The Wayback Machine - https://web.archive.org/web/20060307040157/http://www.mtsu.edu:80/~itconf/proceed97/dvi.html

The Implication of Digital Video Interaction (DVI) Technology in Multimedia Post-Production Techniques

This study explores the power of Digital Video Interaction (DVI) technology as it pertains to its ability to combine multimedia tools to form a single communication engine. The study looks at what DVI is, its historical origins, its importance, how it works as well as where its impact is likely to be felt in the next century. For what may be a very rare occassion, this study explores the potential of DVI in developing countries in terms of new dimensions in personal as well as organizational computing.

The advent of the computer and other twenty-first century technologies has dramatically altered the rules by which software producers and engineers do business in the fields of education. A lot of research concerning the use of multi-media systems in the design, development, and implementation of Hypermedia/Hypertext learning environments continues to be carried out throughout the world.

Thanks to an ingenious marriage of digital technologies known as digital video interactive (DVI), learners can go on expeditions in the comfort of their living rooms. The DVI technology combines motion video, still pictures, multitrack audio, and computer graphics in a single integrated environment controlled by a personal computer which can either be a Macintosh or Windows driven DOS compatible (Bainbridge, 1995; Glass, 1989; Hoffert, 1992; Luther, 1989; Okamura & Mukaida, 1996). Implemented by boards and chips manufactured in quantity by Intel, DVI provides all the facilities necessary to produce truly exciting and colorful interactive-video presentations. The latest DVI technology incorporates full stereo sound and high resolution three dimensional graphics.

What is digital video interaction (DVI)? DVI was conceived at RCA Laboratories in the early 1980's (Glass, 1989; Dixon, 1989; Chen, 1991). This followed a time when RCA had been working on schemes to make its LaserVision analog videodisk system interactive, with unsatisfying results. The RCA research and development team suggested an all digital approach to the unsuccessful analog videodisk interactive system which had been the benchmark to DVI.

The effort continued for six years, while the research team weathered numerous budget cuts and changes in management at RCA (Glass, 1989). In the meantime, RCA dropped out of the video disk and home computer manufacturing businesses and was acquired by General Electric. Despite a warm reception at the 1987 CD-ROM conference, DVI was not originally viewed as a promising technological advancement (Dixon, 1989). In addition, GE's strategic plans did not include this technology as part of the company's future investment strategies. As a result, GE donated the Sarnoff Research Center which had been primarily responsible for the DVI research to SR1 International while still retaining control of the technology. Eventually in October 1988, GE sold the DVI technology to Intel Corporation, the makers of semiconductors, computer chips, and circuit boards for a reported $25 million, an action that surprised most industry analysts (Davis, 1981).

The foresight and vision of Intel, coupled with their dominance in the area of semiconductors and microprocessors has paid off since they acquired this technology in that the basic "plain vanilla" personal computer now sold has a built-in multi-media capability (Davis, 1989). The new network systems coupled with videophones and videoconferencing facilities are three telecommunications sectors that benefit from DVI's compression and decompression techniques (Hoffert, 1992). The most common types of multi-media applications that are appearing on the market place are applying this technology in the areas of education, training and development (Adams, 1995; Chen, 1991). Education and training have been the first large-scale universally understood multi-media submarkets which have successfully attempted to utilize the compressed full-motion, full-screen digital video attributes of DVI.

Already, a few DVI systems provide interactive audio, video, and computer graphics. For instance, popular arcade games such as Dungeons and Dragons let you move about dungeons, fighting monsters in a quest for some "prize" which may include a beautiful princess or some popular pursuit among young players. DVI has also become a very popular platform for training in government and corporate institutions (Chen, 1991; Barron &Orwig, 1995; Plowman &Chambers, 1994). For example, the U.S. Army uses a system called EIDS (Electronic Integrated Digital Systems) for interactive training that simulates aerial and ground combat environments (Kuhn, 1991).

The system has also become very popular in training learners with special disabilities or handicaps in educational and industrial settings (Crowell, 1988; Okamura &Mukaida, 1996; Kuhn, 1991). A key goal of DVI is to eliminate the expense, complexity, and awkwardness of a part - analog / part-digital system by storing and processing everything as digital data. DVI uses a single storage device in a single set of chips to produce live action video, synthetic video, and audio, all under the direct control of a personal computer. The result is a system that is far more interactive and sheer fun to use than anything that has been produced on the market up to now.

