Film-Tech Forum ARCHIVE: What happens to old DCP's

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Posted by Martin McCaffery (Member # 37) on 02-15-2013, 10:17 AM:

It may be too soon to ask, but I'm curious. What happens to DCP films after they've been out of regular circulation for a few years? Do the studios take care of their DCP's the way they take care of their old prints (i.e., not very well).

Let's say I want to run Shrek Foreever After for the kids show. Would the studios send me a hard drive that has been sitting on a shelf for 3 years, or transfer a file to a new hard drive? Will the studio be up migrating all of these files on a server somewhere?

Anyone have experience with this yet?

Posted by Carsten Kurz (Member # 5396) on 02-15-2013, 10:37 AM:

As always, depends.

Some distributors have major contracts with service companies like Deluxe, etc.
The long term preservation of DCPs then needs to be negotiated with them, and will usually cost money. If a DCP is needed, it might come out expensive to copy/ship just one as individual service - could be a few hundred dollars.

Other distributors store their DCPs of their classics, basically on their local fileserver, or individual discs. Last year, a fellow cinema wasn't able to get 'The Social Network' - IMHO an OSCAR winning feature - because 'the harddrive is out to another cinema' ;-)

Some simply abandon their DCPs after a while and then supply BluRays.

Having access to the DCP of course is just one aspect - the other is getting the key.

Some cinemas are able to get a DCP from fellows, then receive the keys from their distributor. One service company in germany states that they do longterm backup of all the keys as a general service, but longterm storage of DCPs has to be negotiated and payed for separately.

I think long-term availability of DCPs is not accounted fully for yet. They have to think about it where and how to do it. As a matter of fact, smaller distributors seem to be more up to the task, distributing their own hard disks, since low quantities and savings are easy to accomplish. There will probably always be a backup of the DCDM (master) somewhere, but most service companies will charge a lot of money to create a single DCP drive from it. So, not too different from 35mm.

- Carsten

Posted by Jack Ondracek (Member # 1466) on 02-15-2013, 11:42 AM:

If a key is generated specifically for your theatre and playdate, what purpose is there to archive old ones?

Posted by Olivier Lemaire (Member # 5579) on 02-15-2013, 12:14 PM:

Most Of The Time: rm -rf /path/to/old/DCP
(but DCDM are safely archived)

Posted by Carsten Kurz (Member # 5396) on 02-15-2013, 12:17 PM:

quote: Jack Ondracek
If a key is generated specifically for your theatre and playdate, what purpose is there to archive old ones?

There is a 'master key' - the 256Bit AES-Key. The individual cinema/server KDMs are generated from it. If you loose the master key, the distribution DCPs are useless and need to be re-encrypted with a new key. At the same time, that master key naturally is 'the key' to secure the content. You don't want it to be circulated around, have multiple redundant copies, etc. Even most distributors do not want to have them, they leave them with the service companies also storing the masters.

- Carsten

Posted by Jack Ondracek (Member # 1466) on 02-16-2013, 01:03 AM:

quote:
quote: Jack Ondracek
--------------------------------------------------------------------------------
If a key is generated specifically for your theatre and playdate, what purpose is there to archive old ones?
--------------------------------------------------------------------------------

There is a 'master key' - the 256Bit AES-Key. The individual cinema/server KDMs are generated from it.

Thanks!

Posted by Mark Hajducki (Member # 1732) on 02-17-2013, 06:02 PM:

Is it possible to create open keys (that can unlock a feature on any server/projector)?

Posted by Marcel Birgelen (Member # 6801) on 02-17-2013, 06:21 PM:

I just hope most studios are smart enough to store their master DCPs in unencrypted form too. Just in case somebody might lose the keys by accident...

In theory, DCPs could be stored forever, without losing a single bit, so not losing any quality at all over time, as long as you keep them on an active, redundant and well maintained storage platform. Also, in theory, storage is getting cheaper all the time, so the costs per old DCP should decrease over time.

Unfortunately, that's just theory. I've seen plenty of old dusty tape libraries, decommissioned SAN systems and piles of old hard disks in the past, that have been considered a valid "digital archival solution". Good luck getting something back from there... Outdated formats, interfaces and file formats abundant.

