Subject: [AVT] Breakfast meeting to discuss timestamp alignment issues

From: "Jonathan Lennox" <[email-masked]>
Date: Mon, 28 Jul 2008 19:10:20 -0400

Following up on the discussion in the WG session on my draft, several of
us will be meeting Tuesday morning to discuss timestamp alignment
issues.

Meet at 8:00 am at the IETF registration desk, and we'll go over to the
breakfast buffet.

-- 
Jonathan Lennox
Vidyo, Inc
[email-masked]

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www.ietf.org/mailman/listinfo/avt

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From: "Jonathan Lennox" <[email-masked]>
Date: Tue, 29 Jul 2008 11:02:43 -0400

Roni Even, Sam Ganesan, Colin Perkins, Thomas Schierl and I (Jonathan
Lennox) met over breakfast this morning.

The issue we discussed is that RFC 3550's definition of multi-session
transmission requires that the session group have a common base session,
which every session member joins and sends RTCP to, so that SSRC
collision detection can be performed.

In principle, however, H.264-SVC's dependency structure doesn't require
a common base layer.  Though in practice we expect most SVC usages to
have one, future codecs using multi-session transmission (notably H.264
Multiview Video Coding [MVC]) may actually have independently-decodable
sessions be useful and common.  My timestamp alignment draft assumed
3550 rules, so there is a conflict.

Several different possible resolutions to this problem are possible, all
with advantages and disadvantages.  Thomas Schierl and I will be writing
an I-D describing the requirements and these possible resolutions, to
make working group discussion concrete.

-- 
Jonathan Lennox
Vidyo, Inc
[email-masked]