DESCRIPTION
The
mixerctl command displays or sets various audio system mixing variables. If a list of variables is present on the command line, then
mixerctl prints the current value of those variables for the specified device. If the
-a flag is specified, all variables for the device are printed. If the
-w flag is specified,
mixerctl attempts to set the specified variables to the given values.
The -d flag can be used to give an alternative mixer device. The default is /dev/mixer.
The -n flag suppresses printing of the variable name.
The -v flag shows the possible values of enumeration and set valued variables. Enumerated values are shown in brackets (“[]”) and set values are shown in curly braces (“{}”).
The exact set of controls that can be manipulated depends on the mixer. The general format (in both getting and setting a value) is
class.name = value
class can have values like
inputs or
outputs, indicating that the control affects the input or output of the mixer, respectively.
name indicates what part of the mixer the control affects. Continuous mixer values, e.g., volume, have numeric values in the range 0-255. If
value can be set for each channel independently, the values are printed separated by commas. Discrete mixer values, e.g., the recording source, have symbolic names. Depending on the mixer it may either be an enumeration or a set.
The suffixes ++ and -- can be used to step through the values of a mixer control. For numeric controls, these operators increase or decrease, respectively, the value by an amount (the delta) suitable to make the control assume the next possible value. For binary controls, these operators toggle between on and off.
The operators += and -= change the value of a mixer control by the indicated number of steps.
EXAMPLES
The command
mixerctl -a -v
can produce
inputs.mic=0,0 volume
inputs.mic.mute=off [ off on ]
inputs.cd=220,220 volume
inputs.cd.mute=off [ off on ]
inputs.dac=220,220 volume
inputs.dac.mute=off [ off on ]
record.record=220,220 volume
record.record.source=mic [ mic cd dac ]
monitor.monitor=0 volume