CD-ROM - INFORMATION OVERKILL - Part 4 Supplied by Brian Burke @~Continued from last issue 25. What on earth does `Red Book', `Yellow Book', etc. mean? "Red Book" is the common name of the "Compact Disc Digital Audio Standard". When a disc conforms to the red book standard, it will usually have "digital audio" printed below the "disc" logo. Most music CDs conform to this standard. "Yellow Book" is the standard for CD-ROM. When a disc conforms to the yellow book, it will usually say "data storage" beneath the "disc" logo. "Green Book" is the CD-I (compact disc interactive) standard. "Orange Book" is the standard for write-once compact discs. "Blue Book" is the standard for LaserDisc. You can get the Red Book and Yellow Book from: ANSI Attn: Sales 1430 Broadway New York, NY 10018 (212) 642-4900 Red Book: CEI IEC 908 Yellow Book: ISO 10149:1989 You can get the Green Book from: American CD-I Association 11111 Santa Monica, Suite 750 Los Angeles, CA 90025 (213) 444-6619 The Orange Book is still proprietary to Philips and Sony, available only to their licensees. ================================================================== 26. What is CD-I? CD-I means "Compact Disc Interactive". It is meant to provide a standard platform for mass consumer interactive multimedia applications. So it is more akin to CD-DA, in that it is a full specification for both the data/code and standalone playback hardware: a CD-I player has a CPU, RAM, ROM, OS, and audio/video/(MPEG) decoders built into it. Portable players add an LCD screen and speakers/ phonejacks. If you want information about Philips CD-I products, you can call these numbers: US: Consumer hotline: 800-845-7301 For nearest store: 800-223-7772 Developers hotline: 800-234-5484 UK: Philips CD-I hotline: 0800-885-885 "Discovering CD-I" is a book available for $45 from: "Discovering CD-I" Microware Systems Corporation 1900 NW 114th Street Des Moines, IA 50325-7077 1-800-475-9000 There are three books by Philips IMS and published by Addison Wesley: "Introducing CD-I" ISBN 0-201-62748-5 "The CD-I Production Handbook" ISBN 0-201-62750-7 "The CD-I Design Handbook" ISBN 0-201-62749-3 Lex van Sonderen periodically posts a CD-I FAQ to comp.multimedia. The latest version of this FAQ is available by anonymous ftp from cdrom.com: /pub/cdi.faq. ================================================================== 27. What is CD-ROM/XA? CD-ROM/XA is an extension to the Yellow Book Standard. A track on a CD-ROM/XA disc can contain computer data, compressed audio data, and video/picture data. Many CD-ROM drives do not support CD-ROM/XA. CD-ROM/XA extends CD-ROM by adding some of the CD-I disc features (such as using Mode 2 tracks with interleaved compressed-audio and other data). Thus CD-ROM/XA (eXtended Architecture) is often called the "Bridge" format between CD-ROM and CD-I... though the relationship is mostly the sector types. CD-ROM/XA applications still require specific code for each target platform. CDROM-XA specifies a `bridge format' so that a CDROM-XA disc can be read on a CD-I player as well as on a PC under MSCDEX (provided that you use a conforming (.SYS) driver. On a normal yellow-book CDROM, a data track contains only mode-1 data sectors. On a CDROM-XA, a data track contains only mode-2 data sectors. A mode-2 sector can be of two formats, form-1 and form-2. A form-1 sector contains 2048 bytes of user data, together with EDC and ECC bytes. A form-2 sector contains 2324 bytes of raw data (e.g. ADPCM audio or video data). If the device driver delivers 2048 bytes of data when MSCDEX asks for it, regardless whether the sector is mode-1 or mode-2/form-1, the PC is CDROM-XA compatible. ================================================================== 28. What are the Rock Ridge extensions? The Rock Ridge extensions use some undefined fields in the ISO-9660 standard to allow full unix-like filenames, symbolic links, and deep directories. "Rock Ridge" is named after the town in the movie "Blazing Saddles" for no particular reason. To receive a copy of the current version of the Rock Ridge specifications, contact Bob Niland, fax 303 229 4545. For information on Unix-based