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 "base/synchronization/lock.h"
9 #include "content/common/media/media_stream_options.h"
10 #include "content/renderer/media/media_stream_video_source.h"
11 #include "content/renderer/media/media_stream_video_track.h"
12
13 namespace {
14
ConstraintKeyExists(const blink::WebMediaConstraints & constraints,const blink::WebString & name)15 bool ConstraintKeyExists(const blink::WebMediaConstraints& constraints,
16 const blink::WebString& name) {
17 blink::WebString value_str;
18 return constraints.getMandatoryConstraintValue(name, value_str) ||
19 constraints.getOptionalConstraintValue(name, value_str);
20 }
21
22 } // anonymouse namespace
23
24 namespace content {
25
26 // Simple help class used for receiving video frames on the IO-thread from
27 // a MediaStreamVideoTrack and forward the frames to a
28 // WebRtcVideoCapturerAdapter on libjingle's worker thread.
29 // WebRtcVideoCapturerAdapter implements a video capturer for libjingle.
30 class WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter
31 : public base::RefCountedThreadSafe<WebRtcVideoSourceAdapter> {
32 public:
33 WebRtcVideoSourceAdapter(
34 const scoped_refptr<base::MessageLoopProxy>& libjingle_worker_thread,
35 const scoped_refptr<webrtc::VideoSourceInterface>& source,
36 WebRtcVideoCapturerAdapter* capture_adapter);
37
38 // WebRtcVideoTrackAdapter can be destroyed on the main render thread or
39 // libjingles worker thread since it posts video frames on that thread. But
40 // |video_source_| must be released on the main render thread before the
41 // PeerConnectionFactory has been destroyed. The only way to ensure that is
42 // to make sure |video_source_| is released when WebRtcVideoTrackAdapter() is
43 // destroyed.
44 void ReleaseSourceOnMainThread();
45
46 void OnVideoFrameOnIO(const scoped_refptr<media::VideoFrame>& frame,
47 const media::VideoCaptureFormat& format,
48 const base::TimeTicks& estimated_capture_time);
49
50 private:
51 void OnVideoFrameOnWorkerThread(
52 const scoped_refptr<media::VideoFrame>& frame,
53 const media::VideoCaptureFormat& format,
54 const base::TimeTicks& estimated_capture_time);
55 friend class base::RefCountedThreadSafe<WebRtcVideoSourceAdapter>;
56 virtual ~WebRtcVideoSourceAdapter();
57
58 scoped_refptr<base::MessageLoopProxy> render_thread_message_loop_;
59
60 // |render_thread_checker_| is bound to the main render thread.
61 base::ThreadChecker render_thread_checker_;
62 // Used to DCHECK that frames are called on the IO-thread.
63 base::ThreadChecker io_thread_checker_;
64
65 // Used for posting frames to libjingle's worker thread. Accessed on the
66 // IO-thread.
67 scoped_refptr<base::MessageLoopProxy> libjingle_worker_thread_;
68
69 scoped_refptr<webrtc::VideoSourceInterface> video_source_;
70
71 // Used to protect |capture_adapter_|. It is taken by libjingle's worker
72 // thread for each video frame that is delivered but only taken on the
73 // main render thread in ReleaseSourceOnMainThread() when
74 // the owning WebRtcVideoTrackAdapter is being destroyed.
75 base::Lock capture_adapter_stop_lock_;
76 // |capture_adapter_| is owned by |video_source_|
77 WebRtcVideoCapturerAdapter* capture_adapter_;
78 };
79
WebRtcVideoSourceAdapter(const scoped_refptr<base::MessageLoopProxy> & libjingle_worker_thread,const scoped_refptr<webrtc::VideoSourceInterface> & source,WebRtcVideoCapturerAdapter * capture_adapter)80 WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::WebRtcVideoSourceAdapter(
81 const scoped_refptr<base::MessageLoopProxy>& libjingle_worker_thread,
82 const scoped_refptr<webrtc::VideoSourceInterface>& source,
83 WebRtcVideoCapturerAdapter* capture_adapter)
84 : render_thread_message_loop_(base::MessageLoopProxy::current()),
85 libjingle_worker_thread_(libjingle_worker_thread),
86 video_source_(source),
87 capture_adapter_(capture_adapter) {
88 io_thread_checker_.DetachFromThread();
89 }
90
~WebRtcVideoSourceAdapter()91 WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::~WebRtcVideoSourceAdapter() {
92 DVLOG(3) << "~WebRtcVideoSourceAdapter()";
93 DCHECK(!capture_adapter_);
94 // This object can be destroyed on the main render thread or libjingles
95 // worker thread since it posts video frames on that thread. But
96 // |video_source_| must be released on the main render thread before the
97 // PeerConnectionFactory has been destroyed. The only way to ensure that is
98 // to make sure |video_source_| is released when WebRtcVideoTrackAdapter() is
99 // destroyed.