There are variations of the multi-media interactive systems on the market these days, and they differ considerably in both delivery and punch. The most common comparisons with DVI are drawn between Compact Disk Read Only Memory (CD-ROM) and Compact Disk Interactive (CD-I) (Barron &Orwig, 1995; Cates; 1993; Chen, 1991; Davis, 1989; Lippman &Butera, 1989).

What are the differences between CD-ROM, compact disc interactive, and digital video interactive? CD-ROM as defined by Phillips/Sony Yellow Book and international Organization for Standardization, is merely a way of encoding data files on CD-ROM disc (Corporate Document, 1989). It does not say anything about what is in the files or how they are used. In the meantime CD-I, is defined as a specification for a complete hardware/software product that includes a CD-ROM player, a Motorola 68000-family Central Processing Unit (CPU) and special audio and video processing hardware (Glass, 1989; Luther, 1989; Plowman &Chambers, 1994). Intended for the consumer market, it is designed for price- sensitive applications; keyboards and read-write storage media are options. CD-I has a wide range of capabilities, including CD quality audio, but it cannot display continuous full- screen, full motion video, and it cannot run on hardware that doesn't precisely conform to the specification. DVI is more generalized technology that does not require specific hardware other than DVI chip set. Unlike CD-I, it is suited for use with forms of mass storage other than CD's, WORM (Write Once Read Many times) disk and magneto-optical disks. Also, it can work as a peripheral of many different kinds of computers. DVI can display full screen, full- motion video, and the internal graphics CPU-as well as the host CPU. It can also be programmed to execute new special effects and data compression or decompression algorithms.

Both CD-I and CD-ROM have always been promulgated primarily as home-oriented technologies (Corporate Document, 1989, Davis, 1989). Developed by Philips GL and introduced jointly by Sony and Philips in 1986, the CD-I standard specifies a 68000 CPU-based, closed system box designed to connect a home television or some other monitor, much the same way a video cassette recorder functions with television (Corporate Document, 1989). CD-ROM incorporates audio-visual transmission for home entertainment and personalized instruction.

DVI can randomly access still images which are of higher quality than those generated via videodisk (Cates, 1993; Corporate Document, 1989; Morris, 1987; Okamura &Mukaida, 1996). Depending on the screen size and the degree of digital compression or how much significant data you are willing to forgo for the sake of saving storage space, tens of thousands of color still pictures can be stored on a 31/2 inch CD-ROM disk. Because the decision on compression are made by the user on a picture to picture basis, there is no limitation on how much material can be stored on a single disk. Compression ratios vary from user to user, but on average, a 10:1 compression ratio is considered sufficient to store an average color picture. In addition, a 31/2 inch disk can store 54,000 random access picture frames. Taking into account the fact that a CD-ROM disc can hold a storage capacity of 550,000,000 bytes (conveniently expressed as 550 megabytes of storage space), the strength in DVI becomes its ability to store large amounts of data. Its additional strength is also its capability of storing in excess of 250,000 pages of text on a 31/inch CD-ROM (Glass, 1989; Luther, 1989).

In motion video, the magic figure is 72 minutes of motion picture video at full frame or 144 minutes at half frame and so on (Cates, 1993; Glass, 1989). DVI can also provide 40 hours of monophonic record and playback or 20 hours of stereophonic sound. At its best, DVI practically provides stereo CD audio. The fact that DVI can provide a combination of 250,000 pages of textual data, 72 minutes of motion video, 54,000 random access frames, 40 hours of audio and high resolution animated graphics, makes this a very powerful technology for multi-media producers and instructional designers and technology specialists.

Video producers who have been keeping their eyes and ears on the industry know about the 3 and 1/2, 5 and 12 inch digital video interactive disks (DVIs). They have been around for the past 15 years as specialized bits of video used in training, education, promotion trailers, points of sale and other applications (Morris, 1987). However, because of the sophistication as well as the expense involved in duplication, there has never been a huge amount of video produced using these special video vehicles. Until the recent introduction of peripherals that can read as well as record Compact Discs (CD's), linear magnetic recording facilities have often been more cost beneficial in the production of corporate as well as educational videos. In production houses and studios, 1/2 inch and 1 inch video cassettes are usually cranked out in sufficient numbers to be distributed in a short period of time. On the other hand, DVI productions, because of their technological demands, have not yet hit the market hard enough to make video producers depend on them for their day to day operations.

