Negotiate H264 profiles in SDP

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 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 385 matching lines @@
 // don't recognize?
 void AddCodecAndMaybeRtxCodec(const VideoCodec& codec,
                               std::vector<VideoCodec>* codecs) {
   codecs->push_back(codec);
   int rtx_payload_type = 0;
   if (CodecNamesEq(codec.name, kVp8CodecName)) {
     rtx_payload_type = kDefaultRtxVp8PlType;
   } else if (CodecNamesEq(codec.name, kVp9CodecName)) {
     rtx_payload_type = kDefaultRtxVp9PlType;
   } else if (CodecNamesEq(codec.name, kH264CodecName)) {
+    // TODO(magjed): Using a hardcoded payload type for RTX H264 does not work
+    // when we have more than one profile. For example, when having both
+    // Constrained Baseline Profile and Constrained High Profile, both
+    // corresponding RTX codecs will end up with the same payload type, causing
+    // failure later on.
     rtx_payload_type = kDefaultRtxH264PlType;
   } else if (CodecNamesEq(codec.name, kRedCodecName)) {
     rtx_payload_type = kDefaultRtxRedPlType;
   } else {
     return;
   }
   codecs->push_back(VideoCodec::CreateRtxCodec(rtx_payload_type, codec.id));
 }
 
 std::vector<VideoCodec> DefaultVideoCodecList() {
@@ skipping 2152 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             ulpfec_config.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket