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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Digital Cinema Package

How do we encrypt a DCP?
Is it like zipping a file with a pasword? that can only be unzipped by entering the password?
Which app is used for this?
 
How do we encrypt a DCP?
Is it like zipping a file with a password? that can only be unzipped by entering the password?
Click to expand...
As I understood in general the process is:
You (publisher) encrypt your content with your secret (private) key. Thats the main key you can generate all kinds of keys using this, and keep it secure of course.
You generate the public (in terms of open, unsecure) key for a particular cinema (projecting system), so this cinema can use it for decryption only.
So zipping with passwords means 2 equal (and need to be kept as secret) keys. And this system allows you to use 2 different keys for encryption and decryption accordingly. And the second key is no need to be in a safe place, it can be openly distributed.
So clip is decrypted "on-line" when it's projected. And it can be decrypted only if publisher made a key for your certain projecting system, so you cannot use the same key in a different cinema.
As I understood.
 
This is too complicated...
Encryption, decryption... this is driving me nuts!
 
Brian Lucas said:
This is too complicated...
Encryption, decryption... this is driving me nuts!
Click to expand...

Unless you're manufacturing commercial DCP's for major theatrical distribution, encryption is not something you should be thinking about or concerned with.
 
I assume in the near future, films festival will accept DCP's, and I think it's not a good idea to send your DCP's to different festivals without encryption.
This is my only concern about this.
 
Brian Lucas said:
I assume in the near future, films festival will accept DCP's, and I think it's not a good idea to send your DCP's to different festivals without encryption.
This is my only concern about this.
Click to expand...

Since festivals often project on more than one screen, you would need separate KDM's for each and every server that's going to be used. I'm not so sure the festival promoters would supply you with that in advance. And I'm also not so sure that you really need to worry about something like piracy at a large festival (which would be the only ones likely to use DCP's as delivery elements), especially for something that hasn't been sold to a distributor yet (which is the case by definition for almost any festival entry I know of).
 
M Most said:
Since festivals often project on more than one screen, you would need separate KDM's for each and every server that's going to be used. I'm not so sure the festival promoters would supply you with that in advance. And I'm also not so sure that you really need to worry about something like piracy at a large festival (which would be the only ones likely to use DCP's as delivery elements), especially for something that hasn't been sold to a distributor yet (which is the case by definition for almost any festival entry I know of).
Click to expand...

This isn't necessarily the case. A single KDM can contain all of the keys for a particular location. This is how it is done for theaters, so they can move content from one screen to another.
 
Does anyone know what the subtitle file should be called and how it is integrated into the XML?

PS. Does anyone know where I can get an FCP XML subtitle file transcoded to TI CineCanvas. I am willing to pay for the transcode? I just have a need to buy Belle Nuit (www.belle-nuit.com) or MacCaption (www.cpcweb.com) for a one shot
 
Hello everybody,

I´m new to this forum but I was reading this great thread for two days and it is amazing, which amount of knowledge has come together in it.

Last year I did research for a small work for university and i finally ended up at Fraunhofers easyDCP(+) and the easyDCP Player. At that time, it was enough for me to find that solution (there is also a hardware based solution from Dolby, the SCC2000 Secure Content Creator, which can be connected to renderfarms but for a price much higher than any easyDCP creator can be). I had also found the opencinematools but I considered them dead cause I couldn´t find tutorials or howtos for using them....I hadn´t found this great forum yet. But now I´m curious about making my first DCPs without the watermark in the upper left corner :drool5: and most important 3D DCPs for my actual work for university.

Concerning the encryption process: yes Pavel, you´re right. easyDCP+ can do the job. When I worked on the task last year, I spoke to the people at Fraunhofers about the encryption process and they told me they can help customers to create the needed keychains , KDMs etc. On the easyDCP+ product page it is metioned, that easyDCP uses software from the openSSL project....

I´m not a software engineer and so the encryption-subject itself is too high for me at the moment, but I just wanted to confim Pavel´s assumption :001_smile: .

Greetings,
Felix


Time: 23:48
Status: Success!

Yeeaaah! I just created my first DCP with OCT! Ok, I involved AfterFX for the X'Y'Z transformation but now I´ll proceed to ImageMagick for the job. Had to solve the

"Expecting uncompressed essence, got format type 65534
File does not begin with FORM header
AUDIO_2.wav: Unknown file type, not ASDCP-compatible essence."


error with the Windows Extensible Wave but with the information from Peter + Wolfgang + SoX I could finish the creating-process!

