i tried cinepak/early quicktime with aniplayer and it works nicely on a CT2 falcon (68030@50MHz with fast ram). on a standard falcon it's pretty slow and i guess it's a slide show on ST.
your best bet is some FLI type of animation format. i know there were various things like videomaster for ST that did 160x100 animation at 25 fps. unfortunately i think it required the anim to be in RAM completely.. although my memory is a bit cloudy.
RE: Video on the ST