High definition dvd

[Gustak]

Hi,

Can some one give me detail about High definition dvd or what you can a HD-DVD. What are the capacities of the disks HD DVD ? i would also like to know about HD-DVD's Compatibility with the existing DVD players which comes with usb and DIvx format support.

Thank you

[Raine]

Originally known as the Advanced Optical Disc (Advanced Optical Disc or AOD), the high definition DVD is in fact an optical disc that uses laser technology blue-violet edge to provide records from a very large capacity and a transfer rate of data very high. Joint Toshiba / NEC, two of approximately 60 manufacturers, these companies have proposed and developed the specifications of the original format. First for the "high-definition video to consumers, the vast storage capacity and transfer rates very high HD DVD discs enable them for archiving and, ultimately, for other applications .

The same physical size as a DVD (12 cm), the HD DVD offers greater densities of data and tracks, which gives between three and six times the storage capacity of a DVD-R regular 4.7 Gb, This fascinating ability is made possible with the use of laser technology at 405 nm (405 thousands of a meter) to blue-violet light (actually violet-purple, see Figure 1) and a scanning head with lens numerical aperture of 0.65 inches. Because the light blue-violet laser has shorter wavelength (405 nm) than red light (650 nm) used in CD and DVD systems, it allows the laser to allow smaller items on the disc surface. As each bit occupies less space, it is possible to store more data on a disk of 4.7 inches.

[JonathanD]

HD DVD has a capacity per layer of 15 GB for a total of 30 GB with dual layer HD DVD. Recently, Toshiba announced a triple layer disc experimental, with a capacity of 51 GB which would enable the disk to be read by a platinum DVD or HD DVD, in fact, two layers are used for storing high-definition content, while the third would be engraved with the characteristics of a standard DVD. Another triple layer completely high definition allows for its hosting 51 GB of data, increasing the capacity of each layer at 17 GB. The protective layer which protects the data layer of HD DVD is 0.6 mm thick the same as the DVD, while Blu-ray is about 0.1 mm d 'thickness. This technology uses a laser diode operating at a wavelength of 405 nm to read and write data. The 2 formats are compatible with DVDs and use the same compression techniques: MPEG-2, Video Codec 1/VC1 format based on Microsoft Windows Media 9/WMV format and H.264/MPEG-4 AVC.

[ThoMas321]

HD DVD discs are backward compatible with DVDs since they adopt the same structure as the related systems DVD red laser currently in use, including the same thickness of surface layer and the same process of reproduction.In fact, the surface layer of an HD DVD is of a thickness of 0.6 mm, exactly the same as that of a standard DVD. It should be noted that the existing DVD players have no ability to play HD DVDs. However, the HD DVD players manufactured with retro compatibility function, can read DVD discs.