[theora] Segmentation Fault

[ogg.k.ogg.k at googlemail.com]

> Do I need to recompile with libkate even though I have no plans to use
> subtitles, or just always pass this --nosubtitles option? It seems

When subtitles are not built in, it should behave as it --nosubtitles
would be present. I'll fix asap. I've tested lightly with support compiled
out and it didn't crash on my test cases, but these are not .vob files.

> FYI: I didn't know about this --nosubtitles option because it isn't
> listed when running ffmpeg2theora --help . Are there others similarly
> not listed?

Subtitles related options are only output if support is compiled in,
as they're noops otherwise.