Blu-ray

What is Blu-ray Disc and how did it come about?
Blu-ray Disc is an optical medium that's used primarily to store large quantities of data or video. But how does it differ to the traditional DVD?

Well, Blu-ray Disc, also known as simply Blu-ray, utilises a blue laser to read and write data to and from the disc. The blue laser operates at a 405 nanometre wavelength - considerably shorter than the 650 nanometre wavelength associated with the red laser used on traditional DVDs.

As a result, and despite measuring the same 12cm in size, a single two-layer Blu-ray disc can store a substantial 50GB of data, significantly more than the 8.5GB capacity of a single two-layer DVD.

But why would we need so much storage on a disc? After all, DVDs have served us well for over a decade. The answer is high-definition movies. DVDs have become the medium of choice for standard-definition movies, but they simply don't provide the capacity required to store high-definition material.

Approximately two hours of high-definition video at a 1080p resolution (1,920x1,080) can consume around 25GB of storage capacity when encoded in MPEG-2 video. It offers greatly-improved image quality, but brings with it the need for larger-capacity optical discs.

In steps Blu-ray and HD DVD. The latter, as you may be aware, was developed by Toshiba as a similar blue-laser alternative to Blu-ray. Having launched in March 2006, HD DVD competed bitterly against Blu-ray until poor sales and lacklustre studio support led to Toshiba announcing the discontinuation of the format in February 2008.

The news left Blu-ray as the sole mainstream successor to DVD, and the format has since grown rapidly to offer over 1,000 movie titles since November 2008.

Developed and promoted by the Sony-led Blu-ray Disc Association, Blu-ray technology has reaped the benefits of being integrated into Sony's PlayStation 3 gaming console. With a Blu-ray drive available in each PlayStation 3 console, the numbers of global Blu-ray users rose rapidly and many believe this to be the deciding factor in HD DVDs demise.

Today, Blu-ray remains the sole consumer option for high-definition movies on an optical medium. Despite higher-than-DVD prices, sales of both Blu-ray players and Blu-ray discs are steadily increasing.

Is it just more storage and better image quality?
Blu-ray is most commonly associated with high-definition visuals and improved image quality, but there are other benefits, too.

The sheer capacity of a Blu-ray disc also allows for improved audio. Although Blu-ray capable devices are required to provide support for only Dolby Digital, DTS and linear PCM, there is optional support for Dolby Digital Plus, Dolby TrueHD, DTS-HD and DTS-HD Master Audio.

Furthermore, Blu-ray movies can take advantage of the extra capacity to include extra bonus material, and in order to protect a Blu-ray disc from everyday wear-and-tear, each disc features a hard-coating polymer layer on its surface.

Then there's a little something called BD-J, which stands for Blu-ray Disc Java. BD-J makes use of Sun Microsystems' Java software environment to create more sophisticated menus and superior special features than those available on DVD. These include interactive menus, picture-in-picture and internet-based bonus material.

Consumers should be aware, however, that not every Blu-ray player can provide all of the aforementioned functionality. At present, Blu-ray players are distinguished by three specific profiles; 1.0, 1.1 and 2.0.

Early Blu-ray players labelled as 1.0 don't include on-board memory and support for features such as picture-in-picture. Whilst Blu-ray profile 1.1 remedies these omissions, it itself is lacking support for internet connectivity. Blu-ray profile 2.0 - at present the most up to date - requires a player to include the capability for an Internet connection, often via a single Ethernet port. By doing so, it allows consumers to take advantage of Blu-ray's complete feature set, including the web-based BD-Live.

Are there any disadvantages?
We've established that Blu-ray is bigger and better, but what else do you need to know? First and foremost, both Blu-ray players and media tend to be more expensive than their DVD counterparts. Secondly, should you happen to take the plunge and opt for a Blu-ray device, you'll require a HD-ready television to take advantage of that increased resolution and image quality.

There's also a matter of region coding. Although most Blu-ray discs from the major Hollywood studios are launched without region-specific restrictions, users should be aware that the restrictions do exist and should you happen to come across a Region A disc, it's unlikely to play on a Region B player.

Blu-ray's region coding is designated as follows:
Region A: East Asia (except Mainland China and Mongolia), Southeast Asia, North America, South America and their dependencies.

Region B: Africa, Southwest Asia, Europe (except Russia), Oceania and their dependencies.

Region C: Central Asia, East Asia (Mainland China and Mongolia only), South Asia, central Eurasia and their dependencies.

What does the future hold for Blu-ray?
As is often the case, each optical medium is eventually superseded by a superior format. For Blu-ray, that threat appears to exist in the form of digital distribution - a method of delivering services via the Internet. Sounds interesting? You can learn more about this technology in our digital distribution TekSpek.

Today, Blu-ray is the de facto standard for high-definition material via an optical medium. If you're looking to watch the latest movies in full high-definition quality, it could be the right technology for you.