But even if we take good care of the bits themselves, we're not there yet. Although DCPs in unencrypted format are pretty straight forward, it still remains to be seen if there is still software and/or hardware around that can handle DCPs in let's say, 40 years from now.

Posted by Martin McCaffery (Member # 37) on 02-17-2013, 06:44 PM:

Reprinted with permission from private email:

quote:

Yes, we (Sony) keep all of our DCPs created for first-run release with the idea that they will be booked for repertory (and they do get booked). So if you wanted to book PLANET 51 or SUPERBAD on DCP, you can do that with us. We started creating DCPs on first-run features around 2006 I believe. We keep them on master drives at Deluxe and replicate a new distribution drive when an order is placed.

We are currently looking at how we are going to archive and migrate these DCPs.

I hope this answers your questions. Feel free to share this information if you like.

Posted by Carsten Kurz (Member # 5396) on 02-17-2013, 07:11 PM:

Amazon offers a business-grade longterm storage service ('Glacier') at around 3US$/month per typical dcp size (from 0.01US$ per GB/month). It's encrypted and redundant. I don't know if I would store masters there, but I think it is solid and safe enough for longterm storage of distribution copies/DCPs.

- Carsten

Posted by Wolfgang Woehl (Member # 6901) on 02-17-2013, 11:51 PM:

Mark, no. Content keys are encrypted with the public part of a server's key pair (see Public Key Cryptography). Meaning there is exactly 1 private key which can decrypt KDM content.

Posted by Frank Angel (Member # 248) on 02-18-2013, 01:27 PM:

If a rep theatre were to play a title via DCP knowing that they will be rebooking it repetitively over the years, pretty much indefinately, hence the word "repertory" -- CINEMA PARADISO and 2001 were two titles we hadn't stopped booking since their first runs -- would it be possible for a rep house to simply copy the encrypted studio hard drive to another hard drive for storage and then use that DCP with an appropriate key issued by the studio...in other words, not relying on the studio's attention or lack thereof to storage/preservation, but leaving that cost in the hands of the exhibitor who has a vested interest in playing a particular title via DCP in the furture as opposed to being told it has to be played via a freakin BluRay, which sounds like what may happen in some cases down the line.

So my question -- is the DCP hard drive itself protected from being copied in any way other than how hard drives are copied? Is all the security encrpytion deconstruced by the software and the key AFTER ingestion? Seems like being able to copy the DCP for storage isn't a threat to the encrypted content, given what has to happen to it before it can be unlocked and played. But then again, we know how the very word COPY makes studio execs brains explode.

Posted by Martin McCaffery (Member # 37) on 02-18-2013, 03:16 PM:

quote: Frank Angel
But then again, we know how the very word COPY makes studio execs brains explode.

Archive, Frank, Archive [evil]

Posted by Wolfgang Woehl (Member # 6901) on 02-18-2013, 04:58 PM:

Frank, yes, DCP distribution disks carry standard filesystems, trivially copied to centralized storage or backup. No "harm" in that.

Of course, film preservation bees of the future will scrounge the globe for old KDMs and media block boards. So if you want to do some good for film history: Keep those KDMs as well. No "harm" in that either, for now.

Posted by Marcel Birgelen (Member # 6801) on 02-18-2013, 05:50 PM:

quote: Frank Angel
So my question -- is the DCP hard drive itself protected from being copied in any way other than how hard drives are copied? Is all the security encrpytion deconstruced by the software and the key AFTER ingestion? Seems like being able to copy the DCP for storage isn't a threat to the encrypted content, given what has to happen to it before it can be unlocked and played. But then again, we know how the very word COPY makes studio execs brains explode.

Like Wolfgang already mentioned, practically all disks are formated in EXT3 format, which is mountable and accessible in almost any recent Linux or UNIX environment.

The security is on a different layer here, it is inside the DCPs itself. The features inside the DCP are encrypted with AES (a strong industry standard encryption method), so you won't be able to read them without a valid key. The files themselves are just that: plain files, nobody stops you from copying them to anywhere you want. So you could, in practice, archive any DCP you get or you deem valuable in the future. The only problem is, that it adds up quite fast.

