Industry Insiders Q&A MASTER THREAD [separate thread for Xbox/Add On & PS3] - Page 3  

Thanks for the answer. I'd love to see you and Amir discuss this further.

The HD-DVD supporters here have presented BD+ as something to be terrified of. What can you tell us about it?

Is there a reason SPE isn't using BD+? Since the players are already BD+ compliant, and it doesn't seem like it would add cost to the discs, I would expect it to be in common use.

Do you really believe this? How can the HD DVD spec possibly have any bearing on what you do to a signal after it's output from the HD DVD player?

The HD DVD spec requires HDCP for 1080 HDMI output, right? There are aftermarket products which can strip the HDCP from the output. Does that mean I can build a compliant HD DVD player with no HDCP output on HDMI? Of course not. Your argument that you can post-process the HD DVD output to get 24p has absolutely no bearing on whether a compliant HD DVD player can be built which supports 24p output.

No, I don't think it's more expensive to output the original 24p, assuming there's nothing in the HD DVD spec (such as what PiP framerates are allowed) which prevents you from simply outputting 24p. There are a raft of posts here, including from respected insiders, that the current HD DVD spec does not address 1080p24 output in such a way that you can build a compliant player without, at a minimum, ignoring content flags which might impact proper stream decoding (see this post for one of many credible references). In this post you acknowledge the spec doesn't fully address issues related to authoring 24p content and that it's being worked on.

Which isn't an option in HD DVD, since 24p encoding isn't allowed for PiP content, correct?

Yes, if they wanted to author non-compliant content, and take their chances that all implementations would still handle it properly.

No, a myth suggests there is no credible basis for the claims. I've provided credible reference to my claims, unlike your first claim (that the fact you can post-process HD DVD output to 24p proves you can output 24p content directly from a compliant HD DVD player.

There are already software players doing 24p rendering. It works fine. It'll be good to get some "best practices" defined just to lock down what the precise player behavior should be in edge cases, but 24p playback from current HD DVD discs is absolutely doable, by a compliant HD DVD player.


Incorrect. You can encode 24p PIP in the exact same manner as the 24p main.


All the content would be compliant.

Can you give an example of where you think there would be a real-world playback problem, even with existing discs? I've thought about this for a while, and I'm not aware of any signifcant issues.

Are there any plans for a HD DVD player to be released in the next few months that does output 1080p24? Specifically without the use of a secondary video processor to convert 1080i60 to 1080p24.

Greetings. No, that's another J.M. -- John

In absence of AACS? Can you please confirm if BD+ is allowed to be used, without AACS present? And if AACS is required, why that is the case if BD+ can stand alone in the face of AACS being broken? I specifically like you to comment about software players in this context.

Note that his question was not whether BD+ has teeth. Clearly someone thinks it does although it is remarkable that despite such value in their minds, BD+ is not and has not been ready for deployment and content has been published without it. The assertion was that life is all well in BD land if AACS is broken. Can you please indicate if AACS is broken, that would be a good thing for BD format? And I am asking a business question here, not a technical one.


Let me ask you this. The hacker claims to have accessed the memory of a software player and grabbed key data to decrypt AACS content. What information do you have that would indicate BD+ code, should it exist and be running in the same software player, is immune to similar attack?

Note that I have done my best to stay away from confidential information from BDA. It is challenging to do so, and the task becomes even more complicated, having this discussion with someone who I don't know if is exposed to full specifications for both technologies and is schooled in matters of copy protection .

We won't be making any pre-announcements like this. But 24p will come just as 1080p did. The reason it is not there yet in stand-alone players is that CE companies loath to implement output formats which their own displays can not handle. They worry about customer support issues should the user set the player to 24p, and their own brand of display going blank. Yes, I know, bad logic but this is the reason you didn't see progressive 1080 support 'till now, despite many of us pushing for 3+ years now (motivated by the need to drive them with PCs btw). And here, I am talking about companies in BOTH camps.


The conversion is as simple as dropping frames from the PiP which costs nothing, or a temporal filter the likes of which is being introduced in TVs at CES which upsample video frame rate to 120Hz. So either logic is pretty straightforward to implement.

