Beyond Linux From Scratch - Version 6.1

Chapter 37. Multimedia Libraries and Drivers

ALSA Utilities-1.0.9a

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-1.0.9

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-6.1 package. 

make install-alsa
[Note]

Note

All channels of your sound card are muted by default. You can use the alsamixer program from the ALSA Utilities to change this.

The first time the dev.d script below is run, 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 using a /etc/dev.d/ handler script that will execute when the device is detected during boot (or when plugged in for USB devices).

While still the root user, create the dev.d script with the following commands: 

install -v -d -m755 /etc/dev.d/snd &&
cat > /etc/dev.d/snd/alsa.dev << "EOF"
#!/bin/sh -e
# This script is called by udevd when a change in a device is
# detected, including initial detection upon bootup.
# udevd sets the environment variables ACTION and DEVNAME.

[ "$ACTION" = "add" ] || exit 0
DEV_BASENAME="${DEVNAME##*/}"
N="${DEV_BASENAME#controlC}"
case "$DEV_BASENAME" in
    controlC[0-7])
        x=0
        while [ $x -lt 20 ]; do
            # Wait up to 20 seconds for /usr to be mounted if necessary
            if [ -f /usr/sbin/alsactl ]; then
                /usr/sbin/alsactl restore $N
                exit 0
            fi
            sleep 1
            x=`expr $x + 1`
        done & # Put the while command in the background and continue
    ;;
esac
exit 0
EOF
chmod -v 755 /etc/dev.d/snd/alsa.dev

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.

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 2005-08-20 14:47:37 -0600