content/renderer/media/video_source_handler.cc

   1 // Copyright (c) 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 #include "content/renderer/media/video_source_handler.h"
   6
   7 #include <string>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/synchronization/lock.h"
  12 #include "base/trace_event/trace_event.h"
  13 #include "content/public/renderer/media_stream_video_sink.h"
  14 #include "content/renderer/media/media_stream.h"
  15 #include "content/renderer/media/media_stream_registry_interface.h"
  16 #include "media/base/bind_to_current_loop.h"
  17 #include "media/video/capture/video_capture_types.h"
  18 #include "third_party/WebKit/public/platform/WebMediaStream.h"
  19 #include "third_party/WebKit/public/platform/WebURL.h"
  20 #include "third_party/WebKit/public/web/WebMediaStreamRegistry.h"
  21 #include "url/gurl.h"
  22
  23 namespace content {
  24
  25 // PpFrameReceiver implements MediaStreamVideoSink so that it can be attached
  26 // to video track to receive the captured frame.
  27 // It can be attached to a FrameReaderInterface to output the received frame.
  28 class PpFrameReceiver : public MediaStreamVideoSink {
  29  public:
  30   PpFrameReceiver(blink::WebMediaStreamTrack track)
  31     : track_(track),
  32       reader_(NULL),
  33       weak_factory_(this) {
  34   }
  35
  36   ~PpFrameReceiver() override {}
  37
  38   void SetReader(FrameReaderInterface* reader) {
  39     if (reader) {
  40       DCHECK(!reader_);
  41       MediaStreamVideoSink::AddToVideoTrack(
  42           this,
  43           media::BindToCurrentLoop(
  44               base::Bind(
  45                   &PpFrameReceiver::OnVideoFrame,
  46                   weak_factory_.GetWeakPtr())),
  47           track_);
  48     } else {
  49       DCHECK(reader_);
  50       MediaStreamVideoSink::RemoveFromVideoTrack(this, track_);
  51       weak_factory_.InvalidateWeakPtrs();
  52     }
  53     reader_ = reader;
  54   }
  55
  56   void OnVideoFrame(
  57       const scoped_refptr<media::VideoFrame>& frame,
  58       const media::VideoCaptureFormat& format,
  59       const base::TimeTicks& estimated_capture_time) {
  60     TRACE_EVENT0("video", "PpFrameReceiver::OnVideoFrame");
  61     if (reader_) {
  62       reader_->GotFrame(frame);
  63     }
  64   }
  65
  66  private:
  67   blink::WebMediaStreamTrack track_;
  68   FrameReaderInterface* reader_;
  69   base::WeakPtrFactory<PpFrameReceiver> weak_factory_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(PpFrameReceiver);
  72 };
  73
  74 VideoSourceHandler::VideoSourceHandler(
  75     MediaStreamRegistryInterface* registry)
  76     : registry_(registry) {
  77 }
  78
  79 VideoSourceHandler::~VideoSourceHandler() {
  80   for (SourceInfoMap::iterator it = reader_to_receiver_.begin();
  81        it != reader_to_receiver_.end();
  82        ++it) {
  83     delete it->second;
  84   }
  85 }
  86
  87 bool VideoSourceHandler::Open(const std::string& url,
  88                               FrameReaderInterface* reader) {
  89   DCHECK(thread_checker_.CalledOnValidThread());
  90   const blink::WebMediaStreamTrack& track = GetFirstVideoTrack(url);
  91   if (track.isNull()) {
  92     return false;
  93   }
  94   reader_to_receiver_[reader] = new SourceInfo(track, reader);
  95   return true;
  96 }
  97
  98 bool VideoSourceHandler::Close(FrameReaderInterface* reader) {
  99   DCHECK(thread_checker_. CalledOnValidThread());
 100   SourceInfoMap::iterator it = reader_to_receiver_.find(reader);
 101   if (it == reader_to_receiver_.end()) {
 102     return false;
 103   }
 104   delete it->second;
 105   reader_to_receiver_.erase(it);
 106   return true;
 107 }
 108
 109 blink::WebMediaStreamTrack VideoSourceHandler::GetFirstVideoTrack(
 110     const std::string& url) {
 111   blink::WebMediaStream stream;
 112   if (registry_) {
 113     stream = registry_->GetMediaStream(url);
 114   } else {
 115     stream =
 116         blink::WebMediaStreamRegistry::lookupMediaStreamDescriptor(GURL(url));
 117   }
 118
 119   if (stream.isNull()) {
 120     LOG(ERROR) << "GetFirstVideoSource - invalid url: " << url;
 121     return blink::WebMediaStreamTrack();
 122   }
 123
 124   // Get the first video track from the stream.
 125   blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
 126   stream.videoTracks(video_tracks);
 127   if (video_tracks.isEmpty()) {
 128     LOG(ERROR) << "GetFirstVideoSource - non video tracks available."
 129                << " url: " << url;
 130     return blink::WebMediaStreamTrack();
 131   }
 132
 133   return video_tracks[0];
 134 }
 135
 136 void VideoSourceHandler::DeliverFrameForTesting(
 137     FrameReaderInterface* reader,
 138     const scoped_refptr<media::VideoFrame>& frame) {
 139   SourceInfoMap::iterator it = reader_to_receiver_.find(reader);
 140   if (it == reader_to_receiver_.end()) {
 141     return;
 142   }
 143   PpFrameReceiver* receiver = it->second->receiver_.get();
 144   receiver->OnVideoFrame(frame, media::VideoCaptureFormat(),
 145                          base::TimeTicks());
 146 }
 147
 148 VideoSourceHandler::SourceInfo::SourceInfo(
 149     const blink::WebMediaStreamTrack& blink_track,
 150     FrameReaderInterface* reader)
 151     : receiver_(new PpFrameReceiver(blink_track)) {
 152   receiver_->SetReader(reader);
 153 }
 154
 155 VideoSourceHandler::SourceInfo::~SourceInfo() {
 156   receiver_->SetReader(NULL);
 157 }
 158
 159 }  // namespace content