100 }
101
102 void WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::
ReleaseSourceOnMainThread()103 ReleaseSourceOnMainThread() {
104 DCHECK(render_thread_checker_.CalledOnValidThread());
105 // Since frames are posted to the worker thread, this object might be deleted
106 // on that thread. However, since |video_source_| was created on the render
107 // thread, it should be released on the render thread.
108 base::AutoLock auto_lock(capture_adapter_stop_lock_);
109 // |video_source| owns |capture_adapter_|.
110 capture_adapter_ = NULL;
111 video_source_ = NULL;
112 }
113
OnVideoFrameOnIO(const scoped_refptr<media::VideoFrame> & frame,const media::VideoCaptureFormat & format,const base::TimeTicks & estimated_capture_time)114 void WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::OnVideoFrameOnIO(
115 const scoped_refptr<media::VideoFrame>& frame,
116 const media::VideoCaptureFormat& format,
117 const base::TimeTicks& estimated_capture_time) {
118 DCHECK(io_thread_checker_.CalledOnValidThread());
119 libjingle_worker_thread_->PostTask(
120 FROM_HERE,
121 base::Bind(&WebRtcVideoSourceAdapter::OnVideoFrameOnWorkerThread,
122 this, frame, format, estimated_capture_time));
123 }
124
125 void
OnVideoFrameOnWorkerThread(const scoped_refptr<media::VideoFrame> & frame,const media::VideoCaptureFormat & format,const base::TimeTicks & estimated_capture_time)126 WebRtcVideoTrackAdapter::WebRtcVideoSourceAdapter::OnVideoFrameOnWorkerThread(
127 const scoped_refptr<media::VideoFrame>& frame,
128 const media::VideoCaptureFormat& format,
129 const base::TimeTicks& estimated_capture_time) {
130 DCHECK(libjingle_worker_thread_->BelongsToCurrentThread());
131 base::AutoLock auto_lock(capture_adapter_stop_lock_);
132 if (capture_adapter_)
133 capture_adapter_->OnFrameCaptured(frame);
134 }
135
WebRtcVideoTrackAdapter(const blink::WebMediaStreamTrack & track,PeerConnectionDependencyFactory * factory)136 WebRtcVideoTrackAdapter::WebRtcVideoTrackAdapter(
137 const blink::WebMediaStreamTrack& track,
138 PeerConnectionDependencyFactory* factory)
139 : web_track_(track) {
140 const blink::WebMediaConstraints& constraints =
141 MediaStreamVideoTrack::GetVideoTrack(track)->constraints();
142
143 bool is_screencast = ConstraintKeyExists(
144 constraints, base::UTF8ToUTF16(kMediaStreamSource));
145 WebRtcVideoCapturerAdapter* capture_adapter =
146 factory->CreateVideoCapturer(is_screencast);
147
148 // |video_source| owns |capture_adapter|
149 scoped_refptr<webrtc::VideoSourceInterface> video_source(
150 factory->CreateVideoSource(capture_adapter,
151 track.source().constraints()));
152
153 video_track_ = factory->CreateLocalVideoTrack(web_track_.id().utf8(),
154 video_source.get());
155
156 video_track_->set_enabled(web_track_.isEnabled());
157
158 source_adapter_ = new WebRtcVideoSourceAdapter(
159 factory->GetWebRtcWorkerThread(),
160 video_source,
161 capture_adapter);
162
163 AddToVideoTrack(
164 this,
165 base::Bind(&WebRtcVideoSourceAdapter::OnVideoFrameOnIO,
166 source_adapter_),
167 web_track_);
168
169 DVLOG(3) << "WebRtcVideoTrackAdapter ctor() : is_screencast "
170 << is_screencast;
171 }
172
~WebRtcVideoTrackAdapter()173 WebRtcVideoTrackAdapter::~WebRtcVideoTrackAdapter() {
174 DCHECK(thread_checker_.CalledOnValidThread());
175 DVLOG(3) << "WebRtcVideoTrackAdapter dtor().";
176 RemoveFromVideoTrack(this, web_track_);
177 source_adapter_->ReleaseSourceOnMainThread();
178 }
179
OnEnabledChanged(bool enabled)180 void WebRtcVideoTrackAdapter::OnEnabledChanged(bool enabled) {
181 DCHECK(thread_checker_.CalledOnValidThread());
182 video_track_->set_enabled(enabled);
183 }
184
185 } // namespace content
186