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Blu-ray Disc and HD DVD

Blu-ray Disc (BD) or
High Definition DVD (HD DVD) players

Remember how stunned you were when you started to watch DVDs instead of videos? Well, get ready for another mind-blowing leap of visual quality when you start to play high definition films on one of the new generation Blu-ray Disc (BD) or High Definition DVD (HD DVD) players.

If you’ve recently bought a new television, hopefully you will have made sure that it is HD Ready so that you can take advantage of High Definition television as it emerges. There’s precious little broadcast programming available right now, however, but you can reap the benefits of your investment straightaway by buying a unit that will play pre-recorded HD films and programmes instead. Unfortunately, the Blu-ray and HD DVD formats are not compatible – you can’t play Blu-ray discs on an HD DVD player, and vice versa – so how do you choose between them?

We can help. Although we can’t predict whether Blu-ray or HD DVD will ultimately win out – if indeed one does – by comparing their features here we can let you make a more informed choice about which standard to opt for:

But first, a quick technology lesson

How they work

Firstly, in case you were wondering why it is even worth bothering about high definition television in the first place, here’s a quick description of the difference between standard definition and high definition video. Standard definition video images have a resolution of 720x576 pixels (or 720x480 in the US and Japan). High definition, on the other hand, can be one of a number of resolutions, all of which are much higher: these range from 1280x720 pixels up to 1,920x1,080. All of these extra pixels allow far greater detail. Other benefits tend to include better encoding and less compression. (For more information, see our TV Buying Guide.)

All of this requires a lot more bytes to store the images. Enter Blu-ray and HD DVD. These are optical format disc systems where the information is read from discs that look like DVDs using a blue laser instead of the red ones that are used on DVD players (hence the name Blu-ray). Blue lasers can be focussed more precisely, so these discs can hold several times more information than a standard DVD, making them perfect for storing high definition moving images and accompanying top quality soundtracks.

In both cases, each pixel is actually made up of three separate cells that are red, green and blue, so that the pixel can display any one of billions of colours made up of a combination of red, green and blue light. The TV picture is created from all the differently coloured pixels on the screen.

Even more is on offer, with far better and more interactive menus and extra features than you’ve ever seen on DVDs, including pop-ups that you can browse while watching a movie and even picture-in-picture video on some players. If you have an Internet connection available, you can sometimes even get further related content from the Web.

So far, so good. The downside, though, is that although they both use the same colour lasers, the two standards are not compatible.

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What’s the difference?

Although both standards offer much higher storage capacity than DVDs, Blu-ray discs have a capacity of 25Gb if recorded on one layer and 50Gb for two layers. HD DVD discs, on the other hand, offer 15Gb and 30Gb for one and two layer recordings respectively. Practically this means that a Blu-ray disc could hold around 8.5 hours of high definition video versus HD DVD’s 5.1 hours. You’ll still get an entire film plus extras on either one, but proponents of Blu-ray point out that it has more leeway to offer extra features and audio tracks, and possibly higher quality encoding in future.

However, in some other aspects, the HD DVD specification appears to exceed the Blu-ray one. For example, the HD DVD spec includes, as standard, support for a greater range of audio codecs, some of which, like Dolby TrueHD, are only optional on Blu-ray players. Also standard for HD DVD but optional for Blu-ray is online compatibility. So you need to check the specs a little more carefully for Blu-ray disc players if you want to use one of those optional audio standards or take advantage of any online hook-ups offered by certain films.

Both specifications include mandatory support for the same video encoding standards, so picture quality is more dependent on how any film is encoded, not on which type of player you have (VC-1 and AVC codecs offer better images than MPEG-2).

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Industry support

Both camps boast a long list of industry supporters, but the Blu-ray list is undoubtedly longer. Which list you find more impressive probably relates to your brand preferences or gaming allegiances.

Blu-ray’s key supporters include Sony, Panasonic, Pioneer, Philips and Samsung, as well as computer manufacturers such as Apple and Dell. HD DVD counts the DVD Forum, Toshiba, Intel, Sanyo and Microsoft among its backers.

