The FAAC project includes the AAC encoder FAAC and decoder FAAD2. It supports several MPEG-4 object types (LC, Main, LTP, HE AAC, PS) and file formats (ADTS AAC, raw AAC, MP4), multichannel and gapless en/decoding as well as MP4 metadata tags. The codecs are compatible with standard-compliant audio applications using one or more of these profiles.
burnCDDA is a console frontend to cdrdao, cdrecord, MPlayer, mpg321, oggdec, mppdec, flac, normalize, and mp3_check. It can be used to create audio CDs from an M3U playlist (the playlist format of XMMS and amaroK) or from files inside a directory. It supports MP3, OGG Vorbis, Musepack, FLAC, WMA, M4A, and WAV files, and it might be the easiest way to copy an audio CD.
mpg321 is a Free clone of mpg123, a command-line MP3 player. It is designed to be a drop-in replacement for mpg123, and therefore its interface has been designed around that of mpg123, without using any of its code. mpg321 has been designed for use with frontends such as gqmpeg, although it is just as useful on the command-line. Unlike mpg123, it supports ESD and ALSA output without recompiling, and it does all MP3 decoding with only fixed-point math by using the mad MPEG audio decoder library.
Mp3blaster is an interactive text-based program that plays several audio file types (MP3, Ogg Vorbis, wav, and sid). It is one of the few audio players for the text console that allows full interactive control during playback. One of its key features is the ability to compose a very flexible playlist (while playing!). It plays most MP3 formats and has full mixer support built in.
The GlobeCom Jukebox is a music jukebox with integrated CDDB-aware ripping and groupware functionality. It is completely configurable from the Web interface, seamlessly integrates ripping from CD to encoded MP3, and supports grouping of songs, peak adjustment, account management for access, streaming of jukebox or single song, themability, album handling, and online help.
MP3do is an "all in one" bash script. It is useful for decoding and mastering audio files. It can decode a list of MP3 or Ogg Vorbis files to WAV or CD-R, auto-convert poor quality MP3s to 44100Hz stereo, check whether all files fit on a CD, normalize all WAV files (adjust the volume to a standard volume level), and burn a CD.
MP3 STATION is a LIRC-aware, plain-text tool set for managing MP3 playback in a car or home with as little user interaction as possible. It can restart the last playlist at the last played track/frame, transparently load directories, transparently recompile playlists, and keep a repository of all the playlists. It also has two simple clients for communicating with cm3s (a curses console client and a very basic one on a parallel port). All programs run under a non-privileged user account.
Flac2All is a multi-threaded script that will convert your collection of FLAC files into either Ogg Vorbis, MP3 (with the Lame encoder), or FLAC, complete with any tags and identical file/folder structure. The script has been stable for about a year now, and it has been known to saturate 8-core machines with parallel conversions. It is useful for people with with large FLAC collections who also want a lossy version for portable media players. If wanted, the script can perform updates by skipping already converted files. It has only been tested on Linux, but it should work without alteration on the other Unix systems with bash and the required dependencies.