Recordable DVDs: Working in harmony

This feature should be sponsored by Nurofen. If you've given any thought to investing in a recordable DVD drive, you may well have concluded that the current fractured market is a bit of a shambles - and you would be right.

With no fewer than five recording formats to choose from, and with drives still retailing at upwards of £100, making a purchase is neither straightforward nor something you want to get wrong.

Yet the benefits are compelling. You can fit 4.37GB of files on a single DVD (discs are misleadingly labelled as 4.7GB), so back-ups become a breeze.

You can make your own full length, high quality, Hollywood style movies and share them with friends. You can also capture a remarkable 72 hours' worth of MP3 music, plus you can copy it to (or play it on) any computer equipped with a DVD-Rom drive and most DVD players.

In short, recordable DVD is the worthy and natural successor to recordable CD, but compatibility is the key. Wouldn't it be rather galling if the DVD player in your living room spat back your discs with an error message when you tried to watch your movie-making results on your TV?

A brief but acronym-ious history
To muddle through this maze, you need to understand a little about the various recordable formats.

First up is DVD-Ram. Like a hard disk, a DVD-Ram drive can read and write data to a disc simultaneously. This makes it ideal for specialist applications such as video recording; you can watch one pre-recorded programme while simultaneously recording another.

This is more the stuff of home entertainment than computers, though, so you'll commonly find DVD-Ram discs used in domestic DVD recorders of the type designed to replace tape-based VCRs.

DVD-Ram discs can be reused (they are 'rewriteable') and come with or without protective covers called caddies, although they cost a packet.

Importantly for our purposes, they cannot be read in a standard DVD-Rom drive or played in a DVD player. This, then, is not the format of choice if you want to share your output.

Next up are the two so-called 'dash' (or, somewhat pejoratively, 'minus') formats, established by Pioneer and the DVD Forum. You will see these written on the page and in product boxes as DVD-R and DVD-RW.

As in the lingo of recordable CDs, the 'R' stands for 'recordable' (use once) and 'RW' for 'rewriteable' (use many times over). Since a DVD-RW drive can use both -R and -RW discs, -R capability is glossed over.

DVD-RW is ideal for recording both data and video discs, with one traditional, significant drawback. When the first drives hit the market (-R in 1997, -RW in 1999), many DVD players (the ones that sit under your TV and play films) could not read their discs.

So along came the breakaway DVD Alliance - original members included HP, Philips and Sony - with an alternative format known as 'plus'. Again, there are recordable and rewriteable variations, expressed respectively as DVD+R and DVD+RW but again, a DVD+RW drive can handle both.

Recognising that recordable DVD technology would only take off commercially if people could watch their home-recorded videos on a television set rather than a monitor screen, the plus format promised and delivered greater compatibility with DVD players.

Share cares
So what can we say for certain about the compatibility of each format with anything other than itself? Well, just to stress the point one last time, DVD-Ram discs are only compatible with DVD-Ram drives. When it comes to the -RW and +RW formats, the waters muddy. Here are the need-to-know facts:

• Most computer DVD-Rom drives can read -RW and +RW discs, so sharing files is usually no problem.

• All recordable DVD drives can read DVD-Rom discs. They can also read audio CD, CD-Rom, CD-R and CD-RW. In fact, most recordable DVD drives can do CD recording as well, which is a handy bonus.

• A +RW format drive can usually read a -RW format disc, but never record to it and, of course, vice versa.
• Most new DVD players can read both -RW and +RW discs. Older players typically do better with the plus format, but this should not be taken as gospel. For instance, our ageing Zenith DVD player read everything except, surprisingly, DVD+RW.

• If you use an Xbox or PlayStation 2 for DVD video playback, it should cope with home-burned discs, but we can offer no guarantees. Users report that experimenting with different brands of disc can help overcome snags.

That's quite a collection of 'most', 'typically' and 'usually' qualifiers, for which we can only apologise. However, it is simply impossible to state unequivocally that any given disc burned on any given drive in any given format will play on any given device or in any other given drive.

