Icecast

Icecast is a streaming media server supporting open standards such as the Ogg Vorbis¹ container format. You can used it to create an internet radio station or live streaming applications. My streaming setup is based on Icecast and drives live streaming without 3rd party services.

Basic setup

I refer to instructions found in the Icecast2 — UberLab 7 documentation and the official Icecast docs. In addition to the basic setup, some settings have to be changed for my needs.

TLS setup

If you didn’t use the UberLab guide, all Icecast access might be unencrypted! You need to enable TLS² manually by inserting <tls>1</tls> in the <listen-socket> block of the icecast.xml configuration file. Additionally, specify a <tls-certificate> in the <path> block and provide a file containing the cert and private key in sequence at the specified location. Finally, restart Icecast server to reload the new configuration.

Fallback mount

Listeners can only play streams while a source client is streaming. In order to offer static media while there’s no source client connected, a fallback mount can be used. I edit the icecast.xml config file and insert:

<mount type="normal">
    <mount-name>/stream.ogg</mount-name>
    <fallback-mount>/file.ogg</fallback-mount>
    <fallback-override>1</fallback-override>
    <fallback-when-full>1</fallback-when-full>
    <bitrate>192</bitrate>
    <type>application/ogg</type>
    <subtype>vorbis</subtype>
</mount>

Change /file.ogg to fit your needs. The provided file should have the same encoding parameters (for example: 192 kbps CBR³) to prevent listener dropouts and must exist in Icecast’s webroot to be accessible. Fileserving must also be activated. (Enabled by default.)

No-cache

Applications playing streams may automatically cache data. This behaviour can lead to looping or aborting media when a fallback override (source client connection) is happening. Using the following HTTP headers configuration in icecast.xml the caching can be disabled:

<http-headers>
    <header name="Cache-control" value="no-cache, no-store, must-revalidate" />
    <header name="Pragma" value="no-cache" />
    <header name="Expires" value="0" />
</http-headers>

Logging level

For a maximum privacy of the listeners log files need to be discarded. Icecast’s logging cannot be disabled, but written to a Null device⁴. This can be done by removing the standard log files access.log and error.log and creating symbolic links as follows:

rm /var/log/icecast/access.log
rm /var/log/icecast/error.log
ln -s /dev/null /var/log/icecast/access.log
ln -s /dev/null /var/log/icecast/error.log

Applications