Exploring recordable DVD

Recordable DVD drives - or DVD writers, as they are sometimes called - are virtually standard equipment on new PCs these days.

If you don't already have one, fitting one is a cinch, thanks to the wide availability of internal and external drives, and prices start from around £200.

Given that the cost of blank discs has dropped to just over a pound a pop, recordable DVD seems an appealing accessory, but is it any more than that?

DVD-Rom drives have been available for several years but the only software to exploit the medium's huge capacity are encyclopaedias and clip-art collections.

So is recordable DVD a solution looking for a problem, or are there really some applications for which it's ideal? To help you decide, we set about finding out just what you can and can't do with recordable DVD.

Making movies
Before recordable DVD drives were widely available or affordable, anybody wanting to showcase a home movie that had been digitally edited on a computer had three options: gather the family around the monitor; copy it to video cassette (and lose much of the quality) or write it to a recordable CD in VideoCD format and play it in a domestic DVD player.

The last option depends upon the player being able to recognise recordable CDs, which some DVD players are unable to do.

Recordable DVD offers some important advantages over CD. Firstly, you can record your movies at a significantly higher quality, thus taking full advantage of a digital camcorder's own extremely high level of quality.

Secondly, you can fit a full hour of DVD-quality footage onto each disc, compared with an hour at best on a VideoCD.

Recordable DVD does not completely overcome compatibility issues, as not every DVD player understands every format of recordable DVD on the market, but the attraction of being able to enjoy professional-quality movies might still warrant an upgrade.

As a further option, a clever (but complicated) compression technology called DivX - the self-billed 'MP3 of video' - reduces DVD video file sizes dramatically without a significant drop in quality.

This means you can fit several full-length movies on a single disc. Unfortunately, you can't then watch them on a DVD player, which rather defeats the purpose. At present, DivX remains strictly for computer use, best suited to shrinking videos for sharing on the internet.

Bigger backups
If backing up your files is a good thing, being able to back them up more easily can only be a better one. DVD scores serious points here because it has an enormous advantage in terms of capacity over CD.

In fact, you need six times as many CDs per backup as you do DVDs. At the very least, this means much less swapping of discs with DVD and a good deal less faff, which should in turn encourage you to back up more regularly.

Furthermore, recordable DVD may even change your backup regime. You might be used to copying the contents of your My Documents folder and perhaps your emails to CD, but what would happen if Windows sustained fatal damage and your computer refused to restart?

At best, you may find yourself having to reinstall Windows and all of your software from scratch; at worst, if you no longer have original installation CD-Roms or serial numbers, you may end up woefully out of pocket.

The answer is a disk image; that is, an exact duplicate of your entire hard disk (or any partition within it). This can be restored in its entirety should disaster strike, or folder by folder if the situation is less severe.

However, even with compression, image files are typically several GBs in size. DVD is thus a far more suitable medium for storing image files than CD, Zip disks or heaven help you, floppies.

The two leading disk imaging programs, PowerQuest Drive Image and Norton Ghost, conveniently chop large image files into DVD-sized chunks, or better still, let you back up directly to a recordable DVD drive.

Vision ...
Set aside a rainy afternoon, weekend or winter, and dig out those shoeboxes stuffed with sepia snaps. Now go into overdrive with a scanner and scan every family photo ever taken through the generations. With a transparency adaptor, you can even capture old slides and negatives.

Finally, copy the resulting digital images to a recordable DVD and you have one complete archive of your family preserved forever.

Since a recorded DVD can be read in just about any DVD-Rom drive, you can distribute copies to any family member who has a computer.

For a more interesting approach, you should consider using software like Microsoft Photo Story to make a photographic slideshow complete with a soundtrack and special effects.

This can then be copied to a recordable CD (in the VideoCD format) and played back on a DVD player. However, while you can copy a much longer slideshow to a DVD than a CD, it is not so simple.

You first need to convert the slideshow into a DVD-compliant Mpeg-2 file and then use DVD-authoring software to burn the disc as if it was a standard DVD movie.

This is as big a rigmarole as it sounds but an application such as the free TMPGEnc will handle the format conversion for you.

