How does DCP-o-matic handle SMPTE IAB (Atmos)? Is it a separate MXF, or does it require Channel 14 mapping?

[RAY-NUE]

Hi everyone,
I am mastering a DCP that requires a Dolby Atmos track using DCP-o-matic (DOM), and I want to clarify how the software structures SMPTE IAB (Immersive Audio Bitstream) within the package.
In DOM's Audio Mapping Matrix, Channel 14 of the 16-channel PCM audio is explicitly labeled for D-BOX (DBS) motion data. This led to my confusion about where the Atmos/IAB data actually goes.
My understanding of the SMPTE DCP specification is that the Atmos/IAB bitstream should NOT be forced into the main 16-channel Audio MXF. Instead, it should be compiled as a completely separate, independent ATMOS/IAB MXF asset inside the DCP folder. The CPL, PKL, and ASSETMAP will then contain the metadata tags pointing the cinema processor (like Dolby CP850 or CP950) to read this separate asset and decode the 3D object panning data, while Channel 14 of the main audio track might just carry an FSK sync pulse or be left for D-BOX.
Could someone confirm if DCP-o-matic follows this exact behavior?
Specifically:
1. When I import a SMPTE IAB MXF or ADM BWF into DOM via the "Add file(s)..." button in the Content tab, does DOM automatically package it as a separate MXF track without requiring any manual mapping in the 16-channel PCM matrix?
2. Will DOM correctly write the CPL and XML metadata so that a Dolby CP850/CP950 can seamlessly recognize the immersive track, sync it, and pan the objects to the ceiling speakers?
I want to make sure there are no conflicts between the D-BOX labeling in the audio matrix and the Atmos/IAB asset package.
Thank you for your insights!

[Carsten]

There is a longish thread about DCP-o-matic and ATMOS here: viewtopic.php?p=10303&sid=c5fe805c33e57 ... da8#p10303

Short answer - yes, it is possible and it has been done.

DCP audio channel 14 will carry the ATMOS TC that is needed to sync the ATMOS/IAB renderer ('ATMOS processor') to the server. The ATMOS audio is carried as an additional Auxiliary MXF file within the SMPTE DCP.