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Re: Codecs for <video> and <audio>

From: Doug Schepers <schepers@w3.org>
Date: Thu, 02 Jul 2009 22:10:28 -0400
Message-ID: <4A4D6894.2040805@w3.org>
To: Maciej Stachowiak <mjs@apple.com>
CC: 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
Hi, Maciej-

Maciej Stachowiak wrote (on 7/2/09 9:47 PM):
> On Jul 2, 2009, at 6:27 PM, Jonas Sicking wrote:
>> On Thu, Jul 2, 2009 at 4:52 PM, Maciej Stachowiak<mjs@apple.com
>> <mailto:mjs@apple.com>> wrote:
>>> - has off-the-shelf decoder hardware chips available
>> Given that this is a requirement that simply isn't satisfiable, I
>> don't think it's a reasonable requirement.
> There are audio and video codecs that have off-the-shelf decoder
> hardware available, so the requirement is definitely possible to
> satisfy.

It's definitely possible.  Is it desirable?  Only if there is a RF video 
codec that also happens to have hardware support.

There are two orthogonal goals here: interoperability and performance. 
The spec must meet the first, and should meet the second.  FWIW, 
whatever the codec HTML5 ends up mandating, I would be very surprised if 
hardware vendors failed to step up in quick order to provide hardware 
support for that codec.

>As it happens, I don't think any video codec satisfying this
> requirement also satisfies all the other requirements. I don't see why
> this is the requirement that should be dropped.

Was there a typo in here?  If this is the lone requirement that cannot 
be met, then it does follow that it's more expendable.

> I understand that it's
> less important to Mozilla than some of the other requirements, so that
> Mozilla is willing to go with a codec that doesn't satisfy it. But for
> other parties this requirement represents large amounts of money at
> stake. For Mozilla, enabling royalty-free downstream distribution of
> Firefox and guaranteeing royalty-free authorability of Web content are
> important priorities. I believe these are the primary reasons H.264 is a
> nonstarter for Mozilla currently. For Apple (and I imagine other
> vendors), ability to deliver a high-quality experience on mobile devices
> at reasonable cost is a high priority. Even considering the goals of the
> W3C as a whole, I don't see a principled reason to override either of
> these requirements.

I might be misunderstanding you.  Obviously, mandating inclusion of Ogg 
Theora/OMS Video/Dirac/whatever does not preclude you also including an 
additional codec, say, H.264 that you find gives a better mobile 
experience.  It doesn't follow that mandating support for one codec that 
might not have hardware support means not supporting a codec that does. 
  The iPhone, at least, has a fair bit of storage that could accommodate 
both codecs.

So, I'm left wondering what your argument here is.

-Doug Schepers
W3C Team Contact, SVG and WebApps WGs
Received on Friday, 3 July 2009 02:10:40 UTC

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