Coding of Natural Audio in MPEG-4

MPEG-4 standardizes natural audio coding at bitrates ranging from 2 kbit/s, suitable for intelligible speech coding, to 64 kbit/s per channel, suitable for high-quality audio coding. Within this range, three categories of coding are defined: parametric coding, Code Excited Linear Predictive coding (CELP) and time/frequency (T/F) coding. The unique contribution of MPEG-4 audio is that not only does it scale across a wide range of bitrates, but it also scales across a broad set of other parameters, such as sampling rate, bandwidth, voice pitch and complexity. This paper presents an overview of the MPEG-4 natural audio coding framework and each of its component coding techniques.

Published

2001-11

Content type

Original Research

DOI

10.5594/M00980

ISBN

978-1-61482-935-5