Mp3Splt-project is a small utility to split mp3 and ogg files selecting a begin and an end time position, without decoding. It's very useful to split large mp3/ogg to make smaller files or to split entire albums to obtain original tracks.
13 of the popular CLI tools/audio players for audio playing and encoding/decoding on Linux: mp3blaster, mpd, music123, cmus, mpg123, ogg123, ripit, oggenc, flac, ogginfo, vorbiscomment, cuebreakpoints, shnsplit.
When I make videos, I almost always use Ogg to encode the audio. Storing the audio in Ogg saves space on my machine without sacrificing quality. However, I invariably need to loop, concatenate, or change the audio in some way, which can be difficult. For many of these tasks I turn to the OGMtools suite to make the process easier.
OggConvert is a simple, GUI-based video transcoder that outputs only to the free Theora and Dirac formats. It couldn't be any easier to use, and it's the quickest way to get a feel for the still-new Dirac codec. No need to tweak pages of arcane settings -- just drag, drop, and watch.
Have a CD collection sitting around waiting to find its place in your new Ubuntu lifestyle? Maybe you have existing non-DRM protected MP3s on Ubuntu and are looking for way to listen to them on Ubuntu without resorting to using MP3 considering its gray area of use.