[whatwg] Codecs for <audio> and <video>

On Wed, Jul 1, 2009 at 2:35 PM, Maciej Stachowiak<mjs at apple.com> wrote:
> However, it's quite clear from even a cursory investigation that H.264 ASICs
> are available from multiple vendors. This would not be the case if they
> weren't shipping in high volume products. As I'm sure you know, ASICs have
> fairly high up-front costs so they need volume to be cost effective.

It's a chicken and egg problem then. Once there is volume in Theora
(speak: uptake), the vendors will adapt their hardware to support it.
But we will not adopt Theora because we require hardware support. I
think requiring hardware support is therefore an unfair requirement -
when H.264 was being standardised, no hardware support (i.e. ASICs)
were available either.

>>> As far as I know, there are currently no commercially available ASICs for
>>> Ogg Theora video decoding. (Searching Google for Theora ASIC finds some
>>> claims that technical aspects of the Theora codec would make it hard to
>>> implement in ASIC form and/or difficult to run on popular DSPs, but I do
>>> not
>>> have the technical expertise to evaluate the merit of these claims.)


> Silvia implied that mass-market products just have general-purpose hardware
> that could easily be used to decode a variety of codecs rather than true
> hardware support for specific codecs, and to the best of my knowledge, that
> is not the case.

I have no deep knowledge in this space, but have spoken to people who
have and was quoting their basic statement. Even if there is no vendor
right now who produces an ASIC for Theora, the components of the
Theora codec are not fundamentally different to the components of
other DCT based codecs. Therefore,  AISCs that were built for other
DCT based codecs may well be adaptable by the ASIC vendor to support
Theora. Even if this would need to be done by the chip vendor - it's
not a fundamental obstacle.

I think the real issue around the "hardware support" requirement is
*not* whether there are existing ASICs for Theora and whether they are
commercially available and used. These can be developed where
necessary - and indeed such new challenges are a good thing for the

Instead, the real issue is what you mentioned above: the statement
that "technical aspects of the Theora codec make it hard to implement
in ASIC form and/or difficult to run on popular DSPs". If this was the
case, it would indeed pose a strong obstacle to the use of Theora.
However, unless I see a detailed technical description on why it is
impossible or very hard/difficult to implement ASICs for Theora, I
believe this is just another urban myth. I'd be very happy for anyone
knowledgeable to prove or bust this myth and clarify the situation.


Received on Tuesday, 30 June 2009 23:03:29 UTC