digital versatile disc
(foldoc) | Digital Versatile Disc
Digital Video Disc
DVD
DVD-R
DVD-ROM
(DVD, formerly "Digital Video Disc") An optical
storage medium with improved capacity and bandwidth compared
with the Compact Disc. DVD, like CD, was initally marketed
for entertainment and later for computer users. [When was it
first available?]
A DVD can hold a full-length film with up to 133 minutes of
high quality video, in MPEG-2 format, and audio.
The first DVD drives for computers were read-only drives
("DVD-ROM"). These can store 4.7 GBytes - over seven times
the storage capacity of CD-ROM. DVD-ROM drives read existing
CD-ROMs and music CDs and are compatible with installed
sound and video boards. Additionally, the DVD-ROM drive can
read DVD films and modern computers can decode them in
software in real-time.
The DVD video standard was announced in November 1995.
Matshusita did much of the early development but Philips made
the first DVD player, which appeared in Japan in November
1996. In May 2004, Sony released the first dual-layer drive,
which increased the disc capacity to 8.5 GB. Double-sided,
dual-layer discs will eventually increase the capacity to 17
GB.
Write-once DVD-R ("recordable") drives record a 3.9GB DVD-R
disc that can be read on a DVD-ROM drive. Pioneer released
the first DVD-R drive on 1997-09-29.
By March 1997, Hitachi had released a rewritable DVD-RAM
drive (by false analogy with random-access memory). DVD-RAM
drives read and write to a 2.6 GB DVD-RAM disc, read and
write-once to a 3.9GB DVD-R disc, and read a 4.7 GB or 8.5 GB
DVD-ROM. Later, DVD-RAM discs could be read on DVD-R and
DVD-ROM drives.
Background (http://tacmar.com/dvd_background.htm). {RCA
home (http://imagematrix.com/DVD/home.html)}.
(2006-01-07)
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