1 // Copyright (c) 2012 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/rtc_video_renderer.h"
6
7 #include "base/debug/trace_event.h"
8 #include "base/message_loop/message_loop_proxy.h"
9 #include "media/base/bind_to_current_loop.h"
10 #include "media/base/video_frame.h"
11 #include "media/base/video_util.h"
12
13 const int kMinFrameSize = 2;
14
15 namespace content {
16
RTCVideoRenderer(const blink::WebMediaStreamTrack & video_track,const base::Closure & error_cb,const RepaintCB & repaint_cb)17 RTCVideoRenderer::RTCVideoRenderer(
18 const blink::WebMediaStreamTrack& video_track,
19 const base::Closure& error_cb,
20 const RepaintCB& repaint_cb)
21 : error_cb_(error_cb),
22 repaint_cb_(repaint_cb),
23 message_loop_proxy_(base::MessageLoopProxy::current()),
24 state_(STOPPED),
25 frame_size_(kMinFrameSize, kMinFrameSize),
26 video_track_(video_track),
27 weak_factory_(this) {
28 }
29
~RTCVideoRenderer()30 RTCVideoRenderer::~RTCVideoRenderer() {
31 }
32
Start()33 void RTCVideoRenderer::Start() {
34 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
35 DCHECK_EQ(state_, STOPPED);
36
37 AddToVideoTrack(
38 this,
39 media::BindToCurrentLoop(
40 base::Bind(
41 &RTCVideoRenderer::OnVideoFrame,
42 weak_factory_.GetWeakPtr())),
43 video_track_);
44 state_ = STARTED;
45
46 if (video_track_.source().readyState() ==
47 blink::WebMediaStreamSource::ReadyStateEnded ||
48 !video_track_.isEnabled()) {
49 RenderSignalingFrame();
50 }
51 }
52
Stop()53 void RTCVideoRenderer::Stop() {
54 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
55 DCHECK(state_ == STARTED || state_ == PAUSED);
56 RemoveFromVideoTrack(this, video_track_);
57 weak_factory_.InvalidateWeakPtrs();
58 state_ = STOPPED;
59 frame_size_.set_width(kMinFrameSize);
60 frame_size_.set_height(kMinFrameSize);
61 }
62
Play()63 void RTCVideoRenderer::Play() {
64 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
65 if (state_ == PAUSED) {
66 state_ = STARTED;
67 }
68 }
69
Pause()70 void RTCVideoRenderer::Pause() {
71 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
72 if (state_ == STARTED) {
73 state_ = PAUSED;
74 }
75 }
76
OnReadyStateChanged(blink::WebMediaStreamSource::ReadyState state)77 void RTCVideoRenderer::OnReadyStateChanged(
78 blink::WebMediaStreamSource::ReadyState state) {
79 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
80 if (state == blink::WebMediaStreamSource::ReadyStateEnded)
81 RenderSignalingFrame();
82 }
83
OnVideoFrame(const scoped_refptr<media::VideoFrame> & frame,const media::VideoCaptureFormat & format,const base::TimeTicks & estimated_capture_time)84 void RTCVideoRenderer::OnVideoFrame(
85 const scoped_refptr<media::VideoFrame>& frame,
86 const media::VideoCaptureFormat& format,
87 const base::TimeTicks& estimated_capture_time) {
88 DCHECK(message_loop_proxy_->BelongsToCurrentThread());
89 if (state_ != STARTED) {
90 return;
91 }
92
93 frame_size_ = frame->natural_size();
94
95 TRACE_EVENT_INSTANT1("rtc_video_renderer",
96 "OnVideoFrame",
97 TRACE_EVENT_SCOPE_THREAD,
98 "timestamp",
99 frame->timestamp().InMilliseconds());
100 repaint_cb_.Run(frame);
101 }
102
RenderSignalingFrame()103 void RTCVideoRenderer::RenderSignalingFrame() {
104 // This is necessary to make sure audio can play if the video tag src is
105 // a MediaStream video track that has been rejected or ended.
106 // It also ensure that the renderer don't hold a reference to a real video
107 // frame if no more frames are provided. This is since there might be a
108 // finite number of available buffers. E.g, video that
109 // originates from a video camera.
110 scoped_refptr<media::VideoFrame> video_frame =
111 media::VideoFrame::CreateBlackFrame(frame_size_);
112 OnVideoFrame(video_frame, media::VideoCaptureFormat(), base::TimeTicks());
113 }
114
115 } // namespace content
116