Re: [xrblock] WGLC for draft-ietf-xrblock-rtcp-xr-loss-conceal-05

[Kevin Gross <[e-mail]>]

I doesn't quite make sense to me.

It seems like reporting in RTP timestamp units would make things better for
both the reporter and reportee. The reporter won't need to maintain a
separate higher-precision counter and then do a conversion for reporting.
(Or not implement a higher-precision counter and under report in the
presence of frequent short events.) The reportee receives higher-precision
reports.

SCS threshold might be better represented as a fraction 0/255 to 255/255.
This resolves your mixed-units concern and allows a wider range of SCS
behavior.

Kevin Gross
[phone]
Media Network Consultant
AVA Networks - www.AVAnw.com <http://www.avanw.com/>, www.X192.org


On Wed, Jun 19, 2013 at 6:35 PM, Qin Wu <[e-mail]> wrote:

> Thanks!
>
> -----Original Message-----
> From: Colin Perkins [mailto:[e-mail]]
> Sent: Thursday, June 20, 2013 1:20 AM
> To: Qin Wu
> Cc: Shida Schubert; xrblock-chairs; xrblock
> Subject: Re: [xrblock] WGLC for draft-ietf-xrblock-rtcp-xr-loss-conceal-05
>
> Qin,
>
> Makes sense, thanks.
>
> Colin
>
>
>
> On 18 Jun 2013, at 04:20, Qin Wu wrote:
> > Good points. I fully agree.
> > However changing measurement unit from RTP timestamp unit to ms may
> cause measurement unit inconsistency.
> >
> > Taking loss concealment metrics block as an example, both 32 bit On-time
> Playout Duration field and 16 bit Mean Playout Interrupt Size uses the same
> measurement unit (ms), if we only change measurement unit for all 32 bit
> fields that carry loss concealment metrics to RTP timestamp unit, this cause
> > Some fields in the block use "ms" as unit, some field uses RTP timestamp
> unit.
> >
> > Taking concealment seconds metrics as another example, "SCS Threshold"
> field also uses milliseconds as unit.
> >
> > Let me know what you think of this?
> >
> > Regards!
> > -Qin
> > -----Original Message-----
> > From: Colin Perkins [mailto:[e-mail]]
> > Sent: Tuesday, June 18, 2013 6:10 AM
> > To: Qin Wu
> > Cc: Shida Schubert; xrblock-chairs; xrblock
> > Subject: Re: [xrblock] WGLC for
> draft-ietf-xrblock-rtcp-xr-loss-conceal-05
> >
> > Qin,
> >
> > The length of time represented by an audio payload tends to be an
> integer number of milliseconds for frame-based codecs, but can have an
> arbitrary length for sample-based codecs. Using RTP timestamp units might
> allow you to precisely match up the timings, if that matters. Plus, don't
> you have RTP timestamp units, but would need to convert to milliseconds?
> >
> > Colin
> >
> >
> >
> > On 13 Jun 2013, at 06:34, Qin Wu wrote:
> >> Colin,
> >> Yes, you are right.
> >> The length of time represented by audio playload in the RTP packet is
> usually measured using ms.
> >> Another rationale is concealment metrics are just terminal related end
> system metrics and its calculation does not need to rely on RTP timestamp
> in the RTP packet.
> >>
> >> Regards!
> >> -Qin
> >> -----Original Message-----
> >> From: [e-mail] [mailto:[e-mail]] On
> Behalf Of Colin Perkins
> >> Sent: Wednesday, June 12, 2013 12:02 AM
> >> To: Shida Schubert
> >> Cc: xrblock-chairs; xrblock
> >> Subject: Re: [xrblock] WGLC for
> draft-ietf-xrblock-rtcp-xr-loss-conceal-05
> >>
> >> Shida,
> >>
> >> I've read the draft, and believe it's in reasonable shape to progress.
> I would be interested in hearing the authors' rationale for choosing ms as
> the measurement unit rather than RTP timestamp units, however. It would
> seem that there might be an argument for using RTP timestamp units, so the
> reports can exactly line-up with the audio data in the RTP packets.
> >>
> >> Colin
> >>
> >>
> >>
> >> On 29 May 2013, at 17:53, Shida Schubert wrote:
> >>> This is an announcement of a 2 weeks XRBLOCK WG last call on
> >>> "Report Block for Concealment metrics Reporting on Audio Applications"
> >>> prior to requesting publication of the document as a proposed standard.
> >>>
> >>> As per discussion at the last meeting, we are running a second
> >>> WGLC on this draft.
> >>>
> >>> Please send your comments, including nits, to the list by the
> >>>
> >>> 12th of June
> >>>
> >>> If you read the draft and you see no issues, concerns, or nits, please
> >>> express the fact that you have no issue progressing the draft on the
> >>> list as well.
> >>>
> >>> The latest version can be found here:
> >>>
> >>> http://tools.ietf.org/html/draft-ietf-xrblock-rtcp-xr-loss-conceal-05
> >>>
> >>> Regards
> >>>
> >>> Shida as co-chair
> >>> _______________________________________________
> >>> xrblock mailing list
> >>> [e-mail]
> >>> https://www.ietf.org/mailman/listinfo/xrblock
> >>
> >>
> >>
> >> --
> >> Colin Perkins
> >> http://csperkins.org/
>
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