Beyond Linux® From Scratch - Version 7.4

Chapter 37. Multimedia Libraries and Drivers

alsa-utils-1.0.27.2

Introduction to ALSA Utilities

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

This package is known to build and work properly using an LFS-7.4 platform.

Package Information

ALSA Utilities Dependencies

Required

alsa-lib-1.0.27.2

Optional

libsamplerate-0.1.8, Dialog and xmlto-0.0.25

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

Installation of ALSA Utilities

Install ALSA Utilities by running the following commands: 

./configure --disable-alsaconf --disable-xmlto &&
make

This package does not come with a test suite.

Now, as the root user: 

make install

Command Explanations

--disable-alsaconf: This switch disables building the alsaconf configuration tool which is incompatible with Udev.

--disable-xmlto: Omit this switch if you have installed xmlto-0.0.25 and don't wish to install pregenerated man pages.

Configuring ALSA Utilities

Config Files

/var/lib/alsa/asound.state

Configuration Information

Note that all channels of your sound card are muted by default. You can use the alsamixer program to change this. Use speaker-test to check that your settings have been applied correctly. You should hear “pink noise” on your speakers.

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

touch /var/lib/alsa/asound.state &&
alsactl store

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

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.

Boot Script

To automatically store and restore volume settings (if udev rule doesn't work for you) when the system is rebooted, install the /etc/rc.d/init.d/alsa boot script from the blfs-bootscripts-20130908 package. 

make install-alsa

Contents

Installed Programs: aconnect, alsactl, alsaloop, alsamixer, alsaucm, amidi, amixer, aplay, aplaymidi, arecord, arecordmidi, aseqdump, aseqnet, iecset and speaker-test
Installed Libraries: None
Installed Directories: /usr/share/sounds/alsa and /var/lib/alsa

Short Descriptions

aconnect

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

alsactl

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

alsaloop

allows creation of a PCM loopback between a PCM capture device and a PCM playback device.

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 2013-09-02 15:18:54 -0700