Yukon doesn't convert anything. What it does is providing a cat type tool that decompresses the video into raw AVI format to stdout. You then pipe it into mencoder which then turns this into whatever video you need. Since AVI is not an mencoder exclusive format I got a bit astonished on why it got pulled into the dep-tree. That said I worked with an older version of Yukon so you never know what happened in the mean time. I'll check the new version out on my gentoo box. I know then exactly what it needs and what not.
EDIT: No way. The old website is down and the linkbox you provided is also down. I'm not sure but did the project not get renamed?