Extending the MPEG-4 AAC codec by perceptual noise substitution
Abstract
Recently introduced, the ISO/MPEG-2 Advanced Audio Coding (AAC) coding technology provides a powerful framework which covers almost any application from simple monophonic compression to full-featured multi-channel coding. Since the AAC codec constitutes the core of the high-qualtiy part of the MPEG-4 audio coder, further enhancements in terms of compression efficiency are desirable for use at very low bitrates. This paper describes the extension of the AAC-based MPEG-4 audio coder by means of the so-called Perceptual Noise Substitution (PNS) technique as it was accepted by MPEG-4.
