bluealsa-autoconfig is a simple program to add and remove ALSA configuration
nodes for BlueALSA Bluetooth PCM and CTL devices. It can also optionally
simulate udev events on Bluetooth audio device connect and disconnect.
See The bluez-alsa project for more
information on BlueALSA.
ALSA has built-in functions to add and remove PCM configuration nodes when sound cards are added or removed. However, it provides no equivalent functionality for software PCM types such as BlueALSA. This is unfortunate because Bluetooth audio devices are more likely to be disconnected during a session, so dynamic management of the ALSA configuration is even more important for Bluetooth than it is for sound cards.
bluealsa-autoconfig aims to rectify that situation by updating the ALSA
configuration dynamically whenever a Bluetooth audio device connects or
disconnects. So, for example, when no Bluetooth audio devices are connected,
aplay -L may show:
$ aplay -L
default
Default Audio Device
sysdefault:CARD=PCH
HDA Intel PCH, ALC236 Analog
Default Audio Device
surround21:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
And then when a Bluetooth device is connected:
$ aplay -L
default
Default Audio Device
sysdefault:CARD=PCH
HDA Intel PCH, ALC236 Analog
Default Audio Device
surround21:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC236 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
bluealsa:DEV=C4:67:B5:37:26:12,PROFILE=sco
Libratone Zipp Mini HFP (CVSD)
Bluetooth Audio Input/Output
bluealsa:DEV=C4:67:B5:37:26:12,PROFILE=a2dp
Libratone Zipp Mini A2DP (aptX)
Bluetooth Audio Output
The last two entries in the above listing have been created by
bluealsa-autoconfig.
As an example GUI application, here's a screenshot of the kodi audio device
selection dialog with the same Bluetooth speaker connected:
bluealsa-autoconfig can also optionally create a new default device
definition that uses a connected BlueALSA device; and it can also optionally
trigger a udev audio device change event to notify ALSA applications when
the configuration has changed.The udev option is particularly important when
using applications such as kodi because otherwise they will not see the
changes to the ALSA configuration and therefore will not display devices
connected after the application started.
In the above kodi example, bluealsa-autoconfig is running as
bluealsa-autoconfig --udev
and /etc/asound.conf contains:
defaults.bluealsa.namehint "%n %p (%c) Bluetooth %s"
bluealsa-autoconfig must be run as root to gain the necessary privileges
for modifying the global ALSA configuration and triggering udev events. See
the manual page for full details.
A systemd service unit file is included.
meson setup builddir
cd builddir
meson compile
sudo meson install
To include the manual page, the application rst2man from the docutils project is required. Many distributions provide this in the package python3-docutils. To enable building and installing the manual page, setup the build directory with
meson setup -Ddoc=true builddir
or, if the build directory has already been set up, change its configuration with
meson configure -Ddoc=true builddir
This project is licensed under the terms of the MIT license.
It includes copies of source code files from the bluez-alsa project, which are also licensed under the MIT license and all rights to those files remain with their original author.