I use Ubuntu too (I have a dual boot with WinXP), but I kinda abandoned this project as I don't have enough infomation about the AMV format. There are some chinese guys that tried to make something like this but their work is incomplete.
You could try to use Wine with the Windows converter. The Wine HQ tested it and it seems to work.
More about it here
http://appdb.winehq.org/appview.php?iVersionId=4749
And the only tutorial I could find is here (in spanish unfortunately)
http://tozani.wordpress.com/2007/03/...-wine-por-fin/
Oh, and thanks for the kind words. All my foreign friends say that it's close to italian (thus latin)
.