Posted by Frank Cox (Member # 6258) on 02-18-2013, 05:58 PM:

And it's "junk data" without a valid key.

I don't see the point, myself.

Posted by Marcel Birgelen (Member # 6801) on 02-18-2013, 06:15 PM:

quote: Frank Cox
And it's "junk data" without a valid key.

I don't see the point, myself.

It's only useful if you consider playing the movie in the future and the new KDM they send you is actually based on this DCP and not some other DCP, containing the same movie.

And... It might also be useful in the far (?) future. If, besides all good intentions of preservation of the studios, all official copies of a certain feature have gone the way of the dodo and you also kept your KDMs and the media block that somehow preserved its own certificate and private key unharmed... Or maybe we have working quantum computers by then that can brute-force 128-bit AES in a matter of seconds.

But of course, why are we worrying? It's not like any studio EVER lost an important movie in the past, isn't it..? [Wink]

Posted by Leo Enticknap (Member # 534) on 02-19-2013, 01:58 AM:

quote: Marcel Birgelen
Or maybe we have working quantum computers by then that can brute-force 128-bit AES in a matter of seconds.

Believe it or not, there is at least one national, taxpayer-funded film archive in Europe which is collecting encrypted DCPs, without the keys, on the assumption that brute-forcing the encryption will one day be possible and that once the copyright term in the content has expired, this will enable it to provide access to this material as public records. Needless to say, the decision of its director to pursue this policy has proven controversial in film archiving circles, to put it mildly.

I suspect that we'll see studios and public sector archives take markedly different approaches with 'born digital' and 'born analogue content'. In terms of the latter, the cost of scanning and basic post-scanning image restoration is plummeting (scanners that will do 2K in real time are already available for around the $150k mark). Given that large film archives have for half a century now been investing in a passive conservation approach to film preservation (i.e. building and maintaining cool, dry vault facilities), I suspect that many will regard DCDMs and DCPs derived from film originals as essentially disposable items, because they can just scan the film again.

The preservation of born digital content is a different issue. The bottom line is that there is no known offline storage medium that can match the proven reliability of the long term storage of film in an atmospherically controlled vault. Unlike with content originated on film, you don't have a film to go back to if you lose your digital asset, and at the moment the only known way to ensure its survival is either a program of regular copying from legacy data storage media to current ones, or an always on solution such as a RAID or MAID. Presumably for master storage the studios and archives will regard the DCDM as the preservation master and the DCP as being of secondary importance (given that the latter can be recreated from the former at any time), but realistically they are looking at spending more per hour of footage per day looking after it than they would have been with film.

Posted by Manny Knowles (Member # 1171) on 02-20-2013, 03:47 PM:

I'm personally in favor of archiving to film.

Every "born digital" movie should be archived as YCM separations, a color internegative made from the YCP's and a positive made from the IN. That way there is a "hard copy" and there is proof that every link in the chain is good. For added measure, a plain-old DI wouldn't hurt.

You may recall that part of the "Star Wars" problem was that the color negatives had faded and the Yellow sep was overexposed.

And I've run a few movies where there seemed to have been registration issues between the sep's or, perhaps, registration issues in printing.

Now, don't get too excited. Because despite my "pro-film" stance on the issue of archiving/preservation, I remain a realist -- and it's not looking like film will be around for ANY (motion picture) purposes in the not-too-distant future.

This issue probably won't become important enough to appear on the industry's corporate radar until an important film is lost.

Which reminds me of this quote from "Airplane!"

quote:
They bought their tickets. They knew what they were getting into. I say, let 'em crash!

Posted by Lincoln Spector (Member # 6835) on 03-01-2013, 06:30 PM:

DCP is a distribution format, not an archival one. When a DCP comes back to the studio, I'd imagine the hard drive is formatted and used to distribute another movie.

I believe that the DCP masters are all kept on the company server, so that they can easily make another DCP when a theater asks for one.

As far as long-term archiving goes...who knows at this point. If it was up to me, everyone would agree on an unencrypted standard using M-Disc media, AND they would preserve everything on film.

But it isn't up to me.

Lincoln