2003.07_Out of the Box-Muse, a Linux Streaming Engine.pdf

LINUX USER

Out of the box

Kissed by the Muse

Now that broadband has come of

the program from the

source code. Of course,

to do so you will need

the C/C++ compiler

gcc , the gtk library and

header files , and the

lame MP3 encoder. If

you have installed the

OGG Vorbis headers

and libraries, these will

also be used.

The MuSE source

archive is available on

the subscription CD or

from http://muse.dyne.

org/ . A current version

of lame (3.93.1) is

available from http://

lame.sourceforge.net/ .

Follow these steps first to compile and

install lame :

age, live audio streaming from your

own machine has become a genuine

possibility thanks to adequate band-

width and tools such as Icecast. The

question remains as to what to feed

to your Icecast Server. MuSE provides

a convenient streaming source.

Quickly turning your computer into

the latest DJ, able to mix the audio

Figure 1: Four Channel MuSE

channels to your desire.

The top panel of the MuSE window

provides six buttons with the following

functions (from left to right) Let’s stream

(connect to the streaming server), Add

channel , Line In (use a microphone),

Speaker (output via local soundcard),

Vumeters , and Hall of Fame (list of pro-

grammers).

MuSE also provides a character based

console provided you specified the --

with-rubik option in the configure and

set the -g ncurses flag when launching

the application. Figure 2 shows you what

the ncurses v version looks like.

In the GUI variant each channel has its

own set of controls, such as volume,

play, stop and pause keys, a song posi-

tion indicator and a playlist. Channels

can be controlled independently. In our

BY CHRISTIAN PERLE

Streaming Engine , a general tool

for mixing up to six audio channels

that can be either local MP3 and OGG

Vorbis files or streams from other Shout-

cast or Icecast Servers [2]. You can

additionally mix in your soundcard’s

microphone input signal.

MuSE can either output the results

locally via your soundcard, and/or send

them to an Icecast Server as a stream.

The server can then broadcast the stream

to any attached clients.

tar xzf lame-3.93.1.tar.gz

cd lame-3.93.1

./configure && make

su (enter root password)

make install ; strip /usr/ U

local/bin/lame

exit

The second step involves compiling

MuSE :

tar xzf MuSE-0.8.tar.gz

cd MuSE-0.8

./configure --with-x && make

su (enter root password)

make install ; strip /usr/ U

local/bin/muse

exit

Do-It-Yourself

As MuSE provides processor specific

optimization, it makes sense to compile

Christian Perle

currently works as

a developer at

secunet Security

Networks AG.

Christian discovered

Linux in 1996, after

playing around with the Sinclair ZX 81,

Atari ST and finally IBM PC. When not

hacking Linux stuff he can often be

found playing guitar and “Magic: The

Gathering“.

No Antenna

Even if you do not use an Icecast server,

MuSE is still worth having, as you can do

a trial run before you go on air. To do so,

enter muse & in an xterm or konsole

session to launch the program.

Figure 1 shows the GUI interface for

MuSE with four channels present, in

this case.

OUT OF THE BOX

There are thousands of tools and utilities for

Linux.“Out of the box” takes a pick of the

bunch and each month suggests a little pro-

gram, which we feel is either absolutely

indispensable or unduly ignored.

July 2003

www.linux-magazine.com

MuSE

T he name MuSE stands for Multiple

Out of the box

LINUX USER

As is usually the case,

the command line pro-

vides quicker access to

MuSE ‘s server prefer-

ences than the GUI

dialog box. The follow-

ing syntax tells MuSE to

connect to the server at

1.2.4.8 and use port

8000 . The MP3 stream

format with a bitrate of

56 Kbit/s and a 22.05

kHz sample rate are

specified. MuSE uses the

password ‘letmein’ to access the server:

icecast -P 8282

Figure 2: MuSE in character based mode

You can then change the server settings

for MuSE to 127.0.0.1 and port 8282 .

Online radio listeners can now attach to

your machine and, provided you have

sufficient bandwidth, enjoy your selec-

tion of music. The Icecast server

provides a simple console that displays

status information. The console also pro-

vides a shutdown command that allows

you to down the icecast server. It makes

sense to use a firewall to prevent users

on the Internet from connecting to your

server – this will avoid copyright

infringements if you happen to “broad-

cast” commercial songs.

example, only channels 3 and 4 are actu-

ally playing, and the volume has been

reduced to 30 per cent on channel 4.

Right clicking will display the drop-

down menu for a playlist, allowing you

to add new tracks to the list, or remove

existing tracks. This allows you to use

MuSE as a simple digital mixing desk

with multiple playlists and cross-fading.

muse -e mp3 -b 56 -r 22050 -s U

1.2.4.8:8000 -p letmein &

Just Checking

You can easily use a local MP3 player,

such as Xmms , to check your streaming

output. To ensure that

the player has exclu-

sive access to your

soundcard, you will

need to set the -o flag

when launching MuSE

to prevent the stream-

ing

After establishing the connection to the

server, you can attend to the channels

and playlists and

finally launch the

streaming output on

the server.

Of course the

streaming server can

also be run on the

server that provides

the streaming source. This is why we

added icecast to the subscription CD, to

complete your broadcasting equipment.

Follow these steps to install icecast :

Stream and Let(‘s) Stream

It is common to use an external Icecast

server for streaming across the Internet,

ensuring that the server has sufficient

bandwidth to serve any attached clients.

The Let’s stream button allows you to

configure access to the server; Figure 3

shows the dialog box to match.

Figure 4: XMMS listening in

tool

from

accessing the soundcard.

Now select Play location in the main

Xmms menu, or press [Ctrl+l]. Type

“http://127.0.0.1:8282” in the text box.

After a short delay while the stream is

buffered, your reception test should be

up and running (Figure 4).

All that remains for us to say is: Get

radio active!

tar xzf icecast-1.3.12.tar.gz

cd icecast-1.3.12

./configure && make

su (enter root password)

make install

strip /usr/local/icecast/bin U

/icecast

ln -s /usr/local/icecast/bin U

/icecast /usr/local/bin/icecast

exit

INFO

[1] Muse - Linux music editor,

http://muse.seh.de/

[2] Icecast - Open free streaming audio,

http://www.icecast.org/

[3] Ogg Vorbis - Audio encoding,

http://www.vorbis.com/

Figure 3: Configuring the server

The following command launches the

local Icecast server:

GLOSSARY

MP3: Abbreviation for MPEG 1 Audio Layer 3. A

technique that allows CD quality audio data

to be compressed to about 1/11th of their orig-

inal size without audible loss of quality.

OGG Vorbis: The patent free alternative to

MP3 [3].

Icecast: A system for transmitting live audio

streams to one or more receivers. An MP3 or

OGG signal is used as the source.

Compiler: When the source code of a program

is “translated” (compiled), the compiler cre-

ates a binary format program that is

executable by a machine from legible source

code files.

Header files: The header or include files con-

tain lists of the functions and parameters

stored in a library. The C(++) compiler needs

this information to translate the program.

Major distributions typically add the dev or

devel suffix to the name of a header package

for a library.

Port: This is where network connections

“dock”. Ports are assigned numbers, many of

which specify a service. Programs that bind to

ports can provide services via that port, such

as file transfer or remote login.

www.linux-magazine.com

July 2003

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