Winff is a GUI fronted for the very well-known FFmpeg, which works on Windows and Linux (unfortunately it doesn't work on Mac OS X).
WinFF 1.2.0 was released a few days ago and it brings 2 new very interesting features: preview and cropping for videos.
WinFF is a easy to use graphical interface to the command line FFmpeg video and audio tool. WinFF makes it easy to encode many videos to a wide range of formats all at once. Its FFmpeg back-end should handle just about any video you have.