Re: [AVT] 3GPP timed text: draft-ietf-avt-rtp-3gpp-timed-text-01.txt

Jose, all,

> Once again, our target is to have this draft for WGLC **before 3GPP's
> Release 6 deadline: March'04**.

I understood that 3GPP did not yet decide to support streaming of timed 
text in release 6 or any other release. Furthermore I understand that 3GPP 
has a liaison with W3C and MPEG so as to arrive at a solution in these 
three bodies with a maximum level of commonality. From this perspective I 
suggest that IETF is careful with defining an RTP payload format only for 
3GPP timed text, without taking the effort of W3C and MPEG into account, 
unless there are really urgent reasons for doing so.

Best regards,

Jan van der Meer

"Jose Rey" <rey@panasonic.de>
Sent by: 
avt-admin@ietf.org
2003-09-18 02:51 PM

        To:     <avt@ietf.org>
        cc:     (bcc: Jan vanderMeer/EHV/CE/PHILIPS)
        Subject:        [AVT] 3GPP timed text: draft-ietf-avt-rtp-3gpp-timed-text-01.txt
        Classification: 

Hi all,

be informed that a new revision (-01) of the draft presented in the
Vienna Meeting has been sent to the IDs manager.  Meanwhile you can
download it from:

http://www.pel.panasonic.de/ietf/docs/draft-rey-avt-rtp-3gpp-timed-text-
01.txt

This draft specifies a payload format for the timed text format defined
in 3GPP.  The new revision contains the following (main)
additions/changes:

- abstract and introduction re-arranged. Moved section "Basics of the
3GP File Structure" to end of the document as Annex B.
- SLEN, SIDX and SDUR lengths fixed to 16, 16 and 24 bits, respectively.
- New OPTIONAL header, SPLDESC, added to transport sample description
in-band.
- fragmentation possibilities are specified in annex a. FHDR tailored
for these cases.
- Section 4 on payload format expanded: text header, fragment header and
sample description header are fully specified.
- SMIL usage section added.

In particular, there are a few items on which feedback is highly
appreciated:

- we fixed the header fields after some comments were done on the
complexity of having variable header lengths. Are the values now ok for
everybody?
- the sample description information is transmitted using SDP and base64
encoding just like proposed for h264, since like there, these pieces of
information might get big.  Optionally a header (SPLDESC) can be
implemented that allows in-band transmission of sample description, for
example, for live streaming.  Is this transmission scheme acceptable?
Are there any other options we missed?

Once again, our target is to have this draft for WGLC **before 3GPP's
Release 6 deadline: March'04**. Please send your comments asap and
thanks in advance for your feedback!

cheers,

José

PS: I will be on vacation three weeks from now.  I will answer all
feedback upon my return.

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