From b4ab381ce372f065b003cac925d10b34d978da71 Mon Sep 17 00:00:00 2001
From: stefan <stefan@webrtc.org>
Date: Fri, 9 Jun 2017 06:12:11 -0700
Subject: [PATCH] Use the configured remote ssrc instead of relying on the
 first received packet RtpStreamReceiver.

This solves an issue where if the first packet happens to be an RTX packet, it is recovered with an incorrect SSRC.

BUG=webrtc:5654

Review-Url: https://codereview.webrtc.org/2928123002
Cr-Commit-Position: refs/heads/master@{#18512}
---
 webrtc/video/rtp_video_stream_receiver.cc | 11 ++++-------
 webrtc/video/rtp_video_stream_receiver.h  |  2 +-
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/webrtc/video/rtp_video_stream_receiver.cc b/webrtc/video/rtp_video_stream_receiver.cc
index 0a946975d7..14e5958c0b 100644
--- a/webrtc/video/rtp_video_stream_receiver.cc
+++ b/webrtc/video/rtp_video_stream_receiver.cc
@@ -127,6 +127,7 @@ RtpVideoStreamReceiver::RtpVideoStreamReceiver(
 
   rtp_rtcp_->SetRTCPStatus(config_.rtp.rtcp_mode);
   rtp_rtcp_->SetSSRC(config_.rtp.local_ssrc);
+  rtp_rtcp_->SetRemoteSSRC(config_.rtp.remote_ssrc);
   rtp_rtcp_->SetKeyFrameRequestMethod(kKeyFrameReqPliRtcp);
 
   for (size_t i = 0; i < config_.rtp.extensions.size(); ++i) {
@@ -217,7 +218,7 @@ bool RtpVideoStreamReceiver::AddReceiveCodec(const VideoCodec& video_codec) {
 }
 
 uint32_t RtpVideoStreamReceiver::GetRemoteSsrc() const {
-  return rtp_receiver_->SSRC();
+  return config_.rtp.remote_ssrc;
 }
 
 int RtpVideoStreamReceiver::GetCsrcs(uint32_t* csrcs) const {
@@ -302,10 +303,6 @@ int32_t RtpVideoStreamReceiver::OnInitializeDecoder(
   return 0;
 }
 
-void RtpVideoStreamReceiver::OnIncomingSSRCChanged(const uint32_t ssrc) {
-  rtp_rtcp_->SetRemoteSSRC(ssrc);
-}
-
 // This method handles both regular RTP packets and packets recovered
 // via FlexFEC.
 void RtpVideoStreamReceiver::OnRtpPacket(const RtpPacketReceived& packet) {
@@ -481,7 +478,7 @@ void RtpVideoStreamReceiver::ParseAndHandleEncapsulatingHeader(
       return;
     }
     if (!rtp_payload_registry_.RestoreOriginalPacket(
-            restored_packet_, packet, &packet_length, rtp_receiver_->SSRC(),
+            restored_packet_, packet, &packet_length, config_.rtp.remote_ssrc,
             header)) {
       LOG(LS_WARNING) << "Incoming RTX packet: Invalid RTP header ssrc: "
                       << header.ssrc << " payload type: "
@@ -623,7 +620,7 @@ bool RtpVideoStreamReceiver::IsPacketRetransmitted(const RTPHeader& header,
     return false;
   // Check if this is a retransmission.
   int64_t min_rtt = 0;
-  rtp_rtcp_->RTT(rtp_receiver_->SSRC(), nullptr, nullptr, &min_rtt, nullptr);
+  rtp_rtcp_->RTT(config_.rtp.remote_ssrc, nullptr, nullptr, &min_rtt, nullptr);
   return !in_order &&
       statistician->IsRetransmitOfOldPacket(header, min_rtt);
 }
diff --git a/webrtc/video/rtp_video_stream_receiver.h b/webrtc/video/rtp_video_stream_receiver.h
index e298803c3f..736f513697 100644
--- a/webrtc/video/rtp_video_stream_receiver.h
+++ b/webrtc/video/rtp_video_stream_receiver.h
@@ -112,7 +112,7 @@ class RtpVideoStreamReceiver : public RtpData,
                               int frequency,
                               size_t channels,
                               uint32_t rate) override;
-  void OnIncomingSSRCChanged(uint32_t ssrc) override;
+  void OnIncomingSSRCChanged(uint32_t ssrc) override {}
   void OnIncomingCSRCChanged(uint32_t CSRC, bool added) override {}
 
   // Implements VCMFrameTypeCallback.