Re: [payload] WGLC for VP8 Payload

Ali do you really want me to add that to the draft?

On Fri, Dec 14, 2012 at 2:55 PM, Jonathan Lennox <jonathan@vidyo.com> wrote:

> What I think Ali meant was to add some text describing the implications of
> this design choice for splicers – i.e., if these features are in use, they
> must re-write packets indefinitely following a splice.****
>
> ** **
>
> *From:* pwestin@google.com [mailto:pwestin@google.com] *On Behalf Of *Patrik
> Westin
> *Sent:* Friday, December 14, 2012 5:47 PM
> *To:* Ali C. Begen (abegen)
> *Cc:* Jonathan Lennox; payload@ietf.org;
> draft-ietf-payload-vp8@tools.ietf.org
>
> *Subject:* Re: [payload] WGLC for VP8 Payload****
>
> ** **
>
> Well he did not have a point in my mind. This is what he wrote.****
>
> ** **
>
> "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."****
>
> ** **
>
> The worst thing that can happen in a draft is to leave ambiguity, which we
> don't have in the current draft. However if we do it the way H.264 SVC do
> we could introduce such ambiguity****
>
> ** **
>
> On Fri, Dec 14, 2012 at 2:30 PM, Ali C. Begen (abegen) <abegen@cisco.com>
> wrote:****
>
> Are you at least planning to put some text around the point Jonathan
> brought up?****
>
> ** **
>
> *From: *Patrik Westin <pwestin@webrtc.org>
> *Reply-To: *"pwestin@webrtc.org" <pwestin@webrtc.org>
> *Date: *Friday, December 14, 2012 4:53 PM****
>
>
> *To: *"Ali C. Begen" <abegen@cisco.com>****
>
> *Cc: *Jonathan Lennox <jonathan@vidyo.com>, "payload@ietf.org" <
> payload@ietf.org>, "draft-ietf-payload-vp8@tools.ietf.org" <
> draft-ietf-payload-vp8@tools.ietf.org>****
>
>
> *Subject: *Re: [payload] WGLC for VP8 Payload****
>
> ** **
>
> Trying to send this again since my previous message did not reach the list.
>
> Thanks for pointing out the inconsistency. We've submitted a new
> draft that fixes that problem. ****
>
>
> The second issue was intentional. We'll keep it this way.****
>
> ** **
>
> On Thu, Dec 13, 2012 at 8:55 AM, Ali C. Begen (abegen) <abegen@cisco.com>
> wrote:****
>
> 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
> >>
> >>
> >>_______________________________________________
> >>payload mailing list
> >>payload@ietf.org
> >>https://www.ietf.org/mailman/listinfo/payload
> >
>
> _______________________________________________
> payload mailing list
> payload@ietf.org
> https://www.ietf.org/mailman/listinfo/payload****
>
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