sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (01/03/91)
CD-ROM has been around for a while @ 550MB/disk. Will we see a second-generation CD-ROM format with something like 2 GB of storage, and downward compatability with current CD-ROM formats? Isn't more-than-550MB a necessity when you start playing with DVI/interactive video? (Unless you want to play games with compression all the time...) Doug Mohney, Operations Manager, CAD Lab/ME, Univ. of Maryland College Park * Ray Kaplan was right *
jimf@idayton.field.intel.com (Jim Fister) (01/03/91)
sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes: >CD-ROM has been around for a while @ 550MB/disk. Will we see a >second-generation CD-ROM format with something like 2 GB of storage, and >downward compatability with current CD-ROM formats? Isn't more-than-550MB a >necessity when you start playing with DVI/interactive video? (Unless you want >to play games with compression all the time...) Disclaimer: I only know what I read, which can often be dangerous. CD-ROM formats as defined by the Yellow Book published by Phillips and Sony combined with the ISO9660 standard defines the format for storing data on a CD. The Phillips-Sony Red Book defines another format, CD-DA, which audio disks use. CD-DA gives you 750MB of storage on a standard disk and CD-ROM gives you 660MB at some incredible error rate (10^-12). I don't think that there's much room to add to that at this time, mainly because of the technology used to master the disk. As far a DVI goes (which I know a bit about,too and I didn't get it all from books) a CD-ROM can hold up to 70 min. of full-screen, full-motion video with good quality stereo audio. This is fine for almost all the applications running today. If a person needs more, he or she can always go to multiple CDs or to big and expensive hard drives for more storage. My reference for a lot of this was _Digital Video in the PC Environment_ by Arch C. Luther, Second Edition, McGraw-Hill. Just so you know. Greetings from the Rocking Metropolis. JimF
sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (01/05/91)
In article <1991Jan3.151718.3398@idayton.field.intel.com>, jimf@idayton.field.intel.com (Jim Fister) writes: >sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes: > >>CD-ROM has been around for a while @ 550MB/disk. Will we see a >>second-generation CD-ROM format with something like 2 GB of storage, and >>downward compatability with current CD-ROM formats? Isn't more-than-550MB a >>necessity when you start playing with DVI/interactive video? (Unless you want >>to play games with compression all the time...) > >Disclaimer: I only know what I read, which can often be dangerous. >As far a DVI goes (which I know a bit about,too and I didn't get it all from >books) a CD-ROM can hold up to 70 min. of full-screen, full-motion video with >good quality stereo audio. This is fine for almost all the applications >running today. #1 Basic Rule of Thumb for Computing Power (Speed/Storage) : It's never enough. It might be nice to have a superset which could store 2GB Doug Mohney, Operations Manager, CAD Lab/ME, Univ. of Maryland College Park * Ray Kaplan was right *
ts@cup.portal.com (Tim W Smith) (01/05/91)
< As far a DVI goes (which I know a bit about,too and I didn't get it all from < books) a CD-ROM can hold up to 70 min. of full-screen, full-motion video with < good quality stereo audio. This is fine for almost all the applications (I don't know anything about DVI - I had never heard of it until this discussion, so forgive me if the following questions are stupid) How does this work? Assume 700 meg of data (for easy computing) and we get 10 meg for each minute of video, or 170 KBytes per second, or (assuming 30 frames per second) about 6 KBytes/frame. And for the audio, if there are 16 bits per sample and 20,000 samples per second (I'm trying to give a generous definition of good quality stereo), we need 200 Meg for the audio, so that cuts the video down to maybe 4 KBytes/frame. So how do they get good video from this? Compress the heck out of it? How hard is this to decode? Why don't CDV discs use this (they only get something like 5 minutes of video on these)? Tim Smith