Film-Tech Forum ARCHIVE: Encrypted HD-SDI signal type?

This is topic Encrypted HD-SDI signal type? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Carsten Kurz (Member # 5396) on 08-01-2014, 07:05 AM:

Am I right to assume that the encrypted HD-SDI signal from a conventional server towards the projector is still a valid 2k/24p HD-SDI Signal? That is, a full SMPTE 292/372 spec signal, just with garbage content? I am asking towards using it for a timing source. I don't care for the scrambled image content.

- Carsten

Posted by Steve Guttag (Member # 268) on 08-01-2014, 08:04 AM:

I would have to say yes. It can certainly go through a proper HDSDI switcher and that wouldn't work if it didn't conform.

Posted by Mattias Mattsson (Member # 4308) on 08-02-2014, 12:12 PM:

A related question: Is there a way to disable link encryption for uencrypted content on Doremi servers?

On dolby servers you can use the linkEncryption.sh script with an OFF argument, but I have not found a way to do the same on a Doremi system.

Posted by Carsten Kurz (Member # 5396) on 08-03-2014, 07:02 AM:

What effect would that have in a typical cinema environment? Would the Dolby still accept the projector for playout, playing unencrypted content okay, but showing scrambled image with encrypted content? Or would it stop playback?

- Carsten

Posted by Marin Zorica (Member # 1716) on 08-03-2014, 07:15 AM:

If you disable secure link on dolby it will still play unencrypted content, but not crypted.

Posted by Mattias Mattsson (Member # 4308) on 08-12-2014, 03:47 PM:

Found the answer to this. Apparantly you could (as root) do:

# echo -n 0> /doremi/etc/cinelink

to disable link encryption. A value of "2" is the default.

Posted by Scott Norwood (Member # 30) on 08-12-2014, 04:12 PM:

Wouldn't it make more sense if these systems defaulted to encrypting the HD-SDI link for encrypted content and leaving unencrypted content unencrypted? Or is there a visible on-screen glitch when switching from an encrypted to a non-encrypted signal (or vice-versa)?