feat: move mixer device name to configuration

See #36

cmd/daemon/main.go

@@ -93,7 +93,7 @@ func (app *App) newAppPlayer(creds any) (_ *AppPlayer, err error) {
 	if appPlayer.player, err = player.NewPlayer(
 		appPlayer.sess.Spclient(), appPlayer.sess.AudioKey(),
 		!app.cfg.NormalisationDisabled, *app.cfg.NormalisationPregain,
-		appPlayer.countryCode, *app.cfg.AudioDevice,
+		appPlayer.countryCode, *app.cfg.AudioDevice, *app.cfg.MixerDevice,
 		*app.cfg.VolumeSteps, app.cfg.ExternalVolume,
 	); err != nil {
 		return nil, fmt.Errorf("failed initializing player: %w", err)
@@ -312,6 +312,7 @@ type Config struct {
 	DeviceType            *string  `yaml:"device_type"`
 	ClientToken           *string  `yaml:"client_token"`
 	AudioDevice           *string  `yaml:"audio_device"`
+	MixerDevice           *string  `yaml:"mixer_device"`
 	Bitrate               *int     `yaml:"bitrate"`
 	VolumeSteps           *uint32  `yaml:"volume_steps"`
 	InitialVolume         *uint32  `yaml:"initial_volume"`
@@ -368,6 +369,10 @@ func loadConfig(cfg *Config) error {
 		cfg.AudioDevice = new(string)
 		*cfg.AudioDevice = "default"
 	}
+	if cfg.MixerDevice == nil {
+		cfg.MixerDevice = new(string)
+		*cfg.MixerDevice = "default"
+	}
 	if cfg.Bitrate == nil {
 		cfg.Bitrate = new(int)
 		*cfg.Bitrate = 160

config_schema.json

@@ -65,6 +65,11 @@
           "description": "Which audio device should be used for playback, leave empty for default",
           "default": "default"
         },
+        "mixer_device": {
+          "type": "string",
+          "description": "Which audio mixer should be used for volume control, leave empty for default",
+          "default": "default"
+        },
         "server": {
           "type": "object",
           "properties": {

output/driver_unix.go

@@ -26,6 +26,7 @@ type output struct {
 	channels   int
 	sampleRate int
 	device     string
+	mixer      string
 	reader     librespot.Float32Reader
 
 	cond *sync.Cond
@@ -47,12 +48,13 @@ type output struct {
 	err chan error
 }
 
-func newOutput(reader librespot.Float32Reader, sampleRate int, channels int, device string, initialVolume float32) (*output, error) {
+func newOutput(reader librespot.Float32Reader, sampleRate int, channels int, device string, mixer string, initialVolume float32) (*output, error) {
 	out := &output{
 		reader:     reader,
 		channels:   channels,
 		sampleRate: sampleRate,
 		device:     device,
+		mixer:      mixer,
 		volume:     initialVolume,
 		err:        make(chan error, 1),
 		cond:       sync.NewCond(&sync.Mutex{}),
@@ -141,13 +143,18 @@ func (out *output) openAndSetup() error {
 }
 
 func (out *output) openAndSetupMixer() error {
+	if len(out.mixer) == 0 {
+		out.mixerEnabled = false
+		return nil
+	}
+
 	if err := C.snd_mixer_open(&out.mixerHandle, 0); err < 0 {
 		return out.alsaError("snd_mixer_open", err)
 	}
 
-	cdevice := C.CString(out.device)
-	defer C.free(unsafe.Pointer(cdevice))
-	if err := C.snd_mixer_attach(out.mixerHandle, cdevice); err < 0 {
+	cmixer := C.CString(out.mixer)
+	defer C.free(unsafe.Pointer(cmixer))
+	if err := C.snd_mixer_attach(out.mixerHandle, cmixer); err < 0 {
 		return out.alsaError("snd_mixer_attach", err)
 	}
 

output/output.go

@@ -34,12 +34,17 @@ type NewOutputOptions struct {
 	// This feature is support only for the unix driver.
 	Device string
 
+	// Mixer specifies the audio mixer name.
+	//
+	// This feature is support only for the unix driver.
+	Mixer string
+
 	// InitialVolume specifies the initial output volume.
 	InitialVolume float32
 }
 
 func NewOutput(options *NewOutputOptions) (*Output, error) {
-	out, err := newOutput(options.Reader, options.SampleRate, options.ChannelCount, options.Device, options.InitialVolume)
+	out, err := newOutput(options.Reader, options.SampleRate, options.ChannelCount, options.Device, options.Mixer, options.InitialVolume)
 	if err != nil {
 		return nil, err
 	}

player/player.go

@@ -62,7 +62,7 @@ type playerCmdDataSet struct {
 	paused  bool
 }
 
-func NewPlayer(sp *spclient.Spclient, audioKey *audio.KeyProvider, normalisationEnabled bool, normalisationPregain float32, countryCode *string, device string, volumeSteps uint32, externalVolume bool) (*Player, error) {
+func NewPlayer(sp *spclient.Spclient, audioKey *audio.KeyProvider, normalisationEnabled bool, normalisationPregain float32, countryCode *string, device, mixer string, volumeSteps uint32, externalVolume bool) (*Player, error) {
 	p := &Player{
 		sp:                   sp,
 		audioKey:             audioKey,
@@ -75,6 +75,7 @@ func NewPlayer(sp *spclient.Spclient, audioKey *audio.KeyProvider, normalisation
 				SampleRate:    SampleRate,
 				ChannelCount:  Channels,
 				Device:        device,
+				Mixer:         mixer,
 				InitialVolume: volume,
 			})
 		},