JPEG2000 sequence image extraction ?

[Lucius]

Hi all,

Is it possible to extract a JPEG2000 sequence and a WAVE file when opening a DCP?

I only find options to export in Quicktime / MP4 with recompression.

Thanks.

[carl]

It's not possible from inside DoM but you can use the command-line tool `asdcp-unwrap` from asdcplib to do that, if that helps.

[Lucius]

Yes, I know asdcp-unwrap. But I'm not sure it works from an encrypted DCP and by providing a DKDM.

You need the cipher in plain-text, I think. But how to get the cipher from a DKDM?

[carl]

Ah I see. I don't know of an easy way to do that... Maybe it's not so hard to add this feature to DCP-o-matic...

[Lucius]

Ah I see. I don't know of an easy way to do that... Maybe it's not so hard to add this feature to DCP-o-matic...

That would be great.

[Carsten]

Should be possible to create an unencrypted DCP with DCP-o-matic without recompression if you get a DKDM. This intermediate step could also be useful to conform the images into a single reel MXF, without any offsets, etc, which would make it easier to extract the images in one go.

[carl]

Should be possible to create an unencrypted DCP with DCP-o-matic without recompression if you get a DKDM. This intermediate step could also be useful to conform the images into a single reel MXF, without any offsets, etc, which would make it easier to extract the images in one go.

Good point!

[reels]

Yes, I know asdcp-unwrap. But I'm not sure it works from an encrypted DCP and by providing a DKDM.

You need the cipher in plain-text, I think. But how to get the cipher from a DKDM?

Getting the cipher from (D)KDM is pretty easy, there is a reference implementation in the "Digital Cinema System Specification: Compliance Test Plan" available here in C++.

Or you can use Wolfgang Woehl's "kdm-decrypt.rb" available in the Digital Cinema Tools Distribution.

You just point it to the (D)KDM and the RSA private key file which you can create yourself (the key is in the config.xml) or by choosing "Export all KDM decryption settings..." and just keep the "BEGIN RSA PRIVATE KEY" part.

But I must admit that being able to create a new unencrypted DCP sounds pretty useful.

[Lucius]

Thank you, it works great!