how to convert video files to mp4 / mpeg-4 or 3gp files?

You may try wondershare media converter,it is a good converter.

http://www.flashontv.com/media-converter.html#141

ivy
March 2009

You need the third party software to help you, I always use aimersoft video converter, it can easily convert video to other video audio files with high quality, and it also provides powerful editing function, that's really nice, you can check it out here for free
http://www.aimersoft.com/video-converter.html

Carina
August 2008