CompuServe Thread

Photo CD Question

4 messages in this thread
#29166From: giorgio ocaOct 22, 1992 11:53 AM
Just yesterday Kodak Italia has started a massive campaign to promote the photo CD stuff. Spot on national TV and magazine and all this kind of stuff. Obviously the Kodak office in Milan doesn't knowreader that plays photo-CD on television and plays also audio CD. So now I'm here to ask some question about photo CD: 1) The Photo-CD architecture needs some additional hardware to standard CdRom or is only a software question. For example if I have a CdRom connected to the SoundBlasterPro Card (the standard multimedia upgrade package, here is definitively a best seller) will it be able to read photo-CDs with appropriate software or I'll need a noew cdrom reader??? 2) What is the difference between mono and multi session??? 3) Are the photo-CD based over a standard ISO-9660 format with special information written that requires additional software or is a completely new format??? 4) Is there some file online explaining all that one needs to know about photo-CD??? Thanks for Help Greetings from Italy
#29526From: Matt SeitzOct 27, 1992 12:17 AM
1) The Photo-CD architecture needs some additional hardware to standard CdRom or is only a software question. For example if I have a CdRom connected to the SoundBlasterPro Card (the standard multimedia upgrade package, here is definitively a best seller) will it be able to read photo-CDs with appropriate software or I'll need a noew cdrom reader??? A: In theory, the first session of a PhotoCD could be read by most standard CD-ROM drives if the proper device driver were written for them. In fact, it's very difficult to write such a driver. A CD-ROM XA drive has built in support for CD-ROM XA sector format that makes it much easier to write a device driver for it to read discs with CD-ROM XA sectors (PhotoCD uses the CD-ROM XA sector format). In short, you will probably need a new CD-ROM reader. 2) What is the difference between mono and multi session??? A: Current audio CDs and CD-ROM consist of three main sections: a) the Lead-In section, which contains a list of all the tracks in the Program Area. b) the Program Area, which contains all the information (audio or data) stored on the disc c) the Lead-out area, a buffer that lets the CD reader know it has reached the end of the disc. The new CD-WO specification for appendable CDs allows you to record multiple Lead-In, Program Area, and Lead-out areas. They are recorded sequentially: Lead In 1->Program Area 1->Lead out 1->Lead in 2->Program Area 2->Lead out 2-> etc. Each set of one Lead In, Program Area, and Lead out is called a Session. A mono or single session disc is a disc that has only one Lead In, Program Area and Lead out. A multi-session disc has two or more Lead In, Progam Area, and Lead out areas. Existing CD readers interpret the first Lead-out area as always being the end of the disc, and will not read past it. New multisession CD readers can read past the first Lead Out to read additional sessions on the disc. 3) Are the photo-CD based over a standard ISO-9660 format with special information written that requires additional software or is a completely new format???
#29527From: Matt SeitzOct 27, 1992 12:18 AM
3) Are the photo-CD based over a standard ISO-9660 format with special information written that requires additional software or is a completely new format??? The PhotoCD uses a format called Bridge Disc. This format uses a modified version of the ISO 9660 format to handle multisession discs. A standard ISO 9660 driver would be able to access files in the first session, but not any other sessions. A Bridge Disc driver would be able to read files in all the sessions.
#29576From: Eric Bee HawleyOct 27, 1992 1:34 PM
Matt – Good answer… -> Eric