[whatwg] Scripted querying of <video> capabilities

[Tim Starling]

Dave Singer wrote:
> I think this is a good idea, but one rapidly runs into the problems
> talked about in the 'bucket' RFC, notably that there is not a
> universal language for naming codecs (4ccs etc).  But it's proved
> useful in the past.
>
> In general, the source fallbacks are also a way to 'probe' this,
> albeit in a very different way.
>
> I'm not sure you can always get a definitive answer to the question
> "if I gave you a file with this (extended) MIME type, could you play
> it?" and I am fairly sure that asking the implementation to enumerate
> all the types it could support would be hard.

If you can't get an answer to that question, then how will the browsers
implement <source> fallbacks? What I'm suggesting is basically the same,
except without the requirement to download a video file.

All the issues with type names are also present with <source>.

-- Tim Starling