Faster YUV conversion in WebrtcVideoCapturerAdapter.

remoting/protocol/webrtc_video_capturer_adapter.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/protocol/webrtc_video_capturer_adapter.h"
 
 #include <utility>
 
+#include "third_party/libjingle/source/talk/media/webrtc/webrtcvideoframe.h"
+#include "third_party/libyuv/include/libyuv/convert.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
 
 namespace remoting {
+namespace protocol {
 
 // Number of frames to be captured per second.
 const int kFramesPerSec = 30;
 
 WebrtcVideoCapturerAdapter::WebrtcVideoCapturerAdapter(
     scoped_ptr<webrtc::DesktopCapturer> capturer)
     : desktop_capturer_(std::move(capturer)) {
   DCHECK(desktop_capturer_);
 
-  thread_checker_.DetachFromThread();
-
   // Disable video adaptation since we don't intend to use it.
   set_enable_video_adapter(false);
 }
 
 WebrtcVideoCapturerAdapter::~WebrtcVideoCapturerAdapter() {
   DCHECK(!capture_timer_);
 }
 
-webrtc::SharedMemory* WebrtcVideoCapturerAdapter::CreateSharedMemory(
-    size_t size) {
-  return nullptr;
-}
-
-void WebrtcVideoCapturerAdapter::OnCaptureCompleted(
-    webrtc::DesktopFrame* frame) {
-  scoped_ptr<webrtc::DesktopFrame> owned_frame(frame);
-
-  // Drop the owned_frame if there were no changes.
-  if (!owned_frame || owned_frame->updated_region().is_empty()) {
-    owned_frame.reset();
-    return;
-  }
-
-  // Convert the webrtc::DesktopFrame to a cricket::CapturedFrame.
-  cricket::CapturedFrame captured_frame;
-  captured_frame.width = owned_frame->size().width();
-  captured_frame.height = owned_frame->size().height();
-  base::TimeTicks current_time = base::TimeTicks::Now();
-  captured_frame.time_stamp =
-      current_time.ToInternalValue() * base::Time::kNanosecondsPerMicrosecond;
-  captured_frame.data = owned_frame->data();
-
-  // The data_size attribute must be set. If multiple formats are supported,
-  // this should be set appropriately for each one.
-  captured_frame.data_size =
-      (captured_frame.width * webrtc::DesktopFrame::kBytesPerPixel * 8 + 7) /
-      8 * captured_frame.height;
-  captured_frame.fourcc = cricket::FOURCC_ARGB;
-
-  SignalFrameCaptured(this, &captured_frame);
-}
-
 bool WebrtcVideoCapturerAdapter::GetBestCaptureFormat(
     const cricket::VideoFormat& desired,
     cricket::VideoFormat* best_format) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  // For now, just used the desired width and height.
-  best_format->width = desired.width;
-  best_format->height = desired.height;
-  best_format->fourcc = cricket::FOURCC_ARGB;
-  best_format->interval = FPS_TO_INTERVAL(kFramesPerSec);
+  // The |capture_format| passed to Start() is always ignored, so copy
+  // |best_format| to |desired_format|.
+  *best_format = desired;
   return true;
 }
 
 cricket::CaptureState WebrtcVideoCapturerAdapter::Start(
     const cricket::VideoFormat& capture_format) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!capture_timer_);
-  DCHECK_EQ(capture_format.fourcc,
-            (static_cast<uint32_t>(cricket::FOURCC_ARGB)));
 
   if (!desktop_capturer_) {
     VLOG(1) << "WebrtcVideoCapturerAdapter failed to start.";
     return cricket::CS_FAILED;
   }
 
-  // This is required to tell the cricket::VideoCapturer base class what the
-  // capture format will be.
-  SetCaptureFormat(&capture_format);
-
   desktop_capturer_->Start(this);
 
   capture_timer_.reset(new base::RepeatingTimer());
   capture_timer_->Start(FROM_HERE,
-                        base::TimeDelta::FromMicroseconds(
-                            GetCaptureFormat()->interval /
-                            (base::Time::kNanosecondsPerMicrosecond)),
-                        this,
+                        base::TimeDelta::FromSeconds(1) / kFramesPerSec, this,
                         &WebrtcVideoCapturerAdapter::CaptureNextFrame);
 
   return cricket::CS_RUNNING;
 }
 
 // Similar to the base class implementation with some important differences:
 // 1. Does not call either Stop() or Start(), as those would affect the state of
 // |desktop_capturer_|.
 // 2. Does not support unpausing after stopping the capturer. It is unclear
 // if that flow needs to be supported.
@@ skipping 51 matching lines @@
   desktop_capturer_.reset();
 