... sound ...
You can also copy a substantial amount of MP3 music onto one DVD. In fact, a single disc can play non-stop on a computer's DVD-Rom drive for around 72 hours without repeating a track, outlasting even the wildest weekend-long party.

There is a snag, though. While many DVD video players will happily decode and play MP3 files that have been recorded on a CD, the same is not true of recordable DVD. Even a DVD player that recognises all recordable formats will return a frustrating error message when fed an MP3 DVD.

There is a workaround of sorts that involves turning individual MP3 files into a continuous movie soundtrack - the "movie" itself need be nothing more than a single frame - but it's horribly complicated and probably not worth doing unless you're really desperate.

... and dodgy ground
Finally, there's always the possibility of ripping and copying other CDs and DVDs. You could, for instance, fit dozens of smallish programs on a single DVD or make a direct copy of a large DVD release like a multimedia encyclopaedia and continue until you've backed up your entire software collection.

You might see this as a form of insurance against loss or damage but the copyright cops will take a different view. You could even make copies of commercial movies if you have the patience and will to work with encryption-cracking software.

The catch, as we reported in issues 132 and 138, is that this kind of thing is illegal - at which point we consider it best to leave it as a matter between you, your conscience and your solicitor.

Best practice
At the end of the day, a recordable DVD can be seen as a big CD or a very, very big floppy disk. You use it in much the same way for much the same purpose and the added convenience of greater capacity is genuinely useful, particularly for backups and digital archival.

Ultimately though, it is exclusively the technology's inherent suitability for making and importantly, sharing high-quality home movies that sets it apart from its predecessors and makes it a must-have for video enthusiasts.

Sizing up
So how big is a DVD anyway? The first thing to appreciate is that a 4.7GB disc is not 4.7GB in size at all but rather 4.37GB. Disc manufacturers use the gigabyte = one billion bytes definition, whereas to your computer, a gigabyte is calculated as 1024 x 1024 x 1024 bytes (1,073,741,824 bytes).

The consequence is that only 4.37GB of computer data fit on a disc. That eternal confusion aside, what can you store on a single DVD? Here's a rough and ready reckoner of how many files can be stored on each:

ITEM/PER DVD/PER CD

Word text documents / 1,000,000 / 160,000

Jpeg images / 6,000 / 960

MP3 files / 1,100 / 180

Windows XP disk image / 3 (with no other applications installed) / 0.45

One-hour movie / 1 (DVD-quality) / 1 (VideoCD quality) or 0.5 (SVCD quality)

Stop the rot
One of the great unknowns about DVD media is lifespan. The history of recordable CD is not particularly encouraging in this respect, with some discs reportedly degrading after only a couple of years or even mere months (a degraded disc develops errors and can become completely unreadable).

If you were one of recordable CD technology's early adopters, now would be a very good time to dig out your old discs and copy their contents to DVD, or even just to fresh CDs, while you still can.

Paying a premium for branded media over cheaper unlabelled discs may help and certainly can't hurt. It's also wise to make multiple copies of DVDs that you intend to archive.

We suggest going even further and keeping a separate copy of important files on a hard disk for safe-keeping. Further still, be prepared to transfer your DVD recordings to a more robust form of media in the future.

The bottom line, which we are just beginning to reach, is that optical media may simply be unsuited to long-term storage. Back to the drawing board, then.

CONTACTS:

DivX
www.divx.com

PowerQuest
www.powerquest.com

Microsoft
www.microsoft.com/uk
(Photo Story is part of the Plus! Digital Media Edition pack)

Symantec
www.symantec.com

TMPGEnc
www.tmpgenc.net

Recordable DVD formats
DVD-Ram
A record/rewrite format that's great for data storage and time-shifted video recording. However, DVD-RAM discs can't be read by DVD-Rom drives, nor can they be played in DVD video players.

DVD-R/RW (the 'dash' or 'minus' formats)
Ideal for data and movies, the only problem being limited compatibility with some older video players and drives.

DVD+R/RW (the 'plus' formats)
Offer the greatest all-round compatibility and the format's future is seemingly secure with Microsoft backing it.