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Re: [AVT] RE: <draft-ietf-avt-rtp-vmr-wb-03.txt>: sampling rate

Qiaobing Xie <Qiaobing.Xie@motorola.com> Fri, 24 September 2004 12:04 UTC

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Date: Fri, 24 Sep 2004 19:53:14 +0800
From: Qiaobing Xie <Qiaobing.Xie@motorola.com>
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To: Colin Perkins <csp@csperkins.org>
Subject: Re: [AVT] RE: <draft-ietf-avt-rtp-vmr-wb-03.txt>: sampling rate
References: <0B08EA1BF5F6304992CDC985EE02209E02A74365@sdebe002.americas.nokia.com> <1225B53B-03EB-11D9-A048-000A957FC5F2@csperkins.org> <41433EE5.3030604@motorola.com> <4145B1B6.4090000@ericsson.com> <6654897A-0D36-11D9-A100-000A957FC5F2@csperkins.org>
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Cc: Magnus Westerlund <magnus.westerlund@ericsson.com>, avt@ietf.org, sassan.ahmadi@nokia.com
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Hi, Colin,

Colin Perkins wrote:

<snip>
>> In the VMR-WB case I would think that having only one timestamp rate 
>> of 16kHz does not effect codec operation and would simplify the 
>> handling when one has some senders that do use 8kHz, especially when 
>> gateways need to encoded sometime 8kHz material from pre-recorded 
>> responses and in other cases WB channel data. This do avoid the need 
>> to perform RTP timestamp rate switches.
> 
> But in the process you make senders that support multiple codecs more 
> complex, since they can't use the sampling rate to drive the media clock 
> for all codecs.

I'd think that the saving (in terms of reduction to the system design and signaling 
complexity) by avoiding performing RTP timestamp rate switches (as Magnus pointed out above) 
far overweighs the ability of using the sampling rate to drive the media clock.

regards,
-Qiaobing


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