The Linux Sound Playing HOWTO
Yoo C. Chung, wacko@laplace.snu.ac.kr
v1.5, 7 November 1997
This document lists applications for Linux that play various sound
formats.
1. Introduction
This is the Sound Playing HOWTO. It lists the many sound formats and
the applications that can be used to play them. It also lists some
hacks and advice on using these applications. There are also some
other interesting applications related to sound not directly related
to playback. However, this document does not describe how one can
setup a Linux system for sound support. Refer to the Linux Sound
HOWTO by Jeff Tranter for instructions on setting up a Linux system
for sound support and the supported sound hardware.
This deals with normal user sound applications. That is, it is only
concerned about what the average user needs to know on the application
side of sound, not exotic stuff like speech synthesis, or hardware
stuff which is dealt in the Sound HOWTO.
1.1. Copyright of this document
This document can be freely distributed and modified (I would
appreciate it if I were notified of any modifications), as long as
this copyright notice is preserved. However, it cannot be placed
under any further restrictions, and a modified document must have the
same copyright as this one. Also, credit must be given where due.
1.2. Copyright of the listed applications
If there is no mention of any copyright, then the application is under
the GNU General Public License.
1.3. Where to get this document
The most recent official version of this document can be obtained from
the Linux Documentation Project . The
most recent unofficial version of this document can be obtained from
.
A Korean version of this document (very outdated) is available at
.
A Japanese version of this document is available at
.
1.4. Feedback
I am not omniscient, and I don't use all the applications in here (a
few I can't even try), so there are bound to be mistakes. Also,
programs usually continuously evolve, so documentation tends to get
out of date. Therefore, if you find anything wrong, please send me
any corrections. Suggestions or additions to this document are
welcome, too.
1.5. Acknowledgments
All the authors of the applications in this HOWTO. Also, Hannu
Savolainen for the great sound driver and Linus Torvalds for the great
underlying OS.
I'd also like to thank Raymond Nijssen (raymond@es.ele.tue.nl), Jeroen
Rutten (jeroen@es.ele.tue.nl), Antonio Perez (aperez@arrakis.es), Ian
Jackson (ijackson@gnu.org), and Peter Amstutz
(amstpi@freenet.tlh.fl.us) for their information and help.
2. Playing Various Sound Formats
There are many kinds of sound formats (WAV, MIDI, MPEG etc.). Below,
we list the various formats and the applications that can be used to
play them.
2.1. MIDI
MIDI stands for Musical Instrument Device Interface. MIDI files
usually have the extension .mid. They contain sequencing information,
that is, information on when to play what instrument in what way, etc.
Depending on your hardware (and maybe the software you use to play
them), the sound might be awesome, or it might be downright crappy.
2.1.1. The adagio package
This package includes mp (a command-line MIDI file player) and xmp (an
XView based MIDI file player, not to be confused with the module
player also called xmp). You will need the SlingShot extensions to
use xmp. It also contains other programs for playing Adagio scores.
If you have a GUS, mp can also play MOD files (see section ``Modules''
for more information on modules).
One little annoying bug (as of version 0.5 on some hardware) is that
the sound breaks at the end. Namely, instead of ending the sound the
way the MIDI file specifies, it ends by playing the note right before
the last one in a long interval. It hasn't stopped me from using mp,
but it might prevent someone from using it for `real' work. It also
starts up relatively slowly.
The package does not mention any copyright (at least none that I can
find), so I assume it can be freely redistributed and modified. (By a
strict interpretation of copyright law, nothing gives one the right to
do these things, but I somehow doubt that this was the intention of
the author.)
It is a port of the CMU MIDI Toolkit to Linux (though there was enough
added to make this questionable) by Greg Lee
(lee@uhunix.uhcc.hawaii.edu).
It can be obtained by anonymous FTP from tsx-11.mit.edu at
/pub/linux/packages/sound/adagio05.tar.gz. The binaries included here
are in a.out format (linked with ancient libraries), and the xmp
binary segfaults in a X11R6 environment (XFree86 3.1.1, libc 4.7.2).
The mp binary works fine in an a.out environment.
