Linux audio

GUI Audio Conversion

Nautilus Audio Converter

Install with

sudo apt-get install wavpack mppenc libmpcdec3 faac flac vorbis-tools faad lame libid3-3.8.3-dev nautilus-script-audio-convert

libid3-3.8.3-dev needed for id3tag.

See Ubuntu Geek - Simplest way to convert audio file(s) on Ubuntu Linux

CLI Audio Conversion

Decoding FLAC

flac -d source.flac -o output.wav
flac -d source.flac -c                 # Write output to stdout

Encoding MP3

lame -m auto --preset standard input.wav output.mp3
lame -m auto --preset extreme input.wav output.mp3
lame -m auto --preset insane input.wav output.mp3