Dolby Digital

How it works single layer disc contains a new format three times more information than the layer DVD. On single-layer disc can accommodate up to 15 gigabytes of data on two levels – up to 30. The developers had submitted three-layer HD DVD version with a total capacity of up to 51 gigabytes. The capacity of each layer in the latter case was increased to 17GB, though compatibility with players, released until 2007, is not guaranteed. As a file system can be used ISO 9660 or UDF version 2.5. It supports all video formats, from low-quality CIF (352×288) and standard SDTV (720×576) to all types of HDTV (1280×720, 1920×1080), coded as in distributed by MPEG2, and in the new VC-1 and AVC.

Audio – 2 channels to 8 channels 24bit/192kHz 24bit/96kGts encoded in PCM, DTS, Dolby Digital EX, Dolby Digital Plus and Dolby True HD. Supported and additional audio track – in formats DTS-HD High Resolution Audio or DTS-HD Master Audio. In the drive uses a blue-violet laser with a wavelength of 405 nm, numerical aperture is much lower than in the blu-ray (0,85), slightly higher than that of DVD (0,6) and is 0.65. The protective layer is the same as in the DVD – 0,6 mm. It is this increased thickness of the protective layer has led to the fact that each information layer of the format contains less information than the layers of blu-ray discs – through such a thickness can not focus the laser beam so as compact as a competing technology. .

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