Battle of the Blues

As if there were not enough recordable DVD standards, two new ones, based on the blue laser, offer as big an increase in storage as the DVD did over the CD.

As the DVD (digital video disc) celebrates its seventh birthday, the popular video format that was born out of a clash between two rival technologies—pitting Time Warner and Toshiba against Philips and Sony—is once again poised for a winner-takes-all battle of standards. Reminiscent of the DVD rivalries in the early 1990s, two separate camps are once again vying for technological leadership.

The tussle this time is over which DVD recording standard will prevail. Lined up on one side is a consortium of nine firms, including Sony, Philips, Samsung, Sharp and Thomson Multimedia, that backs a scheme called Blu-Ray. On the other side is a partnership between NECand Toshiba, with a recording protocol that has yet to be named.

This is not the first time a recordable DVD has been introduced. An alphabet soup of recording technologies—including DVD-R, DVD-RAM, DVD-RW, DVD+RW and DVD+R—has emerged over the past couple of years, each to have its day before being eclipsed by another. But with so many confusing standards, and each offering only a modest 4.7 gigabytes of storage, consumer interest has remained limited.

The difference this time is that the makers have boosted the DVD's storage capacity more than sixfold. By doing this, they can offer enough storage space for a two-hour movie to be recorded in flawless high- definition video, or for more than ten hours of standard TV-quality broadcasting. If the price of the blank discs can be made low enough, Blu-Ray and its rival could at last offer a realistic replacement for the crude but still widely used VCR(video-cassette recorder). And that is a market really worth squabbling over.

The Blu-Ray and NEC/Toshiba systems are based on similar technology. Rather than trying to improve the ubiquitous red laser that drives today's DVD players, engineers in both camps have adopted the recently developed blue-violet laser as a way of packing greater volumes of data on to a single DVD. A red laser pumps out light at a wavelength of 650 nanometres (billionths of a metre); a blue-violet laser operates at a shorter 405 nm. The shorter the wavelength, the smaller the point the laser beam can be focused on. And the smaller the zones in which data can be stored and read back from, the greater the number of bits (ie, binary digits of ones and zeros) that can be crammed on to a disc. The NEC/Toshiba blue-laser disc can hold up to 20 gigabytes of data; the Blu-Ray consortium's stores 27 gigabytes.

The Blu-Ray's proponents believe they can push their disc capacity up to 50 gigabytes—about 10 gigabytes more than the NEC/Toshiba team's maximum projected size. But the NEC/Toshiba design will be “backwardly compatible” with today's DVDs. That could be a significant advantage in the marketplace, saving videophiles from having to replace their film collections, or having to use a second player for older discs. Also, because the NEC/Toshiba design is based on the same 0.6 millimetre substratum as today's DVDs (as opposed to Blu-Ray's 0.1 mm), it should allow consumer-electronics firms and disc producers to use their existing manufacturing plant to make players and blank discs.

Whether the DVD Forum, an industry-wide standards body, will have the clout to get the warring sides to agree on a single standard for a high-definition recordable DVD is a moot point. At the moment, the omens are not good. Yet even if there is no single blue-laser recording standard, the technology could provide a shot in the arm for the moribund high-definition television (HDTV) protocol.

Both blue-laser formats are capable of streaming data at a blinding 36 megabytes per second (six times faster than data can be read off an ordinary DVD), making them fast enough to paint an HDTV screen in real time. Film buffs looking for the ultimate in picture quality could thus create renewed interest in this much-promised, much-delayed, digital viewing experience.