[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"
 
 namespace media {
 
 class VideoFrame;
 
 namespace cast {
 
 class CastTransportSender;
 class VideoEncoder;
+class VideoFrameFactory;
 
 typedef base::Callback<void(base::TimeDelta)> PlayoutDelayChangeCB;
 
 // Not thread safe. Only called from the main cast thread.
 // This class owns all objects related to sending video, objects that create RTP
 // packets, congestion control, video encoder, parsing and sending of
 // RTCP packets.
 // Additionally it posts a bunch of delayed tasks to the main thread for various
 // timeouts.
 class VideoSender : public FrameSender,
@@ skipping 12 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);
 
+  // Creates a |VideoFrameFactory| object to vend |VideoFrame| object with
+  // encoder affinity (defined as offering some sort of performance benefit). If
+  // the encoder does not have any such capability, returns null.
+  scoped_ptr<VideoFrameFactory> CreateVideoFrameFactory();
+
  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);
@@ skipping 26 matching lines @@
   // 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_