(2022-12-26, 03:17)gregeeh Wrote: I have been doing a lot of reading and searching to try and learn more about the different audio formats and I think I have discovered why the AAC movie sound was corrupted. The issue with the movies sound only happens with AAC Movies and I had to select 2 Channels to hear the sound correctly.
Several comments I read suggest that AAC is not a supported eARC/ARC codec and hence why it needs transcoding in my instance. Their exact comments of one are:
It isn't that your amp doesn't support AAC, it's that AAC is a codec that cannot be passthrough over any of HDMI, ARC, or spdif/toslink, it isn't part of the supported codec list. AAC never reaches/touches your amp. If a codec cannot be passthroughed then it has to be decoded in the client device into uncompressed PCM.
Thanks once again for your input.
It's true that AAC bitstreaming/passthrough over eARC/ARC/HDMI in general isn't widely supported (it's pretty/vanishingly rare).
However this in't really relevant to your use case as with transcoding disabled and channels configured to 5.1 Kodi is outputting the AAC 5.1 audio from the movie file not as bitstreamed AAC but as 5.1 multichannel PCM that has been decoded from the AAC audio.
Kodi is doing, as the client device, precisely what your quote states client devices should do with 5.1 AAC :
Quote:If a codec cannot be passthroughed then it has to be decoded in the client device into uncompressed PCM.
As you aren't trying to bitstream/passthrough 5.1 AAC over eARC/HDMI you aren't hitting an AAC incompatibility. (In old versions of Kodi there was an AAC Passthrough option offered for bitstreaming/passthrough of AAC audio - but because support for AAC bitstreaming was so rare it was largely untested and removed a long time ago. (You now only get AC3/DD, E-AC3/DD+, DTS, Dolby True HD and DTS HD as options for passthrough, along with transcode to 5.1 AC3/DD)
Does Kodi + your Sonos system do the same muffled audio thing with all 5.1 AAC movies output as PCM (i.e. channels set to 5.1 and no transcoding) - or just one particular one?
If you configure channels to be 5.1 and disable all passthrough/bitstream of codecs - so everything is decoded to 5.1 - do other 5.1 AC3/DD, E-AC3/DD+, DTS, True HD, DTS HD 5.1/7.1 movies sound odd?
I have a regular Kodi set-up with a Denon AVR and a 5.0 speaker system (no sub woofer) and as the UK DVB-T2 HD platform uses 5.1 AAC for multichannel audio, I listen to a some 5.1 recorded TV audio via this route via various Kodi playback solutions, and it's always decoded to 5.1 PCM. I don't hear the issues you are hearing. I'll set-up an N2 with CoreElec (it's not my daily driver at the moment) - and see if I get similar issues with 5.1 audio (though I'm not using eARC - I route my Kodi playback directly via the AVR along with my UHD BD player, my PS2, PS5, Apple TV4K and Sky Q)