If not, any plans to support it soon ?
It probably works with pass through, but using libdcadec to pass it as PCM won’t work
Atmos is not supported as it’s normally part of TrueHD which can’t be passed through by Pi.
It seems Atmos can be added to Dolby Digital Plus, which the Pi can passthrough, so that may work currently, although it’s not something I’ve ever tested.
In theory ffmpeg could add support for decoding the Atmos data and mixing the channels appropriately which we could output as PCM data, but only if you have 8 or fewer speakers. So far I don’t believe the Atmos data has been reverse engineered.
Just stating the obvious. Atmos is an optional addition to the base audio track, so the base audio will still play just like it does with non-Atmos tracks, without the additional speaker positioning/height info.