Re: Right usage of TTML for video

On Mon, Jun 24, 2013 at 4:42 PM, Eunice Yu <yonhee.yu@gmail.com> wrote:

> Hello people.
> I'm very new to TTML and FCC regularion brought me here. after short
> surveying, still very confused about how to deal with TTML in modern
> browser implementation.
>
> I can see several links which seem to demonstrate TTML.
> http://www.cwmwenallt.com/ttml/ttml-demo.htm
> http://www.html5labs.com/HTML5CaptionDemo/
>
> and they are all something like using track element.
>
> <video width="640" height="480" controls>
>   <source src="video.mp4" type="video/mp4" />
>   <track src="ttml.xml" kind="subtitles"srclang="en" label="English" />
> </video>
>

this is correct on the surface syntax, the real issue is whether the
browser directly supports rendering TTML or not; some do, some don't; it is
sort of like SVG, at one point, many browsers didn't support SVG format
directly, but now most do, at least on desktop browsers

there is some work afoot to add TTML support to some of the browsers that
don't support it today, so I expect the level of support to improve over
time; in the mean time, you may find it necessary to use client side
scripting to parse TTML into HTML/CSS for rendering purposes on the
browsers that don't yet support it;


>
> but I am not sure if that is right implementation based on current
> standard. if it is, it's wired that track does not have mime type. and if
> it's not, I don't see any HTML element who requires TTML as text subtitles.
>

this is similar to the <video/> and <img/> elements that similarly don't
require support for any specific video or image format; the <track/>
element doesn't dictate which text track formats are to be supported either;


>
> so my question is where web developers are suppose to put TTML and on
> which element should browser work to make it happen?
>
> on second thought, javascript can request and parse specific xml(TTML
> here) and display them being styled somewhere on the web page. can I say
> TTML is only for this?
>
> Any comments would be very helpful.
>
> Thank you in advance.
> Eunice
>