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DRM in the cinema

astortheatreblog.wordpress.com

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Re: DRM in the cinema

#41

Post by __david__ »

quanticle wrote: post #21
tantalor wrote: post #17

> the projectionist can’t test to see if the KDM works or that the quality of the film is right before show time This seems like a simple and critical feature. If the distributor wishes to impose these extreme constraints on the projectionist, then the projectionist needs to know its going to work well in advance. The projectionist shouldn't even need to be in the room when the movie starts. I've run into this patter…

Except that in this case, you can't test. The only way to test is to load the movie, load a key and play the movie. No key? No movie, and no test. In addition, there is no way the distributor will let you have a "test" key. One of those would be manna from heaven for any unsavory projectionist who wanted to make high quality copies from theater prints.

That's just a software deficiency. There's no reason the software couldn't use the KDM to get the keys and decrypt a frame or 2 (or even a few seconds worth) of the (MXF) film footage as a test, regardless of the time. The encryption isn't numerically tied to clock-times--it's only enforced by the software (which now that I think about it may be enforced by legal contracts somewhere).

> One of those would be manna from heaven for any unsavory projectionist who wanted to make high quality copies from theater prints.

Not really. The keys and image decryption happen in a tamper-resistant "FIPS can" in the media server and then are re-encrypted and sent across a bus to the projector. Some newer projectors have the FIPS can directly inside so that there are no physically exposed interfaces with anything other than the full-blown AES encrypted frames. Having a KDM means you can play the movie but you can't ever actually get to the data.

Fun fact: before DCinema there used to be people who owned tele-cine scanners mounted in the back of flatbed trucks that would go around to theaters and pay unscrupulous employees to borrow the film for a couple hours. They'd have an very nice scan of the movie for pirate DVDs the day the movie came out.

Re: DRM in the cinema

#42

Post by mwilcox »

tantalor wrote: post #14

The story links to an "https" URL, which is odd for several reasons, 1. Since when does a blog need to be secure? 2. The certificate is issued to "*.wordpress.com", which is useless. Each subdomain under wordpress.com should have a distinct certificate since they have a distinct author. The certificate should be specific to the author, not the host. - I realize it is not realistic to assign unique IP addresses to eac…

Sorry, this was my fault. I have a Chrome extension that forces everything to https, and forgot to remove it when I submitted the link.

Re: DRM in the cinema

#43

Post by __david__ »

wtracy wrote: post #36
pilif wrote: post #32

Earlier quoted context omitted.

In order to get an accurate prediction whether the presentation is going to work or not, the key must be valid for decrypting the whole movie. If it is, then it can provide no more piracy protection because then you would use it to decrypt the movie independently of the projection system. If the key is only good to decrypt a random part of the movie, then the test says nothing about the success or failure of the key…

That actually happens: Screenings have been interrupted because the internet connection to the projector gets cut. :-/

That makes no sense. The KDM is a self contained public-key encrypted message containing the decryption keys. It requires no internet connection to verify and extract the keys, and it certainly doesn't need to do it during the movie. In fact, most projectors are not even connected directly to the internet.

Re: DRM in the cinema

#44

Post by __david__ »

smacktoward wrote: post #2

This is the part that made me cringe: The [DRM key] arrives as an email zip attachment that then needs to be unzipped, saved onto a memory stick and uploaded onto the server. Seriously? That's how we're delivering time-sensitive digital information? In 2012 ? Ugh, it makes my head spin. Is there some reason that the projector can't be connected to the network directly, so the vendor can push the key straight to it wi…

I think the limiting factor is that (crazily enough) it's hard to get internet to a lot of the places that projectors are located. Internet seems ubiquitous to us in houses/apartments but it's apparently hard to get it when your theater is in the middle of a mall or in some old building.

I believe there's a push to start distributing the encrypted films over satellite but that has its own problems because now many theaters have to start negotiating "roof rights" with their landlords.

Re: DRM in the cinema

#45

Post by jgh »

wvenable wrote: post #39
astrodust wrote: post #38

Earlier quoted context omitted.

Since the chance of a new Blu-Ray standard coming out that supports 4K is zero and given that the movies are already encoded in this format for the cinema, stands to reason these will get ripped, transcoded, and dumped on BitTorrent as soon as High-DPI screens become more common on computers. 1080p looks great and all, but 4K is simply stunning in comparison.

In your own home, with a standard 50" TV, would there actually be any visible difference between 1080p and 4K? Aren't we reaching the limits of human perception?

Did Apple not just release a notebook with a 200-something dpi screen?

Re: DRM in the cinema

#47

Post by Thlom »

smacktoward wrote: post #2

This is the part that made me cringe: The [DRM key] arrives as an email zip attachment that then needs to be unzipped, saved onto a memory stick and uploaded onto the server. Seriously? That's how we're delivering time-sensitive digital information? In 2012 ? Ugh, it makes my head spin. Is there some reason that the projector can't be connected to the network directly, so the vendor can push the key straight to it wi…

This is already happening. The company I work for deliver services that push both KDMs and DCPs (features, trailers advertisement) to Theatre Management Systems (TMS) and screen servers.

Re: DRM in the cinema

#48

Post by Thlom »

ditoa wrote: post #34
Groxx wrote: post #27

Earlier quoted context omitted.

They already are in quite a few circumstances. It hasn't collapsed the industry yet - there are other reasons to go to a movie theater than to see the movie. As a concrete example, there are tens of thousands of seeders of Prometheus right now at a couple sites I just checked. And quite a few people I know, who know exactly how to use torrents, went to see it in the theater.

Several thousand seeders of a CAM copy of Prometheus not a 1080p BluRay rip. Big difference!

Audio and video watermarking is soon mandatory and playback will be impossible without it. Guess that will stop much of the CAM business.

Re: DRM in the cinema

#49

Post by arethuza »

jgh wrote: post #45
wvenable wrote: post #39

Earlier quoted context omitted.

In your own home, with a standard 50" TV, would there actually be any visible difference between 1080p and 4K? Aren't we reaching the limits of human perception?

Did Apple not just release a notebook with a 200-something dpi screen?

I don't know about you, but I sit somewhat further away from our 50" TV than I do to this 17" laptop. Probably about 4m or so.

Having said that, even at that distance high quality HD content is noticeably better than standard resolution content.

Re: DRM in the cinema

#50

Post by lambada »

sparknlaunch wrote: post #40

Totally interesting insight into the cinema world. My only questions is why they waited so late to test if the film would play? (I am sure there is a technical reason.)

FTA: "The KDM unlocks the content of the file and allows the cinema to play the film. It is time sensitive and often is only valid from around 10 minutes prior to the screening ..." Without the KDM being unlocked they can't test it, so the earliest opportunity is 10 minutes before the screening.
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