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

[Colin Perkins <csp at csperkins.org>]

Ye-Kui,

Synchronisation and timestamp mapping across sessions is a standard  
part of RTP. Again, no new mechanisms are needed.

Colin



On 28 Mar 2008, at 10:26, <Ye-Kui.Wang at nokia.com> wrote:
>
> Roni,
>
> But we are talking about session multiplexing, not about a single
> stream.
>
> BR, YK
>
>> -----Original Message-----
>> From: ext Even, Roni [mailto:roni.even at polycom.co.il]
>> Sent: Friday, March 28, 2008 10:13 AM
>> To: Wang Ye-Kui (Nokia-NRC/Tampere); csp at csperkins.org
>> Cc: avt at ietf.org
>> Subject: RE: [AVT] Some comments to subsection 8.1.1
>> indraft-ietf-avt-rtp-svc-08
>>
>> YK,
>> You are talking about a single stream and this is standard RFC
>> 3550. If you want it some place add it to RFC 3984 but I would
>> say that no payload mention it.
>> Roni
>>
>>> -----Original Message-----
>>> From: avt-bounces at ietf.org [mailto:avt-bounces at ietf.org] On  
>>> Behalf Of
>> Ye-
>>> Kui.Wang at nokia.com
>>> Sent: Friday, March 28, 2008 12:10 AM
>>> To: csp at csperkins.org
>>> Cc: avt at ietf.org
>>> Subject: Re: [AVT] Some comments to subsection 8.1.1
>> indraft-ietf-avt-rtp-
>>> svc-08
>>>
>>>
>>>
>>>>> 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.
>>>>
>>>
>>> By defining I meant adding something saying that the NTP
>> timestamp is
>>> derived for each packet (according to RFC 3550) and each NAL unit's
>> NTP
>>> timestamp is equal to the NTP timestamp of the packet the
>> NAL unit is
>>> carried in. This makes the description better, and I think it is
>> aligned
>>> with what you said above.
>>>
>>> BR, YK
>>> _______________________________________________
>>> Audio/Video Transport Working Group
>>> avt at ietf.org
>>> https://www.ietf.org/mailman/listinfo/avt
>>



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


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Audio/Video Transport Working Group
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