[ogg-dev] Ogg/Kate preliminary documentation

Ralph Giles giles at xiph.org
Mon Feb 11 15:13:06 PST 2008

On 11-Feb-08, at 2:27 AM, ogg.k.ogg.k at googlemail.com wrote:

> The idea behind the category field was for a player program to  
> automatically
> classify the kate streams as being the "same". eg, if you have 16  
> streams,
> in 8 languages, 8 of them having the category "subtitles" and the  
> rest having
> the category "director comments", then the program could present a  
> list of
> two available stream types, "subtitles" and "director comments", in  
> addition to
> the language selection.

You followed. And there's nothing wrong with having an indication  
embedded in a particular codec's stream. One can do the same thing  
with the comment headers supported by most of the other codecs we  
have. However, given that this is a special case of a requirement  
that's shared by most stream types, and that we have this skeleton  
stream for global and per-substream interpretation instructions, it  
makes sense to standardize a way of saying category "director  
comments", language "German" there as well. It also makes more sense  
to declare inter-stream relationships like Translation-of or Overlay- 
on at a higher level, so the streams remain self-contained after  
demux. If a Skeleton is not present one could fall back to heuristics  
and similar tags in embedded in the various streams.


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