premastering software supporting the Rock Ridge extensions contact: Young Minds Inc. 1910 Orange Tree Lane Suite 300 Redlands, CA 92374 714 335-1350 714 798-0488 FAX ================================================================== 29. What is ECMA 168? ECMA 168 is a volume and file format standard for write-once CD and CD-ROM. It was approved as a European standard by the ECMA General Assembly in June of 1992. It provides for full Orange Book functionality, including multisession recording, track-at-once recording, and packet recording. When used with an Orange Book writer, this will allow write-once CD to be used more like a general-purpose storage peripheral than is possible using ISO 9660. ECMA 168 also incorporates the functionality of Rock Ridge: the ability to use Unix style filenames, Unix permissions, and deep directory hierarchies. Much thought was put into character set issues, and ECMA 168 accommodates multiple-byte character sets such as ISO 10646. Although ECMA 168 is not upward-compatible with ISO 9660, it is possible to write a "conformant disc" containing both sets of volume and file structures. If such a disc is Yellow Book compatible (a CD-ROM or a CD-WO written disc-at-once), it could be read on either an ISO 9660 system or an ECMA 168 system. There are many common elements between ECMA 168 and ECMA 167, which is a new standard intended primarily for WORM and erasable optical disks. Hopefully this will encourage developers to support both standards. The title of the standard is "Volume and File Structure of Read-Only and Write-Once Compact Disc Media for Information Interchange". This standard expands upon the ISO-9660 CD-ROM standard. At the current time, it is not known of any companies which support ECMA 168 in their products. A new draft international standard on CD-ROM/CD-WO format: ISO/IEC DIS 13490 Volume and File Structure of Read-only and Write-once Compact Disc Media for Information Interchange is currently undergoing letter ballot process and voting may end at end of August, 1993. DIS 13490 is also the ECMA Standard 168, which is derived from the Frankfurt Group proposal. Copies of this draft standard should be available at the ANSI or ECMA office. DIS 13490 is designed to support both the CD-ROM (yellow book) and CD-WO (orange book) conforming media. In addition, DIS 13490 removed many unnecessary restrictions of ISO 9660, and is compatible with ISO 9660 at the directory and file structures level. DIS 13490 conforming discs can also be made to be read by both ISO 9660 and DIS 13490 conforming receiving systems. ================================================================== 30. Is a short technical introduction to these standards available? There is a good short general article on CD-Rom and it's many variations (CD-XA, CD-I, CDTV, PhotoCD) called MULTIMEDIA IN A MUDDLE by Barry Fox in the New Scientist (London, ISSN# 0262-4079) vol. 131 no. 1787 (Sep 21, 1991) pp.35-38 There is a very good article by Bill and Lynne Jolitz "Inside the ISO-9660 Filesystem Format" in the December 1992 Dr. Dobbs Journal. Detailed source code examples are provided. They are planning follow-up articles covering Rock Ridge, CDI and CDROM-XA. The SAMS book "Principles of Digital Audio" by Ken C. Pohlmann (ISBN 0-672-22634-0) deals primarily with audio CDs but there are sections dealing with CD-ROM, CD-I, DVI, CD-V, CD-WO, Erasable CD, CD + G and CD + MIDI. There is a good brief explanation of all these standards in the paper: "Compact Disc Terminology" Nancy Klocko Disc Manufacturing Inc. 1409 Foulk Road, Suite 202 Wilmington, DE 19803 1-800-433-DISC Here is some information from the paper: Standards: Red Book == CD-Audio Yellow Book == CD-ROM Mode-1 is for computer data Mode-2 is for compressed audio data and video/picture data CD-ROM/XA == an EXTENSION to Yellow Book and defines a new type of track. CD-ROM Mode 2, XA Format, is used for computer data, compressed audio data, and video/picture data. A CD-ROM / XA track may interleave Mode 2 compressed audio and Mode 2 data sectors. Additional hardware is needed to separate these when playing the disc. The hardware is programmed