|Stable release||1.15.3 / April 2, 2013|
|Written in||C, Assembly|
|License||GNU Lesser General Public License version 2.1|
mpg123 is a free software cross-platform command-line MPEG audio player whose library, libmpg123, is noted for its speed at decompressing MPEG audio files. As the name suggests, it supports MPEG-1 and -2, layers 1, 2, and 3. Its most common use is to play MP3 files.
mpg123 makes use of hand-written assembly optimizations which use SIMD instructions to perform the iDCT part of the MPEG decoding quicker than any other MP3 player. This makes it probably the most resource-efficient MP3 player and library there is.
The last stable version (0.59r) produced by the original authors, Michael Hipp and Oliver Fromme, dated 19 June 1999, was licensed under a non-commercial, no-derivative proprietary software license, although the source code was available. The official development of mpg123 and its library, mpglib, had ceased for several years, and as some serious security holes emerged, patches were submitted by third party developers for the Debian and Gentoo Linux packages, as well as the FreeBSD ports collection.
In 2006, a new maintainer stepped up, reinstating work towards the release of a new official mpg123 package entirely under the LGPL. Near the end of 2007, after several releases in the 0.6.x series that included all known security fixes, version 1.0 was released under the LGPL v2.1, with libmpg123 branded as a full-featured replacement for mpglib.