Re: [rtcweb] Stephan Wenger's choices

[Gunnar Hellstrom <[e-mail]>]

On 2013-12-28 22:24, Ron wrote:
> On Sat, Dec 28, 2013 at 11:20:28AM -0800, Eric Rescorla wrote:
>> Even if we mandate H.261, there is a reasonable chance of their
>> expectations being thwarted, since they might well expect that
>> the quality of video would be comparable, yet it will not.
> You don't get much more thwarted than "no video for you", the only
> direction from there is up.  Given a device with a ~4 inch screen,
> viewed from a foot or two away, possibly in open daylight, maybe
> even while bouncing around on a bus or train or while walking,
> maybe with a bunch of scratches on the screen or a plastic cover,
> there's a fair bet that a significant percentage of viewers wouldn't
> be able to pick the difference between it and a perfectly lossless
> image stream anyway.
>
> Is it going to be worse than NTSC television?  How many people were
> happy enough to keep buying and watching those?  How many still
> would if it was all that they could get?
H.261 has only CIF and QCIF formats defined. Modern cameras tend to not 
support these formats anymore, more often delivering formats like QVGA , 
VGA and various wide screen formats. And applications adapt to these 
modern cameras.
Using H.261 sometimes and modern codec sometimes will create situations 
when you will get unpleasant compromises in video formats, such as 
cropped pictures, or pictures with unused margins, or processing-costly 
remapping that also reduces quality.

That together with the low quality makes it not desirable.

Gunnar
>
>
> Sure it might not look optimal on your studio monitor, or your floor
> to ceiling boardroom conference screen, or to eyes that have spent
> years picking out visual artifacts from lossy codecs.  But we're not
> ruling out those people being able to use state of the art codecs
> that have no hope at all of running on minimal devices.  We're looking
> for a baseline that poses the minimal challenge to everything being
> able to support it, for the broadest scope of interoperability.
>
> Things that can will always negotiate up from that.  What is the
> technical reason for setting the lowest bar so high that many of the
> supposed target devices will never be able to reach it?  There would
> seem to be few real barriers to making a more inclusive choice here,
> so why don't we just do that and move on?
>
>    Ron
>
>
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