Video Compression: The first and most exciting component of DVI is advanced video data compression. Extremely good compression, especially of video, is necessary because an uncompressed video image takes up large amounts of memory. DVI addresses this problem by providing extremely efficient compression and fast decompression of video information. Since the greater part of a video image doesn't change from frame to frame, only the differences between successive frames are recorded. Special hardware to handle compression mechanisms like a CLUT (Color Look Up Table) and chrominance subsampling is built into the DVI chip set. Additional propriety techniques pack make the system even more versatile (Glass, 1989; Luther, 1989).

The compression algorithms take into account the fact that only decompression must be done in real time, shifting as much of the computational burden as possible to the device that compresses the video(Glass, 1989; Dixon, 1989). The final result is more than an hour of full screen motion video and multichannels audio on a single CD-ROM disc all of which can be played back in real time.

Currently, the practical minimum size of a compressed video frame is about 15k bytes (Luther, 1989). More compressions usually introduce undesirable artifacts. However, because the DVI hardware is easily reprogrammed, none of the compressions algorithms are fixed in stone. This flexibility is letting DVI grow as the state of the art advances, while allowing new systems to be downward compatible.

The DVI hardware can also compress and decompress still images with compression ratios of up to 25-to-1 (Glass, 1989; Okamura &Mukaida, 1996). Exact reproductions of detailed graphics and illustrations can be done at ratios between 2-to-1 and 3-to-1. For film and video producers, the digital nature of DVI provides versatility that has never been dreamed of nor fully developed to its capacity. DVI can produce resolutions ranging from VHS quality at 30 frames per second, to an eye-popping 1,000- pixel- per line HDTV (High Definition Television) quality when played at much slower frame rates. This is equivalent to viewing a high resolution theatrical film production on your televisions screen. The system can be made to vacillate from VHS to HDTV at the flick of its own internal software.

Audio compression: The compression of audio information poses different, but equally challenging problems. Audio doesn't exhibit as much regularity as video, so it's not as easy to interpolate future wave forms from earlier ones (Glass, 1989; Luther, 1989). Also, audio must be contiguous. Most of us are used to video sequences that jump from take to take, but discontinuity in an audio signal can be jarring.

DVI provides audio compression via an ADPCM (for adaptive differential pulse code modulation) algorithm and uses special buffering techniques to prevent discontinuities in the sound, even during the long step times of CD-ROM heads (Glass, 1989; Luskin, 1993). Typically, the compressed audio will take from 4k to 16k bytes per second (more if there are more tracks).

The audio accompanying the video also can be whatever the user desires. When the system is purring along at 30 fps, the accompanying audio is FM-stereo quality. If the user programs the record-playback system and indicates that they are going to dispense with the video or some other visual effect, then the audio quality can become as good as regular audio CD (Glass, 1989; Luther, 1989). At the other extreme, the user can program the system so that it plays a long audio-only recording that can dispense up to 40 hours of commentary quality on one disc side. In such a length of time, one can look at perhaps a series of photomated pictures, slides, or graphics which are accompanied with audio commentary, music and sound effects. This process is enhanced by the fact that the board that does all the DVI manipulations, generally performs better, faster and is more versatile than any graphics board on the market today.

For the film or video producer, DVI development is further good news in that the system's digital versatility makes it possible to recombine video footage already on the disc into new interactive productions (Luskin, 1993). For a film producer who undertakes projects that require multiple copies but with edited content and special effects on each duplicate, DVI allows them the possibility of making only one disc at half the cost, then rearranging its contents via software to produce subsequent duplicates. DVI technology's ability to rearrange video already on disc (i.e., essentially performing edits on cuts, mixes, dissolves, special effects, etc. already scripted onto the disc), does limit itself to simple rearrangements that have been attempted on the 3 and 1/2, 5, and 12-inch discs. The system enables the producer to pull video from various parts of the disc and combine them on the screen, simultaneously (Luther, 1989).

Because of the additional capabilities of peripherals that can generate special audio-visual effects, the system's editorial functions are becoming limitless. For example, an elementary calculus course could demonstrate simple differentiation and integration using abstract symbols and graphics. An advanced course from the same disc could combine these elementary contents with advanced concepts, such as multiple integration, and show them simultaneously on the same screen-even though they would have been stored on the disc at separate points. In general, partial-screen motion video cuts can be stored at separate points on the disc and recombined under software orders to form either an elementary or advanced exposition. This amounts to editing an already-pressed disc. It's just one of the advantages that has made DVI the door-opener that has long been needed in the interactive disc market.

