chapter  4
18 Pages

The Perceptual Audio Coder

PAC is a perceptual audio coder that is flexible in format and bit rate, and provides high-quality audio compression over a variety of formats from 16 kbps for a monophonic channel to 1024 kbps for a 5.1 format with four or six auxiliary audio channels, and provisions for an ancillary (fixed rate) and auxiliary (variable rate) side data channel. In all of its forms it provides efficient compression of high-quality audio. For stereo audio signals, it provides near compact disc (CD) quality at about 56-64 kbps, with transparent coding at bit rates approaching 128 kbps.