Enable video stats reporting when using WebRTC

remoting/protocol/webrtc_video_renderer_adapter.cc

Index: remoting/protocol/webrtc_video_renderer_adapter.cc
diff --git a/remoting/protocol/webrtc_video_renderer_adapter.cc b/remoting/protocol/webrtc_video_renderer_adapter.cc
index 1320b9c6b1d86ef3d64cdf146f9c0dda93b57d8a..5896022fe4d15c02dbf4e92f5e1ae8523ddb98b0 100644
--- a/remoting/protocol/webrtc_video_renderer_adapter.cc
+++ b/remoting/protocol/webrtc_video_renderer_adapter.cc
@@ -15,12 +15,12 @@
 #include "base/task_runner_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/threading/worker_pool.h"
+#include "remoting/protocol/client_video_stats_dispatcher.h"
 #include "remoting/protocol/frame_consumer.h"
 #include "remoting/protocol/frame_stats.h"
 #include "remoting/protocol/video_renderer.h"
-#include "third_party/libyuv/include/libyuv/convert_argb.h"
+#include "remoting/protocol/webrtc_transport.h"
 #include "third_party/libyuv/include/libyuv/convert_from.h"
-#include "third_party/libyuv/include/libyuv/video_common.h"
 #include "third_party/webrtc/media/base/videoframe.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
 
@@ -52,12 +52,27 @@ std::unique_ptr<webrtc::DesktopFrame> ConvertYuvToRgb(
 }  // namespace
 
 WebrtcVideoRendererAdapter::WebrtcVideoRendererAdapter(
-    scoped_refptr<webrtc::MediaStreamInterface> media_stream,
+    const std::string& label,
     VideoRenderer* video_renderer)
-    : media_stream_(std::move(media_stream)),
+    : label_(label),
       video_renderer_(video_renderer),
       task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      weak_factory_(this) {
+      weak_factory_(this) {}
+
+WebrtcVideoRendererAdapter::~WebrtcVideoRendererAdapter() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  webrtc::VideoTrackVector video_tracks = media_stream_->GetVideoTracks();
+  DCHECK(!video_tracks.empty());
+  video_tracks[0]->RemoveSink(this);
+}
+
+void WebrtcVideoRendererAdapter::SetMediaStream(
+    scoped_refptr<webrtc::MediaStreamInterface> media_stream) {
+  DCHECK_EQ(media_stream->label(), label());
+
+  media_stream_ = std::move(media_stream);

[Irfan, 2016/08/09 17:00:37]

std::move on scoped_refptr is unclear to me. What does it accomplish ?

[Sergey Ulanov, 2016/08/10 18:07:44]

It generates slightly more optimal code compared to simple assignment as the
ref-counter doesn't need to be incremented and then decremented.

+
   webrtc::VideoTrackVector video_tracks = media_stream_->GetVideoTracks();
   if (video_tracks.empty()) {
     LOG(ERROR) << "Received media stream with no video tracks.";
@@ -71,12 +86,11 @@ WebrtcVideoRendererAdapter::WebrtcVideoRendererAdapter(
   video_tracks[0]->AddOrUpdateSink(this, rtc::VideoSinkWants());
 }
 
-WebrtcVideoRendererAdapter::~WebrtcVideoRendererAdapter() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  webrtc::VideoTrackVector video_tracks = media_stream_->GetVideoTracks();
-  DCHECK(!video_tracks.empty());
-  video_tracks[0]->RemoveSink(this);
+void WebrtcVideoRendererAdapter::SetVideoStatsChannel(
+    std::unique_ptr<MessagePipe> message_pipe) {
+  // Expect that the host also creates video_stats data channel.
+  video_stats_dispatcher_.reset(new ClientVideoStatsDispatcher(label_, this));
+  video_stats_dispatcher_->Init(std::move(message_pipe), this);
 }
 
 void WebrtcVideoRendererAdapter::OnFrame(const cricket::VideoFrame& frame) {
@@ -86,24 +100,54 @@ void WebrtcVideoRendererAdapter::OnFrame(const cricket::VideoFrame& frame) {
     LOG(WARNING) << "Received frame with playout delay greater than 0.";
   }
 
-  std::unique_ptr<ClientFrameStats> stats(new ClientFrameStats());
-  // TODO(sergeyu): |time_received| is not reported correctly here because the
-  // frame is already decoded at this point.
-  stats->time_received = base::TimeTicks::Now();
-
   task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&WebrtcVideoRendererAdapter::HandleFrameOnMainThread,
-                 weak_factory_.GetWeakPtr(), base::Passed(&stats),
+                 weak_factory_.GetWeakPtr(), frame.transport_frame_id(),
+                 base::TimeTicks::Now(),
                  scoped_refptr<webrtc::VideoFrameBuffer>(
                      frame.video_frame_buffer().get())));
 }
 
+void WebrtcVideoRendererAdapter::OnVideoFrameStats(

[Irfan, 2016/08/09 17:00:37]

It is not entirely clear how the logic here in OnVideoFrameStats() works
alongside similar stats logic in FrameRendered(). Perhaps, I should walk over
and understand.

[Sergey Ulanov, 2016/08/10 18:07:44]

Added some comments to make the logic here easier to understand.

+    uint32_t frame_id,
+    const HostFrameStats& host_stats) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  while (!client_stats_queue_.empty() &&
+         client_stats_queue_.front().first != frame_id) {
+    client_stats_queue_.pop_front();
+  }
+
+  if (client_stats_queue_.empty()) {
+    host_stats_queue_.push_back(std::make_pair(frame_id, host_stats));
+    return;
+  }
+
+  // The correspond frame has been received. Report stats for it.
+  FrameStats frame_stats;
+  frame_stats.client_stats = client_stats_queue_.front().second;
+  frame_stats.host_stats = host_stats;
+  client_stats_queue_.pop_front();
+  video_renderer_->GetFrameStatsConsumer()->OnVideoFrameStats(frame_stats);
+}
+
+void WebrtcVideoRendererAdapter::OnChannelInitialized(
+    ChannelDispatcherBase* channel_dispatcher) {}
+void WebrtcVideoRendererAdapter::OnChannelClosed(
+    ChannelDispatcherBase* channel_dispatcher) {}
+
 void WebrtcVideoRendererAdapter::HandleFrameOnMainThread(
-    std::unique_ptr<ClientFrameStats> stats,
+    uint32_t frame_id,
+    base::TimeTicks time_received,
     scoped_refptr<webrtc::VideoFrameBuffer> frame) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
+  std::unique_ptr<ClientFrameStats> stats(new ClientFrameStats());
+  // TODO(sergeyu): |time_received| is not reported correctly here because the
+  // frame is already decoded at this point.
+  stats->time_received = time_received;
+
   std::unique_ptr<webrtc::DesktopFrame> rgb_frame =
       video_renderer_->GetFrameConsumer()->AllocateFrame(
           webrtc::DesktopSize(frame->width(), frame->height()));
@@ -114,10 +158,11 @@ void WebrtcVideoRendererAdapter::HandleFrameOnMainThread(
                  base::Passed(&rgb_frame),
                  video_renderer_->GetFrameConsumer()->GetPixelFormat()),
       base::Bind(&WebrtcVideoRendererAdapter::DrawFrame,
-                 weak_factory_.GetWeakPtr(), base::Passed(&stats)));
+                 weak_factory_.GetWeakPtr(), frame_id, base::Passed(&stats)));
 }
 
 void WebrtcVideoRendererAdapter::DrawFrame(
+    uint32_t frame_id,
     std::unique_ptr<ClientFrameStats> stats,
     std::unique_ptr<webrtc::DesktopFrame> frame) {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ -125,12 +170,34 @@ void WebrtcVideoRendererAdapter::DrawFrame(
   video_renderer_->GetFrameConsumer()->DrawFrame(
       std::move(frame),
       base::Bind(&WebrtcVideoRendererAdapter::FrameRendered,
-                 weak_factory_.GetWeakPtr(), base::Passed(&stats)));
+                 weak_factory_.GetWeakPtr(), frame_id, base::Passed(&stats)));
 }
 
 void WebrtcVideoRendererAdapter::FrameRendered(
-    std::unique_ptr<ClientFrameStats> stats) {
-  // TODO(sergeyu): Report stats here
+    uint32_t frame_id,
+    std::unique_ptr<ClientFrameStats> client_stats) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  client_stats->time_rendered = base::TimeTicks::Now();
+
+  while (!host_stats_queue_.empty() &&
+         host_stats_queue_.front().first != frame_id) {
+    host_stats_queue_.pop_front();
+  }
+
+  if (host_stats_queue_.empty()) {
+    // Keep the stats object when the video_stats channel is connected.
+    if (video_stats_dispatcher_ && video_stats_dispatcher_->is_connected())
+      client_stats_queue_.push_back(std::make_pair(frame_id, *client_stats));
+    return;
+  }
+
+  // We have HostFrameStats for the frame, so we can report stats for it.
+  FrameStats frame_stats;
+  frame_stats.host_stats = host_stats_queue_.front().second;
+  frame_stats.client_stats = *client_stats;
+  host_stats_queue_.pop_front();
+  video_renderer_->GetFrameStatsConsumer()->OnVideoFrameStats(frame_stats);
 }
 
 }  // namespace protocol