[theora] How to add metadata to an Ogg file?

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

> If I recall correctly, there was a tool to add metadata (artist, title,
> location...) to an existing Ogg file, without re-encoding it, but I
> can't find it any more.

oggz-comment (from liboggz) for any Ogg codec that uses Vorbis
comments (including Theora).

http://xiph.org/oggz/