Re: [MMUSIC] Some more APPID questions

[Harald Alvestrand <[e-mail]>]

On 11/03/2013 11:35 PM, Roni Even wrote:
>
>> -----Original Message-----
>> From: Harald Alvestrand [mailto:[e-mail]]
>> Sent: 04 November, 2013 12:31 AM
>> To: Roni Even; 'mmusic'
>> Subject: Re: [MMUSIC] Some more APPID questions
>>
>> On 11/03/2013 10:49 PM, Roni Even wrote:
>>> Hi Harald,
>>> The current draft is still not mature enough and the presentation will
>>> have some information which is not there and some of the text in the
>>> 00 version that is not in the 01 version may come back.
>>>
>>> An SSRC can have multiple appIds example is in a three camera system
>>> one appID for active speaker which is now the left camera having a
>>> different appID
>>>
>>> The uniqueness of appID should be per media packet stream.
>>>
>> so if you have
>>
>> ssrc A: appid 45
>> ssrc B: appid 27
>>
>> this means exactly the same thing as
>>
>> ssrc A: appid 45
>> ssrc B: appid 45
>>
>> ?
>>
>> This seems to create issues when you have a single appid that is moving
> around
>> between SSRCs.
> [Roni Even] The mapping from AppID to SSRC should be in SDES or RTP header
> extension, example is appID 45 that can be first SSRC A and then SSRC B if
> appId represent the active speaker. 
>

But if uniqueness of appids is per SSRC, then SSRC B might already be
using appid 45 for something else.

If we're using an appid for some property that can jump around between
SSRCs, the uniqueness of that appid must be guaranteed over the whole
context it's jumping around inside, I think. I'm worried if I can't
figure out what that context is.

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