The Vorbis (.ogg) format is audio only, not video. You'd be able to convert it to MP3, WAV, AAC, etc -- not a video file.
I use BeLight. It's freeware, no ads.
You can download it here:
http://www.digitalFAQ.com/forum/vide...ght-audio.html
That specific download is ready-to-use, too. Other sites require you to compile multiple downloads into a functional application.
The Vorbis video format is a .ogv file.