AAC 5.1 / 7.1 Help

Hi,

So I’ve read through a bunch of threads, but I’m still coming up short. I have my Odroid N2 setup with CoreELEC 9.2. I am using the following settings:

Set speaker channels to 2.0
Enable AC3
Enable Dolby Transcoding

That sends surround sound to my Denon receiver, but the audio is super choppy…

I’m totally stumped.

I think you’re supposed to set speaker channels to 7.1

Thanks so much! The first solution I came up with, prior to your reply, was setting the quality to Low. That worked, but upping things to 7.1 works with Medium. I haven’t tested High yet. Gracias!

If your amp is connected via HDMI and not incredibly ancient - then it will handle 5.1/7.1 multichannel PCM. If that’s the case set your speaker channels to 5.1/7.1 and this will disable transcode to AC3 (which is really only there for those people who have older, SPDIF/Toslink connections)

Try latest nightly builds, they fully support multi channel PCM.

@noggin 9.2 doesn’t have LPCM support.

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Yes indeed - apologies - I should have noticed the OP wasn’t on nightlies. I had to do exactly the same switch to get 5.1 FLAC (as used on some self authored stuff) and 5.1 AAC (as used by Freeview HD in the UK) to work in 5.1 PCM on my set-up.

Sorry, with those nightlies, a S912 device would deal correctly with a multichannel PCM or that fix is just for NG?

Thanks

S905/S905X/S912 have always supported multichannel PCM. The above discussion is only relevant for -ng builds.

@Newoski, if you haven’t read the Kodi audio quickstart guide, I highly recommend it - Kodi - Audio quickstart guide

That’s a great page - but arguably the advice for “AVR HDMI (no HD Audio)” may not be always correct - unless the way DTS-HD MA/HRA and Dolby True HD are handled has changed?

In the situation that covers (where an AVR can’t decode HD Audio) if you enable DD/DTS passthrough and play DTS HD MA/HRA or Dolby True HD tracks you’ll get the lossy core (or secondary DD stream) bit streamed, if you disable passthrough you’ll get lossless decode to PCM 5.1/7.1. (That was the case at one point certainly - and I don’t think it’s changed?)

Why should you loose something if using passthrough?
AVR receives original stream and if it support it, than you have a sound.

If your amp supports HDMI 5.1/7.1 PCM and DD/DTS passthrough, but not Dolby True HD and DTS HD MA passthrough, then in passthrough mode Kodi will just output the DD/DTS core/secondary streams (as EDID means it knows neither the TV nor AVR support DTS HD MA or Dolby True HD bitstreams) and you’ll get the lower quality lossy DD/DTS streams. In this case if you disable passthrough and you decode in Kodi and output in PCM 5.1/7.1 Kodi can decode the full quality lossless True HD and DTS HD streams output losslessly, as well as decoding DD and DTS lossy with no quality loss over bitstreaming (*)

That use case is particularly for AVRs that can’t decode a True HD or DTS HD MA/HRA bitstream, so where pass through for those won’t work.

(There were a generation of AVRs that supported PCM 5.1/7.1, but didn’t support HD Audio, over HDMI)

(*) losing DD/DTS metadata may mean some loudness processing for late night listening may not be as good though.