Re: [MMUSIC] Possible BUNDLE alternative syntax: explicit m-line for bundled session

On Aug 9, 2012, at 9:57 , Bernard Aboba wrote:

> 
> Harald said: 
> > Bernard, since I'm so easily confused by how people transmit layers of 
> > layered codecs, can you illustrate the particular scheme you want to 
> > use, and can't think of how to represent in Jonathan's scheme?
> 
> [BA]  I am looking at RFC 5583 "Signaling Media Decoding Dependency in SDP". An
> example of how this would be used with H.264/SVC is included in RFC 6190, Section 7.3.4:
> 
>       a=group:DDP L1 L2
>       m=video 20000 RTP/AVP 96
>       a=rtpmap:96 H264/90000
>       a=fmtp:96 profile-level-id=4de00a; packetization-mode=0;mst-mode=NI-T;
>       a=mid:L1
>       m=video 20002 RTP/AVP 97
>       a=rtpmap:97 H264-SVC/90000
>       a=fmtp:97 profile-level-id=53001F; packetization-mode=1;
>        mst-mode=NI-TC; sprop-operation-point-info=<2,0,1,0,53000c,
>       3200,352,288,384,512>,<3,1,2,0,53001F,6400,704,576,768,1024>;
>       a=mid:L2
>       a=depend:97 lay L1:96
> 
> 
> Here the a=depend line is expressing the decoding dependency (layered in this case). 
> 
> Let us assume that there is also audio, as in Jonathan's example:
> 
>        m=audio 10000 RTP/AVP 0 8 97
>        a=mid:foo
>        b=AS:200
>        a=rtpmap:0 PCMU/8000
>        a=rtpmap:8 PCMA/8000
>        a=rtpmap:97 iLBC/8000
> 
> 
> Does the entire SDP offer with BUNDLE and dependency grouping  look like this (ignoring RTP/RTCP mux for the moment)? 
> 
>        v=0
>        o=alice 2890844526 2890844526 IN IP4 
> host.atlanta.com
> 
>        s=
>        c=IN IP4 
> host.atlanta.com
> 
>        t=0 0
>        a=group:BUNDLE foo L1 L2 baz
> 
>        a=group:DDP L1 L2
>        m=audio 10000 RTP/AVP 0 8 98
>        a=mid:foo
>        b=AS:200
>        a=rtpmap:0 PCMU/8000
>        a=rtpmap:8 PCMA/8000
>        a=rtpmap:98 iLBC/8000
>        a=candidate:1 1 UDP 1694498815 
> host.atlanta.com
>  10000 typ host
>        m=video 20000 RTP/AVP 96
>        a=rtpmap:96 H264/90000
>        a=fmtp:96 profile-level-id=4de00a; packetization-mode=0;mst-mode=NI-T;
>        a=mid:L1
>        m=video 20002 RTP/AVP 97
>        a=rtpmap:97 H264-SVC/90000
>        a=fmtp:97 profile-level-id=53001F; packetization-mode=1;
>        mst-mode=NI-TC; sprop-operation-point-info=<2,0,1,0,53000c,
>       3200,352,288,384,512>,<3,1,2,0,53001F,6400,704,576,768,1024>;
>        a=mid:L2
>        a=depend:97 lay L1:96
>        a=candidate:1 1 UDP 1694498815 
> host.atlanta.com
>  20002 typ host
>        m=bundle 10000 RTP/AVP 0 8 96 97 98
>        a=mid:baz
>        b=AS:1200
>        a=full-rtpmap:0 audio/PCMU/8000
>        a=full-rtpmap:8 audio/PCMA/8000
>        a=full-rtpmap:98 audio/iLBC/8000
>        a=full-rtpmap:96 H264/90000
>        a=full-rtpmap:97 H264-SVC/90000
>        a=depend:97 lay L1:96
>        a=candidate:1 1 UDP 1694498815 
> host.atlanta.com
>  10000 typ host
> 
> 
>  

I think it will work better if it just looked like 

       v=0
       o=alice 2890844526 2890844526 IN IP4 host.atlanta.com
       s=
       c=IN IP4 host.atlanta.com

       t=0 0
       a=group:BUNDLE foo L1 L2 baz

       a=group:DDP L1 L2
       m=audio 10000 RTP/AVP 0 8 98
       a=mid:foo
       b=AS:200
       a=rtpmap:0 PCMU/8000
       a=rtpmap:8 PCMA/8000
       a=rtpmap:98 iLBC/8000
       a=candidate:1 1 UDP 1694498815 host.atlanta.com 10000 typ host
       m=video 20000 RTP/AVP 96
       a=rtpmap:96 H264/90000
       a=fmtp:96 profile-level-id=4de00a; packetization-mode=0;mst-mode=NI-T;
       a=mid:L1
       m=video 20002 RTP/AVP 97
       a=rtpmap:97 H264-SVC/90000
       a=fmtp:97 profile-level-id=53001F; packetization-mode=1;
       mst-mode=NI-TC; sprop-operation-point-info=<2,0,1,0,53000c,
      3200,352,288,384,512>,<3,1,2,0,53001F,6400,704,576,768,1024>;
       a=mid:L2
       a=depend:97 lay L1:96
       a=candidate:1 1 UDP 1694498815 host.atlanta.com 20002 typ host

that seems to have all the same information as the version with m=bundle thing and AFAIC some firewalls are going to remove all the stuff under the m=bundle line as it is not a recognized media type. 

> 
> 
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