MKV is a container
ISO is a container of M2TS files (container also).
It's just like an envelope for the video and audio

ISO - can be decoded because Himedia right now supports decoding Dolby TrueHD or Dolby Atmos to PCM audio t.e. compatible
with all receivers and mini audio systems (like yours)
But the problem with MKV still exists, that's why I've started this topic. Right now you can convert all of your movies
from MKV to M2TS (it's not easy) or just wait Himedia to solve it as a problem.
Regards
or...what a container does mean?
sorry i'm "green" about....