I've used format factory it converts almost any audio and video to almost any format.
Format Factory is a multifunctional media converter.
Provides functions below:
All to MP4/3GP/MPG/AVI/WMV/FLV/SWF.
All to MP3/WMA/AMR/OGG/AAC/WAV.
All to JPG/BMP/PNG/TIF/ICO/GIF/TGA.
Rip DVD to video file , Rip Music CD to audio file.
MP4 files support iPod/iPhone/PSP/BlackBerry format.
Supports RMVB,Watermark, AV Mux.
and completely free.
http://www.formatoz.com/index.html [This message has been edited by mikeathome1 (edited 09-05-2009).]