content/renderer/media/video_track_adapter.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_
   6 #define CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_
   7
   8 #include <vector>
   9
  10 #include "base/macros.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/time/time.h"
  13 #include "content/renderer/media/media_stream_video_track.h"
  14 #include "media/base/video_frame.h"
  15
  16 namespace content {
  17
  18 // VideoTrackAdapter is a helper class used by MediaStreamVideoSource used for
  19 // adapting the video resolution from a source implementation to the resolution
  20 // a track requires. Different tracks can have different resolution constraints.
  21 // The constraints can be set as max width and height as well as max and min
  22 // aspect ratio.
  23 // Video frames are delivered to a track using a VideoCaptureDeliverFrameCB on
  24 // the IO-thread.
  25 // Adaptations is done by wrapping the original media::VideoFrame in a new
  26 // media::VideoFrame with a new visible_rect and natural_size.
  27 class VideoTrackAdapter
  28     : public base::RefCountedThreadSafe<VideoTrackAdapter> {
  29  public:
  30   typedef base::Callback<void(bool mute_state)> OnMutedCallback;
  31
  32   explicit VideoTrackAdapter(
  33       const scoped_refptr<base::MessageLoopProxy>& io_message_loop);
  34
  35   // Register |track| to receive video frames in |frame_callback| with
  36   // a resolution within the boundaries of the arguments.
  37   // Must be called on the main render thread. |frame_callback| is guaranteed to
  38   // be released on the main render thread.
  39   // |source_frame_rate| is used to calculate a prudent interval to check for
  40   // passing frames and inform of the result via |on_muted_state_callback|.
  41   void AddTrack(const MediaStreamVideoTrack* track,
  42                 VideoCaptureDeliverFrameCB frame_callback,
  43                 int max_width, int max_height,
  44                 double min_aspect_ratio,
  45                 double max_aspect_ratio,
  46                 double max_frame_rate,
  47                 double source_frame_rate,
  48                 const OnMutedCallback& on_muted_state_callback);
  49   void RemoveTrack(const MediaStreamVideoTrack* track);
  50
  51   // Delivers |frame| to all tracks that have registered a callback.
  52   // Must be called on the IO-thread.
  53   void DeliverFrameOnIO(
  54       const scoped_refptr<media::VideoFrame>& frame,
  55       const media::VideoCaptureFormat& format,
  56       const base::TimeTicks& estimated_capture_time);
  57
  58   const scoped_refptr<base::MessageLoopProxy>& io_message_loop() {
  59     DCHECK(thread_checker_.CalledOnValidThread());
  60     return io_message_loop_;
  61   }
  62
  63  private:
  64   virtual ~VideoTrackAdapter();
  65   friend class base::RefCountedThreadSafe<VideoTrackAdapter>;
  66
  67   void AddTrackOnIO(
  68       const MediaStreamVideoTrack* track,
  69       VideoCaptureDeliverFrameCB frame_callback,
  70       const gfx::Size& max_frame_size,
  71       double min_aspect_ratio,
  72       double max_aspect_ratio,
  73       double max_frame_rate);
  74   void RemoveTrackOnIO(const MediaStreamVideoTrack* track);
  75
  76   void StartTrackMonitoringOnIO(
  77     const OnMutedCallback& on_muted_state_callback,
  78     double source_frame_rate);
  79
  80   // Compare |frame_counter_snapshot| with the current |frame_counter_|, and
  81   // inform of the situation (muted, not muted) via |set_muted_state_callback|.
  82   void CheckFramesReceivedOnIO(const OnMutedCallback& set_muted_state_callback,
  83                                uint64 old_frame_counter_snapshot);
  84
  85   // |thread_checker_| is bound to the main render thread.
  86   base::ThreadChecker thread_checker_;
  87
  88   scoped_refptr<base::MessageLoopProxy> io_message_loop_;
  89
  90   // |renderer_task_runner_| is used to ensure that
  91   // VideoCaptureDeliverFrameCB is released on the main render thread.
  92   scoped_refptr<base::SingleThreadTaskRunner> renderer_task_runner_;
  93
  94   // VideoFrameResolutionAdapter is an inner class that is created on the main
  95   // render thread but operates on the IO-thread. It does the resolution
  96   // adaptation and delivers frames to all registered tracks on the IO-thread.
  97   class VideoFrameResolutionAdapter;
  98   typedef std::vector<scoped_refptr<VideoFrameResolutionAdapter> >
  99       FrameAdapters;
 100   FrameAdapters adapters_;
 101
 102   // Running frame counter, accessed on the IO-thread.
 103   uint64 frame_counter_;
 104
 105   // Frame rate configured on the video source, accessed on the IO-thread.
 106   float source_frame_rate_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(VideoTrackAdapter);
 109 };
 110
 111 }  // namespace content
 112
 113 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_