Xref: utzoo comp.graphics:14440 comp.sys.next:9707 Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!unmvax!pprg.unm.edu!topgun!mustang!nntp-server.caltech.edu!piglet!madler From: madler@piglet.caltech.edu (Mark Adler) Newsgroups: comp.graphics,comp.sys.next Subject: Re: Next machine as animation platform Keywords: NeXTdimension, JPEG Message-ID: <1990Nov15.115234.4438@nntp-server.caltech.edu> Date: 15 Nov 90 11:52:34 GMT References: <85866@tut.cis.ohio-state.edu> <2463@dover.sps.mot.com> <4072@amc-gw.amc.com> Sender: news@nntp-server.caltech.edu Distribution: usa Organization: California Institute of Technology, Pasadena Lines: 20 Nntp-Posting-Host: piglet.caltech.edu kenb@d9.amc.com (Ken Birdwell) figures: >> But if you figure the a 24 bit image (640*480*3) takes a little under >> a meg (921600 bytes) ... >> ... about 60 minutes at 72:1, which I assume to be fairly low quality. The compression ratios apply to the YUV image, which averages 16 bits per pixel instead of 24 (since the U and V are actually 320x480). This gives 614400 bytes. Even so, this would require a compression ratio of 44:1 to get 60 minutes on a 1.4G drive. The C-Cube chip shows some degradation at 50:1, but one could argue that it's still better than you'd get on a normal analog TV. On another note, the standard for digital TV (used by digital VTR's) is 720x243 (before interlacing, giving about 720x484 since there are two empty lines). I wonder why NeXT is using 640x480? I hope they weren't influenced by (shudder) Mac's or PC's. Mark Adler madler@piglet.caltech.edu