Beyond Linux® From Scratch - Version 6.3

Chapter 35. Multimedia Libraries and Drivers

ALSA Utilities-1.0.13

Introduction to ALSA Utilities

The ALSA Utilities package contains various utilities which are useful for controlling your sound card.

Package Information

ALSA Utilities Dependencies

Required

ALSA Library-1.0.13

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/alsa-utils

Installation of ALSA Utilities

Install ALSA Utilities by running the following commands: 

./configure &&
make

This package does not come with a test suite.

Now, as the root user: 

make install

Configuring ALSA Utilities

Config Files

/etc/asound.state

Configuration Information

Use a bootscript to store the values at shutdown.

As the root user, install the init script /etc/rc.d/init.d/alsa included in the blfs-bootscripts-20080816 package. 

make install-alsa

Note that all channels of your sound card are muted by default. You can use the alsamixer program from the ALSA Utilities to change this. Use speaker-test to check that your settings have been applied correctly.

The first time the alsactl program is run from the udev rule below, it will complain that there is no state in /etc/asound.state. You can prevent this by running the following commands as the root user: 

touch /etc/asound.state &&
alsactl store

The volume settings will be restored from the saved state by Udev when the device is detected (during boot or when plugged in for USB devices).

As the root user, install a new Udev rules file to create the audio device nodes and run the restore script: 

cat > /etc/udev/rules.d/40-alsa.rules << "EOF"
# /etc/udev/rules.d/40-alsa.rules

# When a sound device is detected, restore the volume settings
KERNEL=="controlC[0-9]*", ACTION=="add", RUN+="/usr/sbin/alsactl restore %n"
EOF
chmod -v 644 /etc/udev/rules.d/40-alsa.rules

All sound devices are not accessible for any user except root and members of the audio group. Add any users that might use the sound devices to that group: 

usermod -a -G audio <username>
[Note]

Note

You may need to log out and back in again to refresh your group memberships. 'su <username>' should work as well.

Contents

Installed Programs: aconnect, alsaconf, alsactl, alsamixer, amidi, amixer, aplay, aplaymidi, arecord, arecordmidi, aseqnet, aseqdump, iecset, and speaker-test
Installed Libraries: None
Installed Directories: None

Short Descriptions

aconnect

is a utility for connecting and disconnecting two existing ports in the ALSA sequencer system.

alsaconf

is a configuration tool which tries to detect the sound cards on your system and write a suitable configuration file for ALSA. This program is incompatible with udev and hotplug.

alsactl

is used to control advanced settings for the ALSA sound card drivers.

alsamixer

is an ncurses-based mixer program for use with the ALSA sound card drivers.

amidi

is used to read from and write to ALSA RawMIDI ports.

amixer

allows command-line control of the mixers for the ALSA sound card drivers.

aplay

is a command-line soundfile player for the ALSA sound card drivers.

aplaymidi

is a command-line utility that plays the specified MIDI file(s) to one or more ALSA sequencer ports.

arecord

is a command-line soundfile recorder for the ALSA sound card drivers.

arecordmidi

is a command-line utility that records a standard MIDI file from one or more ALSA sequencer ports.

aseqdump

is a command-line utility that prints the sequencer events it receives as text.

aseqnet

is an ALSA sequencer client which sends and receives event packets over a network.

iecset

is a small utility to set or dump the IEC958 (or so-called “S/PDIF”) status bits of the specified sound card via the ALSA control API.

speaker-test

is a command-line speaker test tone generator for ALSA.

Last updated on 2008-05-09 08:00:42 -0500