[theora] Closed Captioning

Holger Waechtler holger at convergence.de
Thu Dec 5 04:06:31 PST 2002

Ralph Giles wrote:
> On Wednesday, December 4, 2002, at 09:16  pm, Joe Straitiff wrote:
>> The main difference between the US and European versions are that the
>> european versions are all graphical (they do have sections talking about
>> character based encoding but it's so vague and up to implementation that
>> I've never seen anyone use it) and the US is fully character based.  
>> So the
>> DVB is similar to DVD's subtitling, i.e. they use a graphics rendering 
>> model
>> and push graphics through on their stream.
> Vector or raster graphics?

runlength encoded 1-, 2- 4- or 8-bit bitmaps. The encoding is pretty 

<p>> We intend to use mng for raster overlays, which provides a superset of 
> image-based subtitles. Of course character based ones are more flexible 
> and accessible for alternate uses, but there are enough cases where the 
> control (or simplicity) of graphic overlays make them worthwhile.

ounds good.


--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'theora-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.

More information about the Theora mailing list