[mythtv-users] repost: nuppel video mpeg4 question

[Matt]

mpeg4 is an ambiguous term, what variant of mpeg4 is being used?

If I demux the video files using the modified version of mencoder, I 
should be able to mess with the files on a windoze box, correct?

I tried to do this but the resulting avi had a fourcc tag of "NUV1". 
This file would no longer playback in the modified version of mplayer 
(no video)

Is there a way to fully demux/unencapsulate the files without actually 
reconverting the data