Linux has a pretty good video and audio converter called FFmpeg. FFmpeg also converts sample rates, and resizes video on the fly with a high quality polyphase filter. Many input formats (mpeg, mpg, avi, mov, wmv and even flv) are supported.
However, FFmpeg is a command line tool and therefore it might be difficult to use. But don’t worry, here comes WinFF – a GUI that allows you to use FFmpeg to convert any video type. It is a cross platform utility (it runs both in Linux and Windows).
A short tutorial presenting WinFF is available here.
