there are many programs to do the above. It all depends on ur sourcs and destination. I mean ur ripping it from a DVD, or from a big Avi. and if ur source be for PC or ipod or what?
if for PC i recommend Dr. Divx. because it worked fine for me.
But there are too many Xvid converters. I recomment also the ImToo tools.
If u want any of the above PM me