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

Maciej Stachowiak mjs at apple.com
Wed Jul 1 00:12:08 PDT 2009

I'm not sure I have much useful information to add to this discussion,  
but I wanted to address a few points:

On Jun 30, 2009, at 10:54 PM, Gregory Maxwell wrote:

> Then please don't characterize it as "it won't work" when the
> situation is "it would work, but would probably have unacceptable
> battery life on the hardware we are shipping".

I don't believe I ever said "it won't work" or made any claim along  
those lines. All I said was that some products use dedicated hardware  
for H.264, and no such hardware is available for Theora. There was an  
implication that this claim was a smokescreen because really it was  
all just programmable hardware; that is not the case.

> The battery life question is a serious and important one, but its
> categorically different one than "can it work at all".  (In particular
> because many people wouldn't consider the battery life implications of
> a rarely used fallback format to be especially relevant to their own
> development).

If Theora is only going to be a rarely used fallback format, then it  
doesn't seem like a great candidate to mandate in external specs.  
Indeed, others have argued that inclusion in the HTML5 spec would  
drive far greater popularity. If it's going to be widely used, it  
needs power-efficient implementations on mobile.

Battery life is a very important consideration to mobile devices. To  
give an example of a concrete data point, the iPhone 3G S can deliver  
10 hours of video playback on a full charge. It's not very persuasive  
to say that availability of hardware implementations is unimportant  
because, even though battery life will be considerably worse, video  
will still more or less function.

On Jun 30, 2009, at 11:03 PM, Silvia Pfeiffer wrote:

> 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.

I believe the wide availability of H.264 hardware is in part because H. 
264 was developed through an open standards process that included the  
relevant stakeholders. In addition, H.264 was included in standards  
such as Blu-Ray, HD-DVD and 3GPP. This created built-in demand for  
hardware implementations. I believe hardware implementations were  
available before H.264 saw significant deployment for Web content.

It's not clear if a similar virtuous cycle would repeat for other  
codecs. Might happen, but it took a lot of industry coordination  
around H.264 to build the ecosystem around it that exists today. So I  
don't think it's reasonable to assume that hardware implementations  
will just appear.


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