content/renderer/media/media_stream_video_track.h

   1 // Copyright 2013 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_MEDIA_STREAM_VIDEO_TRACK_H_
   6 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
   7
   8 #include <vector>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/gtest_prod_util.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "base/threading/thread_checker.h"
  14 #include "content/common/content_export.h"
  15 #include "content/public/renderer/media_stream_video_sink.h"
  16 #include "content/renderer/media/media_stream_track.h"
  17 #include "content/renderer/media/media_stream_video_source.h"
  18
  19 namespace content {
  20
  21 // MediaStreamVideoTrack is a video specific representation of a
  22 // blink::WebMediaStreamTrack in content. It is owned by the blink object
  23 // and can be retrieved from a blink object using
  24 // WebMediaStreamTrack::extraData() or MediaStreamVideoTrack::GetVideoTrack.
  25 class CONTENT_EXPORT MediaStreamVideoTrack : public MediaStreamTrack {
  26  public:
  27   // Help method to create a blink::WebMediaStreamTrack and a
  28   // MediaStreamVideoTrack instance. The MediaStreamVideoTrack object is owned
  29   // by the blink object in its WebMediaStreamTrack::ExtraData member.
  30   // |callback| is triggered if the track is added to the source
  31   // successfully and will receive video frames that match |constraints|
  32   // or if the source fail to provide video frames.
  33   // If |enabled| is true, sinks added to the track will
  34   // receive video frames when the source deliver frames to the track.
  35   static blink::WebMediaStreamTrack CreateVideoTrack(
  36       MediaStreamVideoSource* source,
  37       const blink::WebMediaConstraints& constraints,
  38       const MediaStreamVideoSource::ConstraintsCallback& callback,
  39       bool enabled);
  40
  41   static MediaStreamVideoTrack* GetVideoTrack(
  42       const blink::WebMediaStreamTrack& track);
  43
  44   // Constructor for local video tracks.
  45    MediaStreamVideoTrack(
  46        MediaStreamVideoSource* source,
  47        const blink::WebMediaConstraints& constraints,
  48        const MediaStreamVideoSource::ConstraintsCallback& callback,
  49        bool enabled);
  50   virtual ~MediaStreamVideoTrack();
  51
  52   virtual void SetEnabled(bool enabled) OVERRIDE;
  53   virtual void Stop() OVERRIDE;
  54
  55   void OnReadyStateChanged(blink::WebMediaStreamSource::ReadyState state);
  56
  57   const blink::WebMediaConstraints& constraints() const {
  58     return constraints_;
  59   }
  60
  61  protected:
  62   // Used to DCHECK that we are called on the correct thread.
  63   base::ThreadChecker thread_checker_;
  64
  65  private:
  66   // MediaStreamVideoSink is a friend to allow it to call AddSink() and
  67   // RemoveSink().
  68   friend class MediaStreamVideoSink;
  69   FRIEND_TEST_ALL_PREFIXES(MediaStreamRemoteVideoSourceTest, StartTrack);
  70   FRIEND_TEST_ALL_PREFIXES(MediaStreamRemoteVideoSourceTest, RemoteTrackStop);
  71   FRIEND_TEST_ALL_PREFIXES(VideoDestinationHandlerTest, PutFrame);
  72
  73   // Add |sink| to receive state changes on the main render thread and video
  74   // frames in the |callback| method on the IO-thread.
  75   // |callback| will be reset on the render thread.
  76   // These two methods are private such that no subclass can intercept and
  77   // store the callback. This is important to ensure that we can release
  78   // the callback on render thread without reference to it on the IO-thread.
  79   void AddSink(MediaStreamVideoSink* sink,
  80                const VideoCaptureDeliverFrameCB& callback);
  81   void RemoveSink(MediaStreamVideoSink* sink);
  82
  83   // |FrameDeliverer| is an internal helper object used for delivering video
  84   // frames on the IO-thread using callbacks to all registered tracks.
  85   class FrameDeliverer;
  86   scoped_refptr<FrameDeliverer> frame_deliverer_;
  87
  88   blink::WebMediaConstraints constraints_;
  89
  90   // Weak ref to the source this tracks is connected to.  |source_| is owned
  91   // by the blink::WebMediaStreamSource and is guaranteed to outlive the
  92   // track.
  93   MediaStreamVideoSource* source_;
  94
  95   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoTrack);
  96 };
  97
  98 }  // namespace content
  99
 100 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_