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Re: Codecs for <video> and <audio>

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Fri, 3 Jul 2009 12:42:03 +1000
Message-ID: <2c0e02830907021942p277131c0y9c09cd587eea8921@mail.gmail.com>
To: Maciej Stachowiak <mjs@apple.com>
Cc: Doug Schepers <schepers@w3.org>, Jonas Sicking <jonas@sicking.cc>, Joe D Williams <joedwil@earthlink.net>, robert@ocallahan.org, Ian Hickson <ian@hixie.ch>, David Singer <singer@apple.com>, public-html@w3.org
On Fri, Jul 3, 2009 at 12:23 PM, Maciej Stachowiak<mjs@apple.com> wrote:
>
> I don't know of any codec that meets the other three requirements but not
> this one. As far as I can tell, of the four stated requirements, Ogg Thora
> only satisfies "is implementable without cost and distributable by anyone".
> I think H.264 satisfies all the requirements except that one. So if we were
> to take your principle that the one requirement that can't be met should be
> dropped, that would argue in favor of dropping the royalty-free requirement.
> But I don't think that argument is reasonable.

The royalty-free requirement is the only one that applies to all W3C
technology and can therefore not be dropped.

All other requirements have been made up for the video and audio case.

All but the HW requirement are increasingly met by Theora (see also
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-June/020626.html):
I say increasingly, because an increasing number of large sites are
supporting Theora and the quality has increased through recent
improvements to the reference encoder, examples of which compared well
with H.264.

The only requirement that Theora does not meet is the Hardware
implementation requirement - and over on WHATWG there was an extensive
discussion about this topic. Here are some points of interest:
* Theora is simpler than H.264, so there are probably devices that
work well with software-only Theora - hardware support for H.264 was
only required because of its high complexity
* trial implementations of Theora for HW exist, so it is not a
fundamenal problem that Theora cannot be implemented on HW
* HW vendors would kill themselves to be able to offer Theora on a
chip to Apple should Apple need this
* H.264 HW implementations did not exist before H.264 got standardised
either and it was not an inhibiting factor for H.264 standardisation

For more details, please refer to the archive of the WHATWG mailing
list, thread at
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-June/020658.html
.

> If all or a significant proportion of Web video goes Ogg-only, it will
> deliver a second-rate experience on mobile devices for the foreseeable
> future. Lack of hardware support means that this is not an easily solvable
> problem.

This is an assumption that has no proof. HW support will be created
quickly if Web video goes Theora for baseline codec (btw: it will
never go Ogg-only and that is not the intention). Further, I have seen
Theora decoded on Symbian S60 devices 6 years ago in software and it
was real-time decoding, so the need for HW support is not even proven.
It is a requirement that makes sense for H.264, but not necessarily
for Theora.

Regards,
Silvia.
Received on Friday, 3 July 2009 02:43:05 UTC

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