[ortc] Section 8.3: Match Rules Issue

aboba has just created a new issue for 
https://github.com/openpeer/ortc:

== Section 8.3:  Match Rules Issue ==
In the SDP below (from Chrome Canary M51), we would need to set:

encodings[].fec.ssrc = 3254585230; 
encodings[].fec.mechanism = "red+ulpfec";  
encodings[].rtx.ssrc = 3254585230; 

The problem is that in Section 8.3 there is a statement that: 
If ssrc_table[ssrc] is already set to a value other than receiver, 
then receiver.receive() will throw an InvalidParameters exception.

Therefore the third statement above (setting the SSRC for rtx)  will 
generate an exception.  However, the SDP is ok because one can 
distinguish the RTX via the PT field. 

Inaki said: 

"How is ORTC supposed to map this?:

a=rtpmap:100 VP8/90000
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=rtcp-fb:100 goog-remb
a=rtcp-fb:100 transport-cc
a=rtpmap:101 VP9/90000
a=rtcp-fb:101 ccm fir
a=rtcp-fb:101 nack
a=rtcp-fb:101 nack pli
a=rtcp-fb:101 goog-remb
a=rtcp-fb:101 transport-cc
a=rtpmap:116 red/90000
a=rtpmap:117 ulpfec/90000
a=rtpmap:96 rtx/90000
a=fmtp:96 apt=100
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=101
a=rtpmap:98 rtx/90000
a=fmtp:98 apt=116
a=ssrc-group:FID 2224031971 3254585230
a=ssrc:2224031971 cname:oC/i06PA+Lda+t1P
a=ssrc:3254585230 cname:oC/i06PA+Lda+t1P"

Please view or discuss this issue at 
https://github.com/openpeer/ortc/issues/408 using your GitHub account

Received on Wednesday, 9 March 2016 19:46:11 UTC