amixer.1

alsa-utils-1.0.14编译声卡驱动所需要的一些文件源码

.TH AMIXER 1 "11 Aug 2000"
.SH NAME
amixer \- command-line mixer for ALSA soundcard driver
.SH SYNOPSIS
\fBamixer\fP [\fI\-option\fP] [\fIcmd\fP]
.SH DESCRIPTION
\fBamixer\fP allows command-line control of the mixer for the ALSA
soundcard driver.
\fBamixer\fP supports multiple soundcards.

\fBamixer\fR with no arguments will display the current mixer settings
for the default soundcard and device. This is a good way to see a list
of the simple mixer controls you can use.

.SH COMMANDS

.TP
\fIhelp\fP
Shows syntax.

.TP
\fIinfo\fP
Shows the information about a mixer device.

.TP
\fIscontrols\fP
Shows a complete list of simple mixer controls.

.TP
\fIscontents\fP
Shows a complete list of simple mixer controls with their contents.

.TP
\fIset\fP or \fIsset\fP <\fISCONTROL\fP> <\fIPARAMETER\fP> ...
Sets the simple mixer control contents. The parameter can be the volume
either as a percentage from 0% to 100% with \fI%\fP suffix,
a dB gain with \fIdB\fP suffix (like -12.5dB), or an exact hardware value.
The dB gain can be used only for the mixer elements with available
dB information.
When plus(+) or minus(\-) letter is appended after
volume value, the volume is incremented or decremented from the current
value, respectively.

The parameters \fIcap, nocap, mute, unmute, toggle\fP are used to
change capture (recording) and muting for the group specified.

The optional modifiers can be put as extra parameters to specify
the stream direction or channels to apply.
The modifiers \fIplayback\fP and \fIcapture\fP specify the stream,
and the modifiers \fIfront, rear, center, woofer\fP are used to specify
channels to be changed. 

A simple mixer control must be specified. Only one device can be controlled
at a time.

.TP
\fIget\fP or \fIsget\fP <\fISCONTROL\fP>
Shows the simple mixer control contents.

A simple mixer control must be specified. Only one device can be controlled
at a time.

.TP
\fIcontrols\fP
Shows a complete list of card controls.

.TP
\fIcontents\fP
Shows a complete list of card controls with their contents.

.TP
\fIcset\fP <\fICONTROL\fP> <\fIPARAMETER\fP> ...
Sets the card control contents. The identifier has these components: iface,
name, index, device, subdevice, numid. The next argument specifies the value
of control.

.TP
\fIcget\fP <\fICONTROL\fP>
Shows the card control contents. The identifier has same syntax as for
the \fIcset\fP command.

.SH OPTIONS

.TP
\fI\-c\fP card

Select the card number to control. The device name created from this
parameter has syntax 'hw:N' where N is specified card number.

.TP
\fI\-D\fP device

Select the device name to control. The default control name is 'default'.

.TP
\fI\-s\fP | \fI\-\-stdin\fP

Read from stdin and execute the command on each line sequentially.
When this option is given, the command in command-line arguments is ignored.

Only sset and cset are accepted.  Other commands are ignored.
The commands to unmatched ids are ignored without errors too.

.TP
\fI\-h\fP 
Help: show syntax.
.TP
\fI\-q\fP
Quiet mode. Do not show results of changes.

.SH EXAMPLES

.TP
\fBamixer \-c 1 sset Line,0 80%,40% unmute cap\fR
will set the second soundcard's left line input volume to 80% and
right line input to 40%, unmute it, and select it as a source for
capture (recording).\fR

.TP
\fBamixer \-c 1 \-\- sset Master playback -20dB\fR
will set the master volume of the second card to -20dB.  If the master
has multiple channels, all channels are set to the same value.

.TP
\fBamixer \-c 1 set PCM 2dB+\fR
will increase the PCM volume of the second card with 2dB.  When both
playback and capture volumes exist, this is applied to both volumes.

.TP
\fBamixer \-c 2 cset iface=MIXER,name='Line Playback Volume",index=1 40%\fR
will set the third soundcard's second line playback volume(s) to 40%

.TP
\fBamixer \-c 2 cset numid=34 40%\fR
will set the 34th soundcard element to 40%

.SH BUGS 
None known.
.SH AUTHOR
\fBamixer\fP is by Jaroslav Kysela <[e-mail]>.
This document is by Paul Winkler <[e-mail]> and Jaroslav Kysela <[e-mail]>.