webrtcbin: make more robust and allow SDP without mid and direction attributes
Submitted by Daniel F
I was trying to establish WebRTC session between GStreamer and FreeSwitch (1.6.20~64bit). It turned out that FreeSwitch does not include mid and direction attributes in its SDP. GStreamer was trying to strictly follow JSEP standard, and was rejecting that SDP. Please make it more robust and start accepting such incorrect SDPs.
When direction attribute is missing, you can revert to RFC 4566 behaviour:
"If none of the attributes "sendonly", "recvonly", "inactive",
and "sendrecv" is present, "sendrecv" SHOULD be assumed as the
default for sessions that are not of the conference type
"broadcast" or "H332" (see below)."
SDP without a=mid can be accepted when RTP bundling is not needed (e.g. when there is only one stream).