I use debian and "aptitude install faad" works for me...

NAME
faad — Process an Advanced Audio Codec stream

SYNOPSIS
faad [options] [-w | -o <output_filename> | -a <output_filename>]
input_filename

DESCRIPTION
This utility provides a command line interface to libfaad2. This pro‐
gram reads in MPEG‐4 AAC files, processes, and outputs them in either
Microsoft WAV, MPEG‐4 AAC ADTS, or standard PCM formats.