Re: [payload] WGLC for VP8 Payload

Thanks, the authors just rev'ed the draft to fix the first issue. I hope
they will address the second issue first in the list and then reflect the
agreement in the next revision. I will hold on to the doc write-up till
then.

-acbegen

-----Original Message-----
From: Jonathan Lennox <jonathan@vidyo.com>
Date: Thursday, December 13, 2012 11:29 AM
To: "Ali C. Begen" <abegen@cisco.com>, "payload@ietf.org"
<payload@ietf.org>
Cc: "draft-ietf-payload-vp8@tools.ietf.org"
<draft-ietf-payload-vp8@tools.ietf.org>
Subject: RE: [payload] WGLC for VP8 Payload

>Hi, Ali --
>
>I just wanted to make sure the issue had been considered; if the WG
>agrees that the current design is okay given the limitations I've
>mentioned, I'm not going to object.
>
>Discussion of the issue might be helpful in the document.
>
>-----Original Message-----
>From: Ali C. Begen (abegen) [mailto:abegen@cisco.com]
>Sent: Tuesday, December 11, 2012 7:13 PM
>To: Jonathan Lennox; payload@ietf.org
>Cc: draft-ietf-payload-vp8@tools.ietf.org
>Subject: Re: [payload] WGLC for VP8 Payload
>
>The first one should be fixed by the authors thru a quick revision. As
>for the second one, I will ask the authors reply. Also if there are
>others who strongly think one way or another, lets discuss it.
>
>Jonathan, are you ok if the authors simply acknowledge this in the draft
>(assuming they agree with you) or do you actually not like this at all?
>
>-acbegen
>
>-----Original Message-----
>From: Jonathan Lennox <jonathan@vidyo.com>
>Date: Tuesday, December 11, 2012 11:49 AM
>To: "payload@ietf.org" <payload@ietf.org>
>Subject: Re: [payload] WGLC for VP8 Payload
>
>>Hi -- I have two comments on this draft.  Sorry for being late.
>>
>>First of all, an editorial matter: Section 6 says the format has no
>>parameters, but section 6.1 lists two optional parameters (max-fr and
>>max-fs).
>>
>>
>>Secondly, more substantively, I note that the payload format's rules on
>>KEYIDX and TL0PICIDX impose a fair bit of overhead on boxes that wish
>>to splice together VP8 streams, since both values are required to
>>always increment consecutively in a bitstream (if they're being used).
>>
>>By contrast, the equivalent fields of the H.264 SVC payload format (in
>>the PACSI) just say that IDRPICID must be different in consecutive IDR
>>frames, without requiring that the value increment by 1; and TL0PICIDX
>>resets to 0 on every IDR frame, rather than carrying on continuously.
>>(H.264's IDR frames are analogous for these purposes to VP8's essential
>>keyframes).
>>
>>This means that an H.264 SVC splicer -- as long as it doesn't get
>>unlucky, such that the two streams it's splicing happen to have
>>identical IDRPICID values at the splice point -- can just transition
>>from one bitstream to another at any IDR frame.
>>
>>By contrast, following a splice, a VP8 splicer must re-write both these
>>fields for the rest of the lifetime of the stream, since they each have
>>only one valid possible value following the splice.
>>
>>The VP8 payload format's decision is a reasonable design choice -- as
>>compared to the H.264 SVC rules, it removes some ambiguity between
>>splice points and packet loss, giving decoders somewhat greater
>>visibility as to what's going on in the bitstream, and also allows
>>TL0PICIDX and KEYIDX to be orthogonal options because they increment
>>independently.  However, I wanted to make sure this had been considered
>>explicitly by the working group, and we had consensus that it was the
>>right decision.
>>
>>(Note well disclaimer: Vidyo has an IPR declaration against the VP8
>>payload -- see <http://tracker.tools.ietf.org/ipr/1622/>.)
>>
>>
>>On Dec 5, 2012, at 9:20 PM, Ali C. Begen (abegen) wrote:
>>
>>> I have not seen any comments on the list. Please review the draft and
>>>post  your comments on the list.
>>> 
>>> Thanks.
>>> -acbegen
>>> 
>>> -----Original Message-----
>>> From: "Ali C. Begen" <abegen@cisco.com>
>>> Date: Monday, November 19, 2012 3:15 PM
>>> To: "payload@ietf.org" <payload@ietf.org>
>>> Subject: [payload] WGLC for VP8 Payload
>>> 
>>>> Hi everyone,
>>>> 
>>>> We had a WGLC for this draft earlier this year and there have been a
>>>>few  updates to the document. I am starting a 2nd WGLC. Please review
>>>>and  comment on the list by December 10th.
>>>> 
>>>> https://datatracker.ietf.org/doc/draft-ietf-payload-vp8/?include_tex
>>>> t=1
>>>> 
>>> https://www.ietf.org/mailman/listinfo/payload
>>> 
>>
>>--
>>Jonathan Lennox
>>jonathan@vidyo.com
>>
>>
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>