[PROBLEM] Bluetooth Audio output (Transmitter)

[ppianigiani]

(3rd Jun, 2021 04:16 AM)Nachteule Wrote:  Anyway if you delete the 00-disable-autospawn.conf or set autospawn=yes pulseaudio starts automatically when Kodi is started

OK, I was able to have pulseaudio started automatically with Kodi, but in this case I was never able to have my BT HPs working fine.

From all the testing I've made, in order to have Kodi's GUI and videos&addons sounds on my BT HPs, it seems there are 2 strict conditions that must be met:

1. pulseaudio MUST be already running when kodi starts
2. 'bluetoothctl connect <dev>' command MUST be executed when pulseaudio is already running
   

I guess I can sort of explain the second point (I suspect that a 'pulseaudio' sink MUST already exist in order to successfully connect a BT output device) and I easily tested it on my 'rc.local approach': swapping the execution order, with "bluetooth connect <dev>" command before "pulseaudio --start", no way I can get sounds from my HPs, while the other way around always works fine.

I'm not sure of the second point, but I've tested it in 2 different ways:

• running kodi service with autostart and pulseaudio with autospawn=yes, while executing "bluetoothctl connect" from /etc/rc.local => doesn't work, no sound from HPs, neither the "connection active" prompt
• running kodi service with autostart and pulseaudio with autospawn=yes, while executing "bluetoothctl connect" from USERRUN script, with option "xbmc start" =>doesn't work either, no sound from HPs, neither the "connection active" prompt
  

The point is that when pulseaudio is automatically started with kodi, it's actually started AFTER kodi (pulseaudio pid always higher than kodi pid) and that's why I'm supposing pulseaudio MUST be already running when kodi starts to have it working fine, even if I can't explain why. Does this make any sense to you?

Many thanks!

EDIT
I've added one more test:

• pulseaudio and kodi service started from /etc/rc.local
• "bluetoothctl connect <dev>" executed from USERRUN script, with option "xbmc start"
  

In this case, my HPs never get connected, Kodi crashes immediately and I never see the GUI...
This seems quite a confirmation of the first condition, but once more I can't explain why.