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

ogg.k.ogg.k at googlemail.com ogg.k.ogg.k at googlemail.com
Fri Nov 14 03:30:25 PST 2008

>> (odd, I did get this reply for Silvia, but not the original post)
> Hmm, it was properly CCed to the list.

Yes, I found it in the spam bucket for some reason...

> Chapters are a list of timepoints stored in the metadata. They are an
> information for player software that is usually used to allow the user
> to jump to certain significant points within a stream. This probably

I don't think anything currently in Ogg can do this. The closest I can
think of is CMML's clip concept, but you'd still have to parse the entire
stream to find them all.
One could build an index of them to place them in a Skeleton message
header though, but there is nothing to do that AFAIK.

> Chapters like this are mainly used on video DVDs, but are also defined for
> SVCD and OGM containers. My personal use is watching movies from SDcard
> or harddisk. I'm the type of guy who often wants to watch only some
> parts of a movie, and chapters greatly simplify finding a certain scene
> (or skip one that is too exciting...).

If you are transcoding a DVD, you might want to look at the diffs directory
in libkate, there is a patch to Thoggen (Linux based DVD transcoder) that
automatically converts DVD subtitles to Kate streams, though it also requires
a set of patches to GStreamer (also found in the same directory) to be applied.

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