High-definition optical disc format war that involved compressing HD content onto dual-layer DVD-9 discs. In spite of this decision, the DVD Forum's Steering Committee announced in April 2002 that it was pursuing its own blue-laser high-definition solution. In August, Toshiba and NEC announced their competing standard Advanced Optical Disc, which was finally adopted by the DVD Forum and renamed "HD DVD" the following year after being voted down twice by Blu-ray Disc Association members, prompting the U.S. Department of Justice to make preliminary investigations. Three new members had to be invited and the voting rules changed before the initiative finally passed. The competing standards had
Optical disc rotation (Constant linear velocity (CLV), Constant angular velocity (CAV), or zoned-CAV), the composition of lands and pits, and how much margin is unused is at the center and the edge of the disc. Second-generation optical discs were for storing great amounts of data, including broadcast-quality digital video. Such discs usually are read with a visible-light laser (usually red); the shorter wavelength and greater numerical aperture allow a narrower light beam, permitting smaller pits and lands in the disc. In the DVD format, this allows 4.7 GB storage on a standard 12 cm, single-sided, single-layer disc; alternatively, smaller media, such as