51–60 of 124 posts
It's remarkable that they do all this in the context of box office revenues cratering. In 2024 American theaters has less gross ticket sales than they did in 1982, in constant dollars. The whole thing of movie theaters is just over.
Basically they are a tar[1] of images with a bunch of audio streams for different speaker configurations. depending on the quality settings, they can be encoded for higher colour space (ie 16 bit log per channel)
Even with lossless jpeg2000, these packages can be huge.
But, back in 2011, the biggest problem was encoding jpeg2000 required hardware to get anything near realtime performance. (I also think there were dedicated DCP packaging machines, but I never actually saw one.)
One of my colleagues decided the best way to ship the finalised movie was to open up an NFS port on sohonet and let the technicolor hook the DCP packager directly.
it worked, but our CTO diplomatically asked them to stop.
[1] not actually but conceptually similar
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It also contains watermarks. So theatres which failed to prevent recording will run into serious issues. See https://dcpomatic.com/forum/viewtopic.php?t=2372
If the software to watermark is widely available (as it appears to be) then an adversary has all they need to corrupt any existing watermark. These steganographic watermarks depend on no knowledge of the process. If the method is particularly ingenious (one of the inputs is centrally stored entropy which the extractor references by trialing them all) then knowledge of the process alone may not be sufficient to obtain…
Put it this way -- You've got huge amounts of cover data (a hard drive's worth) and a desire to encode at most, what, 128 bits of data, across about two hours, with as much redundancy as possible. There are plenty of patents that explain in detail how.
My friend considers this a moderately distasteful problem, and mostly works on steganalysis, identifying where steganographic techniques have been used, as he thinks it's more interesting and frequently more morally justified...
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There are no high quality pirated versions though. The streaming version and even blu-ray is compressed way heavier than these DCP files. I’d buy these cinema versions of films in a heartbeat if they were availble.
1080p/4k as encoded by the streaming sites / blu-ray is sufficiently high quality for virtually all of the viewing public. You're weird (no offense).
A 4k movie, even from a Blu-Ray, may look very nice when watched at a normal speed, but if you look at the individual frames in order to distinguish some details during a sequence with fast movements, the quality is very bad and it may be impossible to see the details that you want to see.
At the levels of compression that are typical for movies distributed by encoding with H.264, H.265 and the like, I have never seen any movie that still looks high quality when slowed down during fast action.
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Totally possible that watermark identifies cinemas and showtimes uniquely, and that pirates are due for a lifetime of prosecution. Or that studios will shut down some cinemas, until it stops. For 15 years you let paid options progress. Then fewer people pirate, then you catch the rest. At the beginning you don’t see it putting its clamps; then suddenly you don’t find piracy anywhere.
> For 15 years you let paid options progress. [...] then suddenly you don’t find piracy anywhere. And then they completely ruined it with fragmentation. When all I need to watch everything I wanted to watch was three subscriptions (Netflix, Hulu, and HBO), I was totally fine with the ~$40/mo and reasonably-ok-UX offered. But now it's a mess. I need subscriptions to 7 or 8 different services (which now each cost twice…
I know Netflix doesn't support anything beyond 720p or so on Linux, but that never bothered me. Otherwise it just works. Is your Firefox out of date?
> The piracy scene seems stronger than ever these days.
I hope so. A lot of damage was done. If it wasn't for archive.org a lot of older, regional stuff would not even be accessible. We need piracy if only for the collective digital archives.
I refuse to take out more than one subscription. We just hop services.
JPEG 2000 for each frame? I wonder what they use for decompression. JPEG 2000 decompressors are really slow. Most couldn't keep up with frame rate without GPU support.
Dedicated hardware, not even regular GPUs. JPEG2000 decompression has a rather complex entropy decoding part which is not easily parallisable.
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1080p/4k as encoded by the streaming sites / blu-ray is sufficiently high quality for virtually all of the viewing public. You're weird (no offense).
I do not think that's weird. A 4k movie, even from a Blu-Ray, may look very nice when watched at a normal speed, but if you look at the individual frames in order to distinguish some details during a sequence with fast movements, the quality is very bad and it may be impossible to see the details that you want to see. At the levels of compression that are typical for movies distributed by encoding with H.264, H.265 a…
Earlier quoted context omitted.
There are no high quality pirated versions though. The streaming version and even blu-ray is compressed way heavier than these DCP files. I’d buy these cinema versions of films in a heartbeat if they were availble.
1080p/4k as encoded by the streaming sites / blu-ray is sufficiently high quality for virtually all of the viewing public. You're weird (no offense).
Is this not a problem? It’s not a good idea to reuse the same key to encrypt very similar files. Similar to ECB. See the famous penguin https://words.filippo.io/the-ecb-penguin/
I’m surprised they don’t use something like XTS commonly used for disk encryption. It derives a unique key for each block/frame and allow you to access each individual blocks/frames non sequentially.
Even with all of this onerous encryption and DRM, it's not hard to find pirated copies of movies. It makes me think that the sacrifice in ownership rights for the theaters over their equipment isn't worth it.
Most pirated copies aren't from theatrical releases; they mostly come out when the titles are available on streaming/blu-ray. DRM might be a failure in other fields, but it's working pretty well in this particular case.