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Microsoft Longhorn To Support HD DVD Format
MSDVD writes "Microsoft's Japanese Division reported that its upcoming operating system, code-named Longhorn, will support HD DVD format. HD DVD is an enhanced version of the standard DVD technology. According to online reports, Microsoft is pushing the next-generation blue-laser DVD technology like NEC and Toshiba. Blue-light technology can read and write data much faster and at higher densities, which is needed for high-definition content. Few Japanese companies said they will have HD DVD content based DVDs by next year to support the players."
I'm glad that Microsoft will support this :)
English is easier said than done.
HD DVD is a blue laser disc format but the manufacturing techniques are similar to those for red-laser discs.
As explained the main difference is that BluRay places the recording layer 0.1 mm below the surface of the media to maximize data capacity at around 27gb for single and 54 gb for dual layer. This will require disc manufacturers to build new factories because this is completely different from DVD and CD specifications. Because of this the layer of protective plastic will be very thin which some have speculated will initially require either a special layer of protective plastic which has been reported to decrease reliability or it will require the discs to be contained in a cartridge (think magneto-optical). Carts would, of course, increase production costs and REALLY increase end user costs.
HD DVD places the recording layer at 0.6mm below the surface which is currently the standard used by DVD so that DVD manufacturing plants can make either format discs on the same assembly lines. This is at a cost, though, with a reduced capacity at 15gb for single layer and 30 gb for dual layer. And, of course, the existing protective layer will be sufficient as it is the same as the standard DVD.
The actual codecs supported will be the same for both formats. Both will support MPEG-2, MPEG-4, and (probably) Microsoft's WM9 codecs. As part of Microsoft's deal to get WM9 included in the HD DVD spec it was forced to open the specification to allow competitors to make products for encoding and decoding. Their benefit will be a share of the royalties for products that encode or decode HD-DVD content and sales of encoding/decoding software that they produce, but the deal does not include in any way a monopoly on encoder/decoder software.
The main difference, as stated, is the distance for the recording layer from the surface of the media which changes the maximal capacity because of the effect on the intensity of the laser as it passes through the media.