Re: [AVT] 3GPP timed text draft: more generic?

On Monday, Aug 11, 2003, at 09:15 Europe/London, Jose Rey wrote:
> Colin Perkins wrote:
>> A specific payload format for 3GPP timed text might be
>> appropriate, but I
>> would like to understand the options and alternatives before
>> we make that
>> choice. Is 3GPP the only body doing timed and/or decorated
>> text? If not,
>> what are the alternatives, and how do they relate?
>>
>> --
>
> at the moment there are at least two more standardisation bodies
> interested in timed text: MPEG and W3C.
>
> - MPEG is currently defining their own TT format based on 3GPP TT (see
> Committee Draft of ISO/IEC 14496-17 from July'03 Meeting in Trondheim)
> by defining the access unit structure, the stream type, the object type
> indication and decoder specific info of the timed text samples. The
> definition of these items enables the transport over RTP using the
> mpeg4simple draft. The work in MPEG is assumed to be finalised around
> July 2004.
>
> - W3C is at a very early stage in defining a timed text authoring
> format. It has recently (May'03) published a draft for use cases and 
> requirements of a timed text authoring format:
> http://www.w3.org/TR/2003/WD-tt-af-1-0-req-20030515/. This draft has a
> rather long list of requirements and lists many functionalities. In my
> understanding W3C targets to a generic format with rich functionality. 
> I
> don't know how quick it may develop (anyone?).

I believe SMPTE may also have timed text work in their Digital Cinema 
group?

> None of these above is an option for us, because 1) the only timed text
> format in 3GPP is 3GPP timed text 2) 3GPP has not adopted the 
> mpeg4simple for
> transport and 3) for this 3GPP timed text format we need an RTP payload
> format within the current 3GPP Release 6 schedule (i.e. March'04).

I agree that using the MPEG4-simple format doesn't make sense, and that 
the W3C schedule looks to be too long for 3GPP requirements.

-- 
Colin Perkins
http://csperkins.org/

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