High Definition Players:

Make the most of your HDTV with HD content

By The Vann’s Editorial Team

In the era of high-definition television, home entertainment technology must be able to convey the massive amounts of audio and visual information involved in creating high-definition content. High-definition televisions offer native 1080p resolution, HD digital tuners and HDMI inputs to access content broadcast in hi-def. If you've invested in a 1080p television, wouldn't it be nice to get content at that level from all your sources? Some television networks broadcast in HD, but what about your DVD library? Sadly, current DVD technology is not capable of providing high definition content. Using a red laser to read and write data on a disc, DVDs hold around 5 GBs of information. Of those 5 GBs, only about 20 percent is the actual movie. Around 40 percent is the audio content, and the remaining 30 to 40 percent covers the menus and "special features." This often means that the audio content is only in stereo or 5.1-channel, or on rare occasions, DTS. And the video portion is standard definition. In essence, current DVDs don't deliver all the entertainment features your 1080p television can handle.

You've probably heard, however, of the newest format being touted by manufacturers and the entertainment industry. A new breed of DVDs that can hold up to five times as much content as current DVDs that lets studios offer high definition content for home viewing, including better picture quality, up to 7.1-channel surround sound, and extensive menu and special-features options. But, wait, you don't have just one option, you have two!

HD DVD and Blu-ray are the two newest DVD formats, offering expanded space on a disc the same size as traditional DVDs. Each uses a blue-violet laser, which has a shorter wavelength than the red laser used in current DVD technology. The blue-violet laser can be focused with greater precision so data is packed more tightly and takes up less space. In this way, a disc of the same physical proportions that can store only 5 GBs using a standard red laser can store 15 (HD DVD) to 25 (Blu-ray) GBs on a single layer disc or 30 (HD DVD) to 50 (Blu-ray) GBs on a dual layer disc using a blue-violet laser.

The proportions of content are roughly the same (20-30 percent actual movie, 40 percent audio, and 30-40 percent menus and special features). But with that much additional space, everything is expanded. First, the visual content is increased into high-definition, meaning the picture is crisp, colorful and rich, with a resolution of up to 1080p. The audio reaches its full potential through stereo, 5.1, Dolby Digital True HD, 7.1, and DTS. Sound is pure and smooth. But the best part may be all the space for special features. Typically, a DVD includes some deleted scenes, maybe some commentary by the director, and possibly some still photos. Discs using the new technology include interactive menus, footage that didn't make it into the final cut — such as outtakes, deleted scenes, and alternate endings — multiple versions of the movie such as widescreen, 4:3, the uncensored version, and the director's commentary version. And that's only the beginning of the possibilities. Games, music videos, or anything related to the movie can fit on the disc. The possibilities are endless.

So if both HD DVD and Blu-ray offer these benefits, what's the difference, you ask? Here's a brief rundown of each of these high definition technologies.

HD DVD

Toshiba and Hitachi are HD DVD's founders and main supporters, providing research and development as well as marketing efforts. The format officially approved by the DVD Forum, HD DVD is more alike current DVD than is Blu-ray. Though the blue-violet laser can write more closely packed information, which is obvious with the HD DVDs ability to store 15 GBs of information on a single-layer disc and 30 GBs on a dual-layer disc, its physical construction is the same as red-laser DVDs. This means that production requirements for HD DVD discs are not that different than today's DVD discs, so there isn't a huge jump in price.

HD DVD even offers up to a triple-layer disc, meaning a total storage capacity of 45 GBs of information on one disc. The goal is to make both the discs themselves, and the players, backward compatible. The HD DVD group is working to make sure the disc contains the red-laser version of the movie so it can play in a standard DVD player. Many HD DVD players offer a red laser to read non-HD DVDs. Content protection, specified by AACS LA, is part of current HD DVD offerings, and Audio Watermark Protection may be used in the future. With these content protection technologies, HD DVD players identify and refuse to play discs that have been illegally copied.

One of the key attributes of the higher-content discs is the ability to include more specialized features, such as interactivity. For HD DVD, this has been an easy transition. Interactive content is developed using the HDi Interactive Format, a technology governing such interactive features a s playlist files, subtitles, menus, bookmarks, and picture-in-picture.

At this point, Universal Studios is exclusively backing HD DVD, and Paramount Pictures, the Walt Disney Company, Warner Bros., and Buena Vista Home Entertainment are producing both HD DVD and Blu-ray versions of their movies. There are currently over 300 videos available in the HD DVD format, with more coming soon.

Blu-ray

Almost as soon as red-laser DVDs became part of the home-entertainment industry, Sony began working on an improved format. These efforts produced the Blu-ray available today. Using the same laser as HD DVD technology, Blu-ray actually writes information more densely than its competitor, allowing for great storage. That's why a Blu-ray disc will hold 25 GBs in a single-layer and 50 GBs in a double-layer disc. However, in order for the laser to be able to read the more closely packed information, a thinner protective surface layer, called a hard-coat, made of different material than that for HD DVD is applied to the Blu-ray disc. At 0.1 mm, it's much thinner than the 0.6 mm protective layer used by DVD and HD DVD. With this difference, production of the Blu-ray discs becomes more complicated and therefore more costly, making Blu-ray discs and players more expensive than their competitors.

Blu-ray's dual-layer disc offers 50 GBs of storage, which can handle four hours of high-definition MPEG-2 video content. While it isn't mandatory, the Blu-ray Disc Association (the body governing manufacturers of Blu-ray technology) recommends that manufacturers include backward-compatibility in their products. Blu-ray players are, therefore, able to read and write CD, DVD, and Blu-ray discs. One of the associated companies, JVC, is working on technology that would allow Blu-ray discs to play on standard red-laser DVD players, but that technology isn't currently available.

To protect content, Blu-ray utilizes its own digital rights management technology called BD+. The Mandatory Managed Copy system is also part of their protection feature. In this system, while a user can copy content to a limited extent, he or she must first register with the content provider to get permission. ROM-Mark is another form of protection, where a watermark is inserted into ROM-based media during replication, which Blu-ray players will then check for. Finally, Blu-ray must also follow the guidelines set by AACS.

Blu-ray primarily uses Sun Microsystem's Java software to author interactive components. There is the future possibility of updating Blu-ray content on the internet via a Java virtual machine, opening a whole new realm of possibilities for the depth of Blu-ray disc content and interactivity.

Studios exclusively backing the Blu-ray format include 20th Century Fox, Electronic Arts, MGM Studios, Sony Pictures Entertainment, and Vivendi Universal Games. Of course, previously mentioned studios (Buena Vista, Paramount, Disney, and Warner Bros.) are supporting both Blu-ray and HD DVD.

Currently, over 400 titles have been released on Blu-ray Disc.

HD DVD and Blu-ray both offer advanced audio and video codecs along with a tremendous amount of storage space. Together, these features allow manufacturers to deliver an unprecedented HD experience. While Blu-ray discs store more data, they are more costly to produce and so more costly to purchase compared to the HD DVD format. Both are backed by a number of big-name studios, and both formats appear in gaming systems.