Captions (was Re: Shifting gears for a second (was RE: Codecs for <video> and <audio>))

Hi Matthew,

Let's not invent yet another caption file format. There are already
plenty out there, amongst them srt and the new DFXP of the W3C Timed
Text working group. I think these are more than adequate for
captions./.

Also, there have been a large number of proposals to link external
caption files to videos, amongst them:

http://esw.w3.org/topic/HTML/MultimediaAccessibilty
http://wiki.whatwg.org/wiki/Video_captioning
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2008-December/017732.html
http://lists.w3.org/Archives/Public/public-html/2008Sep/att-0118/html5-media-accedssibility.html

Most of them look rather similar, so let's see what implementations
and experiments the browser vendors come up with. So far we have had a
set of javascript implementations of some of the proposals and general
javascript hacks (see e.g. the examples pointed out at
http://blog.gingertech.net/2009/03/12/progress-on-captions-for-html5-video/).

Cheers,
Silvia.

On Sat, Jul 4, 2009 at 11:26 AM, Matthew
Ratzloff<matt@builtfromsource.com> wrote:
> On Fri, Jul 3, 2009 at 2:39 AM, Silvia Pfeiffer <silviapfeiffer1@gmail.com>
> wrote:
>>
>> 10 years ago I was mkaing the same arguments that you are. But now,
>> after having tried to push for time-aligned text inside audio-visual
>> files for so long, I have come to the conclusion that it is actually
>> easier to deal with separate files than with captions inside media
>> files. As external files, they are easier to edit, easier to share,
>> easier to access, easier to parse, easier to handle on a server (e.g.
>> in a database) and generally easier to manage.
>
> Agreed.  Perhaps this is naive, but something like the following seems
> sensible to me:
> <video src="videos/video.ogg" captions="videos/video_captions.xml"/>
> Where video_captions.xml could contain something like:
> <captions>
>   <caption lang="en-US" start="23" end="42" position="23,43">English
> caption</caption>
>   <caption lang="en-US" start="43" end="84">Another caption</caption>
>   <caption lang="fr-CA" start="23"
> end="42" position="23,43">Légende français</caption>
>   <caption lang="fr-CA" start="43" end="84">Une autre légende</caption>
> </captions>
> Instead of frames, @start and @end could also be specified as times.
>  @position is X and Y from top left, reminiscent of image map positioning.
>  @start and @end would be the only required attributes.
> For convenience, the captions element could exist within the video element
> as well instead of being referenced in another file.  Internal captions
> would also allow them to be scriptable via the DOM.
> -Matt

Received on Saturday, 4 July 2009 02:42:02 UTC