You will need a bit of hackery to compile it. Actually, it's not much
of a hackery. All you have to do is to include the -lfl switch at the
end of SHROBJ and XMPOBJ in the Makefile. This is to link in the flex
library, which is not linked in by default. Then follow the
installation instructions. And don't forget to have XView and the
SlingShot extensions installed if you want to compile xmp.
2.1.2. TiMidity
Some people recommend this experimental program because of good sound
quality (which is very true, it's much better than mp on a Sound
Blaster 16, though it probably won't be much different on soundcards
with wavetable synthesis like the GUS). However, it suffers from high
CPU loads. It plays MIDI by first converting MIDI to WAV and then
plays the WAV (you can also convert a MIDI file to a WAV file without
playing if you want). This is the reason for its CPU intensive
nature.
It also has an optional ncurses, SLang, Tcl/Tk or Motif interface.
You need Gravis Ultrasound patch files to use this. Look into the FAQ
included with TiMidity for more information.
The author is Tuukka Toivonen (tt@cgs.fi).
The latest version of TiMidity can be found at the TiMidity home page
. This page also contains a link to
a small library of GUS patches.
2.1.3. playmidi
This is a MIDI player that plays to FM, GUS, and external MIDI. It is
supposed to have a faster startup time compared to other MIDI players.
It is also able to play Creative Music Files, Microsoft RIFF files,
and large MIDI archives from games such as Ultima 7.
It has an X interface and a SVGA interface. It also has an option for
real time playback with tracking all the notes on each channel and the
current playback clock (included automatically with xplaymidi and
splaymidi).
You should do something like
$ splaymidi foo.mid; stty sane
if you are going to use the SVGA interface, since it doesn't reset the
terminal tty mode properly. The SVGA interface may be removed in the
near future.
It was written by Nathan Laredo (laredo@gnu.org or
laredo@ix.netcom.com).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/playmidi-2.3.tar.gz.
2.2. Modules
Modules (in computer music) are digital music files, made up of a set
of samples and sequencing information, telling the player when to play
which sample (instrument) on which track at what pitch, optionally
performing an effect, like vibrato for example.
An advantage it has over MIDI is that it can include almost any kind
of sound (including human voices). Another is that it sounds just
about the same on any platform, because the samples are in the module.
A disadvantage it has is that it has a much larger file size compared
to MIDI. Another one is that it has no real standard format (the only
`real' one is the ProTracker, which many modules aren't quite
compatible with). It originated on the Amiga.
The most common format has the extension .mod. There are many other
extensions depending on what format they are in.
2.2.1. tracker
This very portable program (it has been ported to many platforms)
plays Soundtracker and Protracker music modules. It uses 16 bit
stereo output, and I consider the quality to be very good. If you
need a simple way to reduce CPU load use the -mono option.
This is a giftware program (quoting the author). It is by Marc Espie
(Marc.Espie@ens.fr).
A version of this with the Makefile already tweaked for Linux can be
obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/tracker-4.3-linux.tar.gz.
2.2.2. gmod
This is a music module player for the Gravis Ultrasound card. 4/6/8
channel MOD, 8 channel 669, MultiTracker (MTM), UltraTracker (ULT),
FastTracker (XM), and ScreamTracker III (S3M) are the supported
formats.
It requires a version 3.0 or later sound driver. And a GUS, of
course. You may need to modify the kernel to make volume control work
the way you want.
This has an X interface. It uses the QT toolkit (needs version 0.99
or greater). Check the QT toolkit homepage for
information on QT.
This can be freely distributed. It was originally written by Hannu
Savolainen, and now maintained by Andrew J. Robinson
(robinson@cnj.digex.net).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/gmod-3.1.tar.gz.
2.2.3. MikMod
This portable module player plays XM, ULT, STM, S3M, MTM, MOD and UNI
formats. (The UNI format is an internal format used by MikMod.) It
has support for zipped module files. It uses 16 bit stereo for the
sound output. Use the -m option (for mono output) if you need a
simple way to lower the CPU load.
The Unix version can either use ncurses or Tcl/Tk for its interface.
It can also be used as a library, not just an independent program.
