From 53da307cc5dccca41dea02b515880850a85278f7 Mon Sep 17 00:00:00 2001 From: c0dev0id Date: Tue, 14 Nov 2023 11:46:25 +0100 Subject: [PATCH] Update 2023-11-14 11:46:23 --- ...penBSD_sndio_and_multiple_devices.draft.pm | 59 +++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 src/posts/2023-11-14_OpenBSD_sndio_and_multiple_devices.draft.pm diff --git a/src/posts/2023-11-14_OpenBSD_sndio_and_multiple_devices.draft.pm b/src/posts/2023-11-14_OpenBSD_sndio_and_multiple_devices.draft.pm new file mode 100644 index 0000000..b4b18e6 --- /dev/null +++ b/src/posts/2023-11-14_OpenBSD_sndio_and_multiple_devices.draft.pm @@ -0,0 +1,59 @@ +# OpenBSD sndio and mutiple devices + +## Automatic audio device switch + +OpenBSD automatically detects the system audio device. But often this is not enough. I want to plug in a USB headset and audio should automatically switch to it. + +You can start sndiod with additional `-F` flags, which define additional devices, which are switched to in order when they appear. + +``` +# sndiod -f rsnd/0 -F rsnd/1 -F rsnd/2 -F rsnd/3 +``` + +You can set these flags permanently with: +``` +# rcctl set sndiod flags -f rsnd/0 -F rsnd/1 -F rsnd/2 -F rsnd/3 +``` + +This configuration allows up to 3 additional USB devices to be connected and sndiod will switch to the last one connected. + +If you have multiple devices connected and want to switch to a specific one, you can do so with: + +``` +$ sndioctl server.device=0 +$ sndioctl server.device=1 +$ sndioctl server.device=2 +... +``` + +## Record from one device, but play back on another... + +Let's say I want to connect USB microphone, but I want to to play back sound on another device. + +This works by setting the environment variables `AUDIORECDEVICE` and `AUDIOPLAYDEVICE` accordingly. + +Example: +``` +export AUDIORECDEVICE=snd/1 +export AUDIORECDEVICE=snd/0 +``` + +However, sndiod expects every device to play and record. So the above example would work to play on the system, but record on a headset. + +If the devices are more limited, the sndio flags need to be more specific, like this: + +``` +# rcctl set sndiod flags -f rsnd/0 -m play -s play -f rsnd/1 -m rec -s rec +# rcctl restart sndiod +$ export AUDIOPLAYDEVICE=snd/0.play +$ export AUDIORECDEVICE=snd/1.rec +``` + +This creates a "play" sub device on the first audio device (system audio). And a sub device "rec" on the first USB device. The default is "play,rec", which would not work on my USB microphone. The -m switch describes what the device can do. The -s switch defines the sub device name. + +And now... everything works as expected. + +``` +$ aucat -o test.wav # record from microphone +$ aucat -i test.wav # play on system speaker +```