An MP3 Server in Linux

Configuring Linux to stream MP3 music over a TCP/IP network

is a matter of installing and configuring just two RPMs. These are Icecast–an

MP3 server, and Shout–which streams MP3 data to the MP3 server for

broadcasting. On the client side, you’ll need MP3 players like Winamp for

Windows, or X11amp and Mpg123 for Linux. So, let’s get going on how to

configure Linux for playing MP3s over your network.

We’ve given both Icecast and Shout RPMs in the CD with this

issue. You’ll find them in the \cdrom\linux directory. To install the RPMs,

mount the CD, go to this directory and type the following:

rpm -ivh icecast*.rpm

rpm -ivh shout*.rpm

Now, to configure Icecast, you have to edit the file

icecast.conf located in the directory /etc/icecast. The entries in this file are

in the form:

parametername parameter

Go to the parameter mount_fallback, and set its value to 1 or

0. So, when a stream requested by a client is not found, a value of 1 will

broadcast a default stream–the oldest stream on your server–over your

network, while a value of 0 will give an HTTP 404 error instead.

Next,

go to the encoder_password, admin_password, and oper_password. These would have

a default value of hackme. Give a password for each. Of these, encoder_password

is important as you’ll need it later for configuring Shout. The admin_password

is used to access the admin console of the Icecast server. The oper_password

authorizes the person with administrative rights to use operator commands. We

gave the same password for each as follows:

encoder_password pcq

admin_password pcq

oper_password pcq

Now,

scroll down until you find the parameter hostname, port, and server_name. Change

the server_name to the hostname of your Linux machine–you can find this by

typing hostname at the command line console. Leave the rest to default.

Now, scroll down till you find the parameter staticdir.

Change this to the directory where you’ll store MP3 files, for example:

staticdir /opt/mp3

Now save the file, place your MP3 files in this directory and

run Icecast by typing:

icecast -b

The -b parameter makes it a daemon (background process).

Clients can now access MP3 files stored in the directory you’ve

specified. To play a file in Winamp or X11amp, the client will have to type the

following URL:

http://shekhar.PCQLABS:8000/file/rock.mp3

Here, shekhar.PCQLABS:8000 is the machine name and port

number, and /file/rock.mp3 will play the file rock.mp3.

If you’re using mpg123–a command line MP3 player for

Linux, type:

mpg123 http://shekhar. PCQLABS: 8000/file/rock.mp3

The filename (rock.mp3) should be correct. You can also see a

list of all the MP3 files in the directory by entering the following URL in a

browser:

http://shekhar.PCQLABS: 8000/file/

Configuring Shout for streaming

If you want to stream MP3s over your network–instead of

individual clients connecting to the server to access MP3 files–you have to

configure Shout. This requires editing a file called shout.conf found in the

/etc/icecast directory. This file is also in the form:

parametername parameter

If you’re running Shout and Icecast on the same machine,

leave server_name to localhost. If it’s on a different machine, change it to

the server_name you’d given in the icecast.conf file. However, you must

confirm that the machine running Shout is able to locate the machine running

Icecast by its name (in our case, it was shekhar.PCQLABS).

Leave the port to default, and change the password to the

encoder password you’d given earlier.

The next line is:

mount default

This defines a stream named default. You can make

configuration files–shout.conf–with different mount names such as rock,

jazz, techno, etc, instead of default. Each of these can have a different

playlist, and you can run more than one copy of Shout with each configuration

file using the -C command line parameter (as we’ve shown later in this

article).

Now, leave the playlist parameter as it is. It specifies the

name of the playlist file as shout.playlist. Set the parameter loop–which is

"yes" by default–to "no" if you don’t want it to play

the songs on your playlist repeatedly. You can shuffle the songs in the playlist

by setting shuffle to "yes". Last, set the parameter daemon to

"yes" to run Shout as a background process. Save the file.

Now you need to construct the shout.playlist file. To include

all MP3 files in all mounted partitions:

find / -name *.mp3 -print > shout.playlist

To include only MP3 files in a specific directory:

find /opt/mp3 -name *.mp3 -print > shout.playlist

Copy shout.playlist in /etc/icecast directory, and run Shout

by typing shout at the console. By default, it looks for a configuration file

shout.conf in /etc/icecast. If you want to run more than one copy of Shout using

different configuration files:

shout -C file>.

A detailed documentation of Shout is located in /usr/doc/shout-0.8.0.

Find the PID (ProcessID) of Shout. When it’s running, you

can send the following signals to it:

kill -s SIGINT

to play the next song

kill -s SIGUSR1

to reshuffle the playlist

kill -s SIGHUP

to make Shout re-read the configuration files.

Configuring clients

In Winamp and X11amp, press CTRL-L and feed the URL as:

http://shekhar.PCQLABS:8000/default

If you’re running more than one copy of Shout with

different playlists having different mount (stream) names–for example, rock,

jazz, etc:

http://shekhar.PCQLABS:8000/rock

http://shekhar.PCQLABS:8000/jazz

You can also use the IP address of the Linux machine running

Icecast. But remember to specify port 8000.

If you’re using mpg123, fire it up at the console as:

mpg123 http://shekhar.PCQLABS: 8000/default

Shekhar Govindarajan