DVD

After a lifespan of ten years, during which time the capacity of hard disks increased a hundred-fold, the CD-ROM finally got the facelift it required to take it into the next century when a standard for DVD, initially called digital video disc but eventually known as digital versatile disc, was finally agreed during 1996.

The movie companies immediately saw a big CD as a way of stimulating the video market, producing better quality sound and pictures on a disc that costs considerably less to produce than a VHS tape. Using MPEG-2 video compression, the same system that will be used for digital TV, satellite and cable transmissions, it is quite possible to fit a full-length movie onto one side of a DVD disc. The picture quality is as good as live TV and the DVD-Video disc can carry multi-channel digital sound.

For computer users, however, DVD means more than just movies, and whilst DVD-Video grabbed most of the early headlines, it was through the sale of DVD-ROM drives that the format made a bigger immediate impact in the marketplace. In the late-1990s computer-based DVD drives outsold home DVD-Video machines by a ratio of at least 5:1 and, thanks to the enthusiastic backing of the computer industry in general and the CD-ROM drive manufacturers in particular, by early in the new millennium there were more DVD-ROM drives in use than CD-ROM drives.

Initially, the principal application to make use of DVD's greater capacity has been movies. However, the need for more capacity in the computer world is obvious to anyone who already has multi-CD games and software packages. With modern-day programs fast outgrowing CD, the prospect of a return to the multiple disc sets which had appeared to gone away for ever when CD-ROM took over from floppy disc was looming ever closer. The unprecedented storage capacity provided by DVD lets application vendors fit multiple CD titles (phone databases, map programs, encyclopaedias) on a single disc, making them more convenient to use. Developers of edutainment and reference titles are also free to use video and audio clips more liberally. And game developers can script interactive games with full-motion video and surround-sound audio with less fear of running out of space.

History

When Philips and Sony got together to develop CD, there were just the two companies talking primarily about a replacement for the LP. Decisions about how the system would work were carried out largely by engineers and all went very smoothly. The specification for the CD's successor went entirely the other way, with arguments, confusions, half-truths and Machiavellian intrigue behind the scenes.

It all started badly with Matsushita Electric, Toshiba and the movie-makers Time/Warner in one corner, with their Super Disc (SD) technology, and Sony and Philips in the other, pushing their Multimedia CD (MMCD) technology. The two disc formats were totally incompatible, creating the possibility of a VHS/Betamax-type battle. Under pressure from the computer industry, the major manufacturers formed a DVD Consortium to develop a single standard. The DVD-ROM standard that resulted at the end of 1995 was a compromise between the two technologies but relied heavily on SD. The likes of Microsoft, Intel, Apple and IBM gave both sides a simple ultimatum: produce a single standard, quickly, or don' t expect any support from the computer world. The major developers, 11 in all, created an uneasy alliance under what later became known as the DVD Forum, continuing to bicker over each element of technology being incorporated in the final specification.

The reasons for the continued rearguard actions was simple. For every item of original technology put into DVD, a license fee has to be paid to the owners of the technology. These license fees may only be a few cents per drive but when the market amounts to millions of drives a year, it is well worth arguing over. If this didn't make matters bad enough, in waded the movie industry.

Paranoid about losing all its DVD-Video material to universal pirating, Hollywood first decided it wanted an anti-copying system along the same lines as the SCMS system introduced for DAT tapes. Just as that was being sorted out, Hollywood became aware of the possibility of a computer being used for bit-for-bit file copying from a DVD disc to some other medium. The consequence was an attempt to have the U.S. Congress pass legislation similar to the Audio Home Recording Act (the draft was called "Digital Video Recording Act") and to insist that the computer industry be covered by the proposed new law.

Whilst their efforts to force legislation failed, the movie studios did succeed in forcing a deeper copy protection requirement into the DVD-Video standard, and the resultant Content Scrambling System (CSS) was finalised toward the end of 1996. Subsequent to this, many other content protection systems have been developed.