Once upon a time, a DVD seemed like a massive amount of storage, but now that hard disks have reached a terabyte in size, even dual-layer DVDs are starting to look inadequate. It was clear that a new optical format was needed but, like London buses, now that we've waited for some time, two have arrived at once: Blu-ray and HD-DVD. Our first taster comes in the form of LG's reassuringly cryptic GBW-H10N Blu-ray burner.
Aside from more satisfying storage, the primary reason for the existence of Blu-ray and HD-DVD is the data required by high-definition video. Using MPEG-2 compression, a DVD can pack a two-hour movie into less than 8.5GB, using a data rate of 8Mbits/sec. But the video is at a resolution of 720 x 576 (in Europe), whereas the top HD resolution is 1080p - or 1,920 x 1,080 - exactly five times as many pixels per frame. Even using more efficient compression, such as MPEG-4 AVC H.264, a DVD clearly has insufficient space. Hence Blu-ray and HD-DVD were born. The former packs 25GB per layer, and the latter 15GB, and both are currently capable of supporting dual-layer discs, although more than two layers have been demonstrated for both formats.
There are currently three different options for video compression on Blu-ray and HD-DVD: the venerable MPEG-2, Microsoft's VC-1 (a derivative of Windows Media Video 9), and MPEG-4 AVC H.264. However, whichever compression is used, the same content protection system called AACS is applied to commercial discs. Unlike DVD's CSS, which applies a static key for entire ranges of players, AACS uses a different key for each device. CSS was broken very quickly, and couldn't then be fixed, as the same key was used in every DVD player - break the key, and everybody's DVD player would be broken. With AACS, the content industry is hoping for better luck, as it's much easier to simply blacklist the compromised key. So, theoretically, only the culprit device will be disabled, rather than an entire range of hardware or software.
When playing Blu-ray and HD-DVD movies, the encryption system extends beyond the player, so the drive and playback software aren't the only parts that need to be kosher. The signal is also encrypted when sent across any digital link to a display, such as DVI or HDMI. This part of AACS is called HDCP, and both your graphics card and monitor need to support it for a PC Blu-ray drive to play commercial Blu-ray movies. As you can tell, the movie studios are trying not to take any chances, and have succeeded in dictating a series of draconian designs to hardware and software manufacturers. Playing commercial Blu-ray discs isn't as easy as playing DVDs - you can't just pop in the drive and be sure that everything will work. You won't be alone then, if you smile when we tell you that the convoluted HDCP chain has inspired a hacker called muslix64 into cracking AACS.
At least LG has kept its part of the bargain, since unlike Samsung's early SH-B022 Blu-ray drive, which had no AACS support on release, its GBW-H10N is ready to show Blu-ray movies. In theory, LG's drive is also a cut above Pioneer's BDR-101A. Whereas the latter boasts single-speed burning to BD-RE (re-writable Blu-ray discs), and dual-speed to BD-R (write-once Blu-ray discs), the LG doubles both figures. The Pioneer also lags behind the LG in nominal DVD writing and re-writing speeds, topping out at 8x for DVD-R and +R, while LG claims 12x in both cases. The LG also reads and writes CDs, unlike the Pioneer, although its write speed is a miserable 8x.
PERFORMANCE Since the LG is the first Blu-ray drive we've had in the lab, we had to add a few extra tests on top of our usual suite of optical drive benchmarks. As well as writing files to Blu-ray discs, we also compared video playback between Blu-ray and DVD versions of the same commercial movie release. For the burning test, we gathered together a 23GB mixture of files. To assess movie playback quality, we called upon the excellent S.W.A.T. - a film so bad, even cops dial 911 to report it as a crime against humanity.
All the tests were performed with the LG hooked up to our current graphics test rig, based around an Intel Core 2 Extreme X6800 clocked to 3.19GHz, with 2GB of RAM on Intel's 'Bad Axe' D975XBX motherboard. We equipped this with an HDCP-compatible ATi Radeon X1900GT connected to Dell's gob-smacking 30in 3007WFP TFT via DVI, with CyberLink's PowerDVD Ultra as the software video player.
Of course, we were desperate to see how much better Blu-ray movies look than DVDs, so this was the first test we performed. However, there's a bit more to Blu-ray than there is to DVD, thanks to the paranoia we described earlier about content protection. This made itself evident during our testing. Although the Dell 3007WFP allegedly supports HDCP, as indeed does our chosen graphics card, both commercial Blu-ray discs movies we tried to play failed, aborting after a few seconds. However, a Blu-ray video we had burned ourselves from HD camcorder footage played without a hitch. There was another curious glitch as well. We initially tried playing the movies with the Dell monitor set to its maximum 2,560 x 1,600 resolution, but even our homemade video appeared to be zoomed into the top left-hand corner. Only when we reduced the resolution to 1,920 x 1,080 did video playback appear normal, although the commercial discs still wouldn't play.
When we switched to a 24in Samsung SyncMaster 244T TFT with a native 1,920 x 1,200 resolution, the Blu-ray movies played faultlessly. We haven't managed to confirm that the 3007WFP has problems with its HDCP support, although our results would seem to point in this direction.
While the Blu-ray version of S.W.A.T. was noticeably better quality than the DVD version, the differences weren't as eye-popping as you might expect. The detail was clearly superior, and the dynamic range improved as well. But if you're expecting to be blown away by the difference, then you might feel a little disappointed if you're watching on a 24in display. From our experience, a massive screen or projector is required to really see the benefit of Blu-ray.
Although LG claims less than cutting-edge DVD writing and re-writing speeds for its drive, we didn't find its performance much below par. Indeed, while the latest 18x DVD writers, such as Samsung's Super-WriteMaster SH-182M, can despatch a DVD+R in five minutes and 22 seconds, the LG took only 27 seconds longer. Writing to DVD-R with the LG was slower, but it would have been a respectable result even if the drive were rated at 16x. The DVD re-writing tests were hampered by a lack of 8x DVD+RW media, but the LG performed as expected with our 4x DVD+RW and 6x DVD-RW media. Dual-layer performance was only marginally slower than you'd expect for a 4x drive, although drives now boast 8x dual-layer writing, and compatible discs are readily available.
You probably won't be buying the LG for its DVD writing abilities, however. Its performance when writing to Blu-ray wasn't great though. Although the drive boasts 4x writing and 2x re-writing, only 2x media is currently available. As a result, it took more than two hours to write or re-write Blu-ray. It will be a big relief when 4x media becomes more widely available. Rounding off performance, CD writing is as miserable as you'd expect for an 8x drive, but at least it can read CDs at a respectable 40x.
CONCLUSION It's easy to become excited by the concept of Blu-ray - or HD-DVD for that matter. Hooked up to a projector and a massive screen, HD video is a big step closer to a cinematic experience at home, even if the improvements aren't as obvious on a 24in TFT computer screen. The LG is also reasonably well executed and, with its respectable DVD writing performance and CD capabilities, it ranks as the first Blu-ray drive to arrive with the features required to replace your DVD burner. Just take a look at the price though. It isn't a misprint - the LG is nearly £450, and this is likely to be a better form of content protection than anything that AACS or HDCP can supply.
Author: James Morris
LG GBW-H10N