nixpkgs/modules/services/audio/alsa.nix
Eelco Dolstra 6f8e30313f * The "audio" group should always exist, even if the ALSA module is
disabled, because udev rules refer to it.

svn path=/nixos/trunk/; revision=30229
2011-11-04 17:40:00 +00:00

77 lines
1.3 KiB
Nix

# ALSA sound support.
{ config, pkgs, ... }:
with pkgs.lib;
let
inherit (pkgs) alsaUtils;
soundState = "/var/lib/alsa/asound.state";
in
{
###### interface
options = {
sound = {
enable = mkOption {
default = true;
description = ''
Whether to enable ALSA sound.
'';
merge = mergeEnableOption;
};
enableOSSEmulation = mkOption {
default = true;
description = ''
Whether to enable ALSA OSS emulation (with certain cards sound mixing may not work!).
'';
};
};
};
###### implementation
config = mkIf config.sound.enable {
environment.systemPackages = [ alsaUtils ];
jobs.alsa =
{ startOn = "stopped udevtrigger";
preStart =
''
mkdir -m 0755 -p $(dirname ${soundState})
# Load some additional modules.
${optionalString config.sound.enableOSSEmulation
''
for mod in snd_pcm_oss; do
${config.system.sbin.modprobe}/sbin/modprobe $mod || true
done
''
}
# Restore the sound state.
${alsaUtils}/sbin/alsactl -f ${soundState} restore || true
'';
postStop =
''
# Save the sound state.
${alsaUtils}/sbin/alsactl -f ${soundState} store
'';
};
};
}