[ogg-dev] video chapters and subtitles in ogg containers

Conrad Parker conrad at metadecks.org
Fri Nov 14 11:31:45 PST 2008

2008/11/14 Hans J. Koch <hjk at linutronix.de>:
> I guess this is not neccessary. A simple chunk of metadata containing
> the list of times at the beginning of a file would suffice. OGM simply
> uses text stored in comment fields for that. I wouldn't recommend
> comments for a general approach, but whatever format we choose, it
> should probably not be too difficult to specify and implement it.
> Looking at some of the accessibility pages Silvia mentioned, I think
> that ogg specs are very much focused on web video. I'll follow that
> discussion and will remind ogg developers from time to time that there
> are still one or two people who watch videos from good old files on
> their disk ;-)

that's a fair comment :-) we designed CMML for web video, and SIlvia's
current accessibility work is targeting web video. For this discussion
on generic Ogg mechanisms, perhaps we should take plain disk usage
into account too ...

I guess it doesn't help you to say that a web video player can get the
table of contents -- a plain XML file of the CMML clips -- before
playback by requesting the media resource with a Content-Type
preference for text/cmml. Of course that's only the case if the server
supports that, and if it's not a live stream (ie. if all the clips are
known in advance).


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