Preliminary change for new rtc rendering algorithm

content/renderer/media/webrtc/media_stream_remote_video_source.cc

 // Copyright 2014 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 "content/renderer/media/webrtc/media_stream_remote_video_source.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/threading/thread_checker.h"
 #include "base/trace_event/trace_event.h"
 #include "content/renderer/media/webrtc/track_observer.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "third_party/libjingle/source/talk/media/base/videoframe.h"
+#include "third_party/webrtc/system_wrappers/interface/tick_util.h"
 
 namespace content {
 
 // Internal class used for receiving frames from the webrtc track on a
 // libjingle thread and forward it to the IO-thread.
 class MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate
     : public base::RefCountedThreadSafe<RemoteVideoSourceDelegate>,
       public webrtc::VideoRendererInterface {
  public:
   RemoteVideoSourceDelegate(
@@ skipping 13 matching lines @@
       const scoped_refptr<media::VideoFrame>& video_frame);
 
  private:
   // Bound to the render thread.
   base::ThreadChecker thread_checker_;
 
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
 
   // |frame_callback_| is accessed on the IO thread.
   VideoCaptureDeliverFrameCB frame_callback_;
+
+  // WebRTC Chromium timestamp diff
+  int64_t time_diff_us_;
 };
 
 MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate::
     RemoteVideoSourceDelegate(
         scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
         const VideoCaptureDeliverFrameCB& new_frame_callback)
     : io_task_runner_(io_task_runner), frame_callback_(new_frame_callback) {
+  // TODO(qiangchen): There can be two differences between clocks: 1)
+  // the offset, 2) the rate (i.e., one clock runs faster than the other).
+  // See http://crbug/516700
+  time_diff_us_ =
+      (base::TimeTicks::Now() - base::TimeTicks()).InMicroseconds() -
+      webrtc::TickTime::MicrosecondTimestamp();
 }
 
 MediaStreamRemoteVideoSource::
 RemoteVideoSourceDelegate::~RemoteVideoSourceDelegate() {
 }
 
 void MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate::RenderFrame(
     const cricket::VideoFrame* incoming_frame) {
-  TRACE_EVENT0("webrtc", "RemoteVideoSourceDelegate::RenderFrame");
+  base::TimeTicks render_time =
+      base::TimeTicks() +
+      base::TimeDelta::FromMicroseconds(incoming_frame->GetTimeStamp() / 1000 +
+                                        time_diff_us_);
+
+  TRACE_EVENT1("webrtc", "RemoteVideoSourceDelegate::RenderFrame",
+               "Ideal Render Instant", render_time.ToInternalValue());
+
   base::TimeDelta timestamp = base::TimeDelta::FromMicroseconds(
       incoming_frame->GetElapsedTime() / rtc::kNumNanosecsPerMicrosec);
 
   scoped_refptr<media::VideoFrame> video_frame;
   if (incoming_frame->GetNativeHandle() != NULL) {
     video_frame =
         static_cast<media::VideoFrame*>(incoming_frame->GetNativeHandle());
     video_frame->set_timestamp(timestamp);
   } else {
     const cricket::VideoFrame* frame =
@@ skipping 13 matching lines @@
     video_frame = media::VideoFrame::WrapExternalYuvData(
         media::PIXEL_FORMAT_YV12, size, gfx::Rect(size), size,
         frame->GetYPitch(), frame->GetUPitch(), frame->GetVPitch(),
         const_cast<uint8_t*>(frame->GetYPlane()),
         const_cast<uint8_t*>(frame->GetUPlane()),
         const_cast<uint8_t*>(frame->GetVPlane()), timestamp);
     video_frame->AddDestructionObserver(
         base::Bind(&base::DeletePointer<cricket::VideoFrame>, frame->Copy()));
   }
 
+  video_frame->metadata()->SetTimeTicks(
+      media::VideoFrameMetadata::REFERENCE_TIME, render_time);
+
   io_task_runner_->PostTask(
       FROM_HERE, base::Bind(&RemoteVideoSourceDelegate::DoRenderFrameOnIOThread,
                             this, video_frame));
 }
 
 void MediaStreamRemoteVideoSource::
 RemoteVideoSourceDelegate::DoRenderFrameOnIOThread(
     const scoped_refptr<media::VideoFrame>& video_frame) {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
   TRACE_EVENT0("webrtc", "RemoteVideoSourceDelegate::DoRenderFrameOnIOThread");
@@ skipping 66 matching lines @@
     case webrtc::MediaStreamTrackInterface::kEnded:
       SetReadyState(blink::WebMediaStreamSource::ReadyStateEnded);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 }  // namespace content