Subject: [AVT] new draft-kristensen-avt-rtp-h264-params-00.txt

From: "Even, Roni" <[email-masked]>
Date: Thu, 21 Jun 2007 14:42:36 +0300

Hi,
This new draft is based on the consensus from the Prague meeting to divide the H264 new parameters to a separate draft.

This draft specifies new H264 subtype optional parameters currently supported and used in H.32x (0,3,4) systems.
The parameters address static macro blocks and sample aspect ratio of the receiver.

Thanks
Roni Even 

A New Internet-Draft is available from the on-line Internet-Drafts 
directories.

	Title		: Parameters for Static Macroblocks and Aspect Ratio in the RTP Payload Format for H.264 Video
	Author(s)	: T. Kristensen, R. Even
	Filename	: draft-kristensen-avt-rtp-h264-params-00.txt
	Pages		: 8
	Date		: 2007-6-19
	
   This document updates RFC 3984.  It defines new optional parameters
   addressing new extensions currently supported in H.323 systems: The
   signalling of the maximum rate of static macroblocks a decoder is
   able to process.  The signalling of the sample aspect ratio supported
   by the sender or the receiver.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-kristensen-avt-rtp-h264-params-00.txt

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

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From: Randell Jesup <[email-masked]>
Date: Thu, 21 Jun 2007 22:30:38 -0400

"Even, Roni" <[email-masked]> writes:
>This draft specifies new H264 subtype optional parameters currently
>supported and used in H.32x (0,3,4) systems.  The parameters address
>static macro blocks and sample aspect ratio of the receiver.

The draft references several tables in specs that aren't always easily
available (or weren't last I know - ITU tends to charge for final versions
of specs).  This makes this draft tougher to evaluate, and tougher to use.

In recvonly and sendrecv streams, sar and esar represent what they are
willing to receive.  It's not clear from this draft how to know what's
being sent for sar (though I assume it's somewhere in the H.264 parameter
sets).  This draft should mention where the actual aspect ratio comes from
for sar (it mentions it for esar - H.264 VUI).

-- 
Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga OS team
[email-masked]
"The fetters imposed on liberty at home have ever been forged out of the weapons
provided for defence against real, pretended, or imaginary dangers from abroad."
		- James Madison, 4th US president (1751-1836)

---

From: "Even, Roni" <[email-masked]>
Date: Fri, 22 Jun 2007 10:21:08 +0300

Randell,
The ITU has opened free access to ITU specifications in pdf format. You
can try the ITU web site and see that you can now download
recommendations.

See H series in the link

http://www.itu.int/rec/T-REC-H/e

and for H.241 inside that web page.

http://www.itu.int/rec/T-REC-H.241-200605-I/en

As for VUI I will add some more text. The sample aspect ratio in H.264
is inside the data stream. In order to decode H.264 you need to
understand the data format since even the geometry is in the parameter
sets message inside the media stream, this is different from H.261 and
H.263 that has pre-defines resolutions.

Roni

> -----Original Message-----
> From: Randell Jesup [mailto:[email-masked]]
> Sent: Friday, June 22, 2007 5:31 AM
> To: Even, Roni
> Cc: [email-masked]
> Subject: Re: [AVT] new draft-kristensen-avt-rtp-h264-params-00.txt
> 
> Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga
OS
> team
> [email-masked]
> "The fetters imposed on liberty at home have ever been forged out of
the
> weapons
> provided for defence against real, pretended, or imaginary dangers
from
> abroad."