(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).