Other Encoders
There are dozens of audio encoders for use with Linux and other operating systems, including the Windows platform. On the average these utilities are small and lightweight and do not require much overhead. Most are free, though there are some that are listed either as Shareware or as a Demo release. A simple Google or Internet search renders dozens of audio encoder listings. Find and use one that fits your platform and encoding needs.
Icecast Supported Encoders
The following are a list of supported encoders for use with the early version of icecast. These may still be partly supported by more recent icecast releases. The most relevant and recommended encoder remains LAME.
- Fraunhofer's MPEG audio tools
l3enc and mp3enc. Available at the following URL: http://www.iis.fraunhofer.de/amm/download/index.html
- Xing Technologies
The xingmp3enc encoder has since been taken over by Real. Consider using an alternative unless you are familiar with Xing or have used it in the past with some success. Download the application from the following URL: http://www.real.com/accessories/?prod=xingmp3encoder
- LAME versions 3.01 and above
Perhaps the most popular encoder yet, LAME is a Dist10-derived MP3encoder, A version later than 3.01 is required in order to use with LiveIce and icecast.
Because MP3 is based on psychoacoustic modeling of what sounds are masked by others, there is a lot of variation in the output of different encoders. Generally the commercial encoders are higher quality than the free encoders and if you're considering using professional grade equipment and doing professional broadcasting or streaming, you should purchase a commercial encoder. Fraunhofer's codec is certainly the best, especially at low bitrates which are required for sending data to modem users. However, they can take a lot of CPU power. Other encoders, such as mp3enc, require more cycles but you can safely encode at up to 32Kbps without worrying about the soundcard buffer overrunning.
Of all the free encoders LAME comes most highly recommended. This is due not only to its cost (free), but because of its wide spread use in most audio encoders today. There is still much development to improve the quality of the output and the speed of the encoder to make this the best free encoder.
Remember that nothing is ever actually played or heard during the encoding process. You can encode MP3 on a computer with no sound card or speakers, if needed. This is how audio encoding is done in some professional organizations, particularly those dedicated to Internet broadcasting. Here one computer may be used for auditioning and selecting files, a second used for the actual encoding process, and a third dedicated to serving the files to the Internet. Of course, the most powerful machine is usually reserved as the encoding machine in such a scenario.
Decoders
If you plan to use mixer mode, icecast needs to be able to decode MP3s stored on your hard drive. This task is best left to an external decoder rather than implementing the functionality in the client itself. This is not on account of any legal reasons, but for the sake of practicality. Incorporating this code into icecast would bloat the application too much when a perfectly reasonable substitution is available. This is where the mpg123 decoder comes into play.
Download the mpg123 source from its web page at the following URL: http://www.mpg123.de/. Install the mpg123 binary somewhere in your path. Version 0.59r and above also allows you to listen to icecast broadcasts.
Many Linux distributions have stopped including mpg123 with their releases for legal reasons. You can decide whether to download and install the program or use an alternative. Another popular MP3 decoder is mpg321, available at: http://mpg321.sourceforge.net/. It is free for personal use, though if incorporating it into another application special permission is required. According to the author, mpg321 is a complete rewrite of earlier scripts that were built on mpg123 and the media player FreeAmp. It has since been revised with better libraries and more features than mpg123.
 | Recent versions of LiveIce have the added capability of reading .wav, .au, .aiff and other file formats using sox. This is a fairly common program for editing and tweaking sound files. Most Linux distributions include sox by default. |