- (nonstandard) Alternative spelling of HD DVD.
- High-Definition/Density DVD.
(1) See also HD DVR.
(2) (High Definition DVD) A short-lived, high-capacity optical disc that held four hours of HD video on a single-sided, single-layer 15GB disk. Sanctioned by the DVD Forum in 2003, it gave way to Blu-ray in 2008. HD DVD was based on the Advanced Optical Disc (AOD) technology from Toshiba and NEC and used a blue-violet laser that read pits half the size of a DVD on tracks packed tighter together. Like Blu-ray, HD DVD supported 1080p resolution and advanced video codecs (see H.264 and VC-1). An advantage for media manufacturers was that, unlike Blu-ray, traditional DVD stamping machines needed only minor modifications to make HD DVDs. The first HD DVD drives were sold in the U.S. in 2006, and Microsoft offered the drive as an Xbox option. Despite its features and support, in 2008, the majority of movie studios and retail outlets chose Blu-ray over HD DVD, and the "format war" was over. HD DVD Formats Used for commercial movies, HD DVD-ROMs were pressed and read only. HD DVD-Rs were recorded once by the user, and HD DVD-RWs were rewritable. Hybrid HD DVDs were announced with HD DVD on one side and DVD on the other. In an attempt to resolve competition, dual-format HD DVD/Blu-ray players were also developed (see "Blu-ray History" in Blu-ray). See HD formats, DVD and DTV. FULL-SIZE HD DVD (120mm) CAPACITIES SINGLE SIDED DOUBLE SIDED HD HD Layers Storage Hours Storage Hours Single 15GB 4 30GB 8 Dual 30GB 8 Triple 51GB 14