Subject: RE: [AVT] Update (-09) of Timed Tex draft (WAS: RE: Comments ondraft-ietf-avt-rtp-3gpp-timed-text-08.txt)

From: "Rey Jose" <[email-masked]>
Date: Wed, 9 Feb 2005 16:51:58 +0100

> 
> Yes, not putting the earliest timestamp in the RTP header 
> will prevent any entity pre-depacketization to determine from 
> when the SDs can be used. Assuming that we avoid this and go 
> with a TYPE 5 packet that has a TS offset field (32 bits). 
> Then we need to add text that the jitter calculation becomes 
> basically useless if one sends dynamic SDs that are repeated. 
> This due to the periodically jump in the TS backwards when 
> one includes the repeated SDs. I would also recommend that 
> the TS offset field is not called SDUR, because this is not 
> the sample duration, it is only a TS offset to the next unit.

Of course, if loosing the meaning of the jitter measurements does not bother anyone, this seems good enough. As you say, 32 instead of 24 bits would allow for any offset that the TS actually permits.

I will adapt the update the draft correspondingly and submit it asap

Cheers,

José

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