Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!sdd.hp.com!cs.utexas.edu!uwm.edu!lll-winken!taco!hobbes.catt.ncsu.edu!kdarling From: kdarling@hobbes.catt.ncsu.edu (Kevin Darling) Newsgroups: comp.sys.amiga.advocacy Subject: Re: AMIGA Message-ID: <1991May8.092400.26725@ncsu.edu> Date: 8 May 91 09:24:00 GMT References: <1991May6.115535.8982@sugar.hackercorp.com> <1991May6.164821.8807@cunixf.cc.columbia.edu> <937@cns.SanDiego.NCR.COM> <1991May8.062658.14796@cunixf.cc.columbia.edu> Sender: news@ncsu.edu (USENET News System) Distribution: usa Organization: North Carolina State University Lines: 34 In <1991May8.062658.14796@cunixf.cc.columbia.edu> es1@cunixb.cc.columbia.edu (Ethan Solomita) writes: In article <937@cns.SanDiego.NCR.COM> dltaylor@cns.SanDiego.NCR.COM (Dan Taylor) writes: > >> Most Amiga animations are stored in a format that does NOT require a >> complete copy of EACH frame image, rather, deltas between frames are >> used whenever possible, usually within a "scene". > > Oh, I have no doubt that a blitter could do 60fps on a > low-res screen, or an 030 on a high-res screen. Note: Playing back ANIMs almost never (if ever) involves the blitter. The idea is to load the info into fast ram, and then the cpu decodes that delta data into chip ram for display. (I suspect many people mistakenly credit the blitter for a lot of things which the cpu actually handles :-). You'd usually lose a lot of speed and waste tons of memory if you brought the data into blitter chip ram first, and/or if you had an ANIM encoded into the larger rectangular areas the blitter is best at. It's a bigger win to have the cpu decode smaller delta chunks instead, y'see. > My question was simply about getting it into memory. Do compressed ANIMs > lend themselves to off-disk loading? I hadn't thought it would be as > easy: frames aren't fixed size. If it is, how much compression do > you usually get? And how about on digitized images? I grabbed a few typical anims and checked for fun... you can decide: Animated Knight/Sword - 320x200x6-planes, 90+ frames, 7-10K each, digitized? The Dream Goes Berserk - 352x440x5-planes, 30+ frames, 13-20K each, anim Disney Screaming Mouse - 352x240x5-planes, 55+ frames, .1- 4K each, cartoon Sneezing Fish on Beach - 320x200x4-planes,160+ frames, .1- 3K each, cartoon AskMeAnything (MMonroe)- 320x200x5-planes, 45+ frames, 12-13K each, digitized cheers - kevin