[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

Jose,

On 13 Apr 2005, at 14:30, Jose Rey wrote:
...

Right now, for TYPE 5 units applies:

o In general, TYPE 5 units MUST receive their
timestamp from
the first non-TYPE 5 unit following them in
the payload. 
           o However, if:


Rey & Matsui
[Page 31]
> Internet Draft Payload Format for 3GPP Timed Text March 29, 2005

               o the payload only contains (one or several) TYPE 5
                  units or,
               o if one or several TYPE 5 units follow a sample of
                  unknown duration (see Section 4.1.2, SDUR
definition),

             then (all) TYPE 5 units MUST use the RTP timestamp.

Is this what you refer as too much complexity? 

Yes. Why not simply state that TYPE 5 units receive a
timestamp indicating when they become available for use?


This last sentence is included. The other issue is where to place them, i.e., currently they are placed as they are read from file. To simplify one could say that they are all placed (regardless to which unit in the payload they apply) at the beginning of the payload before all other units and receive the RTP TS?

Sure, why not? As Dave said later, provided the sample descriptions have a suitable timestamp for (a) their position in the stream and (b) before the timestamp of the first AU that uses them, everything will work. The other rules seem to be unnecessary complexity.

Colin


_______________________________________________
Audio/Video Transport Working Group
avt at ietf.org
https://www1.ietf.org/mailman/listinfo/avt