Synthetic Video: Along with the ability to reproduce compressed video sequences, DVI multimedia engines create computer-generated images in real time (Barron &Orwig, 1996). The hardware supports both bit-mapped graphics and "structured" graphics, and there are facilities for bit mapped ( and, potentially, stroked) text fronts. Further, DVI uses special hardware to perform the warp algorithm, which very quickly maps a pattern or texture onto a simulated two dimensional or three dimensional surface. The sample application called Design and Decorate (DD) demonstrates this feature by, for example, allowing you to "reupholster" sofas and chairs with different fabric patterns in a fraction of a second, then arrange them in a simulated room to see how they will look in real life. The DVI hardware and software generate realistic shadows and textures, and they let you change vantage points almost instantly.

When the RCA research team began developing DVI, they started with their forte, video, instead of computer graphics (Davis, 1989). The system now, however, combines both video and graphics. The result is not only excellent compressed video, but also a graphics approach that sometimes leaves a viewer not able to tell if they are seeing graphics or video. DVI technology is now widely used in combination with such techniques as Stop Motion Animation (SMA), Computer Generated Imagery (CGI) and other combinations of three dimensional animation. The latest Hollywood blockbuster movies almost invariably employ this technology in one way or another. Toy Store and the Terminator series are just the latest illustrations of how the technology is being pushed to its limit.

DVI can do wonders with a computer-generated wire frame of a model interior of a house. This is a technique very familiar in computer aided design (CAD). Adding colors to different fixtures, walls, rooms and furniture has always been done using paint programs such as Adobe Illustrator, Photoshop, etc. and other paint software programs. But DVI can dramatically alter this same pseudo-environment, by adding real objects such as kitchen appliances, home entertainment centers, ceiling fans and grass landscapes that appear through the windows. DVI facilities can also create computer-generated images in real time. The hardware supports both bit-mapped graphics and "structured" graphics, and there are facilities for bit mapped text fonts (Chen, 1991; Davis, 1989). What happens is that the DVI image is transformed into more like a photograph than a graphics illustration. In a way, it is a photograph. What DVI has does is similar to " warping " sample photographs of real fixtures, furniture, grass etc. until they fit the surfaces of the wire frames of the internal decor of the house.

The result is graphics displays that look extremely real. But that's just the first trick DVI provides for this type of multi-media production. Because a computer can recalculate a wire frame and change the viewpoint, the viewer can look at "Pseudohouse interior" from different angles. Further, because DVI also can recalculate all the "warped" photographs to fit them on to the new view, the realistic entertainment center and green landscape, for example, can be reshaped to fit the new view point. In addition to all this, one can change their viewpoint in any part of the interior of the house-at angles that would not have appeared if they were trying to do this with ordinary still or motion picture photography (Plowman &Chambers, 1994). This technique enables DVI to furnish the viewer with a completely reasonable motion synthesis of what might be inside the interior of the whole house. In short, with the appropriate keystroke and joystick maneuver, the viewer is able to tour the interior of the whole house without leaving their workstation. DVI can also redo images so quickly that it can change wire frames, fixtures, and the whole interior and exterior decor on a key stroke.

Another DVI visual illusion resembles cell animation. Very popular in the production of animated sequences or feature films such as Bugs Bunny, The Lion King and Tom and Jerry, this technique allows a background scene or scenes to be recorded to disc (one frame space is all that is required), and that background video can then become a background for many different foregrounds (Cates, 1993; Bainbridge, 1995). Not only is such an arrangement economical on disc geography or space, but in some cases a foreground can be a sparse recording whose "flight path" can be varied at each showing by a few software control bits.

And if a static background is not enough, several contiguous background scenes can be invisibly seamed together. The system can perform the camera operations of panning left or right, tilting up or down, as required to give the illusion of following foreground motion over a larger background. With a joystick, the user could look around anywhere in the entire 360 degree horizon during playback.