   SetCaptureFormat(nullptr);
   SetCaptureState(cricket::CS_STOPPED);
 
   VLOG(1) << "WebrtcVideoCapturerAdapter stopped.";
 }
 
 bool WebrtcVideoCapturerAdapter::IsRunning() {
   DCHECK(thread_checker_.CalledOnValidThread());
-
   return capture_timer_->IsRunning();
 }
 
 bool WebrtcVideoCapturerAdapter::IsScreencast() const {
   return true;
 }
 
 bool WebrtcVideoCapturerAdapter::GetPreferredFourccs(
     std::vector<uint32_t>* fourccs) {
+  return false;
+}
+
+webrtc::SharedMemory* WebrtcVideoCapturerAdapter::CreateSharedMemory(
+    size_t size) {
+  return nullptr;
+}
+
+void WebrtcVideoCapturerAdapter::OnCaptureCompleted(
+    webrtc::DesktopFrame* frame) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  if (!fourccs)
-    return false;
-  fourccs->push_back(cricket::FOURCC_ARGB);
-  return true;
+
+  DCHECK(capture_pending_);
+  capture_pending_ = false;
+
+  scoped_ptr<webrtc::DesktopFrame> owned_frame(frame);
+
+  // Drop the frame if there were no changes.
+  if (!owned_frame || owned_frame->updated_region().is_empty())
+    return;
+
+  size_t width = frame->size().width();
+  size_t height = frame->size().height();
+  if (!yuv_frame_ || yuv_frame_->GetWidth() != width ||
+      yuv_frame_->GetHeight() != height) {
+    scoped_ptr<cricket::WebRtcVideoFrame> webrtc_frame(
+        new cricket::WebRtcVideoFrame());
+    webrtc_frame->InitToEmptyBuffer(width, height, 1, 1, 0);
+    yuv_frame_ = std::move(webrtc_frame);
+
+    // Set updated_region so the whole frame is converted to YUV below.
+    frame->mutable_updated_region()->SetRect(
+        webrtc::DesktopRect::MakeWH(width, height));
+  }
+
+  // TODO(sergeyu): This will copy the buffer if it's being used. Optimize it by
+  // keeping a queue of frames.
+  CHECK(yuv_frame_->MakeExclusive());
+
+  yuv_frame_->SetTimeStamp(base::TimeTicks::Now().ToInternalValue() *
+                           base::Time::kNanosecondsPerMicrosecond);
+
+  for (webrtc::DesktopRegion::Iterator i(frame->updated_region()); !i.IsAtEnd();
+       i.Advance()) {
+      int left =  i.rect().left();

[Jamie, 2016/01/08 23:33:52]

Nit: Unnecessary extra space after =

[Sergey Ulanov, 2016/01/09 01:33:29]

Done.

+      int top =  i.rect().top();
+      int width =  i.rect().width();
+      int height =  i.rect().height();
+
+      if (left % 2 == 1) {
+        --left;
+        ++width;
+      }
+      if (top % 2 == 1) {
+        --top;
+        ++height;
+      }

[Jamie, 2016/01/08 23:33:52]

Is it only the top-left corner that must be on a 2px boundary, or do you also
need to make sure that with and height are even?

[Sergey Ulanov, 2016/01/09 01:33:29]

ARGBToI420() supports odd width and height.

+      libyuv::ARGBToI420(
+          frame->data() + frame->stride() * top +
+              left * webrtc::DesktopFrame::kBytesPerPixel,
+          frame->stride(),
+          yuv_frame_->GetYPlane() + yuv_frame_->GetYPitch() * top + left,
+          yuv_frame_->GetYPitch(),
+          yuv_frame_->GetUPlane() + yuv_frame_->GetUPitch() * top / 2 +
+              left / 2,
+          yuv_frame_->GetUPitch(),
+          yuv_frame_->GetVPlane() + yuv_frame_->GetVPitch() * top / 2 +
+              left / 2,
+          yuv_frame_->GetVPitch(), width, height);
+  }
+
+  SignalVideoFrame(this, yuv_frame_.get());
 }
 
 void WebrtcVideoCapturerAdapter::CaptureNextFrame() {
-  // If we are paused, then don't capture.
-  if (!IsRunning())
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (capture_pending_)
     return;
-
+  capture_pending_ = true;
   desktop_capturer_->Capture(webrtc::DesktopRegion());
 }
 
+}  // namespace protocol
 }  // namespace remoting