[wrxtasy]

hi wrxtasy, won't we get 5.1 optical or 7.1 hdmi passthrough with kodi in android nougat amlogic tv boxes. will that be applicable to kodi krypton only or even with latest kodi versions too. regards. 

Yes generally AML devices running Nougat 7.x Firmware have IEC61937 support for such optical / HDMI audio passthru for use with Kodi Krypton, Leia and Matrix.

You have to manually select in Android Settings > Audio > Digital Sounds > HDMI or SPDIF

AML devices running Oreo 8.1 or Pie 9.x Firmware seem to have lost IEC61937 support. 

many thanks wrxtasy for your valuable time. can you please tell us the difference in[5.1 optical  or 7.1 hdmi] pass through audio quality; android nougat kodi pass through  vs  coreelec kodi passthrough .  any difference at all or same to a good audio receiver. Also can you tell us why is that so difficult or impossible to implement official android api IEC61937 support in all android versions by the android box vendors and manufacturers . is it for economical reasons or any other specific reasons .

5.1 Optical audio quality will be the same, but 5.1 / 7.1 AAC or FLAC decoded straight to 5.1. / 7.1 (L)PCM and output over HDMI to a receiver that can handle such multichannel PCM audio will be superior with CoreELEC.

Virtually all AML Android devices cannot do such Multichannel PCM, so have to decode and then resampled 5.1 / 7.1 AAC or FLAC and repack it into 5.1 only AC3. There will be a further loss in audio quality during the process.

The Google Android OS audio mixer has limitations as well for LPCM oudio output.

It's very strange that the v4.9 AMLogic Linux Kernel used for AML Oreo 8.1 onwards has NO IEC61937 support.
Yet that same v4.9 Kernel used on a 2016 Mi Box running Oreo 8.0 does have IEC61937 support.

Looks like some audio patches have been left out of the Oreo 8.1 / Pie 9.0 SDK that AMLogic distributes to hardware vendors for some unknown reason.