This is how i do it.INFRANVIEW (PC)is good at pulling frames from a AVI save them as JPG or BMP ,now when done you should have a folder full of JPG's lots of JPG's copy this folder to your UAE folders i use folders called FramesPC,FramesIFF i then batch proccess these frames in PPaint i use the shift down proccess, the batch proccess is to convert them to iff once in IFF format DPaint or PPAINT can make a ANIM from the files, i know it maybe a long way round to do this but using UAE to proccess the files is very very quick only when i move the IFF files to my real amiga does things slow down a bit.Or you may like to try Mainactor for the PC it will load and save ANIM8 files but i found the resulting ANIM to be buggy when played on a real Amiga.Hope it helps.
Jabar.