Connect the new video rendering path to the compositor.

media/renderers/video_renderer_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_RENDERERS_VIDEO_RENDERER_IMPL_H_
 #define MEDIA_RENDERERS_VIDEO_RENDERER_IMPL_H_
 
 #include <deque>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
+#include "base/timer/timer.h"
 #include "media/base/decryptor.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_log.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/video_decoder.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_renderer.h"
 #include "media/base/video_renderer_sink.h"
 #include "media/filters/decoder_stream.h"
+#include "media/filters/video_renderer_algorithm.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 class TickClock;
 }
 
 namespace media {
 
 // VideoRendererImpl creates its own thread for the sole purpose of timing frame
 // presentation.  It handles reading from the VideoFrameStream and stores the
@@ skipping 36 matching lines @@
   // PlatformThread::Delegate implementation.
   void ThreadMain() override;
 
   void SetTickClockForTesting(scoped_ptr<base::TickClock> tick_clock);
 
   // VideoRendererSink::RenderCallback implementation.
   scoped_refptr<VideoFrame> Render(base::TimeTicks deadline_min,
                                    base::TimeTicks deadline_max) override;
   void OnFrameDropped() override;
 
+  void enable_new_video_renderer_for_testing() {
+    use_new_video_renderering_path_ = true;
+  }
+
+  void SetBackgroundRenderingForTesting(bool enabled, base::TimeDelta timeout);

[xhwang, 2015/04/29 06:51:55]

nit: Add comment, or s/timeout/background_rendering_timeout/ to make it self
explanatory.

[DaleCurtis, 2015/04/30 03:49:37]

Done.

+
  private:
   // Creates a dedicated |thread_| for video rendering.
   void CreateVideoThread();
 
   // Callback for |video_frame_stream_| initialization.
   void OnVideoFrameStreamInitialized(bool success);
 
   // Callback for |video_frame_stream_| to deliver decoded video frames and
   // report video decoding status.
   void FrameReady(VideoFrameStream::Status status,
@@ skipping 24 matching lines @@
   // Returns true if the renderer has enough data for playback purposes.
   // Note that having enough data may be due to reaching end of stream.
   bool HaveEnoughData_Locked();
   void TransitionToHaveEnough_Locked();
 
   // Runs |statistics_cb_| with |frames_decoded_| and |frames_dropped_|, resets
   // them to 0, and then waits on |frame_available_| for up to the
   // |wait_duration|.
   void UpdateStatsAndWait_Locked(base::TimeDelta wait_duration);
 
+  // Called after we've painted the first frame.  If |time_progressing_| is
+  // false it Stop() on |sink_|.
+  void MaybeStopSinkAfterFirstPaint();
+
+  // Resets and primes the |background_rendering_timer_|, when the timer fires
+  // it calls the BackgroundRender() method below.
+  void RestartBackgroundRenderTimer();
+
+  // Called by |background_rendering_timer_| when enough time elapses where we
+  // haven't seen a Render() call.
+  void BackgroundRender();
+  void BackgroundRender_Locked();
+
+  // Return true if there is no more room for additional buffered frames.

[xhwang, 2015/04/29 06:51:55]

nit: Return_s_

[DaleCurtis, 2015/04/30 03:49:37]

Done.

+  bool HaveReachedBufferingCap();
+
+  // Starts or stops |sink_| respectively. Do not call while |lock_| is held.
+  void StartSink();
+  void StopSink();
+
+  // Fires |ended_cb_| if there are no remaining usable frames and
+  // |received_end_of_stream_| is true.  Sets |rendered_end_of_stream_| if it
+  // does so.  Returns algorithm_->EffectiveFramesQueued().
+  size_t MaybeFireEndedCallback();
+
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
+  // Enables the use of VideoRendererAlgorithm and VideoRendererSink for frame
+  // rendering instead of using a thread in a sleep-loop.  Set via the command
+  // line flag kEnableNewVideoRenderer or via test methods.
+  bool use_new_video_renderering_path_;
+
+  // Sink which calls into VideoRendererImpl via Render() for video frames.  Do
+  // not call any methods on the sink while |lock_| is held or the two threads
+  // might deadlock. Do not call Start() or Stop() on the sink directly, use
+  // StartSink() and StopSink() to ensure background rendering is started.
   VideoRendererSink* const sink_;
 
   // Used for accessing data members.
   base::Lock lock_;
 
   // Provides video frames to VideoRendererImpl.
   scoped_ptr<VideoFrameStream> video_frame_stream_;
 
   // Flag indicating low-delay mode.
   bool low_delay_;
@@ skipping 74 matching lines @@
 
   // Keeps track of the number of frames decoded and dropped since the
   // last call to |statistics_cb_|. These must be accessed under lock.
   int frames_decoded_;
   int frames_dropped_;
 
   bool is_shutting_down_;
 
   scoped_ptr<base::TickClock> tick_clock_;
 
+  // Algorithm for selecting which frame to render; manages frames and all
+  // timing related information.
+  scoped_ptr<VideoRendererAlgorithm> algorithm_;
+
+  // Indicates that Render() callbacks from |sink_| have timed out, so we've
+  // entered a background rendering mode where dropped frames are not counted.
+  bool is_background_rendering_;
+
+  // Allows tests to disable the background rendering task.
+  bool should_use_background_renderering_;
+
+  // Manages expiration of stale video frames if Render() callbacks timeout.  Do
+  // not access from the thread Render() is called on.  Must only be used on
+  // |task_runner_|.
+  base::OneShotTimer<VideoRendererImpl> background_rendering_timer_;
+
+  // Indicates whether or not media time is currently progressing or not.
+  bool time_progressing_;
+
+  // Indicates that Render() should only render the first frame and then request
+  // that the sink be stopped.
+  bool render_first_frame_and_stop_;
+
+  // The time to wait for Render() before firing BackgroundRender().
+  base::TimeDelta background_rendering_timeout_;
+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<VideoRendererImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoRendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_VIDEO_RENDERER_IMPL_H_