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Jaroslav Kysela 2001-05-15 12:11:08 +00:00
parent 6f75a56d2c
commit 2a026a8a12

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.TH ALSACTL 1 "25 Nov 1998"
.TH ALSACTL 1 "15 May 2001"
.SH NAME
alsactl \- advanced controls for ALSA soundcard driver
.SH SYNOPSIS
\fBalsactl\fP [\fIoptions\fP] [\fIstore\fP|\fIrestore\fP] <card #>
\fBalsactl\fP [\fIoptions\fP] [\fIstore\fP|\fIrestore\fP] <card # or id>
.SH DESCRIPTION
\fBalsactl\fP is used to control advanced settings for the ALSA
@ -14,14 +14,14 @@ you have come to the right place.
.SH INVOKING
\fBalsactl\fP [\fIoptions\fP] [\fIstore\fP|\fIrestore\fP] <card #>
\fBalsactl\fP [\fIoptions\fP] [\fIstore\fP|\fIrestore\fP] <card # or id>
.SS Commands
\fIstore\fP saves the current driver setup for the selected soundcard
\fIstore\fP saves the current driver state for the selected soundcard
to the configuration file.
\fIrestore\fP loads driver setup for the selected soundcard from the configuration file.
\fIrestore\fP loads driver state for the selected soundcard from the configuration file.
If no soundcards are specified, setup for all cards will be saved or
loaded.
@ -34,7 +34,7 @@ Help: show available flags and commands.
.TP
\fI-f, --f\fP file
Select the configuration file to use. The default is /etc/asound.conf
Select the configuration file to use. The default is /etc/asound.state
.TP
\fI-d, --debug\fP
@ -45,7 +45,7 @@ Use debug mode: a bit more verbose.
Print alsactl version number.
.SH FILES
\fI/etc/asound.conf\fP (or whatever file you specify with the
\fI/etc/asound.state\fP (or whatever file you specify with the
\fB-f\fP flag) is used to store current settings for your
soundcards. The settings include all the usual soundcard mixer
settings. More importantly, alsactl is
@ -58,81 +58,6 @@ necessary for some soundcard features (e.g. enabling/disabling
automatic mic gain, digital output, joystick/game ports, some future MIDI
routing options, etc).
.SS Configuration File Syntax
There are some terms in the config file that bear explaining. The
"capabilities" comments before each line tells you some
characteristics of each channel. This is purely informational; these
are not flags you can set. Capabilities are listed below.
.TP
\fIhardware-mute\fP
The soundcard itself is capable of muting the channel.
Otherwise, kernel midlevel code will set the volume to minimum when an
application requests muting on this channel.
.TP
\fIjoin-mute\fP
Muting this channel can \fBonly\fP be
toggled for left and right at the same time, \fBnot\fP independently
-- even if you can control the volumes for left and right independently!
.TP
\fIstereo\fP
The channel is stereo.
.TP
\fIrecord\fP
The channel may be used as a recording source.
.TP
\fIjoin-record\fP
Recording from this channel can only be toggled for \fBboth\fP left
and right at once; they cannot be toggled independently.
.TP
\fIrecord-by-mute\fP
This channel can be recorded even if it's muted, so you can avoid
feeding your record source back to the speakers.
.TP
\fIexternal-input\fP
The channel
controls a signal from an external input (like Line-In or CD). This
serves to distinguish external source channels from onboard
source channels (like OPL-3 synth).
.TP
\fIdigital\fP
This channel is fed to an onboard digital mixer for possible hardware
processing (for instance, surround-sound processing if your card has it).
.PP
The configuration file also has \fIboolean switches\fP
which are used to toggle certain card-specific advanced features. For
example:
; Type is 'bool'.
switch( "MIC Gain", false )
This shows that my card has a switchable mic gain, and that it's
currently turned off. To turn it on, just change "false" to "true,"
save the config file, and run \fBalsactl restore\fP.
.SH EXAMPLES
Let's say I have this entry in /etc/asound.conf for my PCM output.
; Capabilities: stereo hardware-mute digital.
; Accepted channel range is from 0 to 63.
channel( "PCM", stereo( 40 mute, 50 mute ))
When \fBalsactl restore\fP is run, the PCM volume will be set
to 40 for the left and 50 for the right, but both will be
muted. Since this card supports \fIhardware-mute\fP, muting will be done by
hardware rather than by zeroing the levels.
.SH SEE ALSO
\fB
amixer(1),
@ -144,8 +69,5 @@ aplay(1)
None known.
.SH AUTHOR
\fBalsactl\fP is by Jaroslav Kysela <perex@suse.cz>
This document is by Paul Winkler <zarmzarm@erols.com>.
\fBalsactl\fP is by Jaroslav Kysela <perex@suse.cz> and Abramo Bagnara
<abramo@alsa-project.org>. This document is by Paul Winkler <zarmzarm@erols.com>.