Subject: [AVT] "RTP Payload format for uncompressed video" with ancillary data

From: Alejandro Cabrera Obed <[email-masked]>
Date: Tue, 8 Mar 2005 13:48:56 -0300

Dear all,

I've read the past mail about "RTP payload format for uncompressed
video" as a proposed standard. I'm studying the way to transmit HDTV
video uncompressed using this RFC, but I know that for the moment it´s
not possible to transmit both audio and video data with this RFC.

If I read this paragraph from the RFC: "In instances where ancillary
data is being transmitted the sender and receiver can disambiguate 
between ancillary and video data via scan line numbers. That is, the 
ancillary data will use scan line numbers that are not within the
scope of the  video frame.", I ask you:

Is it possible to consider the audio data from the HDTV standard as
"ancillary data" and so transmit also the audio within the RTP Payload
format for uncompressed video with no synchronization problems with
the video data ???

Really thanks ,

Alejandro

-- 
Alejandro Cabrera Obed
[email-masked]

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: Colin Perkins <[email-masked]>
Date: Tue, 8 Mar 2005 11:28:31 -0600

> format for uncompressed video with no synchronization problems with

It's possible, but not recommended. You should either send audio and 
video as separate RTP streams (draft-ietf-avt-uncomp-video-06.txt for 
the video, and probably L16 audio) or you should send a bundled stream 
using the RFC 3497 format.

Colin

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From: Randell Jesup <[email-masked]>
Date: 08 Mar 2005 17:38:30 -0500

>format for uncompressed video with no synchronization problems with

        This is an uncompressed video stream.  RTP with multiple types of
media is normally handled by sending multiple streams, and synchronizing
via RTCP and timestamps.  If you want to send an MPEG2 transport stream,
that's a different beast.  If you want to define an "uncompressed video
plus audio" streamtype, and an RTP packetization for it, you're free to
do so - though most other people probably don't see the need for it.

Ancillary data is typically stuff like close-captioning data, etc.

-- 
Randell Jesup, Worldgate Communications, ex-Scala, ex-Amiga OS team
[email-masked]