Reland of Make RTX pt/apt reconfigurable by calling WebRtcVideoChannel2::SetRecvParameters.

webrtc/video_receive_stream.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 99 matching lines @@
 
     // Decoders for every payload that we can receive.
     std::vector<Decoder> decoders;
 
     // Receive-stream specific RTP settings.
     struct Rtp {
       std::string ToString() const;
 
       // Synchronization source (stream identifier) to be received.
       uint32_t remote_ssrc = 0;
+
       // Sender SSRC used for sending RTCP (such as receiver reports).
       uint32_t local_ssrc = 0;
 
       // See RtcpMode for description.
       RtcpMode rtcp_mode = RtcpMode::kCompound;
 
       // Extended RTCP settings.
       struct RtcpXr {
         // True if RTCP Receiver Reference Time Report Block extension
         // (RFC 3611) should be enabled.
         bool receiver_reference_time_report = false;
       } rtcp_xr;
 
       // See draft-alvestrand-rmcat-remb for information.
       bool remb = false;
 
       // See draft-holmer-rmcat-transport-wide-cc-extensions for details.
       bool transport_cc = false;
 
       // See NackConfig for description.
       NackConfig nack;
 
       // See UlpfecConfig for description.
       UlpfecConfig ulpfec;
 
-      // RTX settings for incoming video payloads that may be received. RTX is
-      // disabled if there's no config present.
-      struct Rtx {
-        // SSRCs to use for the RTX streams.
-        uint32_t ssrc = 0;
+      // SSRC for retransmissions.
+      uint32_t rtx_ssrc = 0;
 
-        // Payload type to use for the RTX stream.
-        int payload_type = 0;
-      };
-
-      // Map from video RTP payload type -> RTX config.
-      typedef std::map<int, Rtx> RtxMap;
-      RtxMap rtx;
+      // Map from video payload type (apt) -> RTX payload type (pt).
+      // For RTX to be enabled, both an SSRC and this mapping are needed.
+      std::map<int, int> rtx_payload_types;
 
       // TODO(brandtr): Remove this member function when internal project has
       // been updated.
-      void AddRtxInfo(int media_pt, int rtx_pt, uint32_t rtx_ssrc) {
-        Rtx r;
-        r.ssrc = rtx_ssrc;
-        r.payload_type = rtx_pt;
-        rtx[media_pt] = r;
+      void AddRtxInfo(int media_pt, int rtx_pt, uint32_t new_rtx_ssrc) {
+        rtx_ssrc = new_rtx_ssrc;
+        rtx_payload_types[media_pt] = rtx_pt;
       }
 
       // RTP header extensions used for the received stream.
       std::vector<RtpExtension> extensions;
     } rtp;
 
     // Transport for outgoing packets (RTCP).
     Transport* rtcp_send_transport = nullptr;
 
     // Must not be 'nullptr' when the stream is started.
@@ skipping 52 matching lines @@
     EnableEncodedFrameRecording(rtc::kInvalidPlatformFileValue, 0);
   }
 
  protected:
   virtual ~VideoReceiveStream() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_RECEIVE_STREAM_H_