James Delahunty
17 Jan 2006 5:54
In an interview with Betanews, Toshiba expert and HD DVD representative Mark Knox, gave some details about the HD DVD optical disc drive technology and also downplayed advantages held by Blu-ray while highlighted some problems with the Sony-developed format. One of the first things he highlighted was Blu-ray's numerical aperture, which is rumored to be the cause of production problems for Blu-Ray. The aperture setting on standard DVD is 0.6, with the setting for HD DVD a slightly smaller 0.65.
The additional capacity is then provided by the blue laser technology. On the other hand, Blu-ray has adopted a 0.85 aperture. This means the divots on the optical layer are smaller and more prone to errors. It also requires a thinner disc and smaller layer spacing, making the disc even more vulnerable. At first, Blu-ray discs were designed with an external cartridge to protect the disc, but now the group is utilizing a protective coating which has not yet been finalized.
Knox also explained why he believed the higher storage capacity advantage held by Blu-ray wasn't a very big issue, at least for movies. He said through the use of better codec technology, an extra 20GB is not needed. The Blu-ray group also revealed to Betanews that most movie discs will not go over the 25GB mark. Knox then went on to point out the manufacturing issues with Blu-ray disc. HD DVD's requirements are similar to those of DVD, eliminating manufacturing problems, whereas there will be little room for error in the Blu-ray manufacturing process, as well as the reading of discs by Blu-ray players, he said.
This could lead to a much higher production flaw rate. Next he refuted claims by the Blu-ray group that its use of Java for interactivity features will make development easier. He explained that the group is actually using a specification from Europe called JEM, which has a high number of instructions, making it "nearly impossible for hardware manufacturers to ensure devices will function under any circumstance." He claimed through HD DVD's use of iHD, a DHTML-based specification, the HD DVD group can verify that every disc will play on every player.
Another issue with Blu-ray is a requirement placed on the group after signing a deal with Fox. Fox demanded to be able to use a stronger copy protection technology in addition to AACS. The HD DVD group rejected the demand but Blu-ray conceded. Fox is unhappy that consumers might be able to use Mandatory Managed Copy to watch movies wherever they please around their homes. The DRM being pushed by Fox could theoretically restrict Mandatory Managed Copy. Managed Copy has been an issue for months ever since Hewlett-Packard demanded that Blu-ray require the technology on all discs.
Betanews also questioned Knox about the notion of limited content in the HD DVD format. He acknowledged that HD DVD does not have as many studios supporting it as its rival touts. However, he said that of the American Film Institute's Top 100 movies, more than 60 were from studios supporting the HD DVD format, and that the group was going to focus on quality and not quantity. He accused the Blu-ray group of simply wanting "as many logos as possible on their PowerPoint slide."
Source:
Betanews