[ogg-dev] kate and W3C timed text

[ogg.k.ogg.k at googlemail.com]

> I've just been asked what the difference was between Kate and the W3C
> timed text format (http://www.w3.org/AudioVideo/TT/) and whether there
> was any compatibility. It migjht be a question and answer to add to
> the OggKate wiki page.

There are similarities. Kate is simpler, and does not piggyback on XML or
CSS (I'm not 100% sure whether W3C timed text uses CSS or a subset of
it, or a lookalike). While I originally recoiled at using CSS due to the
complexity (I don't code CSS, but I'm peripherally aware of the difficulty
in making a conformant browser), I'm now less enclined to reject it offhand.
Since this comes from W3C, it may well be targeted more at browsers, and
existing browsers' implementations of CSS may be leveraged. I'm just
guessing here.

Kate also has a few capabilities that I don't think are in there (I'm thinking
about some motion semantics, such as draw, or text path).

Another interesting thing is SVG, which I briefly had a look at when I was
wondering whether to add animations to Kate when it seemed OggMNG
was not being worked on. That does seem quite complex as well though,
along with scripting, and that made me shy away from it too.

About compatibility, there is absolutely none (intended, at least). This is
not to say that it would be impossible to convert between the two in a lossy
way, however.

While thinking about XML based descriptions, something that I've been
leaving as a background thought is an XML description of a Kate stream,
as that would allow use of XSLT. But I'm thinking aloud again.