[pulseaudio-discuss] Making USB DAC the default sink
jeff_barish at earthlink.net
Wed Dec 14 20:28:32 PST 2011
Someone asked the same question a few months ago, but the answer assumed a
graphical desktop. In my case, the platform is headless.
The problem is that I want a USB DAC, if one is connected, always to be the
default sink. I can use pacmd to set the default sink to the index of the USB
DAC. If I reboot the system, the USB DAC remains the default. However, the
moment I disconnect the USB DAC, the default changes to the internal DAC (the
only other card). If I then reconnect the USB DAC, the default remains the
internal DAC. I have to run pacmd again to restore the default selection to
the USB DAC. It is difficult to do that because the system is headless.
I think I know a solution. I am considering creating a udev rule that
responds to the attachment of the USB DAC. Maybe:
ACTION=="add", SUBSYSTEM=="snd", SUBSYSTEMS=="usb", RUN+="/usr/local/bin/udev-
It calls a shell script that runs
pulseaudio -k && pulseaudio --start --log-target=syslog
so that the USB DAC will be assigned index 1 again (otherwise, I won't know
what index to use in the next step). Then the script will run
pacmd set-default sink 1
to restore the default assignment. I haven't tried it yet because it seems to
me that this problem is not unusual, so surely there is a simpler solution
completely within the domain of pulseaudio.
Actually, the udev rule that I described will not run, so it seems that I
don't have a possible solution. Any suggestions welcome.
More information about the pulseaudio-discuss