It was originally written by Jean-Paul Mikkers (mikmak@via.nl). It is
now maintained by Jake Stine (dracoirs@epix.net). This is shareware
that has to be registered if you want to use it commercially. You
also need permission to redistribute it commercially (non-commercial
redistribution does not need such permission).
This can be found at the MikMod home page
.
2.2.4. xmp
This is a module player (not to be confused with Adagio's xmp) which
can play MOD, S3M, STM, 669, and XM modules (other formats are also
supported, but still experimental or incomplete) on soundcards with
wavetable synthesis (GUS or SoundBlaster 32AWE), or on systems with
SoftOSS (a driver that does software mixing). In the very near future
ordinary DSP output should be possible as well.
An X frontend to xmp is also available.
This was written by Claudio Matsuoka (claudio@brasil.enemy.org) and H.
Carraro Jr.
This can found at the xmp home page
.
2.2.5. s3mod
This plays 4/6/8 track MOD modules and Scream Tracker 3 modules. It
uses 8 bit mono output with a sampling rate of 22000 Hz by default.
You can use the option -s to enable stereo, -b to enable 16 bit
output, and -f to set the sampling frequency. However, the sound
output is worse than tracker (some noise), so I recommend using
tracker instead of s3mod for playing ordinary MOD files (unless you
have an underpowered machine). It has a much smaller CPU load
compared to tracker.
It is copyrighted by Daniel Marks and David Jeske (jeske@uiuc.edu),
but you can do anything you want with it (except that you can't claim
you wrote it).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/s3mod-v1.09.tar.gz.
2.2.6. mod
This beta program plays MODs (15/31-instrument, up to 32 voices),
MTMs, ULTs and S3Ms on the Gravis Ultrasound card. It can also use
packed modules if you have gzip, lharc, unzip, and unarj installed.
It cannot play Powerpacked modules or modules packed with some Amiga
composers ("PACK" signature).
This requires at least version 3.0 of the sound driver. It won't work
with the 2.90-2 or earlier version of the sound driver. The text
interface requires ncurses. There is also an X interface included,
which uses Tcl/Tk.
It was written by Mikael Nordqvist (mech@df.lth.se or
d91mn@efd.lth.se).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/mod-v0.81.tgz.
2.2.7. nspmod
This is an alpha module player which can play MTM, S3M, and MOD
modules. It is intended to be a module player for soundcards without
a DSP (not to be confused with what Creative Labs calls a DSP). It
has a CPU load somewhat similar compared to tracker.
It has a feature which lets modules loop if they want to. The number
of loops can be limited by the -l option. It uses only 8 bit sound
output (as of version 0.1).
This was written by Toru Egashira (toru@jms.jeton.or.jp).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/nspmod-0.1.tar.gz.
2.2.8. yampmod
This alpha program was designed to play 4-channel modules using the
minimum of CPU resources. It was not designed to produce high quality
sound. So the only sound output it produces is 22 kHz mono output.
Also, the output isn't as clean as it should be, reflecting its alpha
status.
It was written by David Groves (djg@djghome.demon.co.uk).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/yampmod-0.1.tar.gz.
2.3. MPEG audio streams
MPEG is a standard specifying the coding of video and the associated
audio for digital storage. MPEG is usually associated with video, but
the audio part of the standard can be used separately. The audio part
of the MPEG standard defines three layers, layer I, II, and III.
Players that can decode higher layers can also decode lower layers
(e.g. layer III players can play layer II files). Layer I MPEG audio
files usually have the extension .mpg (so if there is a file with this
extension that can't be played by a MPEG video player, it's probably
an audio stream), layer II usually have the extension .mp2, and layer
III usually have the extension .mp3. The audio compression is pretty
good. A two megabyte layer II MPEG audio file will probably take up
25 megabytes for a raw PCM sample file with the same quality.
2.3.1. mpg123
This beta program is an efficient MPEG audio stream player, which has
support for layers I, II, and III. It is based on code from many
sources. It is able to play in real time streams that are read by
HTTP (i.e. one can play an MPEG audio stream directly over the World
Wide Web).
