I found on aminet two interesting tools for AmigaOS 3, one which convert IFFs to other formats, and other which claims to convert ANIM5 to AVI or MPG and vice-versa...
I dont know if its true, I dont tried it yet. And its localized in german language, but the program is so small, that this should not be a problem.
[EDIT: in the installer you have the option to localize it to english.]
I am sharing this tiny discovery with you guys!