there is a program on aminet i think, i got mine off of an old Amiga Format CD.
its called CDXLgui can playback and make CDXL's
split an Mpeg down into iff frames, pull the sound out as an Aiff file, point CDXLgui at it and off it goes!
ok so the compression isn't great, but hey, its full screen full fps on an 020/000. can select ham8 or ham6 for playback on aga or ocs/ecs chipsets.