so, as i said the animation datatype and two sub classes are implemented. what concerns amiga iff anim anim3, 5, 7, 8 and j are implemented. the testcases are playing well, except:
1. anim5 elgato example, since anim 108 compression is not yet implemented.
2. few further anim5 examples as esprita and external testcase, (anim5 ham) juggler. where first frame seems not to be drawn. this is being reported to the developer.
3. there are rare cases where the animations and gifs are displaying slight artefacting which may be xor issue. evidently machine.anim has xor=2. same may also be the case with meme.gif. this imho probably isnt a datatype issue but an undocumented behaviour in aros cgx in comparison to amiga rtg systems. i came across a fix submitted by toni few years ago and ill try t trace it down.
4. when playing animations on amiga planar screens the animation buffer is being overflowed. this needs to be fixed, but im not sure this is within the scope of the bounty.
in general the datatype is working equally well on all four tested platforms in clut, hi and fullcolor modes, except there are very few reproducible issues that are likely to be fixed soon anyway. on the other hand the bounty requirements are imo exceeded in other areas, such as implementation of a second subclass, being gif anim.
considering the above, the bounty is in my view essentially fulfilled. looking forward to other reports.