Buyers Guides > Home Cinema

A Quick Guide to DVD and Future Technology

DVD players have become the fastest selling consumer product of all time.

Every mainstream film is now available on DVD (Digital Versatile Disc).

The main advantage of watching a movie via a DVD player is the enhanced picture quality. Picture resolution is much greater than that of VHS, and DVD discs don’t suffer from the problems that affect videotape cassettes. Also, unlike VHS, the picture quality doesn’t degrade so images quality is as good the hundredth time you play the disc as the first.

Even better is DVD’s audio performance. All new DVD movies are encoded in Dolby Digital 5.1. Once decoded, either by the DVD player or a suitable home cinema receiver, this delivers soundtracks through five surround speakers and a subwoofer - the ‘point one’ - creating an amazing cinema in your own home.

Hi-fi experts are also very excited about DVD. This is because the new DVD-Audio format boasts ultra-revealing 24-bit resolution and a stunning 192kHz sampling rate, delivering ‘better-than-CD’ sound. When paired up with quality amplification and speakers the discs really do sound stunningly good.

Other advantages of DVDs include ease-of-use and the array of added features that normally come on the disc. As DVDs are a digital format you can instantly access anywhere on the disc using the chapter system, so there’s no time consuming rewinding or forwarding. In addition nearly every DVD includes extra features, be it the film’s trailer or in-depth interviews with the stars.
One question that continually crops up with DVD players is: ‘what discs can I play on them?’ This all stems from the fact that DVD manufacturers and film distributors have carved the world up into a number of regions, with the United States being Region One, while Europe, including the UK, is Region Two. Because of this discs bought from high street outlets in the UK will, on the whole, be Region Two discs, which will only play in Region Two machines.

Fortunately, most DVD players can now be made multi-region and will therefore play DVDs from any region.

It’s worth noting that many new DVD players can normally handle a raft of other discs. These include: CD; CD-R - a write once audio CD; CD-RW - a rewritable audio CD disc; MP3 encoded discs - the digital audio compression technology that dramatically reduces the amount of data needed to reproduce music and has become the standard way of downloading music files from the internet; VCD (Video Compact Disc), which is essentially a CD that contains MPEG video files, the quality of which is generally rather poor; SVCD (Super Video Compact Disc) discs, which is a higher quality, upgraded version of VCD which can also hold surround sound; finally, there is Kodak Picture CD, which is a disc burnt by the developer containing digital images from the original film.

DVD RECORDERS

Another set of discs which can be watched on DVD players is those produced by DVD recorders - and this technology deserves to be looked at in far more detail.

Each of these designs produces stunning recordings - far superior to VCRs - and boasts all the marvelous editing benefits of a digital-based recording format.

The main problem with DVD recorders is the lack of an international standard. This means that at present there are three different types of DVD recorder available on the market - DVD+RW, DVD-RW and DVD-RAM - as intimidating a line up of acronyms as ever there’s been. These have been developed by respectively Philips, Pioneer and Panasonic.

Moreover, there are issues regarding compatibility with conventional DVD players. DVD-RAM recordings won’t play in any other DVD player, as they are predominantly cartridge based, nor will DVD-RW, and although DVD+RW has greater backwards compatibility, it is still far from universal.

Fortunately, there are solutions to the above problems. By recording onto DVD+R or DVD-R discs (the write once versions), you will be able to play your copy in nearly every machine around, though you then lose the ability to use the disc for recording again. Meanwhile, multi-format machines are being introduced which play at least two of the three recording formats, getting round the entire format war altogether this would be our recommendation if possible until a standard format is decided.

RECENT DEVELOPMENTS

DVD may offer stunning levels of quality, but it is still improving! As we all know the world of home cinema electronics rarely stays still for long. For example, more and more DVD players are now making use of progressive scan technology. This is a new way of drawing the image on a screen and delivers massively improved images.

Equally exciting are the new video connections that are entering the arena. From the very first DVD machine the transfer of audio data from player to AV receiver has been digital domain, yet video has remained the poor relation, using conventional analogue cables.
All that is changing with the advent of DVI and HDMI. Simply put these are two connection systems capable of carrying high-quality digital video signals (although HDMI also has the potential to carry audio data).

DVI (Digital Visual Interface) was first mooted in 1998 and uses Transmission Minimized Differential Signaling (TMDS). This allows the transfer of 24-bit data for RGB signals, broken down into three TMDS signals, one for each colour. DVI also has the capability of doubling this transfer if additional data needs sending, say when using a progressive scan signal.

HDMI (High Definition Multimedia Interface) was dreamed up by consumer electronics companies as an alternative to DVI. You see they needed a much smaller connector, and came up with a few cunning additions while they were at it. HDMI can transfer 5GB/sec of component quality data (wow!) and can also carry high quality audio signals.

One final point, both the above connections offer content protection, so the big movie studios have given the manufacturers their backing this could prove significant for the future.

HARD DISK RECORDERS

Another major development is hard disks, which are actually already with us. Quite a few manufacturers have introduced HDD (Hard Disk Drive) technology into their DVD recorders. Not only do these ingenious devices play and record onto DVDs, but they can also record straight onto, or play from, an enormous hard drive eliminating the need for a disc altogether. Another great feature of HDD + DVD-RAM machines is ‘Time Slip’ technology, which lets you start watching a programme, while the machine is still recording the rest of it!

As hi-fi and computer technologies converge the use of hard disk technology is sure to increase, with HDD devices being used to play back both audio and video data, perhaps from the same machine.

BLU-RAY

Another technological advance has been the development of Blu-ray, or Blu-ray Disc (BD). This is a next-generation optical disc format developed to enable recording, rewriting and playback of high-definition video (HDTV) on huge capacity discs that hold up to 27GBs of data (nearly six times as much as a conventional DVD). There are also plans for even higher capacity discs, which are expected to hold up to a whopping 50GB of data.

Current optical disc technologies use a red laser to read and write data. The benefit of using a blue laser is that it has a shorter wavelength, which means that it's possible to focus the laser beam with even greater precision. This allows data to be packed more tightly on the disc and makes it possible to fit more data on the same size disc. Such players probably won’t hit the stores until 2006 and despite the different type of lasers used, Blu-ray Disc machines will be made compatible with current red-laser technologies and allow playback of CDs and DVDs.

This last point is worth stressing. DVD has been so successful and so deep has its penetration into the market been, even within its relatively short lifespan, that any new machine designed will always play DVDs.

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