According to Abbreviationfinder, HD DVD stands for High-density digital versatile disc. It was an optical storage format developed as a standard for high-definition DVD by Toshiba, Microsoft and NEC companies, as well as various film production companies, it can store up to 30 GB.
This format finally succumbed to its immediate competitor, Blu-ray, as it became the standard successor to DVD. After the downfall of many HD DVD supports, Toshiba decided to stop making more players and continue research to improve its format.
There are single-layer HD DVDs, with a capacity of 15 GB (about 4 hours of high-definition video) and double-layer, with a capacity of 30 GB. Toshiba has announced that a triple layer disk is in development, which would reach 51 GB capacity (17 GB per layer).
In the case of HD DVD-RW the capacities are 15 and 30 GB, respectively, for one or two layers. The transfer speed of the device is estimated at 36.5 Mbps. Image: HD DVD.jpg | thumb | right
HD DVD works with a violet laser with a wavelength of 405 nm.
Otherwise, an HD DVD is very similar to a conventional DVD. The outer layer of the disc is 0.6mm thick, the same as DVD, and the numerical aperture of the lens is 0.65 (0.6 for DVD).
All these data lead to that the production costs of HD DVD discs are somewhat lower than those of Blu-ray, since their characteristics are very similar to those of current DVD.
The video compression formats that HD DVD uses are MPEG-2, Video Codec 1 (VC1, based on the Windows Media Video 9 format), and H.264 / MPEG-4 AVC.
On the copy protection side, HD DVD makes use of an improved version of the DVD CSS, AACS, which uses 128-bit encoding. There is also the inclusion of the ICT (Image Constraint Token), which is a signal that prevents high definition content from traveling on unencrypted media and therefore susceptible to being copied.
In practice, what it does is limit the video output to the resolution of 960×540 if the cable that goes from the player to the television is analog, although the television supports high definition.
The ICT is not mandatory and each company freely decides whether or not to add it to their titles. For example, Warner is in favor of its use while Fox is against it. The AACS requires that titles using the ICT must clearly mark it on the box.
The HD DVD format introduces the possibility of accessing interactive pop-up-style menus, which substantially improves the limited capacity of its predecessor, the conventional DVD, which had a special track dedicated to the film’s menu.
HD DVD makes its foray into the world of video games following Microsoft’s announcement of the marketing of an HD DVD extender for its popular Xbox 360 console.
The 19 of November of 2003, the DVD Forum members decided, with results from eight to six votes, that HD DVD would be the successor of the DVD for HDTV. At that meeting, it was renamed, until then, “Advanced Optical Disc”. The Blu-ray Disc media, which is of greater capacity, was developed outside the DVD Forum and was never put to a vote by it.
The current specification for HD DVD and HD DVD-RW is version 1.0. The specification for the HD DVD-R is at version 0.9.
On February 19, 2008, Toshiba, at a press conference, announced the end of the production and distribution of HD DVD, giving Blu-ray the victory in the so-called “Format War.”
Compatibility with previous technologies
There are already hybrid drives capable of reading and writing CDs, DVDs, and HD DVDs. It has also been possible to develop a hybrid DVD and HD DVD disc, so that you could buy a movie that can be seen on current DVD players and also have high definition if it is inserted into an HD DVD player.
However, such discs need double-sided (on one side DVD double layer and on the other HD DVD single layer), because the data layer is the same in both formats. A single-sided hybrid disc with one layer of DVD and one layer of HD DVD has been achieved.
To support your understanding of the subject, we offer you an animation on the basic operation of an HD-DVD within its respective reader unit:
Animation of an HD-DVD inside the drive, being read by the drive’s laser beam
The HD-DVD integrates a long spiral track to record the information. Each bit is represented by a small slot, which, depending on its depth, determines whether it is a zero or a one.
To read the data, the laser beam from the reader unit uses the physical phenomenon of diffraction against the reflective surface of the disk and determines the depth of the groove; While in the case of writing, depending on the power of the blue laser beam applied to the surface of the disk, the groove will be marked in a different way and will determine the bits (a zero or a one).
This process is commonly called “burning”, if the computer is not receiving data from the HD-DVD, CD or DVD, the disc will still spin at a minimum speed.
HD-DVD Readers and Writers
It is a technology that failed to be introduced to the commercial market, but some reading devices were developed that are mounted in the computer case and allow the reading of HD-DVD discs.
Companies that supported HD DVD
Computer and electronics companies supporting HD DVD included Canon Inc., Digital Theater Systems, Hitachi Maxell Ltd., Intel, Kenwood Corporation, Microsoft, Mitsubishi Kagaku Media Co., Ltd., NEC Corporation, Onkyo Corporation, Sanyo Electric Co., Ltd., Teac Corporation.
Movie studios backing HD DVD included Universal Studios, Paramount Home Entertainment, Dreamworks, The Weinstein Company, Image Entertainment, Magnolia Pictures, Brentwood Home Video, Ryko, Koch / Goldhil Entertainment. It should be noted that Warner Bros., although initially supporting HD DVD, has announced that it will stop producing movies in this format, and thus, will only support Blu-Ray.
HD DVD is currently discontinued, as Toshiba Corporation accepted defeat against the other medium: Blu-ray. These are the words commented by the president of Toshiba corporation: Atsutoshi Nishida: “We have valued the long-term impact of continuing the Next Generation Format War, and we have concluded that a quick decision will be the best for the development of the market.”.
This situation for HD DVD is very bad because now no more HD DVD players or recorders will be promoted, manufactured or marketed. The Toshiba president ended by saying: “We are very disappointed by the company and by the consumers.”
Differences between HD DVD, HD-VMD, Blu-Ray and DVD
Decryption of AACS security of HD DVD discs
At the beginning of 2007, a key was discovered that allows removing the AACS protection from HD DVD and Blu-ray discs  and playing the medium in any operating system, such as the Linux operating system, and in a player that is not necessarily considered. as allowed.
The lawsuit of the AACES Licensing Authority against several Internet sites demanding the elimination of the key from the sites where it was published, alleging violation of the DMCA, generated a great controversy that particularly affected the Digg news site.