The main author is Michael Hipp (Michael.Hipp@student.uni-
tuebingen.de). It may be used and distributed in unmodified form
freely for non-commercial purposes. Inclusion in a collection of free
software (such as CD-ROM images of FTP servers) is explicitly allowed.
The latest version can be obtained from Oliver Fromme's mpg123 page
.
2.3.2. maplay 1.2
This MPEG audio stream player only has support for layer I and layer
II streams, and lacks support for layer III streams. It supports 16
bit sound cards on Linux.
It is pretty CPU intensive, taking up to about 55% CPU time on a 60MHz
Pentium. The output is intolerable on a 66MHz 486 because the CPU
just can't catch up with the sound. If this happens to you, try
playing only one side of the audio stream (with the -l or -r option),
instead of the default stereo.
A slight change in one of the files may be necessary in order to
compile it. Namely, you may need to add the following line to the
beginning of the file configuration.sh.
#! /bin/sh
The author is Tobias Bading (bading@cs.tu-berlin.de). maplay 1.2 can
be obtained by anonymous FTP from ftp.cs.tu-berlin.de at
/pub/multimedia/maplay1.2/maplay1_2.tar.
2.3.3. maplay 1.3b
This is an unofficial modification (i.e. not by the original author)
of maplay 1.2, so that it can run with a much lower load on the CPU.
It accomplishes this mainly by making u-law output actually work on
other platforms besides the SPARC. Note that it uses u-law output by
default, so the sound quality is lower.
The modifications were made by Orlando Andico
(orly@gibson.eee.upd.edu.ph).
This can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/maplay-1.3b-Linux.tar.gz.
2.3.4. maplay3
This is another derivative of maplay 1.2. It adds support for MPEG
Layer 3 audio streams. Currently it seems to have some bugs in its
playback (you may hear some screeching noises). You may have to
twiddle with the options to solve this.
The modifications were made by Timo Jantunen (timo.jantunen@hut.fi or
jeti@cc.hut.fi). It says that it can be used freely, but making money
off of it is not allowed. However, I'm not entirely sure about the
validity of this copyright, since the original maplay is under the GNU
General Public License, which does not allow derivative works to have
a different copyright.
This can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/maplay3.tar.gz.
2.3.5. splay
This beta player is another derivative of maplay 1.2 (actually, it is
a derivative of maplay 1.2+, which is a MS Windows only derivative of
maplay 1.2). It adds support for MPEG Layer 3 audio streams. It is
also able to play WAV files. It can also play audio streams received
over an HTTP connection.
Another feature of splay is that it can be used as a library (under
the LGPL), so that it can be used in other programs. It also tries to
improve performance by using threading (you need pthread to use this
feature) and a little inline assembly.
splay uses a command line interface and an optional X interface (which
uses QT).
If after compiling it doesn't work (e.g. it segmentation faults), try
compiling it again without threading.
This is by Jung Woo-jae (jwj95@eve.kaist.ac.kr).
It can be obtained from splay's home page
.
2.3.6. Sajber Jukebox
This program is a MPEG audio player with a graphical user interface.
It is based on splay, so it includes support for MPEG audio layers up
to III. It is also able to play MPEG audio streams in real time with
the stream being fed by HTTP. It is also easy to configure.
It uses the QT toolkit (at least version 1.2 is required). It also
uses the LinuxThreads library (the included binary only works with
version 0.5).
The author is Joel Lindholm (wizball@kewl.campus.luth.se).
The latest version can be obtained by anonymous FTP from
kewl.campus.luth.se at /pub/jukebox.
2.3.7. amp
This beta MPEG audio player only has support for MPEG Layer 3 audio
streams. It is able to play directly to the soundcard, and it can
output to raw PCM or WAV files. This also gives quite a load on the
CPU (about 60% on a 133MHz Pentium).
This was written by Tomislav Uzelac (tuzelac@rasip.fer.hr). It can be
freely used and distributed, as long as it is not sold commercially
without permission (including it in CD-ROMs that contain free software
is explicitly permitted, though).
It can be obtained by anonymous FTP from ftp.rasip.fer.hr at
/pub/mpeg/amp-0.7.3.tgz.
