src/content/renderer/media/rtc_video_capturer.cc

   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_capturer.h"
   6
   7 #include "base/bind.h"
   8 #include "base/debug/trace_event.h"
   9
  10 namespace content {
  11
  12 RtcVideoCapturer::RtcVideoCapturer(const media::VideoCaptureSessionId id,
  13                                    VideoCaptureImplManager* vc_manager,
  14                                    bool is_screencast)
  15     : is_screencast_(is_screencast),
  16       delegate_(new RtcVideoCaptureDelegate(id, vc_manager)),
  17       state_(VIDEO_CAPTURE_STATE_STOPPED) {}
  18
  19 RtcVideoCapturer::~RtcVideoCapturer() {
  20   DCHECK(VIDEO_CAPTURE_STATE_STOPPED);
  21   DVLOG(3) << " RtcVideoCapturer::dtor";
  22 }
  23
  24 cricket::CaptureState RtcVideoCapturer::Start(
  25     const cricket::VideoFormat& capture_format) {
  26   DVLOG(3) << " RtcVideoCapturer::Start ";
  27   if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
  28     DVLOG(1) << "Got a StartCapture when already started!!! ";
  29     return cricket::CS_FAILED;
  30   }
  31
  32   media::VideoCaptureParams request;
  33   request.requested_format =
  34       media::VideoCaptureFormat(capture_format.width,
  35                                 capture_format.height,
  36                                 capture_format.framerate(),
  37                                 media::ConstantResolutionVideoCaptureDevice);
  38
  39   SetCaptureFormat(&capture_format);
  40
  41   state_ = VIDEO_CAPTURE_STATE_STARTED;
  42   first_frame_timestamp_ = media::kNoTimestamp();
  43   delegate_->StartCapture(
  44       request,
  45       base::Bind(&RtcVideoCapturer::OnFrameCaptured, base::Unretained(this)),
  46       base::Bind(&RtcVideoCapturer::OnStateChange, base::Unretained(this)));
  47   // Update the desired aspect ratio so that later the video frame can be
  48   // cropped to meet the requirement if the camera returns a different
  49   // resolution than the |request|.
  50   UpdateAspectRatio(capture_format.width, capture_format.height);
  51   return cricket::CS_STARTING;
  52 }
  53
  54 void RtcVideoCapturer::Stop() {
  55   DVLOG(3) << " RtcVideoCapturer::Stop ";
  56   if (state_ == VIDEO_CAPTURE_STATE_STOPPED) {
  57     DVLOG(1) << "Got a StopCapture while not started.";
  58     return;
  59   }
  60
  61   SetCaptureFormat(NULL);
  62   state_ = VIDEO_CAPTURE_STATE_STOPPED;
  63   delegate_->StopCapture();
  64   SignalStateChange(this, cricket::CS_STOPPED);
  65 }
  66
  67 bool RtcVideoCapturer::IsRunning() {
  68   return state_ == VIDEO_CAPTURE_STATE_STARTED;
  69 }
  70
  71 bool RtcVideoCapturer::GetPreferredFourccs(std::vector<uint32>* fourccs) {
  72   if (!fourccs)
  73     return false;
  74   fourccs->push_back(cricket::FOURCC_I420);
  75   return true;
  76 }
  77
  78 bool RtcVideoCapturer::IsScreencast() const {
  79   return is_screencast_;
  80 }
  81
  82 bool RtcVideoCapturer::GetBestCaptureFormat(const cricket::VideoFormat& desired,
  83                                             cricket::VideoFormat* best_format) {
  84   if (!best_format) {
  85     return false;
  86   }
  87
  88   // Chrome does not support capability enumeration.
  89   // Use the desired format as the best format.
  90   best_format->width = desired.width;
  91   best_format->height = desired.height;
  92   best_format->fourcc = cricket::FOURCC_I420;
  93   best_format->interval = desired.interval;
  94   return true;
  95 }
  96
  97 void RtcVideoCapturer::OnFrameCaptured(
  98     const scoped_refptr<media::VideoFrame>& frame) {
  99   if (first_frame_timestamp_ == media::kNoTimestamp())
 100     first_frame_timestamp_ = frame->GetTimestamp();
 101
 102   // Currently, |fourcc| is always I420.
 103   cricket::CapturedFrame captured_frame;
 104   captured_frame.width = frame->coded_size().width();
 105   captured_frame.height = frame->coded_size().height();
 106   captured_frame.fourcc = cricket::FOURCC_I420;
 107   // cricket::CapturedFrame time is in nanoseconds.
 108   captured_frame.elapsed_time =
 109       (frame->GetTimestamp() - first_frame_timestamp_).InMicroseconds() *
 110       base::Time::kNanosecondsPerMicrosecond;
 111   captured_frame.time_stamp = frame->GetTimestamp().InMicroseconds() *
 112                               base::Time::kNanosecondsPerMicrosecond;
 113   // TODO(sheu): we assume contiguous layout of image planes.
 114   captured_frame.data = frame->data(0);
 115   captured_frame.data_size =
 116       media::VideoFrame::AllocationSize(frame->format(), frame->coded_size());
 117   captured_frame.pixel_height = 1;
 118   captured_frame.pixel_width = 1;
 119
 120   TRACE_EVENT_INSTANT2(
 121       "rtc_video_capturer",
 122       "OnFrameCaptured",
 123       TRACE_EVENT_SCOPE_THREAD,
 124       "elapsed time",
 125       captured_frame.elapsed_time,
 126       "timestamp_ms",
 127       captured_frame.time_stamp / talk_base::kNumNanosecsPerMillisec);
 128
 129   // This signals to libJingle that a new VideoFrame is available.
 130   // libJingle have no assumptions on what thread this signal come from.
 131   SignalFrameCaptured(this, &captured_frame);
 132 }
 133
 134 void RtcVideoCapturer::OnStateChange(
 135     RtcVideoCaptureDelegate::CaptureState state) {
 136   cricket::CaptureState converted_state = cricket::CS_FAILED;
 137   DVLOG(3) << " RtcVideoCapturer::OnStateChange " << state;
 138   switch (state) {
 139     case RtcVideoCaptureDelegate::CAPTURE_STOPPED:
 140       converted_state = cricket::CS_STOPPED;
 141       break;
 142     case RtcVideoCaptureDelegate::CAPTURE_RUNNING:
 143       converted_state = cricket::CS_RUNNING;
 144       break;
 145     case RtcVideoCaptureDelegate::CAPTURE_FAILED:
 146       // TODO(perkj): Update the comments in the the definition of
 147       // cricket::CS_FAILED. According to the comments, cricket::CS_FAILED
 148       // means that the capturer failed to start. But here and in libjingle it
 149       // is also used if an error occur during capturing.
 150       converted_state = cricket::CS_FAILED;
 151       break;
 152     default:
 153       NOTREACHED();
 154       break;
 155   }
 156   SignalStateChange(this, converted_state);
 157 }
 158
 159 }  // namespace content