Perceptual Audio Coder (Paperback)

High Quality Content by WIKIPEDIA articles! Perceptual Audio Coder (PAC) is an algorithm, like MPEG's MP3 standard, used to compress digital audio by removing extraneous information not perceived by most people. It is used by Sirius Satellite Radio for their DARS service, and iBiquity initially tested it for their IBOC digital radio upgrade for FM and AM, but chose an MPEG4-derived codec instead. The PAC originally developed by Elemedia, a subsidiary of Bell Labs, has a flexible format and bitrate. It provides efficient compression of high-quality audio over a variety of formats from 16 kbit/s for a monophonic channel to 1024 kbit/s 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.