Command-line mpg to avi conversion tool?

[demigod987]

Does anyone know of a command-line tool that can convert a .mpg or .m2v file to a XVid/Divx .avi? I would prefer one that lets you specify desired bitrate and not just desired size.

Background:
I record a lot of things from TV to watch later when I have time. I'm looking for a way to completely automate the process of removing commercials and compressing to .avi. I already have a script set up to do most of it. I run ShowAnalyzer to detect commericals, then use mpgtx to remove the commercials and then demux it. I can use BeSweet to convert the audio to whatever I need, a command-line version of dvd2avi to create a .d2v file if I need it. I can make the script create .avs files, or .vcf files (but not the SetCompData part, I can't figure that out). I can also mux .avi and .mp3 back together. I have everything figured out except for that 1 step. I can't figure out an easy way to compress the .mpg (or demuxed .m2v) file to .avi in a script or from command-line.

EDIT: Sorry if this isn't the most appropriate forum for this question. I read all the forum descriptions and this one seemed to be the best. If I should post in a different forum, just let me know. Thanks!

[Baldrick]

mencoder or ffmpeg