Alright, now this issue has been fully resolved.
Turned out there is an optional feature in creating encrypted MXF files that is called
frame HMAC. The Barco ICMP would crash on trying to play MXF files missing these HMAC
tags.
Both DCP-o-matic and Colorfront Transkoder were not writing these (optional) HMAC tags,
and the Barco ICMP was the only server/media block who would actually crash on these
files.
As a result, I was not able to create encrypted INTEROP or SMPTE DCPs for our Barco ICMP.
The same DCPs would play without any issues on our Sony.
So, this issue now was resolved from both sides: Barco issued a firmware update for the
ICMP (1.2.2.11) which will accept MXF files that do not contain HMAC. Plus, Colorfront
Transkoder AND DCP-o-matic are now writing HMAC.
So, if you have trouble creating encrypted INTEROP or SMPTE DCPs for a Barco Alchemy/ICMP,
either have them update their ICMP software to at least 1.2.2.11, and/or use DCP-o-matic
from version 2.6.31 up.
Here is an explanation of what HMAC is from Mr. John Hurst:
'The HMAC (Hashed Message Authentication Code) is an optional set of values appended
to each encrypted picture frame. It allows the decoder to detect altered or re-ordered
frames. See SMPTE ST 429-6 for the details. Not only is the HMAC optional in the MXF
file, it is also optional decoder behavior, i.e., the decoder can ignore it when it is
present.'
- Carsten