remoting/host/cast_video_capturer_adapter.cc

   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 "remoting/host/cast_video_capturer_adapter.h"
   6
   7 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
   8
   9 namespace remoting {
  10
  11 // Number of frames to be captured per second.
  12 const int kFramesPerSec = 10;
  13
  14 CastVideoCapturerAdapter::CastVideoCapturerAdapter(
  15     scoped_ptr<webrtc::DesktopCapturer> capturer)
  16     : desktop_capturer_(capturer.Pass()) {
  17   DCHECK(desktop_capturer_);
  18
  19   thread_checker_.DetachFromThread();
  20
  21   // Disable video adaptation since we don't intend to use it.
  22   set_enable_video_adapter(false);
  23 }
  24
  25 CastVideoCapturerAdapter::~CastVideoCapturerAdapter() {
  26   DCHECK(!capture_timer_);
  27 }
  28
  29 webrtc::SharedMemory* CastVideoCapturerAdapter::CreateSharedMemory(
  30     size_t size) {
  31   return NULL;
  32 }
  33
  34 void CastVideoCapturerAdapter::OnCaptureCompleted(webrtc::DesktopFrame* frame) {
  35   scoped_ptr<webrtc::DesktopFrame> owned_frame(frame);
  36
  37   // Drop the owned_frame if there were no changes.
  38   if (!owned_frame || owned_frame->updated_region().is_empty()) {
  39     owned_frame.reset();
  40     return;
  41   }
  42
  43   // Convert the webrtc::DesktopFrame to a cricket::CapturedFrame.
  44   cricket::CapturedFrame captured_frame;
  45   captured_frame.width = owned_frame->size().width();
  46   captured_frame.height = owned_frame->size().height();
  47   base::TimeTicks current_time = base::TimeTicks::Now();
  48   captured_frame.elapsed_time = (current_time - start_time_).InMicroseconds() *
  49                                 base::Time::kNanosecondsPerMicrosecond;
  50   captured_frame.time_stamp =
  51       current_time.ToInternalValue() * base::Time::kNanosecondsPerMicrosecond;
  52   captured_frame.data = owned_frame->data();
  53
  54   // The data_size attribute must be set. If multiple formats are supported,
  55   // this should be set appropriately for each one.
  56   captured_frame.data_size =
  57       (captured_frame.width * webrtc::DesktopFrame::kBytesPerPixel * 8 + 7) /
  58       8 * captured_frame.height;
  59   captured_frame.fourcc = cricket::FOURCC_ARGB;
  60
  61   SignalFrameCaptured(this, &captured_frame);
  62 }
  63
  64 bool CastVideoCapturerAdapter::GetBestCaptureFormat(
  65     const cricket::VideoFormat& desired,
  66     cricket::VideoFormat* best_format) {
  67   DCHECK(thread_checker_.CalledOnValidThread());
  68
  69   // For now, just used the desired width and height.
  70   best_format->width = desired.width;
  71   best_format->height = desired.height;
  72   best_format->fourcc = cricket::FOURCC_ARGB;
  73   best_format->interval = FPS_TO_INTERVAL(kFramesPerSec);
  74   return true;
  75 }
  76
  77 cricket::CaptureState CastVideoCapturerAdapter::Start(
  78     const cricket::VideoFormat& capture_format) {
  79   DCHECK(thread_checker_.CalledOnValidThread());
  80   DCHECK(!capture_timer_);
  81   DCHECK_EQ(capture_format.fourcc, (static_cast<uint32>(cricket::FOURCC_ARGB)));
  82
  83   if (!desktop_capturer_) {
  84     VLOG(1) << "CastVideoCapturerAdapter failed to start.";
  85     return cricket::CS_FAILED;
  86   }
  87
  88   // This is required to tell the cricket::VideoCapturer base class what the
  89   // capture format will be.
  90   SetCaptureFormat(&capture_format);
  91
  92   desktop_capturer_->Start(this);
  93
  94   // Save the Start() time of |desktop_capturer_|. This will be used
  95   // to estimate the creation time of the frame source, to set the elapsed_time
  96   // of future CapturedFrames in OnCaptureCompleted().