2.3.8. XAudio
This alpha library was written to be a fast implementation of an MPEG
audio decoding library to be used by various GUI front-ends. It
supports MPEG audio layers I, II, and III. It is capable of random
access to bitstreams. A command-line interface is included. A Motif
(Lesstif) front-end is also included in the Linux version.
This is by Gilles Boccon-Gibod, Alain Jobart and others. The front-
ends to the libary can be freely downloaded. The library itself must
be licensed to be used (a source and binary license is available).
The front-ends to the library can be obtained from XAudio home page
.
2.3.9. Layer 3 Shareware Encoder/Decoder
This is actually a converter that converts MPEG Layer 3 audio streams
to WAV, AIFF, SND, AIFC, or just raw PCM sample files. The Linux
version does not directly output the sound to the soundcard. One has
to first convert it to some other format.
However, when you try to play a converted file using sox, you'll
probably just get noise because the word order in the PCM samples is
not right (at least on Intel platforms). You need to give sox the
option -x to solve this problem. But there are some players that
don't have to be told that the word order is wrong, so you might not
have to worry about this.
If you have a really fast computer (probably at least a 100Mhz
Pentium), then you can try to play MPEG Layer 3 streams directly
without having to first convert the audio file to another format like
in the following example (this example assumes that you're using sox
and playing a 44.1 kHz stereo sample).
$ l3dec foo.mp3 -sto | play -t raw -x -u -w -c 2 -r 44100 -
The number after -r is the sample rate of the audio stream, and the
number after -c depends on whether it is mono or stereo (or even
quad). If this looks too complicated, you can use something like a
shell script or an alias.
This is shareware copyrighted by Fraunhofer-IIS. A demo version for
Linux on x86 systems can be obtained by anonymous FTP from ftp.fhg.de
at /pub/layer3. The demo version only converts layer III audio
streams.
2.4. WAV
Quote from the sox man page:
These appear to be very similar to IFF files, but not the
same. They are the native sound file format of Windows 3.1.
Obviously, Windows 3.1 is of such incredible importance to
the computer industry that it just had to have its own sound
file format.
These usually have the extension .wav.
Also see section ``sox'' and ``bplay'' for other WAV players besides
the ones listed here.
2.4.1. wavplay
This program supports playing and recording with the WAV format. It
uses locking so that only one sound may be played at a time. Its
locking capabilities can also be used separately from its sound
playing capabilities.
In addition to a command-line interface, it also has a Motif
interface,which can be used with Lesstif.
It was originally written by Andre Fuechsel (af1@irz.inf.tu-
dresden.de), but was evolved to the point of being completely
rewritten by Warren W. Gay (bx249@freenet.toronto.on.ca or
wwg@ica.net).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/wavplay-1.0.tar.gz.
2.5. Other stuff
This section lists stuff that play sound formats that don't deserve a
separate section (i.e. formats that have only one player available),
or players that play more than one format.
2.5.1. sox
This program is actually a converter, that is, it converts one sound
format to another. However, some versions of sox, when invoked as
play, plays the sound (the play application in the Sound HOWTO
probably refers to this). It supports raw (no header) binary and
textual data, IRCAM Sound Files, Sound Blaster .voc, SPARC .au
(w/header), Mac HCOM, PC/DOS .sou, Sndtool, and Sounder, NeXT .snd,
Windows 3.1 RIFF/WAV, Turtle Beach .smp, CD-R, and Apple/SGI AIFF and
8SVX formats
Since somewhere in the 1.3.6x kernels, you might have to make a small
change in one file to make it play the sound directly. Namely, you
may have to change line 179 in sbdsp.c from
if (abuf_size < 4096 || abuf_size > 65536) {
to
if (abuf_size < 1 || abuf_size > 65536) {
But then again, you may not have to do this. But doing this won't
break anything.
It is written and copyrighted by many people, and can be used for any
purpose.
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/convert/Lsox-linux.tar.gz.
A more recent version by Chris Bagwell (cbagwell@sprynet.com) (based
on the latest gamma version of the original sox, and includes the
above fix) can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/convert/sox-11gamma-cb3.tar.gz.