Regardless of what the manufacturers or box blurbs proclaim, nothing is certain in the suck-it-and-see world of DVD recording.

Which DVD for me?
Choosing the most appropriate recording format from the perspective of compatibility rather depends on your starting point. For instance, if you only intend to make discs for use solely on your own computer then any format, even DVD-Ram, will suffice.

However, do consider that one day you might need to access your discs on a different system. For example, your computer may be stolen and you have to reinstate back-ups on its replacement. This makes -RW or +RW a safer bet, as you wouldn't have to shell out for another DVD-Ram drive.

If you already own a DVD player and intend to make movies, find out which formats the player supports and shop for a drive accordingly. If the manual doesn't make this clear, a little online research should help (try searching through Google).

Alternatively, if you already own a recordable DVD drive, be sure to buy a DVD player that can cope with its output.

As noted above, most new players handle all formats perfectly. Better still, sidestep compatibility concerns with a multi-format recordable DVD drive. There are three types to choose from:

• DVD-Ram and DVD-RW
• DVD+/-R/RW (DVD+R, -R, +RW and -RW formats combined)
• DVD+/-R/RW (DVD+R, -R, +RW, -RW) and DVD-Ram. All five recording formats in one device.

If you're keen to increase your options, any one of these should do nicely. Incidentally, while Microsoft has famously joined the DVD Alliance and backs the +RW format on grounds of technical superiority (it is almost as well suited to drag-and-drop recording as DVD-Ram), the next generation of Windows will support all DVD formats.

For future reference
The near future at least seems certain to see more multi-format drives and more read-anything devices coming to market. Indeed, it is just possible that there won't be a winner in the DVD format wars in the conventional sense.

One parallel reminds us that VHS ultimately demolished the rival - and some still say technically superior - Betamax format.

Then again, not so long ago, two incompatible and competing dial-up internet access technologies called K56flex and X2 gave everyone with a modem a migraine, only for peace to break out in a face-saving unifying standard called V.90.

So the -RW and +RW camps may just manage to coexist in uneasy harmony until something better comes along and does away with them both.

In fact, the stage is currently being set for a whole new recordable DVD format confrontation in the shape of Blu-ray versus Advanced Optical Disc, but perhaps we'll postpone that particular headache for another day and another issue of Computeractive.

In for the long haul
Compatibility is one thing, but how about a long-term survival strategy? A toddler can destroy a DVD in seconds with jammy fingers or a marker pen, and even a single scratch on the disc can render it jumpy or unusable, so it pays to treat your discs with care before, during and after a recording job.

For really important jobs - a treasured home movie, say, or a hard disk back-up - consider TDK's specially-coated 'ScratchProof' media, available in all R and RW formats (see www.tdk-europe.com).

There is evidence that CDs and DVDs degrade over time, and it might follow that unbranded media will degrade more quickly owing to cheaper chemicals, poorer manufacturing processes and the like.

We don't know for sure, however, and we're reluctant to recommend spending more on media than you need to. For truly critical back-ups, why not make duplicate copies on different brands of media? That way, if one disc degrades 10 or 20 years down the line, you should still have a functional alternative.

Beside all that, here's the funny thing: the cutting-edge DVDs you burn today will be obsolete eventually, thanks to the relentless march of technology.

To ensure immortality, the answer is to upgrade your digital archives whenever you move to a new drive technology. That way, you'll still be able to access your archived holiday videos in the days when we think about DVD as we do punched cards now.

DVD compatibility
We threw a selection of discs at some recordable DVD drives and tested the results in a host of DVD-Rom drives and DVD players. While we found no differences between pricey branded and cheaper, unlabelled media, the recording drive did have a bearing.

For instance, two of our DVD-Rom drives initially balked at both the -RW and +RW formats. However, when we then burned the same media using a different recorder, one of the DVD-Rom drives finally managed to read a +RW disc. Alas, it faltered with -RW and the second DVD-Rom drive still couldn't read either.

Unfortunately, predicting these situations, or even saying anything concrete about them with the hindsight of trial and error, is impossible.