I would like to know how I could convert video files from one format to another.

Examples - Mov to Avi, Rm to Avi, Ogm to Avi, vice versa, etc.

Do I need a special program to do this sorta thing.

I have acess to video software (Adobe Premiere and After Effects) but they don't work with all media types, so I'd like to be able to convert OGM and RM (etc) video files over to AVI or at least MPEG so that I can work with them.

Any help would be greatly appreciated.