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      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(
     13     const media::VideoCaptureSessionId id,
     14     VideoCaptureImplManager* vc_manager,
     15     bool is_screencast)
     16     : is_screencast_(is_screencast),
     17       delegate_(new RtcVideoCaptureDelegate(id, vc_manager)),
     18       state_(VIDEO_CAPTURE_STATE_STOPPED) {
     19 }
     20 
     21 RtcVideoCapturer::~RtcVideoCapturer() {
     22   DCHECK(VIDEO_CAPTURE_STATE_STOPPED);
     23   DVLOG(3) << " RtcVideoCapturer::dtor";
     24 }
     25 
     26 cricket::CaptureState RtcVideoCapturer::Start(
     27     const cricket::VideoFormat& capture_format) {
     28   DVLOG(3) << " RtcVideoCapturer::Start ";
     29   if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
     30     DVLOG(1) << "Got a StartCapture when already started!!! ";
     31     return cricket::CS_FAILED;
     32   }
     33 
     34   media::VideoCaptureCapability cap;
     35   cap.width = capture_format.width;
     36   cap.height = capture_format.height;
     37   cap.frame_rate = capture_format.framerate();
     38   cap.color = media::VideoCaptureCapability::kI420;
     39 
     40   SetCaptureFormat(&capture_format);
     41 
     42   state_ = VIDEO_CAPTURE_STATE_STARTED;
     43   start_time_ = base::Time::Now();
     44   delegate_->StartCapture(cap,
     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 |cap|.
     50   UpdateAspectRatio(cap.width, cap.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 media::VideoCapture::VideoFrameBuffer& buf) {
     99   // Currently, |fourcc| is always I420.
    100   cricket::CapturedFrame frame;
    101   frame.width = buf.width;
    102   frame.height = buf.height;
    103   frame.fourcc = cricket::FOURCC_I420;
    104   frame.data_size = buf.buffer_size;
    105   // cricket::CapturedFrame time is in nanoseconds.
    106   frame.elapsed_time = (buf.timestamp - start_time_).InMicroseconds() *
    107       base::Time::kNanosecondsPerMicrosecond;
    108   frame.time_stamp =
    109       (buf.timestamp - base::Time::UnixEpoch()).InMicroseconds() *
    110       base::Time::kNanosecondsPerMicrosecond;
    111   frame.data = buf.memory_pointer;
    112   frame.pixel_height = 1;
    113   frame.pixel_width = 1;
    114 
    115   TRACE_EVENT_INSTANT2("rtc_video_capturer",
    116                        "OnFrameCaptured",
    117                        TRACE_EVENT_SCOPE_THREAD,
    118                        "elapsed time",
    119                        frame.elapsed_time,
    120                        "timestamp_ms",
    121                        frame.time_stamp / talk_base::kNumNanosecsPerMillisec);
    122 
    123   // This signals to libJingle that a new VideoFrame is available.
    124   // libJingle have no assumptions on what thread this signal come from.
    125   SignalFrameCaptured(this, &frame);
    126 }
    127 
    128 void RtcVideoCapturer::OnStateChange(
    129     RtcVideoCaptureDelegate::CaptureState state) {
    130   cricket::CaptureState converted_state = cricket::CS_FAILED;
    131   DVLOG(3) << " RtcVideoCapturer::OnStateChange " << state;
    132   switch (state) {
    133     case RtcVideoCaptureDelegate::CAPTURE_STOPPED:
    134       converted_state = cricket::CS_STOPPED;
    135       break;
    136     case RtcVideoCaptureDelegate::CAPTURE_RUNNING:
    137       converted_state = cricket::CS_RUNNING;
    138       break;
    139     case RtcVideoCaptureDelegate::CAPTURE_FAILED:
    140       // TODO(perkj): Update the comments in the the definition of
    141       // cricket::CS_FAILED. According to the comments, cricket::CS_FAILED
    142       // means that the capturer failed to start. But here and in libjingle it
    143       // is also used if an error occur during capturing.
    144       converted_state = cricket::CS_FAILED;
    145       break;
    146     default:
    147       NOTREACHED();
    148       break;
    149   }
    150   SignalStateChange(this, converted_state);
    151 }
    152 
    153 }  // namespace content
    154