AUDIOCTL(1) | General Commands Manual | AUDIOCTL(1) |
audioctl
— control
software audio format
audioctl |
[-n ] [-d
device] -a |
audioctl |
[-n ] [-d
device] name ... |
audioctl |
[-n ] [-d
device] -w
name=value ... |
The audioctl
command displays or sets the
parameters that determine the playback and recording format for software
using an audio device. It is most useful when the full
audio(4) API is not available,
e.g. when playing or recording raw audio data from a
sh(1) script, or from the command
line. It does not control the underlying hardware format, which can be
changed with
audiocfg(1).
The variables that can be inspected and changed with
audioctl
are normally per-application and are reset
when a /dev/audioX device is opened. This can be
circumvented by using /dev/soundX instead, which
retains global state.
If a list of variables is present on the command line, then
audioctl
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
audioctl
attempts to set the specified variables to
the given values.
The -d
flag can be used to give an
alternative audio control device, the default is
/dev/audioctl0.
The -n
flag suppresses printing of the
variable name.
To set the playing sampling rate to 11025, you can use
audioctl -w
play.sample_rate=11025
audioctl -w
play=44100,2,16,slinear_le
The old -f
flag is still supported. This
support will be removed eventually.
audiocfg(1), audioplay(1), audiorecord(1), mixerctl(1), audio(4), sysctl(8)
The audioctl
command first appeared in
NetBSD 1.3.
Since the parameters controlled by
audioctl
are global, they can be changed
unexpectedly if another application uses the same audio device.
It is always preferable to use
AUDIO_SETINFO
on a per-process
/dev/audioX device, if the
audio(4) ioctls are available
in the programming environment. Similarly,
audioplay(1) and
audiorecord(1) are more
safe for use in scripting.
March 21, 2021 | NetBSD 10.99 |