| HD DVD, High Density DVD, or | | | | applied to current red laser DVDs in 5, |
| High-Definition DVD is a high-density | | | | 9, 15 and 18 GB capacities which offers |
| optical disc format designed for the | | | | a lower-cost option for distributors, |
| storage of data and high-definition | | | | this type of disk is often called 3x DVD |
| video. | | | | as it has three times the bandwidth of |
| History | | | | regular DVD video. |
| The HD DVD disc is designed to be the | | | | Like the original DVD format, the data |
| successor to the standard DVD format. It | | | | layer of an HD DVD disc is 0.6 mm below |
| can store about three times as much data | | | | the surface. The numerical aperture of |
| as its predecessor. (15 GB per layer | | | | the optical pick-up head is 0.65, |
| instead of 4.7 GB) The HD DVD standard | | | | compared with 0.6 for DVD and 0.85 for |
| was jointly developed by a group of | | | | Blu-ray aperture. Both of the new |
| consumer electronics and PC companies, | | | | formats are backward compatible with |
| spearheaded by Toshiba. On November 19, | | | | DVDs and both employ the same video |
| 2003, the DVD Forum voted to support HD | | | | compression techniques: MPEG-2, Video |
| DVD as the HDTV successor of the | | | | Codec 1 (VC-1) and H.264/MPEG-4 AVC. |
| standard DVD. At this meeting, they also | | | | File systems |
| renamed it HD DVD. The format had | | | | Like previous optical disc formats, HD |
| previously been called the "Advanced | | | | DVD supports several file systems, like |
| Optical Disc" (AOD). | | | | ISO 9660 and Universal Disk Format |
| At CES 2006, Microsoft announced that | | | | (UDF). Currently, all HD DVD titles use |
| there would be an external add-on HD DVD | | | | UDF version 2.5 as the file system, the |
| drive for the Xbox 360 game console; | | | | same one used for Blu-ray releases. |
| this was released in November 2006. Also | | | | Audio |
| at CES [1]2006, companies backing HD DVD | | | | HD DVD can be mastered with up to 7.1 |
| said that nearly 200 titles would be | | | | channel surround sound using linear |
| available for the format by the end of | | | | (uncompressed) PCM, Dolby Digital, Dolby |
| the year. | | | | Digital EX, DTS and DTS ES formats also |
| On March 31, 2006, Toshiba released | | | | used on DVDs. In addition, it also |
| their first HD DVD player in Japan at | | | | supports Dolby Digital Plus and the |
| Y110,000 ($934).[2] HD DVD was released | | | | lossless formats Dolby TrueHD and DTS |
| in United States on April 18, 2006,[3] | | | | HD. Currently, most DVD movies are made |
| with players priced at $499 and $799. | | | | with 5.1 channels of surround sound. |
| The current specification version for HD | | | | There are relatively few titles that |
| DVD-ROM and HD DVD-Rewritable is version | | | | offer 6.1 channels of surround sound. On |
| 1.0. The specification for HD DVD-R is | | | | HD DVD the Dolby formats are mandatory, |
| currently at 0.9. The first HD DVD-ROM | | | | meaning that a Dolby Digital, Dolby |
| drives were expected to be unveiled by | | | | Digital Plus or Dolby TrueHD track may |
| Q4 2006, with mass production to start | | | | be used as the sole soundtrack on a |
| in Q1 2007. The actual product launch of | | | | disc, because every player will have a |
| both CE and PC units occurred in late | | | | decoder that can process any of these |
| 2006. As of December 2006, more than | | | | bitstreams. For lossless audio in movies |
| 120,000 HD DVD's had been sold in the | | | | in the PCM, Dolby TrueHD or DTS-HD |
| United States.[citation needed] | | | | formats, HD DVD discs support encoding |
| As of February 2007, HD DVD is in a | | | | in up to 24-bit/192 kHz for two |
| format war with Blu-ray Disc. | | | | channels, or up to eight channels of up |
| Technical specifications | | | | to 24-bit/96 kHz encoding. For |
| Hardware | | | | reference, even new big-budget Hollywood |
| HD DVD has a single-layer capacity of 15 | | | | films are mastered in only 24-bit/48 |
| GB and a dual-layer capacity of 30 GB. | | | | kHz, with 16-bit/48 kHz being common for |
| There is also a double-sided hybrid | | | | ordinary films. |
| format which contains standard DVD-Video | | | | Video |
| format video on one side, playable in | | | | The HD DVD format supports a wide |
| regular DVD players, and HD DVD video on | | | | variety of resolutions, from |
| the other side for playback in high | | | | low-resolution CIF and SDTV, all video |
| definition on HD DVD players. These | | | | resolutions supported by the DVD-Video |
| hybrid discs make retail marketing and | | | | standard, and up to HDTV formats such as |
| shelf space management easier. This also | | | | 720p, 1080i and 1080p.[6] All movie |
| removes some confusion from DVD buyers | | | | titles released so far have had the |
| since they can now buy a disc compatible | | | | feature encoded in 1080p, with |
| with any DVD/HD DVD player in their | | | | supplements in 480i or 480p. Most titles |
| house. The HD DVD format also can be | | | | are encoded with VC-1. |