Digital Video Disc


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Related to Digital Video Disc: Digital Versatile Disk

Digital Video Disc

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DVD

The standard-definition (SD) optical disc format. Introduced in the U.S. in 1997 and developed by the computer and movie industries, the disc has the same 120mm/4.75" diameter as a CD but holds 4.7GB rather than 700MB. Whereas CDs use only one side, DVDs can be recorded on both sides as well as in dual layers. DVDs have 480 lines of resolution in the U.S. (NTSC) and 576 lines elsewhere (PAL). For high-definition (HD) optical discs with 1,080 lines of resolution, see Blu-ray.

DVD first stood for "digital videodisc;" then "digital versatile disc" and finally just "D-V-D." In practice, DVD refers to all the following DVD formats. Modern DVD drives read and write all CD and DVD formats, except for DVD-RAM, which requires its own drive. For DVD speed ratings (1x, 2x, etc.), see DVD drives. See CSS, DVD region codes and optical disc.

DVD-Video - SD Movies
DVD-Video is the movie format, which uses MPEG-2 compression to provide approximately two hours of video per side at 480i resolution. Blu-ray players also play DVD movies. See DVD-Video, DTV and Blu-ray.

DVD-ROM - Read-Only Data
DVD-ROMs hold data permanently, and like CD-ROMs, they are pressed at the factory. See DVD-ROM.

DVD-R/DVD+R - Recordable (burnable)
DVD-R and DVD+R are competing write-once formats for burning movies or data. They function like high-capacity CD-R discs. DVD-R DL and DVD+R DL are dual layer discs with twice the capacity. See DVD-R and DVD+R.

DVD-RW/DVD+RW - Rewritable
DVD-RW and DVD+RW are competing formats that can be rewritten 1,000 times. Aimed at the consumer, 1,000 rewrites are considered adequate. See DVD-RW and DVD+RW.

DVD-RAM - Rewritable
A DVD-RAM functions like a removable hard disk with a similar file structure. Although DVD-RAMs can be rewritten 100,000 times before they are no longer usable, they are not a popular medium. See DVD-RAM.

DVD-Audio - High-Quality Music
DVD-Audio was designed to supersede the music CD, but like its SACD counterpart, never caught on. However, downloable music is available at the same sampling rates as DVD-Audio. See DVD-Audio and high-resolution audio.

Plus and Minus: +R, +RW, -R, -RW
The formats endorsed by the DVD Forum have a hyphen in their names and are verbalized as "DVD Minus" or "DVD Dash." The competing formats from the DVD+RW Alliance use a plus sign. Starting in 2002, drives supporting both formats were introduced. See DVD Forum and DVD+RW Alliance.

For drive specifications (2x, 4x, 8x, etc.), see DVD drives. For DVD storage specifications, see DVD storage capacities.


Sides and Layers
DVDs come in any combination of single or double sided with single or double layers. This shows the laser beam contacting the recorded surface in all of the possibilities.








DVD vs. CD-ROM
At minimum, the capacity of a DVD is seven times that of a CD-ROM because its tracks, pits and lands are more than twice as dense. It also uses more efficient recording algorithms. Add a second layer or record on both sides of the DVD, and capacity is doubled. (Image courtesy of C-Cube Microsystems.)








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References in periodicals archive ?
Early this year, there were two camps comprising the biggest names in consumer electronics and entertainment, each backing its favorite approach to digital video discs. The two systems were incompatible.
NEW YORK--A group led by Toshiba and Sony last week agreed on common technical specifications for a unified digital video disc standard.
Digital video disc technology, currently being developed by a consortium of manufacturers including Toshiba, Thomson, Sony, Philips and Matshuswta, will take the form of 5-inch compact discs that can play feature-length movies in digital picture and sound.
Initially, DVD stood for Digital Video Disc, but some companies were against having the word video in the name fearing it would not properly convey the versatility of the new format.
A NATIONAL Association of Independent Travel Agencies in the Philippines (Naitas) official has presented to the Department of Tourism the first copy of tour guides' digital video disc (DVD) of Cebu.
DVD, formerly known as digital video disc, will deliver digital audio and video movies on a compact disc.
Cassettes are still the predominant means of recording video, but that may change this fall with the release of Digital Video Discs (DVDs) and Digital Video Disc players, according to media storage vendors.
NEW YORK--Sixty-three percent of people surveyed by Thomson Consumer Electronics said they would definitely or probably buy a DVD (formerly known as digital video disc) player.
LAS VEGAS -- The latest word from Toshiba is that it will send Digital Video Disc players to market sometime during the first quarter of 1997.
The most basic version would be a single-sided SD digital video disc (DVD) with 5 GB capacity - 7.5 times as much as conventional CDs.
The Toshiba group of seven electronics manufacturers favored DVD (the Digital Video Disc), a physical format that bonded together two .6-millimeter layers into a 1.2-millimeter disc that could store a staggering 10 GB (if both sides were used), and about 15 times the capacity of current CD formats.
Nakamura was optimistic about sales next year and said he was looking to the launch of Digital Video Disc products to enhance its sales prospects in 1997.

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