ISBN: 0-07-049816-4
Category: CDI Standard
Subject: J.7    Computer Applications, COMPUTERS IN OTHER
        SYSTEMS, Consumer products
        I.4.0  Computing Methodologies, IMAGE PROCESSING
        , General
        H.4.2  Information Systems, INFORMATION SYSTEMS
        APPLICATIONS, Types of Systems
        D.4.7  Software, OPERATING SYSTEMS, Organization
        and Design, Interactive systems
        I.3.2  Computing Methodologies, COMPUTER
        GRAPHICS, Graphics Systems
PagesinWholeWork: 239
Bibtype: Book
ReviewNo: 8810-0766
Review: COMPUTING REVIEWS TEXT
        \\
        PHILIPS INTERNATIONAL, INC. (ED.)  8810-0766
        \\
        Compact disc-interactive: a designer's overview.
        \\
        McGraw-Hill Inc., New York, NY, 1988, 239 pp., $39.95, ISBN 0-07-049816-4.
        \\
        Compact disc-interactive (CD-I) is intended to be the next generation
        medium after the familiar digital audio compact disc (CD-DA). The physical
        CD-I disc is mechanically identical to the CD-DA disc, but rather than
        storing 72 minutes of digitized stereo sound, it stores combinations of
        video, sound, executable programs, and program data. For audio, there are
        three encoding schemes, which trade off data rate against sound quality.
        For video, several screen resolutions and image encoding techniques trade
        off data rate against picture quality and smoothness of motion. A disc has
        room for only 4.5 minutes of continuous TV-quality video (with nothing else
        on the disc), so the CD designer needs considerable ingenuity to produce
        CDs with interesting moving images.
        \\
        A CD-I player is a fairly powerful computer. It contains a 68000
        microprocessor with a megabyte of RAM, a pointing device such as a joystick,
        a fairly complicated video generator, and some other computer
        paraphernalia. (A major question is whether a CD-I player can be made
        cheaply enough to appeal to the mass market.) It runs an extended version
        of the OS-9 operating system, rechristened CD-RTOS, which provides the
        environment in which CD applications run. For all but the very simplest
        discs, software on the disc is loaded into the CD-RTOS environment, which
        controls the display of material and interaction with the user.
        \\
        So much for the technology, now on to the book. As suggested by the
        subtitle, the book is aimed at people who might want to design CD-I discs
        or at least understand what is involved in doing so. It describes some
        proposed CD-I software the authors expect to be typical. One example is a
        golf video game, with TV-quality images of golf courses and high-fidelity
        sound effects. Others include an interactive multimedia encyclopedia,
        various sorts of music videos, and animated, interactive foreign language
        lessons.
        \\
        The first three chapters give an overview of CD-I, with a taste of some of
        the applications, and promise to finish explaining them later. Chapters 4
        and 5 describe the CD-I design process, give a confusing and incomplete
        description of the technical details of CD-I, and promise to finish
        explaining them later too. Chapter 6 then finishes describing the sample
        applications. Chapter 7, by far the longest in the book, goes into the
        details of disc formats, image, data, and sound encoding techniques, and
        the resources of the player's computer system, and explains a little bit
        about CD-RTOS. The authors intend chapter 7 to be optional, but I found
        that chapter 5 is so sketchy that I needed the later material to make sense
        of it. The organization and style of the book clearly suffer from it having
        been assembled from materials written by a great number of people.
        \\
        The appendices include a 45-page glossary, which reiterates almost the
        entire book, and the rest of the discussion about CD-RTOS.
        \\
        It appears that producing successful CD-I software will be extremely
        difficult. Since full-motion TV takes up so much disc space, authors will
        have to come up with clever combinations of cartoon animation, still video
        images, and snippets of partial-screen full motion. The player arm seeks
        very slowly, so ugly pauses in the program will occur unless the software
        somehow disguises seek time. Limits on the player's data rate and the
        computer's RAM will force compromises in the program; for example, it takes
        about1-2- second to read in a full-screen TV image, so smooth motion is
        possible only if 15 percent or less of the screen changes from frame to
        frame. The book admits all of this, but encourages the reader to think of
        it as an entertaining little puzzle rather than a major technical hurdle.
        \\
        The writing style varies wildly, from dry technical prose to chatty
        first-person narrative. Some of it reads as though it were translated from
        the Dutch, quite possibly because it was. For all of its flaws and its
        unashamed enthusiasm for its topic, though, the book does give the reader a
        feeling for the possibilities of the technology and the effort required to
        create software for it. I can't say I'm ready to rush out and buy a CD-I
        player, but now I understand why I might or might not want to do so.
        \\
        -J. R. Levine, Cambridge, MA
        \\
        GENERALTERMS:   DESI GN, DOCUMENTATION
Editor: Philips International
Title: Compact disc-interactive:  a designer's overview
Year: 1988
GeneralTerm: DOCUMENTATION
        DESIGN
Price: $39.95
Publisher: McGraw-Hill, Inc., New York, NY