During the past few years, DVI has become a component of a much larger training and development environment referred to as Electronic Performance Support Systems (EPSS). EPSS represents a combination of subsystems that include the Internet, the World Wide Web (WWW) and a host of other interactive multimedia distance learning environments. The scarcity of training facilities in the areas of education, commerce, and in government institutions make DVI/EPSS a worthwhile investment in developing countries. Under controlled circumstances, the system can be adapted to be a stand alone instructional environment that is designed to be domain specific when it comes to delivery as well as evaluation and follow-up.

There is growing and compelling evidence that reveals that DVI, as a multimedia engine, has been found to be effective and efficient in many educational and training situations. DVI could prove its usefulness as an alternative to the increasingly scarce live instructors and trainers of trainers at teachers' colleges as well as in commercial and industrial settings. A well-designed DVI expert system would allow most organizations to augment the present conventional methods being used to human resource development. Again, when one takes a cursory look at the fundamental problems of education in Africa as a whole, it is clear that they emanate primarily from the shortage of books, reference manuals, basic instructional literature and appropriate technology.

There are positive as well as negative implications of DVI to multi-media producers. For example, in creating a domain specific learning environment, it seems that the system is so clever that the only thing one has to do is take 10 frames of say a given scene, 25 frames of another, and so on, and DVI will grind out a complete panorama of what you want. This is not the case. For DVI to be used effectively and efficiently, it requires lots of videographers and cinematographers to shoot lots and lots of video, film, still pictures, and graphics. The stills and graphics would have to be photomated to create movement, and where necessary, drama and illusion. This takes a lot of work if the production is to be done right.

It is therefore safe to say in spite of its cleverness and digital versatility, DVI can no way dispense of a good videographer except for those special occasions in education and training when DVI's cleverness and versatility will dispense of passive or elective viewing for a more interactive experience. There is therefore little doubt that DVI is an outstanding technology with a lot of potential in the developing world where, in some cases, experts in education and training tend to be few and far between.

As societies move into the information age, changes are being made in the educational process to ensure that students will have the skills they need in the workplace. By keeping abreast with technological changes in the design, development, and implementation of instructional software, instructional technology specialists and experts can play a key role in restructuring the educational system.

Adams, D. (1995). CD-I and Training: A perfect fit? Performance and Instruction, 34(6), 28-33.

Bainbridge, S.V. (1995). You can't teach soft skills on a computer......can you?. Journal of Instructional Delivery Systems, 9(4), 5-12.

Barron, A. E.&Orwig, G.W. (1995). New technologies for education: A beginner's guide. 2nd Ed. Libraries Unlimited, Inc. Englewood, CO.

Cates, W.M. (1993). Instructional technology: New optical technologies. Clearing House, 66(6), 324-325.

Chen, C. (1991). CD-I and full motion video. Microcomputers for Information Management, 8(1), 53-57.

Chen, C. (1991). The coming of digital visual information age: Implications for information access. Microcomputers for Information Management, 8(4), 255-275.

Davis, D. (1989). Intel and IBM share their multimedia vision. Electronic Business, 13, 2-10.

Dixon, D.F. (1989). Life before the chips: Simulating video digital interactive. Communication ACM 32, 7, 844-861.

Glass, L.B. (1989). Hands on under the hood: Digital video interactive. Byte Magazine, 5, 17-23.

Kuhn, A.D. (1991). Quo vadimus: The 21st century and multimedia. NASA Office of External Relations, Defense, and Intergovernmental Relations Division. NASA Update: State and Local Newsletter 5, 1, 1-15.

Lippman, A. &Butera, W. (1989). Coding image sequences for interactive retrieval. Communication ACM 32, 32(7), 852-860.

Luskin, B.J. (1993). CD-I: From boob tube to teacher's assistant: The birth of Smart TV. Journal of Instructional Delivery Systems, 7(1), 3-5.

Morris, S.K. (1987). Digital video interactive: A new integrated format for multimedia information. Microcomputers for Information Management, 4(4), 249-261.

Okamura, N.H. &Mukaida, L.V. (1996). Public service telecommunications: PEACESAT. Education at a Distance, 10(1), 21-22.

Plowman, L. &Chambers, P. (1994). Working with the new generation of interactive media technologies in schools: CD-I and CDTV. British Journal of Educational Technology, 25(2), 125-134.

________(1989). An introduction to CD-ROM XA. Phillips, Microsoft, and Sony. Microsoft Corporation, Redmond, WA.

Feb	MAR	Apr
	07
2005	2006	2007