[vlc-devel] [PATCH] basic support for embedded kate streams as subtitles in ogg and matroska

ogg.k.ogg.k at googlemail.com ogg.k.ogg.k at googlemail.com
Tue Mar 25 18:14:00 CET 2008


Hi,

> Looks good. However what is the status w.r.t Matroska and
> Ogg "standardization"? I am a bit wary of adding any unsettled extensions to
> the demuxers.

For Matroska, I don't know how this goes to be honest, I've taken a bite at
the namespace for S_KATE. I have a patch soon to be sent for mkvtoolnix
with this,. If there is any kind of process I should follow for the name to be
"registered", feel free to direct me to info about it.

For Ogg, there is no standardization of namespace. A codec is recognized
by its BOS packet and signature. I have patches to oggmerge and liboggz to
recognize kate streams and merge them with proper codec-dependent time
mapping. The signature is 9 bytes long, enough for avoiding collisions in a
BOS packet.

As for the bitstream format itself, rather than the mapping into
containers, it is
now versioned, and I have hooks in the format to be able to add new data
without losing compatibility with older decoders (for a bump in the minor stream
version, that is).

There is a major addition that I am designing at the moment (continuations,
meant for on-the-fly generation of events for streaming scenarios), but I expect
these will be fully parsable by current decoders (using an additional packet
type, which decoders should just ignore).

In theory, anyway :)

Cheers



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