Help to reconnect outputs with wireplumber

[Jean-Philippe Lambert]

Hello,

I am trying to set-up a fleet of headless Raspberry Pi with bluetooth 
speakers.

I was impressed that it works very well with almost the default 
configuration of pipewire.

> pi at dotpi-asterismes-001:~ $ uname -a 
> Linux dotpi-asterismes-001 6.6.31+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.6.31-1+rpt1 (2024-05-29) aarch64 GNU/Linux
> pi at dotpi-asterismes-001:~ $ pipewire --version
> pipewire
> Compiled with libpipewire 0.3.65
> Linked with libpipewire 0.3.65
> pi at dotpi-asterismes-001:~ $ wireplumber --version
> wireplumber
> Compiled with libwireplumber 0.4.13
> Linked with libwireplumber 0.4.13
> pi at dotpi-asterismes-001:~ $ apt list --installed '*blue*'
> Listing... Done
> bluez-firmware/stable,stable,now 1.2-9+rpt3 all [installed,automatic]
> bluez/stable,now 5.66-1+rpt1+deb12u1 arm64 [installed,automatic]
> libbluetooth3/stable,now 5.66-1+rpt1+deb12u1 arm64 [installed,automatic]
> libspa-0.2-bluetooth/stable,now 0.3.65-3+rpt8+deb12u1 arm64 [installed,automatic]
> pi-bluetooth/stable,stable,now 0.1.20 all [installed]


I only changed one bluetooth property, for wireplumber to start without 
login:

> -- load this before /usr/share/wireplumber/bluetooth.lua.d/90-enable-all.lua
> 
> -- do not start and stop bluez with login: always run
> bluez_monitor.properties["with-logind"] = false

However, around 15 minutes after starting the bluetooth speaker, the 
transport is disconnected, not matter if sound is being played or not. 
This might be a problem with bluez, as I had the same problem without 
pipewire, with bluez and jackd. (But not with the speakers, as I can use 
them with phones for hours without interruption.)

The clients are moved to a "Dummy output". When I restart the bluetooth 
speaker, a new transport is created.

> pi at dotpi-asterismes-001:~ $ bluetoothctl 
> [DEL] Transport /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1/fd2 
> [DEL] Endpoint /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1 
> [CHG] Device 10:94:97:24:D0:13 Connected: no
> [CHG] Device 10:94:97:24:D0:13 Connected: yes
> [NEW] Endpoint /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1 
> [NEW] Transport /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1/fd3 
> [CHG] Transport /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1/fd3 Delay: 0x05dc (1500)
> [CHG] Transport /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1/fd3 Volume: 0x002f (47)
> [CHG] Transport /org/bluez/hci0/dev_10_94_97_24_D0_13/sep1/fd3 Volume: 0x0032 (50)
> [Ast-01]# 


> pi at dotpi-asterismes-002:~ $ pw-top
> S   ID  QUANT   RATE    WAIT    BUSY   W/Q   B/Q  ERR FORMAT           NAME                                                             
> R   28   1024  48000 151.2us   0.6us  0.01  0.00    0                  Dummy-Driver
> R   67      0      0  31.4us  82.2us  0.00  0.00    0                   + cpal_client_out
> S   29      0      0    ---     ---   ---   ---     0                  Freewheel-Driver
> S   36      0      0    ---     ---   ---   ---     0                  Midi-Bridge
> S   57      0      0    ---     ---   ---   ---     0                  v4l2_input.platform-bcm2835-isp.2
> S   59      0      0    ---     ---   ---   ---     0                  v4l2_input.platform-bcm2835-isp.3
> S   61      0      0    ---     ---   ---   ---     0                  v4l2_input.platform-bcm2835-isp.6
> S   63      0      0    ---     ---   ---   ---     0                  v4l2_input.platform-bcm2835-isp.7
> S   66      0      0    ---     ---   ---   ---     0                  bluez_output.10_94_97_24_D0_13.1

I would like to automatically reconnect the clients from the dummy 
output to the new 'bluez_output.*' Could you please help me to do that?

Thank you for your help,

Jean-Philippe Lambert