The next step in DVD technology is high definition DVD or HD-DVD. Right
now there are at four different, non compatible formats. Remember the VHS
Beta max wars? when video tape first came out this is what's happening with
DVDs. HD-DVD-9
This uses a red 650 nm laser like current DVDs. Instead of the current
MPEG-2 compression it will use a new codec. The ROM version is slated for
8.5 GB with a bit rate of 11 mps in contrast to the 10 mps of the current
commercial DVD. Shorter films can be set to up to 1080i resolution Advanced Optical Disc
This employs a blue-ultraviolet laser in the 405 nm range and will hold up
to 15 GB of data per side in ROM mode or 20 GB for a film. The same data
depth (how deep the actual layer is) is still 0.6mm like current DVDs. The
bit rate is 36 mps. It is being pushed by Toshiba and NEC. Blu-Ray
This format will hold up to 27 GB per side and has a data depth of 0.1mm. If
the dual layer format takes hold you can potentially have up to 50 GB on a
disc. This will provide about 10 hours of audio/video in standard definition
and a bit rate of 4.7 mps.
Blue-HD-DVD-1 and Blue-HD-DVD-2
These are formats similar to the Blu-Ray but are being explored by Taiwan's
Industrial Technology Research Institute. The ‘1’ version uses a 0.6 mm data
depth while the ‘2’ has the 01 mm. Both use a 405 nm laser
