FEATURE
STRAP
DIGITAL VIDEO DISC
HEAD
DIGITAL DISCORD
INTRO
A format war has been averted, so can we look
forward to a new age of digital video, or this another cunning plan to make us buy
more electronic gadgets we didn’t know we needed?
COPY
The story so far. Since the compact disc
first appeared in the early 1980’s ways have been sought to use it to carry
video, as well as high-quality digital audio. It makes a lot of sense, one
format, one disc, one player. Unfortunately the technology has taken longer to
develop than expected and to make matters worse engineers -- doubtless prompted
by over-zealous marketing people -- blundered up several blind alleys, leaving
behind them utter confusion, and a lot of very irritated consumers.
Then, in 1992 it looked as though the matter
had finally been settled with the announcement of a world-standard, called
Video CD. This allowed up to 65 minutes of digitally compressed video and
high-quality audio to be squeezed on to a standard 12cm disc. Okay, so 65
minutes isn’t enough for a feature film -- you need two or more discs -- the
quality can be a bit iffy, but what the heck, it’s digital, it moves and it’s
in colour. What’s more, discs can be played on CD-i consoles and personal
computers, but only if they’ve been fitted with an expensive full-motion video
cartridge or adaptor.
Unfortunately as we now know CD-i and Video
CD hasn’t been a great success. Not everyone wanted to rush out and buy a video
games machine, to watch a handful of films on disc, that had to be changed
halfway through. In the early days picture quality was dreadful, and in the
mind of many consumers, a poor alternative to VHS VCRs, which have a vast
software base, and can record TV programmes.
It all went quiet again, until the middle of last
year when the first reports of two new digital video disc (DVD) systems began
to seep out. The first one to make the headlines was the result of a joint
venture between Philips and Sony, who went public on the 16th of December. Their
system, originally called HDCD (high density CD) was subsequently renamed MMCD
(multi-media CD) to emphasise its potential as a multi-format entertainment platform.
Six weeks later, on January 24th this year, SDCD (super density CD) was unveiled
amidst considerable media hype. This was being developed by a group of consumer
electronics and movie industry companies, known as the SD Alliance, led by Toshiba
and Time-Warner.
It was clear from the outset that both
systems would have enough capacity for a full-length feature film, and multiple
digital audio channels. In fact the general specifications of the two formats were
remarkably similar, and they shared a good deal of common technology, but the
two groups remained implacably opposed to one another and appeared determined
to go ahead and develop incompatible players and discs, that would reach the
marketplace by the middle of 1996. The scene was set for an expensive and highly
damaging format war, reviving memories of the bloody VHS Vs Beta and laserdisc battles
of the 1980s.
Demonstrations of prototypes of both systems over
the past six months showed picture and sound quality to be excellent, far
better than VHS and as good as, if not better than Laservision. AV performance
was not, and has never been an issue. The Philips-Sony camp pointed to the fact
that their system had more robust data processing, the single-sided discs would
be cheaper to produce, and the development of coding systems and microchips was
at an advanced stage. The SD Alliance’s trump cards were higher capacities,
using bonded double-sided and later multi-layer recording systems, plus they
had the all-important backing of the movie industry; neither side appeared
willing to back-down.
The crunch finally came on August 14th,
following the publication of a press release issued by the influential Computer
Industry Technical Working Group. It expressed concern over the effects of a
format war and urged both sides to work together, to develop a single format. After
that things happened very quickly. A week later a Philips spokesperson admitted
that the two groups were in discussion and on September 15th both sides issued
statements, confirming that they had reached an outline agreement, to develop a
single DVD format, based on key technologies from both systems.
So how will it all work? The discs will use a
0.6mm substrate and based on Toshiba’s bonded multi-layer design, giving a
capacity of 4.7 gigabytes. That’s enough for up to 133 minutes of recording
timer per layer. Philips and Sony’s contribution will be the digital processing,
modulation and error correction systems. The specification allows for a variety
of audio configurations, it appears highly likely that NTSC discs mastered for
US markets will use the six-channel Dolby AC-3 system. It’s less certain what
the rest of the world will get, but here in Europe the Musciam system is a
front-runner for PAL discs. This incompatibility is quite deliberate and
intended to safeguard Hollywood’s copyright protection zones and phased movie
release schedules.
That brings us more or less up to date, there’s
still a few technical loose ends to sort out, and doubtless quite a bit of
political wrangling still to come, including the name of the new format. Spokespersons
for Philips and Sony have told us that no decisions have been made, Toshiba’s
statement makes it clear that they intend to keep the ‘SD’ label. Nevertheless all
things being equal, with the wind in the right direction the first players and
discs could reach the shops next September. Players will be backwards
compatible, able to handle audio-only CDs, and possibly a few other members of
the CD family as well.
But will it fly? The crystal ball is still a bit hazy but one thing is for
certain, we’ve been here before, and no-one will buy a DVD player unless and
until there is a good selection of software at sensible prices. They’re off and
running, stand by your wallets!
BOX COPY 1
RECORDABLE DIGITS
DVD is more than just a playback medium, the
technology exists for recordable discs as well, though the software industry is
deeply concerned about the potential for piracy. Electronic copy protection
systems will have to be in place before domestic DVD recorders appear in the
shops. The same problem is holding back the new high-performance digital video
cassette (DVC) format, originally planned as a successor to VHS. The first DVC camcorders
have recently gone on sale in Japan but homedeck VCRs have been put on hold. An
then there’s digital memory cards or ‘Flash Rams’. Solid-state memory modules
could leapfrog both tape and disc, if the price is right, but don’t junk that
VCR just yet...
BOX COPY 2
DIGITAL TELEVISION
TV is going digital as well. Digital TV
broadcasting (DVB) from satellites has already begun and plans for a
terrestrial digital TV service in the UK in 1997, were outlined by the
Department of Heritage in August, but what does it all mean? The plus points
for digital TV are that it makes more economical use of the airwaves, so you
can cram in more channels. It’s also a big step towards widescreen and high-definition
TV. The downside? Well, more doesn’t necessarily mean better and to receive all
these wonderful new channels you’ll need a new TV and/or a set-top converter
box, more than one if they don’t agree a common standard. Digital TV also means
pay TV, someone’s going to have to pay for it, guess who?
---end---
Ó R.Maybury 1995 0510
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