to separate the audio from the data, decompress the audio and play it out through the audio jacks. At the same time, the hardware passes the data to the computer. NOTE: Additional hardware is needed to play a CD-ROM / XA disc. Several vendors offer an XA interface board that will allow an existing CD-ROM drive to play CD-ROM / XA discs. Green Book == Compact Disc Interactive (CD-I) Orange Book == Recordable Compact disc Standard Part I - CD-MO (Magneto Optical) Consists of optional Pre-Mastered (READ-ONLY) area and a Recordable (re-writable) user area. Part II - CD-WO (Write Once) Orange Book Part II also defines a second type of CD-WO disk called a "Hybrid Disc". This disc consists of a Pre-recorded Area and a Recordable Area. The Pre-recorded area is a READ ONLY area where the information is manufactured into the disc. (This area is written per the Red, Yellow, and Green Book specifications, and can be played on any CD-Player.) The Recordable areas are where additional recordings can be made in one or more sessions. Only the first session on the disc is readable by today's CD-Players; additional software will be needed to read the additional sessions. A TOC (Table of Contents) is written during each recording session. Disc will have multiple TOCs, one for each recording session. Photo-CD is an example of a "Hybrid Disc". CD-Bridge Disc The CD-Bridge Disc defines a way to add additional information in a CD-ROM / XA track in order to allow the track to be played on a CD-I player. the result is a disc that can be played on both a CD-I player connected to a TV set and on a CD-ROM / XA player connected to a computer. An example of a CD-Bridge Disc is the new Photo-CD disc. The Photo-CD disc will be playable in CD-I players, Kodak's Photo CD players and in computers using CD-ROM/XA drives. Photo-CD The Photo CDs will be Mode 2 Form 1 sectors per the CD-ROM / XA specifications. The disc will be written per the Orange Book Part II "Hybrid Disc" specifications. This will allow photographs to be written to the disc in several different sessions. Additionally, the disc will use the CD-Bridge disc format to allow the disc to be readable by both CD-I and CD-ROM / XA players. The photographs written to the disc in the first session will use the ISO 9660 format. These photographs will be readable with the existing CD-ROM / XA players connected to a computer running new software written for the Photo CD picture structure. Additionally, the photographs will be displayable on CD-I Players and Photo CD Players connected to a TV set. Photographs written to disc after the first session will be displayable on CD-I Players and Photo CD players. New software and/or firmware will be needed to read these additional photographs with existing CD-ROM/XA players. ================================================================== 31. Who comes up with these standards? Can I have any input? In the case of the colored books, they have been developed by engineers within Philips and Sony. Few people outside these companies have input into the process. The file format standards (ISO 9660, Rock Ridge, and ECMA 168) have all been developed originally by ad-hoc groups of interested people from various companies in the industry, then have been submitted to established standards organizations (ECMA, ANSI, ISO) for further work there. The CD-ROM Architecture Working Group is an official Standards working Group under the auspices of the IEEE Computer Society by way of the Standards Committee for Optical Disks and Multimedia Platforms (SCODMP) chaired and sponsored by Dr. Lawrence Welsch, PhD. Mike Rubinfeld is presently the Chair of the working group. They are working in accordance with a Project Authorization Request (PAR) for the development of a CD-ROM architecture profile that hopefully will be made into an international standard. The PAR was approved by the Standards Activity Board (SAB) of the IEEE/CS last June and the Architecture Profile will probably be ready for balloting by mid 1993. For more information, contact: Mike Rubinfeld NIST Bldg. 225, MS:B266 Gaithersburg, MD 20899 (301) 975-3064 @~To be continued next issue - o -