City Gloss

There are a layer HD DVD with a capacity of 15 GB (about 4 hours of HD video) and dual-layer, with a capacity of 30 GB. Toshiba has announced it is in development with triple-layer disc, which would reach the 51 GB capacity (17 GB per layer). In the case of HD DVD-RW capabilities are 20 and 32 GB, respectively, for one or two layers. The device transfer rate is estimated at 36.5 Mbps HD DVD work with a violet laser with a wavelength of 405 nm. Otherwise, an HD DVD is much like a conventional DVD. The outer layer of the disc has a thickness of 0.6 mm, the same as the DVD and the numerical aperture of the lens is 0.65 (0.6 for the DVD). All these data lead to the production costs of HD DVD discs are somewhat shorter than those of Blu-ray, because its characteristics are very similar to the current DVD. The video compression formats used by HD DVD MPEG-2 Video Codec 1 (VC1, based on Windows Media Video 9) and H.264/MPEG-4 AVC.In the aspect of copy protection, HD DVD uses an improved version of CSS DVD, AACS, which uses a 128-bit encryption. Then there is the inclusion of the ICT (Image Constraint Token), which is a signal that prevents high-definition content on media traveling unencrypted and therefore capable of being copied. In practice, what it does is limit the output video to 960×540 resolution if the cable from the player’s analog television, even high definition television support. The ICT is not compulsory and each company will decide freely whether or not add to their titles. For example, Warner is in favor of its use while Fox is against it. The AACS requires that titles should use the ICT clear in the box. The HD DVD format introduces the possibility to access interactive menus style pop-up “and thereby substantially improve the limited capacity of its predecessor, the DVD player, which had a special track dedicated to the film menu.The HD DVD makes its foray into the gaming world after Microsoft’s announcement of the placing of an extender for HD DVD for its popular Xbox 360 console.