MIXERCTL(1)                OpenBSD Reference Manual                MIXERCTL(1)

NAME
     mixerctl - control audio mixing

SYNOPSIS
     mixerctl [-anv] [-f file]
     mixerctl [-nv] [-f file] name ...
     mixerctl [-qt] [-f file] name ...
     mixerctl [-q] [-f file] name=value ...

DESCRIPTION
     The mixerctl command displays or sets various audio system mixing
     variables.  If a list of variables is present on the command line,
     mixerctl prints the current value of those variables for the specified
     device.  Variables can also be set at system startup using the
     configuration file mixerctl.conf(5).

     The options are as follows:

     -a       Print all device variables and their current values.  This is
              the default, if no parameters are given to mixerctl.

     -f file  Specify an alternative audio mixing device.  The default is
              /dev/mixer.

     -n       Suppress printing of the variable name.

     -q       Suppress all printing when setting a variable.

     -t       Toggle.  Attempt to select the next possible value of an enum
              (see below).

     -v       Show all possible values of variables.  Enum values are shown in
              `[]' and values belonging to a set are shown in `{}' (see
              below).

     name=value
              Attempt to set the specified variable name to value.

     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

     The class can have values like ``inputs'' or ``outputs'', indicating that
     the control affects the input or output, respectively, to the mixer.  The
     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.

     Variables may take one of three types, again dependent on the mixer:

     1.   Enums.  These may take only one out of a possible list of symbolic
          values or the literal string ``toggle'', which toggles the value,
          e.g. inputs.mic.source=mic0.

     2.   Sets.  These can take one or more of a possible list of symbolic
          values; multiple values are specified as a comma-separated list,
          e.g. record.source=mic,cd.  Additionally, value may be omitted to
          specify the empty set, e.g. record.source=.

     3.   Numbers.  Numerical values may be specified in either absolute or
          relative forms.  The relative form is indicated by a prefix of `+'
          or `-' to denote an increase or decrease, respectively.

ENVIRONMENT
     MIXERDEVICE     The audio mixer device to use.

FILES
     /dev/mixer             Default mixer audio device.
     /etc/mixerctl.conf     mixerctl configuration file.

EXAMPLES
     Show possible values for all mixer variables, and their current settings:

           $ mixerctl -av
           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

     Toggle inputs.dac.mute:

           $ mixerctl -t inputs.dac.mute
           inputs.dac.mute: off -> on
           $ mixerctl inputs.dac.mute=toggle
           inputs.dac.mute: on -> off

SEE ALSO
     aucat(1), audioctl(1), cdio(1), audio(4), mixerctl.conf(5), sysctl(8)

HISTORY
     The mixerctl command first appeared in OpenBSD 2.4.

OpenBSD 4.9                    October 19, 2008                    OpenBSD 4.9