Now it can handle .mp4 files as well as .mp3,.mov,.mpeg,.avi and .mpg
Also it now does not create dupes, it supports multiple file uploads and it should no longer be broken by weird file names.
Enjoy and make sure to read the readme file
also a mycode file is included so you can see just the edits I made to the SilverlightUploadFieldControl.cs file (this should give you an idea of how small and easy to implement this project was)
ps you still need ffmpeg.exe at C:\ffmpeg.exe however that should change in the release coming later this week. Also you have to be using silverlight version 2.0.30226.2 on your computer or it will not work at all and might crash your browser (this is also getting fixed this week)