rate at which this method is called.
   //
   // Note: It is invalid to call this method if InitializationResult() returns
   // anything but STATUS_VIDEO_INITIALIZED.
   void InsertRawVideoFrame(const scoped_refptr<media::VideoFrame>& video_frame,
                            const base::TimeTicks& reference_time);
 
+  // Returns a |VideoFrameFactory| that can be used to create
+  // |media::VideoFrame| objects with potentially better affinity with the
+  // encoder.
+  scoped_refptr<VideoFrameFactory> video_frame_factory() {
+    return video_frame_factory_;
+  }
+
  protected:
   int GetNumberOfFramesInEncoder() const override;
   base::TimeDelta GetInFlightMediaDuration() const override;
   void OnAck(uint32 frame_id) override;
 
  private:
   // Called when the encoder is initialized or has failed to initialize.
   void OnEncoderInitialized(
       const CastInitializationCallback& initialization_cb,
       CastInitializationStatus status);
 
   // Called by the |video_encoder_| with the next EncodedFrame to send.
   void OnEncodedVideoFrame(int encoder_bitrate,
                            scoped_ptr<EncodedFrame> encoded_frame);
 
   // Encodes media::VideoFrame images into EncodedFrames.  Per configuration,
   // this will point to either the internal software-based encoder or a proxy to
   // a hardware-based encoder.
   scoped_ptr<VideoEncoder> video_encoder_;
 
+  // Provides |media::VideoFrame| objects suitable for encoding. The encoder may
+  // provide a specialized instance, otherwise a default implementation is used.
+  scoped_refptr<VideoFrameFactory> video_frame_factory_;
+
   // The number of frames queued for encoding, but not yet sent.
   int frames_in_encoder_;
 
   // The duration of video queued for encoding, but not yet sent.
   base::TimeDelta duration_in_encoder_;
 
   // The timestamp of the frame that was last enqueued in |video_encoder_|.
   RtpTimestamp last_enqueued_frame_rtp_timestamp_;
   base::TimeTicks last_enqueued_frame_reference_time_;
 
   // Remember what we set the bitrate to before, no need to set it again if
   // we get the same value.
   uint32 last_bitrate_;
 
   PlayoutDelayChangeCB playout_delay_change_cb_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<VideoSender> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoSender);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_SENDER_VIDEO_SENDER_H_