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DRM in the cinema

astortheatreblog.wordpress.com

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Re: DRM in the cinema

#61

Post by Thlom »

speleding wrote: post #56
trimbo wrote: post #13

Ex-VFX guy here again. I feel like I have to comment on these threads because I'm thrilled to see 35mm film die.[1] The DRM sucks but.... > There are instances in the US already where some studios are refusing to freight 35mm film prints to cinemas. Yeah, because it's crazy expensive . It costs ~$1500 to strike and ship a 35mm print[2]. Also, did you know that prints are delivered by some specialized delivery company…

The issues mentioned in the blog sound very fixable. How hard could it be to allow a few minutes of unconstrained grace period from the beginning of the movie? That would take care of ensuring the projector works properly. It should also be straightforward to offer functionality that verifies if the digital key is valid before the show starts. I would not be surprised if those options already exist and they simply di…

It is possible to look at each feature on the screen server if it has an associated key and also when and for how long it unlocks.

Re: DRM in the cinema

#62

Post by ropers »

> the industry is shifting – not only its medium, not only its focus, but with it – and most significantly for theatres like us – it’s shifting the element of control

That's a bingo. Like with so many things DRM, where rights are no longer balanced and only the concerns of one side, the DRM-issuing side are ever taken into account, this is a power-grab.

Re: DRM in the cinema

#63

Post by Thlom »

simcop2387 wrote: post #10
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…

Honestly what I love about this fact is that if there's an email delay the movie doesn't play. And if someone learns how to set the clocks back, it no longer matters that it's time sensitive!

The servers have a secure clock which can only be adjusted 6 minutes each year. If it goes out of this limit you will need a special package or code from the manufacturer to adjust it back or in worst case you will have to change the mediablock.

Re: DRM in the cinema

#64

Post by Thlom »

geon wrote: post #51
anigbrowl wrote: post #11

Earlier quoted context omitted.

Live by the sword, die by the sword. If you ask a bunch of hackers how to make a mission-critical application secure, one of the top answers is going to be 'air gap.' In economic terms, security has greater value (to the publishers) than the mild inconvenience of a few shows starting late.

The actual transmission of the key could be done over a custom channel, like a serial connection only used to read the drm key. It would be even more secure than using a usb stick.

The key is useless without the server and feature it is issued for. There is no need to secure the transmission of the key. Automated delivery over http(s) is starting to get more and more normal (most screen servers don't have such capabilities yet, so you will need a Theatre Management System or separate box which will receieve the key and deliver it to the server).

Re: DRM in the cinema

#65

Post by Thlom »

__david__ wrote: post #59
xentronium wrote: post #52

Earlier quoted context omitted.

How do you make sure that system date was not tampered with then?

I cant remember how that works but I suspect the RTC is in the FIPS can and that it takes effort to set it. They wouldn't go to all that effort to put times in the KDM if someone could just bypass it by setting the system date. It's a pretty well thought out system.

Correct. The DCI says the secure clock only can be adjusted 6 min per year, 20-30 min with a code/package from the manufactorer. If it's adjusted over this limit the mediablock will have to be changed.

Re: DRM in the cinema

#66

Post by zmb_ »

forrestthewoods wrote: post #9
spdy wrote: post #4

This is fighting piracy on the wrong level. Some people must be so afraid that someone could copy their "work" that they put a chain on the most trusted place. 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 time and expiring as close to 5 minutes after the scheduled time. This made me shiver...…

As others have said, this seems to be the perfect place to fight piracy. At present time most movies do not have high quality releases until the blu-ray discs are manufactured. When a movie goes to blu-ray 720p and 1080p copies are instantly released online. Having those movies available online opening weekend, if not before opening weekend, could be disastrous.

If someone really wanted to make a pirate version off of a cinema copy, they could. This DRM, like all DRM, is pointless since by definition you must be able to decrypt the stream at some point, and at that point a copy can be made. The rest is just security through obscurity.

Re: DRM in the cinema

#67

Post by Retric »

Thlom wrote: post #48
ditoa wrote: post #34

Earlier quoted context omitted.

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.

I don' think you can prevent analog camera's from recording video with watermarking. If you somehow prevent windows from playing back video based on some watermark scheme someone will just write a Linux program that strips / adds watermarks.

Re: DRM in the cinema

#68

Post by lmm »

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?

From far enough away anything looks good. If you look at the THX recommendations for cinema setup, they add up to something like a 60 degree viewing angle on the screen. To match human eye resolution you want approximately one pixel every 0.3-0.4 arc minutes; let's say 3 pixels / arc minute, or 180 pixels/degree. So for a screen that was "perfect" up to the limits of human perception, taking up a cinema-screen-sized area of your vision, you'd need at least 180*60~=10000 horizontal pixels.

We're approaching the limits of human perception, but we're not there yet; 4K does seem like a useful improvement over 1080

Re: DRM in the cinema

#69

Post by ditoa »

Thlom wrote: post #48
ditoa wrote: post #34

Earlier quoted context omitted.

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.

We already have audio watermarking with Cineva which stops mutes playback on devices such as the PS3. Obviously the media player needs to implement detection of Cineva and then block playback (or audio in the case of Cineva which I believe causes the player the mute the audio). I very much doubt VideoLAN and MPC-HC will implement such things however I can see Windows Media Player and other "official" media players implementing it.

Cineva is interesting as from what I have read it can survive even pretty extreme audio changes so even the audio from a CAM copy with crappy mono sound will still carry the watermark from capture to encoded MP4 (or whatever you capture to). I have not seen any statistics on how successful it actually is at surviving in real world use though.

Re: DRM in the cinema

#70

Post by Thlom »

Retric wrote: post #67
Thlom wrote: post #48

Earlier quoted context omitted.

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

I don' think you can prevent analog camera's from recording video with watermarking. If you somehow prevent windows from playing back video based on some watermark scheme someone will just write a Linux program that strips / adds watermarks.

I guess a lot of the CAM pirates works in the cinema business. With watermarking the studios can find out exactly which auditorium it has been recorded in. I guess that will discourage a few pirates ...
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