HD-DVD (High-Density Digital Versatile Disc) is a type of optical storage capable of storing up to 30GB of storage, developed as standard for high-resolution DVDs by Toshiba, Microsoft and NEC companies and various filmmakers.
HD-DVD Definition and Features
Since this format was based on standard DVD, its rival was lost to Blu-ray. However, after many of HD-DVD’s support subsided, Toshiba decided to stop making more products and continue researching to improve its format.
Later, Toshiba announced the development of a three-layer drive that will reach 51 GB capacity (17 GB per layer).
There are single layer HD-DVDs with a capacity of 15 GB and a double layer with a capacity of 30 GB. And their capacity is 15 and 30 GB, respectively, for one or two layers. The transfer rate of the device is estimated to be 36.5 Mbps.
This format works with a purple laser with a wavelength of 405 nm and is very similar to a traditional DVD. The outer layer of the disc is 0.6mm thick, the same as DVD, and the lens has a numerical aperture of 0.65.
All these data results in the production costs of discs being slightly lower than Blu-ray because their features are very similar to today’s DVD.
In terms of copy protection, CSS of 128-bit encoding uses an enhanced version of AACS.
It also includes ICT (Image Constraint Token), a signal that prevents high-definition content from being transferred in unencrypted media, and therefore can be copied.
In practice, if the player is high definition, but the cable from the player to the television is analog, it limits the video output to 960×540 resolution.
ICT is not mandatory and every company can freely decide whether to include it in their titles. AACS requires titles that use ICT to clearly indicate this in the box.
This format offers access to interactive pop-up menus that significantly increase the limited capacity of traditional DVDs, which has a special track dedicated to the movie’s menu.
It stepped into the world of video games after Microsoft announced the release of an HD-DVD extender for the popular Xbox 360 console.
On November 19, 2003, DVD Forum members decided, with eight to six votes, that HD-DVD will be the successor to DVD for HDTV. At this meeting, it was renamed Advanced Optical Disc until then.
The larger capacity Blu-ray Disc media was developed outside of the DVD Forum and never voted.
Valid features for HD-DVD and HD-DVD-RW are available in versions 1.0 and 0.9.
Toshiba announced at a press conference on February 19, 2008, that its production and distribution was over.
There are already hybrid readers that can read and write CDs, DVDs, and HD-DVDs.
It was also possible to develop a hybrid DVD and HD-DVD disc so that you can purchase a movie that can be seen on existing DVD players and also be high-definition if plugged into a player.
However, since the data layer is the same in both formats, such disks must be double-sided. Later, a unilateral hybrid disk was obtained containing both layers.
Includes a long spiral piece to record information. Each bit is represented by a small slot that determines whether it is zero or zero depending on its depth.
To read the data, the laser beam of the reading unit uses the phenomenon of physical diffraction against the reflective surface of the disc, and in writing, determines the depth of the slot during writing, depending on the strength of the blue laser beam. As a result, the surface of the disk will be marked differently and will determine the bits.
If the computer does not receive data from HD-DVD, CD or DVD, this process is often referred to as writing, the disc will still spin at minimum speed.
Players and Recorders
It is a technology that fails to be put on the commercial market, but some reading devices have been developed that are computer-mounted and allow discs to be read.
Electronics and computer companies that support HDDVD include Canon Inc, Digital Cinema Systems, Hitachi Maxell Ltd, Intel, Kenwood Corporation, Microsoft, Mitsubishi Kagaku Media Co Ltd, NEC Corporation, Onkyo Corporation, Sanyo Electric Co Ltd, Teac Corporation.
Film studios that support this format include Universal Studios, Paramount Home Entertainment, Dreamworks, The Weinstein Company, Image Entertainment, Magnolia Pictures, Brentwood Home Video, Ryko, Koch/Goldhill Entertainment.
It should be noted that although Warner Bros. initially supports HDDVD, it will announce that it will stop producing movies in this format and therefore only support Blu-Ray.
This format is not currently produced as Toshiba Corporation accepts defeat against other media, Blu-ray.
This is very bad for high-density DVDs because more players or recorders will no longer be introduced, produced, or sold in this format.
The head of Toshiba concluded by saying: “The company and consumers were very disappointed with us.”
In early 2007, a key was discovered that allowed you to remove AACS protection from HDDVD and Blu-ray discs and play the media on any operating system such as the Linux operating system, and on an absolutely allowed player.
The lawsuit filed by the AACES Licensing Authority against various Internet sites claiming the removal of the password from the sites where the DMCA has been allegedly infringed has created a major controversy, particularly affecting the Digg news site.