HD DVD Part 2: Mark Knox, Adviser, HD DVD Promotion Group
Talking about digital rights management in HD DVD and Blu-ray
By Charlie White
In this second part of our multi-part exclusive interview with Mark Knox, CENs Charlie White asks the adviser to the HD DVD Promotion Group about the digital rights management used on both Blu-ray and HD DVD, the similarities between the two formats, and what affect these restrictions will have on consumers.
Knox: Part of the discussion with the studios was that the studios are really, really wanted the option -- it's not a mandate that the option -- for some titles to be able to turn off that high-definition analog output. While the final AAC as standard, which is where all this decision-making is taking place, is not quite done yet -- it should be a matter of weeks but is not done yet -- there has been no official statement. The basic conversation is that there would be a ?flag on the disk, and at the studio decided that it wanted to turn that flag on, or to throw that switch, in that case, the player would down-rez from, for example, 1080 down to 640.
CEN: I see, so if there are component outs on the back of that Toshiba player, those can be disabled.
Knox: There are component outs, and if that flag is not thrown, those component outs can pass 1080i out. If the flag is thrown, the data from the disk is down-converted to 640, and then can be up-converted back to 1080. But as you know, that's not the same as the 1080 original lines of detail coming into the system.
CEN: Youre talk about this digital rights management, DRM. A lot of people are concerned about this. How is the HD DVD Digital rights Management better, worse, different from that of Blu-ray? Is everybody going to be really bothered by this once they actually deal with it?
Knox: I don't think the digital rights management is going to get into the typical consumers way at all. Our hope is that it will confound, confuse and utterly frustrate those consumers that are choosing to do some really naughty things.
CEN: Such as make 100 copies of a DVD?
Knox: Right. But for both cases, in Blu-ray and HD DVD, the basic digital rights management bundle is the same thing, and it's known as AACS, the Advanced Access Content System. AACS is a huge and very complex document and standard that was designed to address a lot of things, not just optical disks. For that reason, it had a lot of entities from Hollywood, the IT industry, and from the consumer electronics industry, all participating to reach the ultimate compromise. Frankly, I think we were successful, because you know it's a good compromise when everybody is at least a little bit upset.
CEN: That's a good point.
Knox: Were kind of in a situation where everybody had to give up something in order to reach consensus within the group. So, from a CE perspective, we're not big fans of this down-rez flag thing, obviously, but we are really big fans of something called mandatory managed copy. What that means is, you can now legally make a copy. Don't confuse this with the idea that you can therefore make thousands of copies and go into business.
CEN: Because it puts a mark on there that you've made your copy, and you're done making copies?
Knox: Well, it doesn't mark the disk, but what it does do is, the managed copy takes place in an external device. It's not happening in the player, but that could happen, for example, on a Windows Media Center PC. You take your HD DVD disk, you put it on your Media Center PC, and the PC then creates a secure managed copy that lives on the hard drive of that PC. That managed copy can either be played back right from that PC, or with the right technology it could be screened from the Windows Media PC to the Xbox in the living room, for example, or it could be streamed to any one of dozens of devices that were shown at CES that enable your individual TV to access the content that you happen to have on your computer or other device within your home network.
CEN: Now as you said, this will be available on both Blu-ray and HD DVD, because they both have that same spec, right?
Knox: Yes. We have been pretty clear and specific and unequivocal in saying that this managed copy feature is mandatory for every HD DVD disk.
CEN: And every Blu-ray disk as well, by extension, right?
Knox: Well, that's our understanding. One of the things is, the AACS specification has several layers. The first couple of layers, the physical layer, logical layer, are universal no matter how the AACS standard is used. You then have a specification known as the application specification, and that's how that standard is used within a particular device. So within the application specification for AACS and HD DVD, we are absolutely clear and solid that managed copy is definitely, without a doubt, mandatory, and you're guaranteed that any disk that has the HD DVD logo will give you an option to give you some kind of managed copy.
CEN: Now I take from that name ?managed copy to mean that it's possible to decide what kind of copying can be done. For example, Netflix, when they send these HD DVDs to customers, they want to make it so you can't make any copies of that because they want you to keep sending disks back and forth, right?
Knox: Here's the way the copy is managed: It's much like a lot of video games that are sold on standard DVDs today. You can't play the game unless you put the disk in the drive. So, you've installed the thing in your PC, but it won't let you play Quake 4, or Doom 3 or Far Cry or whatever the game is, unless the disk is there. In the case of managed copy, we may not require the disk to be there all the time, but will start a little timer going, and then every so often, it's going to say, ?Hey buddy, where is that disk? And if you ain't got the disk, you ain't got the movie. So the system is very robust, and the copy that's on the PC is encrypted and it gets unlocked on the fly every time you play it or stream it. There are various hooks and handles in the system so that even though one managed copy is legal, there would be no way for you to duplicate and distribute those copies because whoever you send it to would not have the right keys on their machine to unlock that content. It's part of that same compromise process with the AACS.