HD DVD (High Density DVD, High-Definition DVD or High Definition Digital Video Disc) is a high-density optical disc format designed for the storage of high-definition video and data.

Overview

The HD DVD name is derived from its origination as a high-definition extension of the DVD optical disc format. An HD DVD disc can store substantially more data than a standard DVD, because of the shorter wavelength (405 nm) of the blue-violet laser (DVDs use a 650-nm-wavelength red laser and CDs an infrared 780 nm laser), which allows more information to be stored digitally in the same amount of physical space. In comparison to Blu-ray Disc, which also uses a blue laser, HD DVD has less information capacity per layer (15 gigabytes instead of 25). HD DVD shares the same basic disc structure as a standard DVD: back-to-back bonding of two 0.6 mm thick, 120 mm diameter substrates. The 30 GB dual-layer HD DVDs have been used on nearly every movie released in this format.

The HD DVD standard was jointly developed by a group of consumer electronics and PC companies, spearheaded by Toshiba. It is currently competing with the Blu-ray Disc format for wide adoption as the preferred next generation optical standard, similar to the videotape format war between VHS and Betamax.

On November 19, 2003, the DVD Forum decided that they would back the HD DVD to be the HDTV successor of the DVD. At this meeting they renamed it to HD DVD, while it had been previously called the 'Advanced Optical Disc' (AOD). This is not a very surprising extension of the previous DVD-R/RW versus DVD+R/RW war, where - (dash) was the format defended by DVD Forum, and + (plus) the format defended by the DVD+RW Alliance. The DVD Forum generally has focus on CE (Consumer Electronic) and Japanese market development (where CE happens to be very strong). The DVD+RW Alliance has invested more on the PC market with technologies such as Background Formatting and defect management through 'Mount Rainier' (unreleased).

At CES 2006, Microsoft announced that there will be an external add-on HD DVD drive for the Xbox 360 game console, due in late 2006. Also at CES 2006, 'companies backing HD DVD said that nearly 200 titles would be available for the format by the end of the year.'

On March 31, 2006, Toshiba released their first HD DVD player in Japan at ¥110,000 ($934). HD DVD was released in United States on April 18, 2006, with players priced at $499 and $799.

The current specification version for HD DVD-ROM and HD DVD-Rewritable is version 1.0. The specification for HD DVD-R is currently at 0.9. The first HD DVD-ROM drives were expected to be unveiled by Q4 2006, with mass production to start in Q1 2007. The actual product launch of both CE and PC units occurred in late 2006.

HD DVD has a single-layer capacity of 15 GB and a dual-layer capacity of 30 GB. Toshiba has announced a triple-layer disc which offers 45 GB of storage. HD DVD can offer both the current DVD and HD DVD formats on one disc, which means that special HD DVD discs will play in any DVD player, old or the new high definition players (similar to the Blu-ray/DVD hybrid developed by JVC). This makes retail marketing and shelf space management easier. For consumers, shopping is simplified as they can simply buy a movie that plays in any DVD player in their house, standard definition or high definition. The HD DVD format also can be applied to current red laser DVDs in 5, 9, 15 and 18 GB capacities which offers an even lower cost option to content owners wanting to sell short form content.

The data layer of an HD DVD disc is 0.6 mm below the surface, akin to the common DVD. The numerical aperture of the optical pick-up head is 0.65, compared with 0.6 for DVD and 0.85 for Blu Ray aperture and 0.1 surface layer (a smaller surface layer larger numerical aperture allow for tighter focus and so increased data density). Both of the new formats are backward compatible with DVDs and both employ the same video compression techniques: MPEG-2, Video Codec 1 (VC1) and H.264/MPEG-4 AVC. However, the Blu-ray format is clearly inferior in light of recent comparisons.

