Xref: utzoo comp.ivideodisc:655 comp.multimedia:169 Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnewsh!rkl From: rkl@cbnewsh.att.com (kevin.laux) Newsgroups: comp.ivideodisc,comp.multimedia Subject: Re: DVI questions Message-ID: <1991Feb6.140751.14909@cbnewsh.att.com> Date: 6 Feb 91 14:07:51 GMT References: <573@hydra.bucknell.edu> <1991Jan15.040230.26507@gpu.utcs.utoronto.ca> <4926@mcrware.UUCP> Followup-To: comp.multimedia Organization: AT&T Bell Laboratories Lines: 61 In article <4926@mcrware.UUCP>, eric@mcrware.UUCP (Eric Miller) writes: > In article <809@anaxagoras.ils.nwu.edu> korcuska@plato (Michael Korcuska) writes: > >It seems that by > >the time CD-I has full motion video we might see DVI supporting MPEG. > > DVI and CD-I may well end up both supporting MPEG (I hope so!). As I have said > before, DVI and CD-I will probably co-exist peacefully for many years. The > main difference is how you as a publisher perceive your audience. If you are > publishing "consumer" titles you should publish in a format that will be > supported by 10's of millions of consumer machines. > > If you are publishing "computer user" titles, then you should publish on a > medium that is accessible to a MAC or an IBM/PC. With any luck, the standards > for Full Motion Video will be universal enough so that publishers of > "cross-over" titles don't have to worry about re-mastering all of their data. > (Encyclopedias, reference books, some games...) I think CD-I will just fade away. They have taken too long and not delivered enough. The i750 chipset runs microcode that is dynamically loaded and therefore will be able to run all sorts of compression/decompression algorithms. I can't see Intel not supporting JPEG or MPEG. If they don't write the microcode, I'm sure someone else will. As for computer/consumer titles, a standalone system with the i750 chipset could automatically detect the algorithm needed and load it. I'm not too worried about different publisher's formats. > >650 megs just doesn't provide the > >space for a huge amount of video and the 150KB/sec data transfer rate for > >CDs doesn't leave much room for improving video quality. > > You can fit 72 minutes of high-quality FMV on a CD-I or DV-I disc. That seems > comparable to one side of a laser disc. What with multi-disc players becoming > more popular, I can't see this as a realistic limitation. We are limited > currently to 170 KB/sec of video data, but I will never underestimate the > power of science to pack incredible amounts of data into CDs and to decode it > in real time. While the capacity/data transfer rate of the media is a factor, the decompression time is more critical for video quality. Consider that a frame of FMV must average 5KB in order to be played back at 30 fps. How compressed is that 5KB? The latest i750 chipset provides twice the decode time than the previous generation, allowing for more sophisticated algorithms to be run to decompress the video. This will certainly improve video quality (but doesn't mean that the quality will also be twice as good). 72 minutes of FMV will fit on a CD, but CD-I can only play back into a small window (I think I was told 100 x 64 at COMDEX last November). DVI provides for full screen playback (256 x 240). Lastly, I read in the Feb 91 Byte magazine's Microbytes column, that Iterated Systems has developed a hardware/software combination to deliver FMV on a standard AT computer with a VGA screen. Their system is based on Fractal Transforms. They claim 1.5 minutes of FMV will fit on a 1.44MB floppy, 40 minutes on a 40MB hard drive, and *10* hours on a CD. You need the hardware to compress it, but only the software to decompress it. -- ________________________________________________________________________________ R. Kevin Laux Email: rkl1@hound.att.com AT&T Bell Labs Voice: (908) 949-1160 Holmdel, NJ 07733 Fax: (908) 949-0959 Brought to you by Super Global Mega Corp .com