[whatwg] media resources: addressing media fragments through URIs spec

[Aryeh Gregor]

On Sun, Jul 4, 2010 at 9:19 AM, Silvia Pfeiffer
<silviapfeiffer1 at gmail.com> wrote:
> All of the image formats that you are pointing out have an image mime
> type. I am merely pointing out that to support ogg theora browsers
> would need to support a video mime type in an <img> element. I don't
> see that as the intention of the <img> element, in particular since
> <img> elements do not have transport controls and the like. Otherwise,
> why did we create a <video> element in the first place.

I'd expect that a video in <img> would behave like an animated GIF --
no sound, no APIs to control playback, no browser-provided controls.
You might want this sometimes, especially if you're only selecting one
frame.  Animated images are conceptually different from videos, and
there's no reason you couldn't support the same format for both <img>
and <video>, with those different semantics.  It would be particularly
useful to support video frames as images in places where <video> can't
be used, like for the <video poster> attribute, CSS backgrounds, and
so on.  The video MIME type does not conflict at all with allowing
this kind of usage.

So to cover this use-case, it would be good if there were a way of
explicitly selecting one frame, which could be treated as a video that
contains only one frame.  This might, in turn, be accepted by some
browsers in places where they accept images.  You could do this by
explicitly allowing syntax like #t=10,10, where the start point equals
the end point, as selecting only one frame.  (But I guess this could
be emulated by #t=10,10.001 or something, assuming the frame starts at
exactly t=10.)