This issue of 24p output has been debated elsewhere on the forum several times... ranging back to Ron's comments that Talk cited.

My question: Are the specifications for HD DVD authoring compliancy directed at the DISCS or the PLAYERS?

I maintain that discs are compliant if they are authored with permitted framerates, acceptable bandwidth parametrs, appropriate flags in the stream, etc... and that a player is not mandated in what it can do with those streams.

While there are likely player compliance specs as well (in order to sport the logo), I expect they are things like: must be able to decode audio codec, must support decoding streams for max bandwidth, etc...

IOW: People are confusing what HD DVD specs mandate must be on the disc as opposed to what a player must do.

Is this correct?

Very correct Steve.

I appreciate the discussion on what value BD+ has, should AACS ever be truly compromised. Personally, I am not a fan of a big brother type VM running on anything I own.

That said, I think a lot of people think that BD+ offers a layer of protection on top of AACS, i.e. both must be broken. I don't think this is correct and would like some clarification if possible. To be clear, I believe that if BD+ is implemented it is possible for it to add it's own vulnerabilities without AACS ever being compromised. Right? Is it not handed an AACS free stream? Then one could side step AACS completely if the encrytion or VM engine of BD+ proved to be more vulnerable.

Any corrections to my thinking are welcome.

Very much correct and an astute observation . BD+ sits on the output of AACS. At that point, AACS with all of its countermeasures is out of the picture. If BD+ subsystem is compromised, plugging that hole could be nasty. As Mark Knox once said, BD+ closes one doors, but opens many windows. One would need a revocation scheme just for the boundary between BD+ and AACS. And a scheme to keep it from getting broken again and again. Not fun, not fun at all to develop such things and I say this from experience .

The CPA (Content Participant Agreement) for BD+ is not yet available, so no Blu-ray content provider can legitimately use BD+ at this point in time. Further, the Eligible Code Developer Agreement isn't available either, so no third party can supply/code BD+ for use on BD-ROMs yet. The only BD+ legal done deal is the System Adopter Agreement for BD+, which is mandatory for device manufacturers and costs $20K/year.

Oh, wait, I'm not an insider. Insiders, is this correct?

It adds work, and some uses can require a portion of the disc space. We don't think additional measures are required until illegal copying is demonstrated and causing harm. Better to have tools to protect a release in the millions than in the thousands.

The discussions here make some assumptions about the way that AACS or BD+ work. They do not consist of one tool, but rather a collection of tools (and robustness requirements) that are designed to provide a renewable means of protecting content. It is possible for them to be used independently.

I'm sorry but I fail to understand why any discussion of copy protection techniques is appropriate here unless a consumer is having a playback problem caused by these tools.

As you would expect, both the AACS and BD+ specifications are under license and NDA, so technical discussions about how they work can easily run afoul of those agreements.

It's technology, so those of us who aren't insiders and haven't signed an NDA are free to talk because we don't know anything. Some older AACS specs are public, so those of course can be discussed.

Is there anything you can tell us about BD+?

It is not the question of "what is possible" but what is allowed. Are you saying BD+ is allowed to be used without AACS? If you are not at liberty to say, that is fine too but please indicate so clearly.


Welcome to AVS Forum . We discuss everything here, all the way up to and including how a blue laser is manufactured. So this of kind of subject is very, very common around here although not as of late. A year ago we had hundreds of posts on these topics.


Not in the case of AACS. See the full specs here: http://www.aacsla.com/specifications/. And note in the first pdf that it has Sony in it as one of the authors . Usage requires a license but not the specs themselves.

BD+ data has been leaked in the past in this forum in the form of powerpoint presentations from BDA. Our resident deep throat was one of the guilty parties . Also, CRI which provides foundation technology for BD+, has a public web site with fair amount of technical detail. See http://www.cryptography.com/.

All of the above give folks enough info to ask us pretty pointed questions. Of course, everyone must be careful to not disclose NDA info. And I have made sure of that in my posts, current and past. But because of previous disclosures, I am afraid you won't be able to side step answering questions easily (talking from experience ).

