The Free On-line Dictionary of Computing (30 December 2018):
MPEG-4 AAC Main ProfileA successor of MP3 allowing transparent coding at data rates of 70-75% of that of MP3. It is very different from MP3, only used MDCT, no subband coding. It is much more complex that MP3 and MPEG-2 AAC Low Profile. (2001-12-08)