Toshiba Corp and its friends have upgraded the specification for their double-sided video disk, and 4.7Gb capacity has become up to 5Gb per side on the 4.7 platters. A standard audio Compact Disk is 1.2mm thick, but the approach the team is taking is to make each side separately as a 0.6mm platter and stick the two sides together. They claim – somewhat controversially – that the bonding process, using proven techniques derived from 15 years of industry-wide laser disk manufacturing experience, does not add either cost or production time to the process. A 0.6mm disk is claimed to be better than the standard thicker one because the laser can read data with more precision through a thinner disk, and greater density of data can be encoded on it – approximately the difference between 3.7Gb and 5Gb, they say. Also, thinner disks are claimed to enable shorter manufacturing cycle times.

Higher-fidelity

The disk uses variable-rate MPEG 2 digital image compression, which dynamically allocates data over the full length of a movie. The system supports a peak data-transfer rate of 10M-bits per second and can sustain an average transfer rate of 4.94Mbs for the full 135 minutes on each side, faithfully reproducing the studio video master and rivalling CD-quality audio. The 135-minute side provides a minimum of three language channels and four subtitle channels as suggested by the Hollywood Disc Advisory Group, and could carry as many as eight separate language tracks and 32 sets of subtitles, and the viewer will be able to choose the language and format at play-time. The format can provide also Dolby AC-3 audio for surround sound for viewers with the appropriate equipment. The standard also supports multi-aspect ratio, so a single disk can be played in full-screen, letterbox or new 16 by 9 wide-screen television format. The disk is also compatible with the current audio Compact Disk playback standard. The proponents see the format being used to upgrade audio Compact Disks, where it could be used to provide even higher-fidelity audio – today’s Compact Disks cut off above 20,000Hz, and you may not be able to hear that high, but classical music devotees insist that the high harmonics affect the audible sound; they will also offer longer playing time than conventional compact disks. It is expected that rather than require the disk to be flipped, all players will be designed with separate laser pick-ups to read each side of the disk.

Hollywood

The proponents also say that the new format will support high-definition television when blue laser technology becomes available. They claim that Hollywood producers will support the market launch with at least 250 titles at launch and new releases as soon as they become available in video, although that is a somewhat contentious assertion. With the rival Philips Electronics NV-Sony Corp format slugging it out, fears of a new standards war mirroring the bitter Betamax-VHS video cassette recorder battle of 15 years ago (at that time, Philips had yet a third standard, even better than Betamax, but even less successful) are widely canvassed, although this time, Hollywood is thought to be so determined to have only one standard that any standards wars will be fought out behind the scenes, and all studios will agree to back the same single standard, which may end up as a compromise between the two proposals. That way, consumers would not have to face the decision of which equipment they should buy. Nevertheless commitment to the Toshiba standard is shown by the fact that Time Warner Inc is already manufacturing the new disks at Warner Music Group’s Compact Disk production plant in Olyphant, Pennsylvania and says it has demonstrated that the new double-sided optical disks can be mass-produced on slightly modified existing equipment at costs competitive with other high-density optical disks. No doubt Sony and Philips are already making disks to their rival standard too. The Sony-Philips system stores 3.7Gb on a compact disk – against the 740Kb available in the a

udio standard, and can double its capacity by using two layers, the top one being transparent, and focusing the laser so as to pick up from either. Sony says its disk will be cheaper to manufacture because it can be made with little adjustment to music Compact Disk facilities, and players for it would be able to handle existing audio disks. As to the Toshiba standard, it is also claimed that extensive environmental testing has proven that the disks meet all reliability and performance requirements and do not require a hard shell. The companies lining up behind Toshiba’s new standard are Matsushita Electric Industrial Co Ltd, Thomson Consumer Electronics SA, Hitachi Ltd, Pioneer Electronic Corp, Matsushita’s MCA Inc, and Metro-Goldwyn-Mayer Inc’s MGM/UA studios. Cheerleader support comes from Matsushita affiliate Victor Co of Japan Ltd, Mitsubishi Electric Corp, Nippon Columbia Co Ltd and Turner Broadcasting Corp’s Turner Home Entertainment.

Jurassic Park

Reuters reporter Leslie Adler was at the Beverly Hills launch on Tuesday and notes that the disk can also provide two versions of the same film so that objectionable scenes can be edited out for family viewing, with a parental lock-out feature for the uncensored version. The demonstration included a showing of Jurassic Park in its original English-language version and then immediately, from the same disk, a dubbed version in French. The partners also showed clips from the same films in video tape, laser disk and their new digital video disk format on a split screen so that attendees could compare the quality. Clips of scenes from the films Disclosure and Interview with the Vampire showed discernible, although not dramatic differences in picture quality, with the digital video disk version having superior colour, according to Adler. The digital video disk player and the first disks are planned to be available to consumers in one year with the video disk player expected to be $500, and movie disks likely to cost between $20 and $30 each.