i know about dvdpatcher for mpeg-2 files to change the aspect ratio from 4:3 to 16:9. is there any similar utility for avi files?

i have some avi video generated by a not-widescreen-aware program (muvee autoproducer) that i'd like to import into MS3. but when i import it, it comes in as 4:3, even though the data is actually anamorphic widescreen.

thanks for any pointers.