[wackid]

By local I mean movies played from my NAS.

So you just have the network path mapped as a source in Kodi, using SMB or NFS? If so, there no reason for there to be any issue with the audio output. All of my content is streamed from my NAS via SMB, and HD audio works perfectly (Dolby THD/Atmos, DTS HD-MA)

Hey you mentioned Atmos. I am planning for Atmos too. Just have to wait until Onkyo release their RZ series beasts.
So it will play all Atmos dts:X formats on the Celeron Chromebox?