On Tue, 2006-11-14 at 02:10 -0800, Steve Langstaff wrote: > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > Peter Howard > > Sent: 14 November 2006 00:38 > > To: Asterisk Users Mailing List - Non-Commercial Discussion > > Subject: Problem found Re: [asterisk-users] Headaches with > > Video over SIP > > > Found the problem. Some other people on the list might be > > interested in the problem. > > > > Looking at the initial INVITE call from station 1 to asterisk > > and from asterisk to station 2, you see the following discrepancy: > > > > >From Polycom to asterisk: > > a=rtpmap:109 H264/90000 > > a=rtpmap:96 H263-1998/90000 > > > > >From asterisk to other Polycom: > > a=rtpmap:103 h263-1998/90000 > > a=rtpmap:99 H264/90000 > > > > The latter numbers match the numbers in rtp.c, which clearly > > don't agree with the Polycom's opinion on life. However the > > other Polycom seems to accept asterisk's version, while the > > first Polycom is still working on it's version. > > > > I modified the initialisation of static_RTP_PT in rtp.c to > > match the Polycom values and, hey presto! I have video > > working between the two stations. > > > > However, this doesn't look like a "proper" solution, if there > > are multiple opinions out there of what h263p and h264 (at > > least) should be mapped to. There's also the array > > current_RTP_PT in rtp.c What is that used for? I would have > > thought that either: > > 1) Asterisk should tell _both_ ends what mapping to use, > > 2) Asterisk should update it's own mapping based on what it's > > told (though this would have to be on a call-by-call basis) > > #2 is true (at least for audio, so I guess for video as well). >
Or should be. > Codec identifiers >= 96 refer to dynamic payload types. > Thanks, that's worth knowing. > They have to be negotiated on each SDP offer/answer exchange. > > So for the Polycom->Asterisk traffic, Asterisk should parse the SDP and > say to itself "Hey, the caller wants me to send it H264 marked with > payload type 109, and/or H263-1998 marked with payload type 96." and > adapt it's outgoing payload type marking accordingly. > "should parse the SDP". It's not at 1.4.0-beta3 (or, seemingly, earlier versions). Should I submit a bug report for this? -- Peter Howard URSYS 13 Burwood Rd, Burwood, NSW 2134 Ph: 02 8745 2816 Fax: 02 8745 2828 _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users