Re: [MMUSIC] BUNDLE TEXT: De-mux procedures (June 19th)

[Christer Holmberg <[e-mail]>]

Hi,

>> Christer said: 
>>
>> Don't you mean the configuration of two codecs? For example, if I have 2 m= lines, with exactly the same H.264 configuration in each, 
>> could I use the same PT value in both m= lines? But, if I have different codec configurations in each m= line, I CANNOT use the same PT value for both?
>>
>> ...assuming, of course, that there is some other mechanism to find the right m= line, IF needed.
> 
> If you have different codec configuration (the stuff like a=fmtp that is indexed by PT), I think you MUST use different PTs.
>
> [BA] This advice is consistent with examples from RFC 6190 and other documents. For example, RFC 6190 shows different PTs used for an offer including support for both H.264/AVC and H.264/SVC.  
>
> However, we need to be a bit careful about how we phrase the requirement, exactly.  I do not consider simulcast and layered streams to represent 
> a "different codec configuration" which would require a different PT for each stream (or even a different SSRC).

My hope is that we, in BUNDLE, don't need to specify how endpoints assign their PT values. 

Of course, if there is some mechanism which requires usage of the same PT value in multiple m= lines, we probably need to say something about that in BUNDLE.

Regards,

Christer