Re: [MMUSIC] POF/PAN: SDP group attribute in a POF/PAN?

[Adam Roach <[e-mail]>]

On 10/21/13 17:38, Suhas Nandakumar wrote:
>
>
>
> On Mon, Oct 21, 2013 at 3:29 PM, Paul Kyzivat <[e-mail] 
> <mailto:[e-mail]>> wrote:
>
>     On 10/21/13 5:53 PM, John Leslie wrote:
>
>         Paul Kyzivat <[e-mail]
>         <mailto:[e-mail]>> wrote:
>
>
>             There remains the problem of indicating *which* (if any)
>             group a newly
>             added m-line joins.
>
>
>             Not only don't I see an _answer_ to this -- I don't even
>         think we have
>         a common understanding of the _question_.
>
>             :^(
>
>
>     Here is an example:
>
>     a=group:bundle A B
>     a=group:bundle C D
>     m=audio ...
>     a=mid:A
>     m=audio ...
>     a=mid:B
>     m=video ...
>     m=mid:C
>     m=video ...
>     a=mid:D
>
>     Then we do a POF
>
>     m=video ...
>     a=mid:E
>
>     We want to add this to the 2nd bundle. How do we say that?
>     I'm suggesting:
>
>     m=video ...
>     a=mid:E
>     a=groupref:bundle C
>
>     The only a=group that matches that is the second one, so this
>     implicitly updates that one to:
>
>     a=group:bundle C D E
>
>     Make sense? Its all a hack of course. But everything that is done
>     to SDP is a hack.
>
>
> I think even this case can break if you use FEC based grouping mechanism
>
> a=group:FEC-XR a b c
> a=group:FEC-XR a d
>
> now if we want to add the new "mid e" to the list where i have mid a 
> listed , we end up at the same point.
>
> How about  we can extend groupref to include the entire group line as 
> below
> m=video ...
> a=mid:E
> a=groupref:FEC-XR a d
>
> ==> this would end up as
> a=group:FEC-XR a b c
> a=group:FEC-XR a d e   // new one added to the right line
>
>

This is giving me a strong sense of deja vu.

http://www.ietf.org/mail-archive/web/mmusic/current/msg12427.html

/a