Initialize based on frame sizes in VideoTrackRecorder

content/renderer/media/video_track_recorder.h

 // Copyright 2015 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 CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread_checker.h"
 #include "content/public/common/features.h"
 #include "content/public/renderer/media_stream_video_sink.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 
+namespace base {
+class WaitableEvent;
+}  // namespace base
+
 namespace media {
 class VideoFrame;
 }  // namespace media
 
 namespace content {
 
 // VideoTrackRecorder is a MediaStreamVideoSink that encodes the video frames
 // received from a Stream Video Track. This class is constructed and used on a
 // single thread, namely the main Render thread. This mirrors the other
 // MediaStreamVideo* classes that are constructed/configured on Main Render
@@ skipping 22 matching lines @@
   ~VideoTrackRecorder() override;
 
   void Pause();
   void Resume();
 
   void OnVideoFrameForTesting(const scoped_refptr<media::VideoFrame>& frame,
                               base::TimeTicks capture_time);
  private:
   friend class VideoTrackRecorderTest;
 
+  void InitializeEncoder(const scoped_refptr<media::VideoFrame>& frame,

[mcasas, 2016/06/23 00:27:36]

Can we call this method
ReceiveFirstFrameOnIOThread

and the next one
InitializeEncoderOnMainThread?
(note that I said this latter on before).

[emircan, 2016/06/28 22:10:41]

Done.

+                         base::TimeTicks capture_time);
+  void InitializeEncoderTask(const scoped_refptr<media::VideoFrame>& frame,
+                             base::TimeTicks capture_time,
+                             base::WaitableEvent* async_waiter);
+
   // Used to check that we are destroyed on the same thread we were created.
   base::ThreadChecker main_render_thread_checker_;
 
+  // Used to post initialization on the same thread we were created.
+  const scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+
+  // Task runner where frame encode callbacks must happen.
+  scoped_refptr<base::SingleThreadTaskRunner> origin_task_runner_;
+
   // We need to hold on to the Blink track to remove ourselves on dtor.
   blink::WebMediaStreamTrack track_;
 
   // Inner class to encode using whichever codec is configured.
   scoped_refptr<Encoder> encoder_;
 
+  // Parameters that would be passed to the underlying |encoder_|.
+  const CodecId codec_;
+  const OnEncodedVideoCB on_encoded_video_callback_;
+  const int32_t bits_per_second_;
+
+  // Used to track the paused state during the initialization process.
+  bool paused_before_init_;
+
+  base::WeakPtrFactory<VideoTrackRecorder> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoTrackRecorder);
 };
 
 }  // namespace content
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_