Negotiate H264 profiles in SDP

webrtc/media/base/codec.cc

Index: webrtc/media/base/codec.cc
diff --git a/webrtc/media/base/codec.cc b/webrtc/media/base/codec.cc
index 66bc9ff7d9d0a44f5129707c2cea06172cfe79f8..de1288fbbe34357e843dde81520571cf68632eb2 100644
--- a/webrtc/media/base/codec.cc
+++ b/webrtc/media/base/codec.cc
@@ -17,6 +17,7 @@
 #include "webrtc/base/logging.h"
 #include "webrtc/base/stringencode.h"
 #include "webrtc/base/stringutils.h"
+#include "webrtc/common_video/h264/profile_level_id.h"
 
 namespace cricket {
 
@@ -218,6 +219,20 @@ bool VideoCodec::operator==(const VideoCodec& c) const {
   return Codec::operator==(c);
 }
 
+bool VideoCodec::Matches(const VideoCodec& other) const {
+  if (!Codec::Matches(other))
+    return false;
+  if (!CodecNamesEq(name.c_str(), kH264CodecName))
+    return true;
+  const rtc::Optional<webrtc::H264::ProfileLevelId> profile_level_id =
+      webrtc::H264::ParseSdpProfileLevelId(params);
+  const rtc::Optional<webrtc::H264::ProfileLevelId> other_profile_level_id =
+      webrtc::H264::ParseSdpProfileLevelId(other.params);
+  // Compare H264 profiles, but not levels.
+  return profile_level_id && other_profile_level_id &&
+         profile_level_id->profile == other_profile_level_id->profile;

[hta-webrtc, 2016/11/08 13:59:53]

See comment about matching. This says whether they are the same, not whether an
encoder for one can be decoded by the other.

[magjed_webrtc, 2016/11/08 16:18:26]

Yes, this function compares whether the codecs are the same (and distinguishes
different H264 profiles). It's not supposed to be used to determine whether an
encoder for one can be decoded by the other. I have updated the function comment
to better reflect this. Since we need to send different H264 profiles as
different payload types, this is the natural extension of the current Matches
function that only compares codec names.

+}
+
 VideoCodec VideoCodec::CreateRtxCodec(int rtx_payload_type,
                                       int associated_payload_type) {
   VideoCodec rtx_codec(rtx_payload_type, kRtxCodecName);
@@ -321,7 +336,7 @@ bool IsCodecSupported(const std::vector<VideoCodec>& supported_codecs,
                       const VideoCodec& codec) {
   return std::any_of(supported_codecs.begin(), supported_codecs.end(),
                      [&codec](const VideoCodec& supported_codec) -> bool {
-                       return CodecNamesEq(codec.name, supported_codec.name);
+                       return codec.Matches(supported_codec);
                      });
 }