Hi there I have been developing for a few days a new FFmpeg GUI it has reached the stage where it is more or less finished, and supports all of the common video formats, I have also added FULL Support for windows 7 WTV files.
I know FFmpeg does not support WTV files, but my GUI detects when you select a wtv file and then auto converts it to dvr-ms, where you can then select any video format to convert it.
In other words my GUI will auto detect wtv files, convert them in seconds to dvr-ms, then allow you to select a format to convert with ffmpeg.
I built it on windows 7 and have tested it deeply.
The only catch is you MUST run the program on windows 7, as it uses the microsoft wtv converter.
Let me know how it goes.
Download it from my website: http://cabridetrainsim.zoomshare.com/4.html