[llucax]

Hello everyone, I'm having a weird issue with Stereo upmixing from Stereo (when listening to music) to 5.1. Only 3 channels seem to work: front right, front center and rear left (3 channels are silent: LFE/subwoofer, front left and rear right). When listening to audio that has 6 channels (5.1), all channels work correctly (I tested with a few different test audios and videos using different codecs and all seems to be working fine).

My setup is as follows:

* Raspberry PI 4, using Raspberry Pi OS (not using a special Kodi distro) with Pipewire
* USB DAC, like this one https://www.amazon.com/Optimal-Shop-Exte...07BGS2BS1/ (see full lsusb -v for the device: https://paste.kodi.tv/ayimixeyik)
* Auna Areal 525 DG 5.1 speaker system: https://www.amazon.de/dp/B098R434CP/ (manual: https://use.berlin/media/pdf/download/bda-10036135.pdf)
* The DAC and speakers connected via miniplug - RCA cables.
* Kodi 20.2 installed from the Raspberry Pi OS repos
* Logs: https://paste.kodi.tv/gisunozuho.kodi
* Audio settings screenshot: https://imgur.com/a/Ao6idcw

I also tried to use Best Match for Output Configuration setting.

[llucax]

Just playing with changing options I disabled the Stereo Upmix option and booom! Now I can hear stereo music in all 5.1 channels.

Can anyone explain this? First why Stereo Upmix is sending audio only to 3 channels and second why with is audio in the 5.1 channels with Stereo Upmix disabled?

My only guess is Pipewire is doing the upmixing magic, but that wouldn't explain the sending audio only to 3 channels when Stereo Upmix is enabled...

I'm really puzzled about this!

Thanks!

[jjd-uk]

Looks to you don't have correct device selected in Kodi, according to log the device name for Multichannel PCM output is alsa_output.usb-0d8c_USB_Sound_Device-00.analog-surround-51.2

[llucax]

The default device is detected and the default device is set to alsa_output.usb-0d8c_USB_Sound_Device-00.analog-surround-51.2 in pipewire. I also tried to select alsa_output.usb-0d8c_USB_Sound_Device-00.analog-surround-51.2 explicitly in Kodi and it doesn't change anything.

Also as I said after disabling stereo upmix in Kodi everything works great. I just don't know why.

[jjd-uk]

According to the log the default device selection only supports 2 channels, the only one that support 6 channels (5.1) is the explicit alsa_output.usb-0d8c_USB_Sound_Device-00.analog-surround-51.2

I guess it could be Pipewire being the issue, Pipewire in Kodi is still relatively new. Can't you use ALSA?

[llucax]

Mmm, interesting, the sound card is configured with the 5.1 profile in pipewire. I'm not sure how can I use alsa to be honest (AFAIK alsa is the low level interface in the kernel and it is always used, but I guess you mean using alsa directly without going throughout pipewire?). I never managed to understand the Linux audio stack very well.

Thanks!

[fr0gHaven]

Same issue here; I'm attempting stereo upmixing and getting no sound from front left and rear right speakers.  Ubuntu 23.10.

[Rosensrauk]

I have the same issue except that I am using Coreelec 21. This is very weird.
I was searching for answers about this problem at Coreelec forum but the only thing I found was here.
Coincidence?

[williambarty]

I have the same issue with Kodi Omega on both Coreelec and Windows.  Rear right speaker has no sound with upmix playing through HDMI to AVRs.  Other speakers play normally.

[HeresJohnny]

Same issue with CoreELEC latest Omega.