Enable passing receive stream ID to the decoder factory.

webrtc/api/rtpparameters.h

 /*
  *  Copyright 2015 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 29 matching lines @@
   bool operator==(const RtpCodecParameters& o) const {
     return payload_type == o.payload_type && mime_type == o.mime_type &&
            clock_rate == o.clock_rate && channels == o.channels;
   }
   bool operator!=(const RtpCodecParameters& o) const { return !(*this == o); }
 };
 
 struct RtpParameters {
   std::vector<RtpEncodingParameters> encodings;
   std::vector<RtpCodecParameters> codecs;
+  std::vector<uint32_t> ssrcs;

[pthatcher1, 2016/06/15 19:40:00]

This should match the standard here:

http://w3c.github.io/webrtc-pc/#idl-def-rtcrtpencodingparameters

Which means that RtpEncodingParameters should have one ssrc.  And RtpParameters
should have any SSRCs, only through the RtpEncodingParameters.

[perkj_webrtc, 2016/06/15 20:25:52]

Why is this needed?

[pthatcher1, 2016/06/15 21:08:17]

It's part of the standard.  If you want an explanation of why it's in the
standard, well, that will take a long time :).  Mostly it's useful for apps to
know, and in a later version of WebRTC/ORTC, to set.

 
   bool operator==(const RtpParameters& o) const {
-    return encodings == o.encodings && codecs == o.codecs;
+    return encodings == o.encodings && codecs == o.codecs && ssrcs == o.ssrcs;
   }
   bool operator!=(const RtpParameters& o) const { return !(*this == o); }
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_RTPPARAMETERS_H_