Base A/V synchronization on sync_labels.

webrtc/video/video_receive_stream.cc

Index: webrtc/video/video_receive_stream.cc
diff --git a/webrtc/video/video_receive_stream.cc b/webrtc/video/video_receive_stream.cc
index 91a37076f320cf4dab9858851d788b464d6d6738..b00c269e4c8f38729e0306486c95e3ee56482476 100644
--- a/webrtc/video/video_receive_stream.cc
+++ b/webrtc/video/video_receive_stream.cc
@@ -47,7 +47,8 @@ std::string VideoReceiveStream::Config::ToString() const {
   ss << ", rtp: " << rtp.ToString();
   ss << ", renderer: " << (renderer != nullptr ? "(renderer)" : "nullptr");
   ss << ", render_delay_ms: " << render_delay_ms;
-  ss << ", audio_channel_id: " << audio_channel_id;
+  if (!sync_group.empty())
+    ss << ", sync_group: " << sync_group;
   ss << ", pre_decode_callback: "
      << (pre_decode_callback != nullptr ? "(EncodedFrameObserver)" : "nullptr");
   ss << ", pre_render_callback: "
@@ -241,17 +242,13 @@ VideoReceiveStream::VideoReceiveStream(int num_cpu_cores,
   incoming_video_stream_->SetExternalCallback(this);
   vie_channel_->SetIncomingVideoStream(incoming_video_stream_.get());
 
-  if (voice_engine && config_.audio_channel_id != -1) {
-    voe_sync_interface_ = VoEVideoSync::GetInterface(voice_engine);
-    vie_channel_->SetVoiceChannel(config.audio_channel_id, voe_sync_interface_);
-  }
-
   if (config.pre_decode_callback)
     vie_channel_->RegisterPreDecodeImageCallback(&encoded_frame_proxy_);
   vie_channel_->RegisterPreRenderCallback(this);
 }
 
 VideoReceiveStream::~VideoReceiveStream() {
+  DCHECK(voe_sync_interface_ == nullptr);
   incoming_video_stream_->Stop();
   vie_channel_->RegisterPreRenderCallback(nullptr);
   vie_channel_->RegisterPreDecodeImageCallback(nullptr);
@@ -259,10 +256,6 @@ VideoReceiveStream::~VideoReceiveStream() {
   for (size_t i = 0; i < config_.decoders.size(); ++i)
     vie_channel_->DeRegisterExternalDecoder(config_.decoders[i].payload_type);
 
-  if (voe_sync_interface_ != nullptr) {
-    vie_channel_->SetVoiceChannel(-1, nullptr);
-    voe_sync_interface_->Release();
-  }
   vie_channel_->RegisterCodecObserver(nullptr);
   vie_channel_->RegisterReceiveChannelRtpStatisticsCallback(nullptr);
   vie_channel_->RegisterReceiveChannelRtcpStatisticsCallback(nullptr);
@@ -282,6 +275,19 @@ void VideoReceiveStream::Stop() {
   transport_adapter_.Disable();
 }
 
+void VideoReceiveStream::SetSyncChannel(VoiceEngine* voice_engine,
+                                        int audio_channel_id) {
+  DCHECK(voice_engine != nullptr);
+  if (audio_channel_id != -1) {
+    voe_sync_interface_ = VoEVideoSync::GetInterface(voice_engine);
+    vie_channel_->SetVoiceChannel(audio_channel_id, voe_sync_interface_);
+  } else {
+    vie_channel_->SetVoiceChannel(-1, nullptr);
+    voe_sync_interface_->Release();
+    voe_sync_interface_ = nullptr;
+  }
+}
+
 VideoReceiveStream::Stats VideoReceiveStream::GetStats() const {
   return stats_proxy_->GetStats();
 }