IETF Logo Mail Archive

Re: [AVT] Some comments to subsection 8.1.1 in draft-ietf-avt-rtp-svc-08

Colin Perkins <csp@csperkins.org> Thu, 27 March 2008 21:56 UTC

Return-Path: <avt-bounces@ietf.org>
X-Original-To: ietfarch-avt-archive@core3.amsl.com
Delivered-To: ietfarch-avt-archive@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 6D06C28C705; Thu, 27 Mar 2008 14:56:46 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -100.649
X-Spam-Level:
X-Spam-Status: No, score=-100.649 tagged_above=-999 required=5 tests=[AWL=-0.212, BAYES_00=-2.599, FH_RELAY_NODNS=1.451, HELO_MISMATCH_ORG=0.611, RDNS_NONE=0.1, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xXgB-lolpKFK; Thu, 27 Mar 2008 14:56:46 -0700 (PDT)
Received: from core3.amsl.com (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 932D53A6CCE; Thu, 27 Mar 2008 14:56:35 -0700 (PDT)
X-Original-To: avt@core3.amsl.com
Delivered-To: avt@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id B524E28C92A for <avt@core3.amsl.com>; Thu, 27 Mar 2008 14:56:34 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nwidGuMmnVTe for <avt@core3.amsl.com>; Thu, 27 Mar 2008 14:56:34 -0700 (PDT)
Received: from mr1.dcs.gla.ac.uk (mr1.dcs.gla.ac.uk [130.209.249.184]) by core3.amsl.com (Postfix) with ESMTP id 44B4E3A6E24 for <avt@ietf.org>; Thu, 27 Mar 2008 14:56:26 -0700 (PDT)
Received: from csperkins-dsl.demon.co.uk ([62.49.4.249]:62962 helo=[192.168.0.4]) by mr1.dcs.gla.ac.uk with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.42) id 1Jf02t-0003zw-7N; Thu, 27 Mar 2008 21:54:03 +0000
In-Reply-To: <44C96BEE548AC8429828A3762315034769505A@vaebe101.NOE.Nokia.com>
References: <70765B7ABD04E845863F69CAC91A5ADB01B0DAA4@Xms1.etsihq.org><12919642-CFC2-492C-9FC0-E1381B30CBFA@csperkins.org><1FEB9B9F2EC38343955D02B2AE86AACB7656DF@lan-ex-02.panasonic.de><50365D40-4B93-4B00-A68D-10BF08468D6D@csperkins.org><1FEB9B9F2EC38343955D02B2AE86AACB7FD805@lan-ex-02.panasonic.de> <8BD6448C-729E-4565-990F-8602B931ABE1@csperkins.org> <44C96BEE548AC8429828A3762315034769505A@vaebe101.NOE.Nokia.com>
Mime-Version: 1.0 (Apple Message framework v753)
Message-Id: <679BE374-4583-46BB-A72A-DF2C8BFE7802@csperkins.org>
From: Colin Perkins <csp@csperkins.org>
Date: Thu, 27 Mar 2008 21:54:00 +0000
To: Ye-Kui.Wang@nokia.com
X-Mailer: Apple Mail (2.753)
Cc: avt@ietf.org
Subject: Re: [AVT] Some comments to subsection 8.1.1 in draft-ietf-avt-rtp-svc-08
X-BeenThere: avt@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Audio/Video Transport Working Group <avt.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/avt>, <mailto:avt-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:avt@ietf.org>
List-Help: <mailto:avt-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/avt>, <mailto:avt-request@ietf.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: avt-bounces@ietf.org
Errors-To: avt-bounces@ietf.org

On 27 Mar 2008, at 21:39, <Ye-Kui.Wang@nokia.com> wrote:
...
> Here are some comments to subsection 8.1.1 in draft-ietf-avt-rtp- 
> svc-08,
> titled "The Classical RTP Decoding Order Recovery Mode". Basically I
> don't understand many details of the process described in the draft -
> for those I could guess I have made some suggestions below on how to
> improve the description.
>
> 1. In the following copied text, NTP timestamps of NAL units or
> operation point representations are mentioned. However, NAL units are
> not directly assoicated with NTP timestamps, which are only directly
> assoicated with RTCP SRs. The NTP timestamp for each NAL unit must be
> defined.

The RTCP SR packets define the mapping between the two timelines,  
allowing you to directly derive the NTP timestamps from the RTP  
timestamps in each session. This is the standard RFC 3550 semantics:  
nothing specific to this format needs to be defined.

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


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

v2.31.3 | Report a Bug | By Email | System Status