Amir-

Here's a question I hope I know the answer to. As the owner of an A2, should I be concerned at all about this AACS stuff in terms of its affect on planned software releases? That's all I'm worried about.

Thanks,
Chris

Can the all BD players and all HD DVD players play ordinary CD's?
What about, JPEG files stored on DVD format?

All HD DVD players do. My understanding is that the Sony/Pioneer BD players do not.


I don't really know. Probably easy to look up on the web site of the companies.

There is nothing yet to worry about until the nature of this attack is more understood.

Thanks PaidGeek. From your answer it seems BD+ will be used (at least by Sony) only if other measures are not effective. From the report about the hacker copying a movie using HD-DVD add-on and PowerDVD, I wanted to know if this is a good enough reason for studios to consider BD+.

BD+ has been discussed to death with not much real information; I am sorry for opening that up again!

However, now that the discussion as already started (), any useful info on BD+ is appreciated! What is the relationship between AACS and BD+?

By the way, due to internet, we the consumers want to know everything about the stuff that we buy whether it matters or not! Call us spoiled!

Yeah, going through what little info we've been give (the presentation and website Amir mentioned), there's a lot of scary stuff that's possible with BD+, or SPDC at least.

What can, and can't BD+ do, and more importantly, what will and won't it be allowed to do?

Considering how 'deadly' these hackers are, the lesser information about BD+ out on the public, the better.

...Heck I think that's the real flaw on this whole software security thing, everytime some smartass security experts think they have invented some hacker-proof concept, they went out and bragged about it and (some stupidly challenge the hackers *coughs*vista*coughs*) YOU WILL NEVER WIN AGAINST THE HACKERS

An even better solution is put more security layers on blu-ray and don't tell the public about it.

Wouldn't it be more prudent to simply let the process unfold the way it is intended? The attacks on Vista are disengenous. This isn't a Vista problem it's a AACS problem which is being dealt with by people that know the spec inside and out. Sony's rootkit was the last attempt at DRM that consumers didn't know about and how well did that one end up?

Do we have a time frame on this? I assume people are feverishy working on it now. I guess I'm just a little nervous my new A2 is going to become a paperweight.

Thanks,
Chris

May I ask what you find "scary"? BD+ only operates within the bounds of the player whether it is a hardware or software player. It is basically just a set ot tools that allow the content companies to run more intelligent and updateable tests and operations to make sure content is played on valid players. BD-J allows software companies to run all sorts of programs as well, but the types used for BD+ are naturally designed for protection of content.

Cyberlink makes a software player for both HD-DVD and BD. If the attack that has been posted is valid, it may well be adapted into decrypting BD content as well as HD-DVD (we are investigating). If so, it will certainly be worth considering preparations for adding BD+ to our product. The AACS companies are also going to be looking into this situation and may be able to use the provisions in AACS to fix this problem. Let's hope so, a broken security system for HD content is bad news for all legitimate users regardless of the format they prefer. The studios are all trying to build new businesses around HD content. Not having a reasonably secure format to pursue this is not good for anyone.

That's called "security by obscurity" and it never works.
Paidgeek mentioned that unless the security affected playback, we shouldn't care about it. Unfortunately, a lot of home theater owners nowadays copy their movies up to a centralized server so they (a) don't have to worry about scratching their discs, and (b) can pick the movie they want to watch from a list (see Kaleidescape ). Will BD+ affect their ability to do this? We know that AACS theoretically allows a copy, but what about BD+?

Glad to hear you say these comments as I think it cuts across the spin that this harms only HD DVD. Its bad all around, but yes, if for some reason, AACS isn't able to overcome this (if even true) hurdle then it will be worse for HD DVD.

How soon do you estimate it would take for BD+ to be implemented to your products?

Will this delay any title releases as studios (particularly Sony) hold off in favor of gathering more information and preparing for stronger counter-measures?

No time frame. But there is not a thing that is going to happen to your A2. It has and will continue to playback all the movies you are interested in.