HD DVD had declined to say whether the 51 GB disc was compatible with existing drives and players. Specification 2.0 Part 1 (Physical Specification) for triple layer HD DVD had been approved in November 2007. At the CES 2007, Ritek revealed their high definition optical disc process that extended both competing high definition formats to ten layers, increasing capacity to 150 GB for HD DVD and 250 GB for Blu-ray Disc. A major obstacle to implementing this technology in either format (150 GB HD DVD will not be developed due to HD DVD's discontinuation) is that reader-writer technology available may not be
DVD-Audio DVD-Audio DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio uses most of the storage on the disc for high-quality audio and is not intended to be a video delivery format. DVD-Audio has much higher audio quality than most video DVDs containing concert films or music videos. The first discs entered the marketplace in 2000. DVD-Audio was in a format war with Super Audio CD (SACD), and along with consumers' tastes tending towards downloadable music, these factors meant that neither high-quality disc achieved considerable market penetration; DVD-Audio has been described as