content/renderer/media/webrtc/webrtc_video_track_adapter.cc

   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 #include "content/renderer/media/webrtc/webrtc_video_track_adapter.h"
   6
   7 #include "base/strings/utf_string_conversions.h"
   8 #include "content/common/media/media_stream_options.h"
   9 #include "content/renderer/media/media_stream_video_source.h"
  10 #include "content/renderer/media/media_stream_video_track.h"
  11
  12 namespace {
  13
  14 bool ConstraintKeyExists(const blink::WebMediaConstraints& constraints,
  15                          const blink::WebString& name) {
  16   blink::WebString value_str;
  17   return constraints.getMandatoryConstraintValue(name, value_str) ||
  18       constraints.getOptionalConstraintValue(name, value_str);
  19 }
  20
  21 }  // anonymouse namespace
  22
  23 namespace content {
  24
  25 // Used to make sure |source| is released on the main render thread.
  26 void ReleaseWebRtcSourceOnMainRenderThread(
  27     webrtc::VideoSourceInterface* source) {
  28   source->Release();
  29 }
  30
  31 // Simple help class used for receiving video frames on the IO-thread from
  32 // a MediaStreamVideoTrack and forward the frames to a
  33 // WebRtcVideoCapturerAdapter that implements a video capturer for libjingle.
  34 class WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter
  35     : public base::RefCountedThreadSafe<WebRtcVideoSourceAdapter> {
  36  public:
  37   WebRtcVideoSourceAdapter(
  38       const scoped_refptr<webrtc::VideoSourceInterface>& source,
  39       WebRtcVideoCapturerAdapter* capture_adapter);
  40
  41   void OnVideoFrameOnIO(const scoped_refptr<media::VideoFrame>& frame,
  42                         const media::VideoCaptureFormat& format);
  43
  44  private:
  45   friend class base::RefCountedThreadSafe<WebRtcVideoSourceAdapter>;
  46   virtual ~WebRtcVideoSourceAdapter();
  47
  48   scoped_refptr<base::MessageLoopProxy> render_thread_message_loop_;
  49   // Used to DCHECK that frames are called on the IO-thread.
  50   base::ThreadChecker io_thread_checker_;
  51
  52   // |video_source_| is a libjingle object that must be released on the main
  53   // render thread.
  54   scoped_refptr<webrtc::VideoSourceInterface> video_source_;
  55   // |capture_adapter_| is owned by |video_source_|
  56   WebRtcVideoCapturerAdapter* capture_adapter_;
  57 };
  58
  59 WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::WebRtcVideoSourceAdapter(
  60     const scoped_refptr<webrtc::VideoSourceInterface>& source,
  61     WebRtcVideoCapturerAdapter* capture_adapter)
  62     : render_thread_message_loop_(base::MessageLoopProxy::current()),
  63       video_source_(source),
  64       capture_adapter_(capture_adapter) {
  65   io_thread_checker_.DetachFromThread();
  66 }
  67
  68 WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::~WebRtcVideoSourceAdapter() {
  69   if (!render_thread_message_loop_->BelongsToCurrentThread()) {
  70     webrtc::VideoSourceInterface* source = video_source_.get();
  71     source->AddRef();
  72     video_source_ = NULL;
  73     render_thread_message_loop_->PostTask(
  74         FROM_HERE,
  75         base::Bind(&ReleaseWebRtcSourceOnMainRenderThread,
  76                    base::Unretained(source)));
  77   }
  78 }
  79
  80 void WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::OnVideoFrameOnIO(
  81     const scoped_refptr<media::VideoFrame>& frame,
  82     const media::VideoCaptureFormat& format) {
  83   DCHECK(io_thread_checker_.CalledOnValidThread());
  84   capture_adapter_->OnFrameCaptured(frame);
  85 }
  86
  87 WebRtcVideoTrackAdapter::WebRtcVideoTrackAdapter(
  88     const blink::WebMediaStreamTrack& track,
  89     MediaStreamDependencyFactory* factory)
  90     : web_track_(track) {
  91   const blink::WebMediaConstraints& constraints =
  92       MediaStreamVideoTrack::GetVideoTrack(track)->constraints();
  93
  94   bool is_screencast = ConstraintKeyExists(
  95       constraints, base::UTF8ToUTF16(kMediaStreamSource));
  96   WebRtcVideoCapturerAdapter* capture_adapter =
  97       factory->CreateVideoCapturer(is_screencast);
  98
  99   // |video_source| owns |capture_adapter|
 100   scoped_refptr<webrtc::VideoSourceInterface> video_source(
 101       factory->CreateVideoSource(capture_adapter,
 102                                  track.source().constraints()));
 103
 104   video_track_ = factory->CreateLocalVideoTrack(web_track_.id().utf8(),
 105                                                 video_source.get());
 106
 107   video_track_->set_enabled(web_track_.isEnabled());
 108
 109   source_adapter_ = new WebRtcVideoSourceAdapter(video_source,
 110                                                  capture_adapter);
 111
 112   MediaStreamVideoTrack::GetVideoTrack(track)->AddSink(
 113       this, base::Bind(&WebRtcVideoSourceAdapter::OnVideoFrameOnIO,
 114                        source_adapter_));
 115
 116   DVLOG(3) << "WebRtcVideoTrackAdapter ctor() : is_screencast "
 117            << is_screencast;
 118 }
 119
 120 WebRtcVideoTrackAdapter::~WebRtcVideoTrackAdapter() {
 121   DCHECK(thread_checker_.CalledOnValidThread());
 122   DVLOG(3) << "WebRtcVideoTrackAdapter dtor().";
 123   MediaStreamVideoTrack::GetVideoTrack(web_track_)->RemoveSink(this);
 124 }
 125
 126 void WebRtcVideoTrackAdapter::OnEnabledChanged(bool enabled) {
 127   DCHECK(thread_checker_.CalledOnValidThread());
 128   video_track_->set_enabled(enabled);
 129 }
 130
 131 }  // namespace content
 132