HD DVD can be mastered with up to 7.1 channel surround sound using the linear (uncompressed) PCM, Dolby Digital and DTS formats also used on DVDs. In addition, it also supports Dolby Digital Plus and the lossless formats Dolby TrueHD and DTS HD. Currently, most DVD movies are made with 5.1 channels of surround sound. There are relatively few titles that offer 6.1 channels of surround sound. On HD DVD the Dolby formats are mandatory, meaning that a Dolby Digital or Dolby Digital Plus track may be used as the sole soundtrack on a disc, because every player will have a decoder that can process any of these bitstreams. For lossless audio in movies in the PCM, Dolby TrueHD or DTS-HD formats, HD DVD discs support encoding in up to 24-bit/192 kHz for two channels, or up to eight channels of up to 24-bit/96 kHz encoding. For reference, even new big-budget Hollywood films are mastered in only 24-bit/48 kHz, with 16-bit/48 kHz being common for ordinary films.

The HD DVD format supports a wide variety of resolutions, from low-resolution CIF and SDTV up to HDTV formats such as 720p, 1080i and 1080p. All movie titles released so far have had the feature encoded in 1080p (although the only player currently available that supports 1080p is the Xbox 360 HD-DVD drive), with supplements in 480i or 480p. Most titles are encoded with VC-1.

Physical size Single layer capacity Dual layer capacity Triple layer capacity
12 cm, single sided 15 GB 30 GB 45 GB
12 cm, double sided 30 GB 60 GB 90 GB
8 cm, single sided 4.7 GB 9.4 GB
8 cm, double sided 9.4 GB 18.8 GB

Backward compatibility will be available with all HD DVD players, allowing consumers to have a single drive in their homes to play both HD DVD and DVD discs. There is also a hybrid HD DVD which contains both DVD and HD DVD versions of the same movie on a single disc, providing smoother transition for the studios in terms of publishing movies, and letting consumers with only DVD drives to still use the discs. DVD disc replication companies can continue using their current production equipment with only minor alterations when changing over to the format of HD DVD replication. Due to the structure of the single-lens optical head, both red and blue laser diodes can be used in smaller, more compact HD DVD players.

HD DVD uses a blue-violet 405 nm laser to read information from the disc (DVDs use red 650 nm lasers).

The shorter wavelength reduces diffraction and maintains a smaller spot size of the laser. This allows data to be read from a higher density on the disc surface. While DVDs and HD DVDs will be the same size physically, the ability to store data at a higher density results in a larger total data capacity in HD DVDs.

Commercialized HD DVDs integrate content protection technology specified by AACS LA (Advanced Access Content System License Authority). 'Audio Watermark Protection' is also being considered by AACS for use on HD DVD. If Watermark is adopted by AACS, all HD DVD players will have a sensor that listens for inaudible audio watermarks in the soundtrack of movies. Studios may insert this invisible mark in the soundtracks of theatrical motion pictures. If an HD DVD player does not detect the invisible mark, it means the disc is playing back a copy made from a theatrical print (probably from illegal camcording), and will cause the player to refuse to play the disc. The mark is made by varying the waveform of speech and music in a regular pattern to convey a digital code. These variations are too subtle to be heard by the human ear. Another variation of this system can be used to prevent the playback of discs created by using a camcorder and microphone on a home entertainment center playing a legitimate disc purchased by a consumer. This variation for home entertainment utilizes a watermark that differs from the cinema mark in that it is permitted in normal, signed ROM discs, but generally not permitted on recordable discs.

In addition, HD DVD players must follow AACS guidelines pertaining to outputs over analog connections. This is set by a flag called the Image Constraint Token (ICT), which restricts the resolution for analog outputs without HDCP to 960×540. The decision to set the flag to restrict output ('down-convert') is left to the content provider. Warner Pictures is a proponent of ICT, and it is expected that Paramount and Universal will implement down-conversion as well. As of March 2006, 5 of the 6 studios releasing HD DVD content have announced they will not use ICT/down-conversion for the time being. AACS guidelines require that any title that implements the ICT must clearly state so on the packaging.

While there is no Region Coding in the existing HD DVD specification the DVD Forum is currently developing a regional lockout scheme.

HD DVDs use the iHD Interactive Format to allow interactive content to be authored for discs. iHD is based on web technologies such as HTML, XML, CSS, SMIL, and ECMAScript (JavaScript), so authoring in iHD should be a fairly easy transition for web developers. No existing DVD authoring experience is required. In contrast, Blu-ray Disc content is authored using either a scripting environment for basic content, or a Java-based platform (BD-J) for advanced content. DVD video discs utilize pre-rendered MPEG segments, selectable subtitle pictures, and simple programmatic navigation which is considerably more primitive.

