Revert of Use RtxReceiveStream.

webrtc/video/rtp_video_stream_receiver.cc

Index: webrtc/video/rtp_video_stream_receiver.cc
diff --git a/webrtc/video/rtp_video_stream_receiver.cc b/webrtc/video/rtp_video_stream_receiver.cc
index a14b06504bb6d7d37b8964e646b251b5e033289d..4678b8f0afff36cea95279d27b21812cb3f8a5eb 100644
--- a/webrtc/video/rtp_video_stream_receiver.cc
+++ b/webrtc/video/rtp_video_stream_receiver.cc
@@ -105,6 +105,7 @@
       rtp_receive_statistics_(ReceiveStatistics::Create(clock_)),
       ulpfec_receiver_(UlpfecReceiver::Create(config->rtp.remote_ssrc, this)),
       receiving_(false),
+      restored_packet_in_use_(false),
       last_packet_log_ms_(-1),
       rtp_rtcp_(CreateRtpRtcpModule(rtp_receive_statistics_.get(),
                                     transport,
@@ -145,8 +146,12 @@
   rtp_receive_statistics_->SetMaxReorderingThreshold(max_reordering_threshold);
 
   if (config_.rtp.rtx_ssrc) {
-    // Needed for rtp_payload_registry_.RtxEnabled().
     rtp_payload_registry_.SetRtxSsrc(config_.rtp.rtx_ssrc);
+
+    for (const auto& kv : config_.rtp.rtx_associated_payload_types) {
+      RTC_DCHECK_NE(kv.first, 0);
+      rtp_payload_registry_.SetRtxPayloadType(kv.first, kv.second);
+    }
   }
 
   if (IsUlpfecEnabled()) {
@@ -163,6 +168,11 @@
     strncpy(red_codec.plName, "red", sizeof(red_codec.plName));
     red_codec.plType = config_.rtp.ulpfec.red_payload_type;
     RTC_CHECK(AddReceiveCodec(red_codec));
+    if (config_.rtp.ulpfec.red_rtx_payload_type != -1) {
+      rtp_payload_registry_.SetRtxPayloadType(
+          config_.rtp.ulpfec.red_rtx_payload_type,
+          config_.rtp.ulpfec.red_payload_type);
+    }
   }
 
   if (config_.rtp.rtcp_xr.receiver_reference_time_report)
@@ -485,7 +495,31 @@
     }
     ulpfec_receiver_->ProcessReceivedFec();
   } else if (rtp_payload_registry_.IsRtx(header)) {
-    LOG(LS_WARNING) << "Unexpected RTX packet on media ssrc";
+    if (header.headerLength + header.paddingLength == packet_length) {
+      // This is an empty packet and should be silently dropped before trying to
+      // parse the RTX header.
+      return;
+    }
+    // Remove the RTX header and parse the original RTP header.
+    if (packet_length < header.headerLength)
+      return;
+    if (packet_length > sizeof(restored_packet_))
+      return;
+    if (restored_packet_in_use_) {
+      LOG(LS_WARNING) << "Multiple RTX headers detected, dropping packet.";
+      return;
+    }
+    if (!rtp_payload_registry_.RestoreOriginalPacket(
+            restored_packet_, packet, &packet_length, config_.rtp.remote_ssrc,
+            header)) {
+      LOG(LS_WARNING) << "Incoming RTX packet: Invalid RTP header ssrc: "
+                      << header.ssrc << " payload type: "
+                      << static_cast<int>(header.payloadType);
+      return;
+    }
+    restored_packet_in_use_ = true;
+    OnRecoveredPacket(restored_packet_, packet_length);
+    restored_packet_in_use_ = false;
   }
 }