Enable passing receive stream ID to the decoder factory.

webrtc/media/engine/webrtcvideoengine2.cc

Index: webrtc/media/engine/webrtcvideoengine2.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2.cc b/webrtc/media/engine/webrtcvideoengine2.cc
index 82d32b0e1865dff74586b16030a8731a6634a5ec..79328f354b69c8f673f573fe154a46bf5a5b701c 100644
--- a/webrtc/media/engine/webrtcvideoengine2.cc
+++ b/webrtc/media/engine/webrtcvideoengine2.cc
@@ -919,6 +919,7 @@ webrtc::RtpParameters WebRtcVideoChannel2::GetRtpReceiveParameters(
   for (const VideoCodec& codec : recv_params_.codecs) {
     rtp_params.codecs.push_back(codec.ToCodecParameters());
   }
+  rtp_params.encodings[0].ssrc = it->second->GetPrimarySsrc();
   return rtp_params;
 }
 
@@ -2206,8 +2207,7 @@ WebRtcVideoChannel2::WebRtcVideoReceiveStream::WebRtcVideoReceiveStream(
     const std::vector<VideoCodecSettings>& recv_codecs,
     bool red_disabled_by_remote_side)
     : call_(call),
-      ssrcs_(sp.ssrcs),
-      ssrc_groups_(sp.ssrc_groups),
+      stream_params_(sp),

[sakal, 2016/06/16 09:33:59]

Since we are storing so many variables from StreamParams, might as well store
the whole structure? This also give us access to the GetPrimarySsrcs method.

       stream_(NULL),
       default_stream_(default_stream),
       config_(std::move(config)),
@@ -2247,7 +2247,19 @@ WebRtcVideoChannel2::WebRtcVideoReceiveStream::~WebRtcVideoReceiveStream() {
 
 const std::vector<uint32_t>&
 WebRtcVideoChannel2::WebRtcVideoReceiveStream::GetSsrcs() const {
-  return ssrcs_;
+  return stream_params_.ssrcs;
+}
+
+uint32_t WebRtcVideoChannel2::WebRtcVideoReceiveStream::GetPrimarySsrc() const {
+  std::vector<uint32_t> primary_ssrcs_;

[perkj_webrtc, 2016/06/16 13:28:28]

nit: This is a local variable and should be named primary_ssrcs

[sakal, 2016/06/16 14:29:07]

Done.

+  stream_params_.GetPrimarySsrcs(&primary_ssrcs_);
+
+  if (primary_ssrcs_.empty()) {
+    LOG(LS_WARNING) << "Empty primary ssrcs vector, returning 0";
+    return 0;

[sakal, 2016/06/16 09:33:59]

I am not sure if this should ever happen.

+  } else {
+    return primary_ssrcs_[0];

[sakal, 2016/06/16 09:33:59]

I am not sure if receiving side ever has multiple primary SSRCs.

+  }
 }
 
 WebRtcVideoChannel2::WebRtcVideoReceiveStream::AllocatedDecoder
@@ -2267,7 +2279,8 @@ WebRtcVideoChannel2::WebRtcVideoReceiveStream::CreateOrReuseVideoDecoder(
 
   if (external_decoder_factory_ != NULL) {
     webrtc::VideoDecoder* decoder =
-        external_decoder_factory_->CreateVideoDecoder(type);
+        external_decoder_factory_->CreateVideoDecoderWithParams(type,
+            { stream_params_.id });
     if (decoder != NULL) {
       return AllocatedDecoder(decoder, type, true);
     }
@@ -2461,7 +2474,7 @@ WebRtcVideoChannel2::WebRtcVideoReceiveStream::GetCodecNameFromPayloadType(
 VideoReceiverInfo
 WebRtcVideoChannel2::WebRtcVideoReceiveStream::GetVideoReceiverInfo() {
   VideoReceiverInfo info;
-  info.ssrc_groups = ssrc_groups_;
+  info.ssrc_groups = stream_params_.ssrc_groups;
   info.add_ssrc(config_.rtp.remote_ssrc);
   webrtc::VideoReceiveStream::Stats stats = stream_->GetStats();
   info.decoder_implementation_name = stats.decoder_implementation_name;