The first HD DVD titles released on April 18, 2006 were The Last Samurai, Million Dollar Baby, The Phantom of the Opera by Warner Home Video; and Serenity by Universal Studios.

To date, 125 titles have been released Worldwide, 88 in the United States, and 37 in Japan.

On April 18, 2006, Toshiba released the first HD DVD players for the United States, the Toshiba HD-A1 and Toshiba HD-XA1. They utilize an Intel Pentium 4 processor and contain 1 GB of RAM; the drive mechanism is also an IDE HD DVD drive. The units run a specialized version of the Linux operating system booting off a USB thumbdrive.

On May 16 Toshiba released its first PC with a HD DVD drive, the Toshiba Qosmio 35. This PC is the first to have a slim height optical disc drive. Toshiba's Digital Products Division, introduced Toshiba Qosmio G35-AV600, the latest version of its flagship '4-in-1' audio-video entertainment notebook with new enhancements. The Toshiba G35-AV600 is a complete package featuring Microsoft Windows XP Media Center Edition 2005 and integrated TV tuner, digital video recorder (DVR), virtual surround-sound stereo, and HDMI output. The notebook includes the world's first 1-bit digital amplifier in a notebook PC.

Microsoft has also released an add-on HD DVD drive for the Xbox 360 for $200. The add-on, which attaches to the console via USB 2.0 cable, features component output, but no HDMI output. It outputs 1080p over component for games only. A VGA connection is required for 1080p output from the HD-DVD addon drive. According to Microsoft, the Xbox 360 will not include an internal HD DVD drive in future releases. Toshiba announced second generation HD DVD players for the US this fall, the Toshiba HD-A2 (Expected Pricing and Expected Availability: $499.99, October 2006) and Toshiba HD-XA2 ($999.99, December 2006). The high-end model, the HD-XA2, will feature HDMI 1.3 and 1080p output.

A $150 million dollar advertising campaign is being planned for the HD DVD. The campaign is being handled by Goodby Silverstein & Partners, the same agency that created the 'Got Milk?' campaign.

The campaign will encompass all media: Print, Internet, television, and other outlets. All advertising will boast the tagline 'The Look and Sound of Perfect.' A new Web site was also launched on July 11, 2006, which touts the HD DVD's superior video and audio capabilities and includes trailers of HD DVD movies.

HD DVD is promoted by Toshiba, NEC, Sanyo, Microsoft, Hewlett Packard, Intel, among others. In terms of major studios, HD DVD is currently exclusively backed by Universal Studios and The Weinstein Company (through Genius Products) and is non-exclusively backed by Paramount Pictures, Warner Bros., New Line, HBO, DreamWorks, Image Entertainment, Magnolia Pictures, Brentwood Home Video, Warner Music Group, Ryko, Goldhil Entertainment, and Studio Canal.

HD DVD is product of the DVD Forum which works to promote broad acceptance of DVD products on a worldwide basis, across entertainment, consumer electronics and IT industries. The primary 20 companies involved with the DVD Forum are: Hitachi, Ltd., IBM Corporation, Industrial and Technology Research Institute, Intel Corporation, LG Electronics Inc., Matsushita Electric Industrial Co. Ltd, Microsoft Corporation, Mitsubishi Electric Corporation, NEC Corporation, PIONEER CORPORATION, Royal Philips Electronics, SAMSUNG ELECTRONICS CO., LTD., SANYO Electric Co., Ltd., SHARP CORPORATION, Sony Corporation, THOMSON, Toshiba Corporation, Victor Company of Japan, Limited, Walt Disney Pictures and Television Warner Bros. Entertainment Inc.

Some companies, such as NEC or VidaBox, have developed dual-format or hybrid technologies. NEC is developing a single chip that works with either HD standard, while VidaBox has developed the world's first dual drive compatible player that accommodates both Blu-ray and HD DVD discs.


Wikipedia information about HD DVD. This article is licensed under the GNU Free Documentation License . It uses material from the Wikipedia article 'HD DVD'