2.5.2. bplay
This beta program plays raw audio, WAV, and VOC files. It's also able
to record to these files. It uses a variety of techniques to get the
highest speed possible so that it can run acceptably even on slow
machines. One of these techniques require that the installed programs
be setuid root. The paranoid hoping to use this may want to use the
Debian package by Ian Jackson (ijackson@gnu.org), which disables the
feature that needs the setuid bit.
The author is David Monro (davidm@gh.cs.usyd.edu.au).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/bplay-0.96.tar.gz.
2.5.3. SIDPLAY
This program emulates the Sound Interface Device chip (MOS 6581,
commonly called SID) and the Micro Processor Unit (MOS 6510) of the
Commodore 64. Therefore it is able to load and execute C64 machine
code programs which produce music or sound. In general these are
independent fragments of code and data which have been ripped from
games and demonstration programs and have been transferred directly
from the C64.
It uses a command line interface by default. There are also Tk and QT
interfaces available separately from the main package.
It is maintained by Michael Schwendt (sidplay@geocities.com).
It can be obtained from SIDPLAY's home page
.
2.5.4. RealAudio Player
This lets you listen to sound, which is stored in a proprietary
format, in real time over the Internet without downloading the whole
sound file first. It could be used stand alone, but it is really
intended to be used along with a web browser (the explicitly supported
ones are Mosaic and Netscape). It cannot be used without X (you
wouldn't be able to get it working with Lynx in a text console).
This is by Progressive Networks, Inc. This cannot be redistributed,
modified etc. Look at the license for exact details on what you can
do. It can be obtained by registering with no cost at the RealAudio
home page .
2.5.5. cat
One might think what cat, the sometimes overused concatenating
utility, has to do with playing sounds. I'll show a use of it through
an example.
$ cat sample.voc > /dev/dsp
$ cat sample.wav > /dev/dsp
$ cat sample.au > /dev/audio
Doing a cat of an .au file to /dev/audio will usually work, and if
you're lucky enough that the file has the correct byte order (for your
platform) etc., a cat of a sound file that uses PCM samples (like .wav
or .voc) to /dev/dsp might even sound right.
This isn't a totally useless use of cat. It might be useful, for
example, if you have a sound file that none of your programs
recognize, and you know that it uses PCM samples, then you might be
able to get a very approximate idea on how it sounds like this way (if
you're lucky).
3. Other useful sound utilities
This section has nothing to do with the actual playing of sound files.
Rather, it is a collection of some sound utilities that one might find
useful.
3.1. volume
This is a simple command line interface for controlling the volume
(what else could it be?). It also has a separate program with a
Tcl/Tk interface included in the package for controlling the volume
and playing .au sound files. A very simple Tcl/Tk CD player is also
included.
This is Freeware and it is written by Sam Lantinga
(slouken@cs.ucdavis.edu).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/soundcard/volume-2.1.tar.gz.
3.2. Sound Studio
This is a Tcl/Tk application that supports playback, recording, and
editing of digital sound using sox. It includes sox in the
distribution to avoid compatibility problems.
This was written by Paul Sharpe and N. J. Bailey
(N.J.Bailey@leeds.ac.uk). It may be freely used and redistributed if
a postcard is sent.
It can be found at Sound Studio's home page .
3.3. Tickle Music
This beta Tcl/Tk program is a music file browser that allows you to
play various sound formats as long as an appropriate program to play
it is on your system. By default gmod is used for playing MOD files
and mp for playing MIDI files (you can change the source to use other
programs).
It is written and copyrighted by Shannon Hendrix (shendrix@pcs.cnu.edu
or shendrix@escape.widomaker.com).
It can be obtained by anonymous FTP from sunsite.unc.edu at
/pub/Linux/apps/sound/players/tmusic-1.0.tar.gz.
4. References
1. The documentation included with the applications in this document.
2. The Linux Sound HOWTO. It can be found at the Linux Documentation
Project .
3. The Linux MIDI and Sound Pages
4. MPEG Audio Layer 3 FAQ
5. Programmer's Guide to OSS
6. SoX home page