The support of major movie studios is vital for the success of a technology that is going to be used for watching films, and Blu-ray is again in the lead here, with more studios releasing films on Blu-ray discs than on HD DVD, while a few are supporting both. However, in a major coup for the HD DVD camp, Paramount and DreamWorks announced in August 2007 that they would only release films on HD DVD.

If you tend to rent films rather than buy them, you need to be aware that in the US the rental firm Blockbuster stocks Blu-ray titles in many of its stores but only has HD DVD titles in a limited number of outlets. So you should check what’s on offer near you at the time you plan to buy your player.

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Viewing limitations

One key difference between Blu-ray and HD DVD for UK buyers is that Blu-ray movies are coded by region whereas HD DVD ones currently are not. So while you can buy HD DVD releases in the US (or from US sites that ship to the UK) and they will play in your UK-sourced player, you are limited to European regional versions of Blu-ray discs.

If your choice of technology is strongly influenced by the titles you want to buy or view, make sure you can actually get them in the UK.

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Backwards compatibility

HD DVD players include backwards compatibility with DVDs, while it is optional for Blu-ray players. Some high definition players enhance the DVD signals so that you see a better quality image than when playing them on a DVD player. However, this just applies to standard DVD-ROMs and not necessarily to the other DVD standard variants, including any you may have recorded yourself (such as DVD-R and DVD-RW).

You’ll need to check the specifications of any models you are considering to ensure you will be able to play the discs you want. We advise reading the reviews too, to find out what the quality is like for DVDs and CDs, as the results when they upscale DVDs can vary widely.

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Cost

At the time of writing this guide, it was widely accepted that HD DVD discs and players were cheaper and easier to produce than Blu-ray products, making it a cheaper investment. If you have enough disposable income to buy a player but don’t want to risk more than you need to on a machine that may become obsolete (remember the Betamax vs VHS video player war?), then HD DVD is the better choice – for now.

Whatever way you are tempted to jump, check the specifications carefully to see what standards are implemented in the devices you are considering and read the reviews. Think about what equipment you already have and what else you may need to set up a complete system that really does those high definition videos justice: have a look at our Home Cinema Systems Buying Guide for inspiration.

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Futureproofing

Alternatively, you could look at one of the dual standard (or universal) machines that are emerging. They may not offer all of the optional features for both standards or implement them both perfectly, but they will let you play both types of disc so that you can watch whatever film takes your fancy, rather than being restricted by the preferences of the film studios. Checking the reviews is the best way to find out if this is an option you’ll be happy with.

Your other choice is to opt for a player that doubles up as another device. The Sony PlayStation 3, for example, will play Blu-ray discs or you can buy an add-on for Microsoft’s Xbox 360 which will let it play HD DVDs. In these cases you should check exactly what implementation of the standards you are getting, but at least you know you can continue to play games on them even if the supply of films eventually dries up. (You can find out more about these in our Games Consoles Buying Guide.) Some laptop computers may also feature a high definition video drive.

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Summary of Differences between Blu-ray and HD-DVD
Feature Blu-ray HD-DVD
Storage capacity 25Gb (one layer)
50Gb (two layers) 		15Gb (one layer)
30Gb (two layers)
Maximum hours of HD video Dolby Digital AC-3, DTS, PCM Dolby Digital AC-3, Dolby Digital EX, DTS, PCM, Dolby Digital Plus, Dolby TrueHD
Optional audio codecs Dolby Digital Plus, Dolby TrueHD, DTS HD DTS HD
Video codecs supported MPEG-2, MPEG-4 AVC (H.264), VC-1 MPEG-2, MPEG-4 AVC (H.264), VC-1
Backwards compatibility with DVDs and CDs Optional, so product-dependent Yes for DVD-ROMs; optional for other formats so product-dependent
Regional coding? Yes: three regions (UK is in Region B) No, region-free
Internet support Optional Mandatory

This buying guide was last updated on 8 October 2007 by:
Angela Katsapas.
PriceRunner Content Manager