Depending on what you want to convert, there are freeware apps which can do the job at hand.
- Freeware video converter tools,
Nandub
is a software designed for encoding DivX ;-) and MPEG4v2 compressed AVI files, using the state of the art technology called Smart Bitrate Control.
AutoGK
THE tool for DivX / XviD backup utility. With support of DVDs, MPEG2 (such as DVB captures and transport streams), MPEG1 sources along with AVI/DV sources encoding into your favourite MPEG4 format was never as easy as now!
Virtualdub
is mainly geared toward processing AVI files,