New class AdaptedVideoTrackSource.

webrtc/media/base/videosourceinterface.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MEDIA_BASE_VIDEOSOURCEINTERFACE_H_
 #define WEBRTC_MEDIA_BASE_VIDEOSOURCEINTERFACE_H_
 
 #include "webrtc/media/base/videosinkinterface.h"
 #include "webrtc/base/optional.h"
 
 namespace rtc {
 
 // VideoSinkWants is used for notifying the source of properties a video frame
 // should have when it is delivered to a certain sink.
+
 struct VideoSinkWants {
-  // Tells the source whether the sink wants frames with rotation applied.
-  // By default, any rotation must be applied by the sink.
+  // Tells the source whether the sink wants frames with rotation applied. By
+  // default, any rotation must be applied by the sink. The VideoBroadcaster

[perkj_webrtc, 2016/09/21 08:59:23]

I don't think think the comment about VideoBroadCaster belongs in the interface.
That is an implementation detail.

[nisse-webrtc, 2016/09/21 09:43:59]

The intention is to explain what the rotation_applied flag means. Which I think
belongs here.

Now, the meaning currently is a bit muddy. I think the alternative is to clarify
that even if it is set, the sink might get frames with pending rotation. (And
then it becomes an implementation detail of VideoBroadcaster that it's more
strict, to help current sinks which need that).

What do you suggest, re-phrasing, moving to where?

+  // class ensures that if a sink sets rotation_applied == true, it will never
+  // receive a frame with pending rotation. Unclear if we want to provide that
+  // guarantee in general.
   bool rotation_applied = false;
 
   // Tells the source that the sink only wants black frames.
   bool black_frames = false;
 
   // Tells the source the maximum number of pixels the sink wants.
   rtc::Optional<int> max_pixel_count;
   // Like |max_pixel_count| but relative to the given value. The source is
   // requested to produce frames with a resolution one "step up" from the given
   // value. In practice, this means that the sink can consume this amount of
@@ skipping 10 matching lines @@
   // RemoveSink must guarantee that at the time the method returns,
   // there is no current and no future calls to VideoSinkInterface::OnFrame.
   virtual void RemoveSink(VideoSinkInterface<VideoFrameT>* sink) = 0;
 
  protected:
   virtual ~VideoSourceInterface() {}
 };
 
 }  // namespace rtc
 #endif  // WEBRTC_MEDIA_BASE_VIDEOSOURCEINTERFACE_H_