[whatwg] on codecs in a 'video' tag.

James Graham jg307 at cam.ac.uk
Tue Mar 27 03:56:27 PDT 2007

Bjoern Hoehrmann wrote:
> * Anne van Kesteren wrote:
>> Also, I think the HTML specification should mandate (as SHOULD-level  
>> requirement, probably) support for the various supported image formats as  
>> it gives a clear indication of what authors can rely on and what user  
>> agents have to implement in order to support the web.
> And you think this should be in the "HTML specification" rather than
> some dedicated technologies-that-should-be-implemented-by-visual-desk-
> top-browsers specification why exactly?

I think you are mistaking a requirement for all UAs with one for UAs that 
support the display of images. For UAs that support the display of images, 
authors rely on GIF, JPEG and PNG support being avaliable. The specifcation 
should reflect the reality that any UA with image support that intends to work 
on the web must support these formats.

> Such a "SHOULD" would not apply
> to many "HTML implementations" and not easy to specify (you do not want
> to require full JPEG support, for example, and an authoring tool might
> not support GIF)

I would expect WYSIWYG authoring environments to display a GIF image that I 
wanted to included in a document. I wouldn't expect them to edit that image.

> so you have a SHOULD with many exceptions, decreasing
> the normative force of all other SHOULD-level requirements.

How does this affect the force of any other SHOULD level requirement? Text like 
(example only, I'm sure you can pick it apart) "Graphical UAs which support 
images SHOULD support display of the following formats: JPEG [JPEG], GIF [GIF] 
and PNG [PNG]" has no effect on any other SHOULD-level text.

Returning to the issue of <video>, I strongly believe that without one baseline 
format on which authors can rely, <video> is dead in the water. Mandating a 
baseline format in the spec is the only means to encourage the adoption of a 
format free of known IP issues by big players who can affort the extortionate 
licensing fees needed to implement support for some other formats.

"Eternity's a terrible thought. I mean, where's it all going to end?"
  -- Tom Stoppard, Rosencrantz and Guildenstern are Dead

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