  97   start_time_ = base::TimeTicks::Now();
  98   capture_timer_.reset(new base::RepeatingTimer<CastVideoCapturerAdapter>());
  99   capture_timer_->Start(FROM_HERE,
 100                         base::TimeDelta::FromMicroseconds(
 101                             GetCaptureFormat()->interval /
 102                             (base::Time::kNanosecondsPerMicrosecond)),
 103                         this,
 104                         &CastVideoCapturerAdapter::CaptureNextFrame);
 105
 106   return cricket::CS_RUNNING;
 107 }
 108
 109 // Similar to the base class implementation with some important differences:
 110 // 1. Does not call either Stop() or Start(), as those would affect the state of
 111 // |desktop_capturer_|.
 112 // 2. Does not support unpausing after stopping the capturer. It is unclear
 113 // if that flow needs to be supported.
 114 bool CastVideoCapturerAdapter::Pause(bool pause) {
 115   DCHECK(thread_checker_.CalledOnValidThread());
 116
 117   if (pause) {
 118     if (capture_state() == cricket::CS_PAUSED)
 119       return true;
 120
 121     bool running = capture_state() == cricket::CS_STARTING ||
 122                    capture_state() == cricket::CS_RUNNING;
 123
 124     DCHECK_EQ(running, IsRunning());
 125
 126     if (!running) {
 127       LOG(ERROR)
 128           << "Cannot pause CastVideoCapturerAdapter.";
 129       return false;
 130     }
 131
 132     // Stop |capture_timer_| and set capture state to cricket::CS_PAUSED.
 133     capture_timer_->Stop();
 134     SetCaptureState(cricket::CS_PAUSED);
 135
 136     VLOG(1) << "CastVideoCapturerAdapter paused.";
 137
 138     return true;
 139   } else {  // Unpausing.
 140     if (capture_state() != cricket::CS_PAUSED || !GetCaptureFormat() ||
 141         !capture_timer_) {
 142       LOG(ERROR) << "Cannot unpause CastVideoCapturerAdapter.";
 143       return false;
 144     }
 145
 146     // Restart |capture_timer_| and set capture state to cricket::CS_RUNNING;
 147     capture_timer_->Start(FROM_HERE,
 148                           base::TimeDelta::FromMicroseconds(
 149                               GetCaptureFormat()->interval /
 150                               (base::Time::kNanosecondsPerMicrosecond)),
 151                           this,
 152                           &CastVideoCapturerAdapter::CaptureNextFrame);
 153     SetCaptureState(cricket::CS_RUNNING);
 154
 155     VLOG(1) << "CastVideoCapturerAdapter unpaused.";
 156   }
 157   return true;
 158 }
 159
 160 void CastVideoCapturerAdapter::Stop() {
 161   DCHECK(thread_checker_.CalledOnValidThread());
 162   DCHECK_NE(capture_state(), cricket::CS_STOPPED);
 163
 164   capture_timer_.reset();
 165
 166   SetCaptureFormat(NULL);
 167   SetCaptureState(cricket::CS_STOPPED);
 168
 169   VLOG(1) << "CastVideoCapturerAdapter stopped.";
 170 }
 171
 172
 173 bool CastVideoCapturerAdapter::IsRunning() {
 174   DCHECK(thread_checker_.CalledOnValidThread());
 175
 176   return capture_timer_->IsRunning();
 177 }
 178
 179 bool CastVideoCapturerAdapter::IsScreencast() const {
 180   return true;
 181 }
 182
 183 bool CastVideoCapturerAdapter::GetPreferredFourccs(
 184     std::vector<uint32>* fourccs) {
 185   DCHECK(thread_checker_.CalledOnValidThread());
 186   if (!fourccs)
 187     return false;
 188   fourccs->push_back(cricket::FOURCC_ARGB);
 189   return true;
 190 }
 191
 192 void CastVideoCapturerAdapter::CaptureNextFrame() {
 193   // If we are paused, then don't capture.
 194   if (!IsRunning())
 195     return;
 196
 197   desktop_capturer_->Capture(webrtc::DesktopRegion());
 198 }
 199
 200 }  // namespace remoting
 201