FAAC (Freeware Advanced Audio Coder) is an MPEG-2 and MPEG-4 AAC Audio encoder.

FAAC currently supports MPEG-4 LTP, MAIN and LOW COMPLEXITY object types and
MAIN and LOW MPEG-2 object types. It also supports multichannel and
gapless encoding.

WWW: https://www.audiocoding.com/