New static method I420Buffer::SetToBlack.

webrtc/media/base/videobroadcaster.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 36 matching lines @@
 VideoSinkWants VideoBroadcaster::wants() const {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&sinks_and_wants_lock_);
   return current_wants_;
 }
 
 void VideoBroadcaster::OnFrame(const cricket::VideoFrame& frame) {
   rtc::CritScope cs(&sinks_and_wants_lock_);
   for (auto& sink_pair : sink_pairs()) {
     if (sink_pair.wants.black_frames) {
-      sink_pair.sink->OnFrame(GetBlackFrame(frame));
+      sink_pair.sink->OnFrame(cricket::WebRtcVideoFrame(
+          GetBlackFrameBuffer(frame.width(), frame.height()),
+          frame.rotation(), frame.timestamp_us()));
     } else {
       sink_pair.sink->OnFrame(frame);
     }
   }
 }
 
 void VideoBroadcaster::UpdateWants() {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
 
   VideoSinkWants wants;
@@ skipping 18 matching lines @@
     }
   }
 
   if (wants.max_pixel_count && wants.max_pixel_count_step_up &&
       *wants.max_pixel_count_step_up >= *wants.max_pixel_count) {
     wants.max_pixel_count_step_up = Optional<int>();
   }
   current_wants_ = wants;
 }
 
-const cricket::VideoFrame& VideoBroadcaster::GetBlackFrame(
-    const cricket::VideoFrame& frame) {
-  if (black_frame_ && black_frame_->width() == frame.width() &&
-      black_frame_->height() == frame.height() &&
-      black_frame_->rotation() == frame.rotation()) {
-    black_frame_->set_timestamp_us(frame.timestamp_us());
-    return *black_frame_;
+const rtc::scoped_refptr<webrtc::VideoFrameBuffer>&
+VideoBroadcaster::GetBlackFrameBuffer(int width, int height) {
+  if (!black_frame_buffer_ || black_frame_buffer_->width() != width ||
+      black_frame_buffer_->height() != height) {
+    rtc::scoped_refptr<webrtc::I420Buffer> buffer =
+        new RefCountedObject<webrtc::I420Buffer>(width, height);
+    buffer->SetToBlack();
+    black_frame_buffer_ = buffer;
   }
-  black_frame_.reset(new cricket::WebRtcVideoFrame(
-      new rtc::RefCountedObject<webrtc::I420Buffer>(frame.width(),
-                                                    frame.height()),
-      frame.rotation(), frame.timestamp_us()));
-  black_frame_->SetToBlack();
-  return *black_frame_;
+
+  return black_frame_buffer_;
 }
 
 }  // namespace rtc