[noggin]

@noggin
Thank you for the explanation.
But I noticed another very annoying problem and I wouldn't know how to solve.

When I allow pass-through audio, (disabling synchronizes the sound to the image) and turn off the audio playback system (decoder amplifier) at night to listen to audio on TV, TV audio remains mute and l Image crashes.
To reactivate the feature with the TV I have to disable the pass-through, this is a very annoying thing when I have to switch from TV> HT system and vice versa.
In the old Box Andorid (HiMedia) this was automatic, i would be very happy if there is a way to solve this problem.
Since this problem concerns Kodi perhaps I don't know if it is the case to ask other section of the forum.
Thank you very much

I suspect this is down to Kodi + nVidia Shield TV not fully supporting EDID in terms of controlling audio output.  I think that enabling HD Audio passthrough in Kodi on the Sheild TV means it effectively ignores EDID from the display+AVR, or just the display, and forces HD Audio output over HDMI, whether the display or display+AVR combo supports it or not.

EDID is how the TV and TV+AVR can tell what is connected to them what audio formats they support (when you connect a source to a display, it communicates via data so the source knows what video and audio formats it should be able to send).  If this is ignored, and Kodi sends True HD / DTS HD MA etc. to the TV, but it can't accept it, then you get no sound and all sorts of issues.  I think this is partially because HD Audio isn't officially supported within Android TV and on the Shield TV - though it's possible to send it still via unsupported routes.  I don't know whether EDID support is possible on the Shield TV + Android TV + Kodi combo.    Very few other Android TV platforms support HD Audio at all. 

I just switch passthrough on and off if I need to switch my AVR off.  It's only a couple of button presses after all...

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