The "Ogg Video Tools" is a toolbox for manipulating Ogg video files,
which usually consist of a video stream (Theora) and an audio stream
(Vorbis). It includes a number of handy command line tools for
creating an manipulating these video files, such as for splitting the
different streams.

At the moment there are the following tools available: oggResize,
oggThumb, oggSlideshow, oggCut, oggCat, oggSplit, oggJoin, oggDump,
oggLength, oggSilence and oggScroll.

WWW: http://dev.streamnik.de/oggvideotools.html