Super Video Converter is an easy-to-use frontend for ffmpeg and a bunch of other converters, but it might require administrative privledges, I'm not actually sure. It does do everything I ever need it to without having to go through a command line, and it includes all the converters in it's package so I can quickly install it anywhere I need to manipulate video(like at church when doing the VBS presentation, for example).I would highly suggest NOT to use that software, for it is a nasty malware... it is "legit" in that it does some video conversions (with a really old FFMPEG build), but...
On personal experience (not just what others say about it online), with a anti-rootkit scanner, the SUPER directory and registry files came up positive.
Just my 2 cents. I'd go with benryve's suggestion of WinFF. I also found this, but I don't have any experience with that program.