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BOOT CAMP 256 (17/12/02)
MAKING YOUR OWN CDS & DVDS,
part 6
In the final instalment of our guide to recordable optical
disc we leave behind the relative sanity and clarity of CD-R and CD-RW and enter
the nightmare world of DVD…
It began innocently enough in the early 1990s when several
major consumer electronic companies started work on optical video disc storage
systems as an eventual replacement for VHS. At one point there were more than
half a dozen rival formats but by 1994 two systems emerged as the front-runners,
High Density CD (HDCD) from Sony and Philips and Super Density CD (SDCD) from
Toshiba and Time Warner. In 1995 the two formats united to become the Digital
Video Disc, though this was swiftly changed to Digital Versatile Disc following
pressure from the computer industry, keen to exploit DVD’s potential for data
storage and software distribution.
DVD Video has gone on to become a rip-roaring success as a
carrier for movies, thanks to a combination of better picture quality,
multi-channel surround sound, rapid scene access, interactive features and bonus
material. Meanwhile development of a recordable version of DVD continued, and
this is where anyone trying to get to grips with the technology usually starts
to glaze over…
In 1997 the DVD Forum agreed the specification for DVD-R and
DVD-RAM, the record once, and rewritable variants, which are broadly similar in
the way they work to CD-R and CD-RW (data on DVD-RAM discs can selectively
erased, so they work like gigantic floppies). However, early DVD-RAM discs were
fragile and had to be contained within a protective ‘caddy’, which ruled against
them being used in homedeck video players.
The first computer DVD-RAM drives appeared in 1998, meanwhile
several companies were working on ‘cross platform’ DVD formats suitable for both
data storage and movies. The first to emerge was DVD-RW from Pioneer in 1999.
This is an extension of DVD-R/RAM and has done reasonably well in the PC market
but had limited success as a video recording format due to lack of industry
support. Next came Philips/Sony with the maverick DVD+R/RW format in 2000;
although not officially endorsed by the DVD Forum it has started to gain a
foothold for video recording thanks to aggressive marketing by Philips. Late
last year DVD-RAM resurfaced as a home video format using record-once DVD-R and
more robust DVD-RAM discs that could be removed from their caddies and played on
compatible homedeck video players, though to date only a very small handful of
players have this facility. Panasonic and Hitachi are currently marketing a
range of homedeck video recorders and DVD-R/RAM camcorders (the latter using
miniature 8cm discs).
There are major compatibility problems with all three formats
and there’s a very good chance that a disc created on one homedeck video
recorder or PC will refuse to play in another. The whole thing is a complete
mess but there is a gleam of hope in the shape of a new generation of universal
DVD PC drives, video players and recorders, going under the banner ‘DVD-Multi’,
that play all flavours of pre-recorded and recordable DVD media.
That brings us more or less up to date but next year a new
even higher capacity optical disc format, called Blu-Ray, is due to be launched
by a consortium of home entertainment and computer companies. Blue lasers have a
much shorter wavelength than conventional CD/DVD lasers, which allows even more
data to be crammed onto a disc, upwards of 27 gigabytes, compared with the 650Mb
of CD and 4.37Gb of DVD. Now it appears there’s dissention amongst the Blu-Ray
backers and a very good chance of a split with yet another format war in
prospect.
So where does all that leave recordable DVD in the context of
home computers? DVD-ROMs are still quite rare for commercial software, very few
applications require that much space, but many new PCs are now fitted with
DVD-ROM/CD-RW drives and with suitable software can play DVD videos and this is
a popular option on laptop PCs.
DVD writers or ‘burners’ have recently begun to drop in price
and the cheapest models now sell for less than £200. So far most are of the
DVD-R/RW variety but Panasonic drives can also read and write DVD-RAM discs. The
first DVD Multi drives have also begun to appear and prices do not appear to be
significantly higher than existing DVD burners. Format issues aside the big
advantage of recordable DVD over CD-R/RW is storage capacity, which makes it an
attractive proposition for data backup and archiving and the programs bundled
with DVD burners works in almost exactly the same way as CD-R/RW software. At
the moment relatively few PCs have DVD-ROM drives so it is limited as means of
transporting large volumes of data.
The biggest success story for recordable DVD though, is for
‘authoring’ DVD videos. With a fast enough PC and the right software packages
it’s possible to create slick, professional looking productions from camcorder
footage, with interactive menus and chapter selection screens. In theory discs
should be playable on DVD homedecks but compatibility remains a problem. We’ll
probably wonder what all the fuss was about in a few years but for the moment at
least it’s best to regard recordable DVD as a work in progress and unless you
have a very specific need for a DVD burner, that can’t be met by recordable CD,
it may be wise to wait for the dust to settle.
Next week – Giving your PC a health check
JARGON FILTER
CADDY
Plastic case containing a recordable disc, protecting it from
physical damage and surface contamination (greasy finger marks etc.)
DVD FORUM
Industry body responsible for developing and policing
technical standards
RAM
Random
Access Memory, the facility to read and write data rapidly from any part of a
storage medium, whether it’s an optical or magnetic disc, or a solid-state
memory device.
TOP TIP
DVD-ROM drives and burners are almost identical in
construction to their CD-ROM cousins and most drives will benefit from a regular
run-through with a good quality CD/DVD cleaner kit. Once every two or three
months is usually enough but it may be worth doing more often if the PC is kept
in a dusty or smoky atmosphere. Recordable DVDs are also very similar to their
CD counterparts and most rewritable types can endure a minimum of 1000
read/write cycles. They are also physically quite robust but you should avoid
handling them as much as possible, and they should always be stored in their
protective cases, away from extremes of heat and cold, humidity and very bright
light.
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