[FFmpeg-devel] [PATCH] attachments support in matroska demuxer

[Loren Merritt]

On Wed, 2 Jan 2008, Rich Felker wrote:
> On Wed, Jan 02, 2008 at 06:49:28AM +0200, Uoti Urpala wrote:
>>
>> Extradata may happen to be identical, but subtitles can refer to "the
>> same font" in a stricter sense. If you demux a .mkv file into separate
>> files, a natural format is to have an audio file (or files), a video
>> file, a .ssa/.ass file (or files) and a bunch of font files. Nobody
>> splits video/audio tracks into separate "standard extradata" and "main
>> content" parts.
>
> I agree here too. Most subtitle 'codecs' already have an extradata
> format of their own, text-based, separate from the binary ttf data.
> Most likely it's the "header text" which would appear at the beginning
> of the subtitle file if it were flat text. So it would be rather
> problematic to try to munge the fonts together with this...

You can put fonts in SSA extradata, using a variant of uuencoding. I 
haven't seen this recently, but I have some movies using this from before 
matroska.

--Loren Merritt