Wonderful!
 
Last edited:
Ok, now I tried to use a workflow with ffmpeg and ImageMagick. Works fine and I get a nice folder full of *.tif files after all.

But when I use them with the image_to_j2k.exe I get the message
"AdobeDeflate compression support is not configured", he renders the tile and creates the j2c file but it is only 2KB large an contains just a black screen.

That didn´t occur when I converted the Tiffs created by AfterFX, there everything was fine. Can anybody help me with that? I´m confused because that workflow with the open source applications is just what worked for most the people here and I thought the thing with AfterFX would cause more trouble....but now it´s completely different for me.

I use WinXP 32bit.

Thank you very much,

greetings

Felix
 
Felix_Opahle said:
Ok, now I tried to use a workflow with ffmpeg and ImageMagick. Works fine and I get a nice folder full of *.tif files after all.

But when I use them with the image_to_j2k.exe I get the message
"AdobeDeflate compression support is not configured", he renders the tile and creates the j2c file but it is only 2KB large an contains just a black screen.

That didn´t occur when I converted the Tiffs created by AfterFX, there everything was fine. Can anybody help me with that? I´m confused because that workflow with the open source applications is just what worked for most the people here and I thought the thing with AfterFX would cause more trouble....but now it´s completely different for me.

I use WinXP 32bit.

Thank you very much,

greetings

Felix
Click to expand...

I've had that kinds of errors working with tiffs that's why now I use ppm's as temp image format (video->ppm->tiff->DCP). The reason for me was that adobe (and maybe other applications) adds some unknown tags in tiffs, that image_to_j2k cannot recognize, so it gives up.
You can check how it's done in my script here as well as use it.

Felix, look at ImageMagick's '-compress' options ('convert -list compress') and try 'none' or 'lzw'. It seems your version of openjpeg is linked against a libtiff lacking deflate support. Wonder why, though ...
Click to expand...
And why is it named "AdobeDeflate" is there any adobe app's in his workflow?
 
Compression problem solved

Compression problem solved

Thanks, Wolfgang and Pavel, I could solve the issue.

I finally used the -compress option by myself last night and with the compression forced to "lzw" or "none" everything was fine. But I also wondered why the ImageMagick used adobe deflate by default, I thought "none" would be the standard compression setting in tiff.

Concerning the libtiff in OpenJpeg I can only imagine that the OpenJpeg I downloaded has been tweaked in some way. I couldn´t download it from www.openjpeg.org becaue the site seems to be down for some days, I always get "network timeout"....can anybody confirm that or lays the problem at my browser? I was glad to find in a topic in this thread a link to a google code page, where I could download an openjpeg package. But the ImageMagick is genuine from their project page.

Thanks Pavel, I already used your cool script as guideline for my own command line batch commands and to understand the whole thing with the command line.
But when you mention, you use video->ppm->tiff->dcp then you also incorporate the tiff in one step. My chain is video(mov uncompressed)->png(via ffmpeg)->tiff(gamma and colorspace xyz via Imagemagick)->j2c(via image_to_j2k in OCT)->DCP. But as it seems to work now, the search for the error is mainly academic task :-) (sorry don´t know if you can say this in english that way)

Now the next thing will be 3D DCPs and I think your script will show me the way. Thank you very much.

Best regards,

Felix
 
But when you mention, you use video->ppm->tiff->dcp then you also incorporate the tiff in one step.
Click to expand...
Yes, I've told not quite correctly. On some steps of my experiments, when I used tiffs for everything, some tags (as I remember adobe) incorporated in it. And it caused image_to_j2k's errors (thanks to Wolfgang showing me the way to solve it). And that's why I used ppm before tiff as well as ppm contain no tags.
 
Yes, I think I remember you talking about those tag-problems when I was reading through the amount of pages of this thread. I was surprised when my AfterFX Workflow didn´t create errors on the j2c encoding site.

Has anyone information about any reason, why openjpeg.org went offline? Or is it just a temporal failure?

And one last thing: are people still working on the encryption task? I see for tests or short films and so on, encryption is not really important but for a complete and fully functional workflow it would be interesting.

Thanks

greetings

Felix
 
Felix, openjpeg code lives at http://code.google.com/p/openjpeg/downloads/list

Wrt encryption etc., yes, working on it on and off. It's not number 1 on the list of things, though. But eventually we'll need it for some of our restoration projects. There's a number of use-cases outside of mainstream anti-piracy efforts.
 
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