Perceptual Audio Coder
Perceptual Audio Coder (PAC) is a
Development
The original version of PAC developed by James Johnston and Anibal Ferreira at AT&T's 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. For stereo audio signals, it is claimed that it provides near-CD quality at about 56-64 kbit/s, with transparent coding at bit rates approaching 128 kbit/s.[1]
Over the years PAC has evolved considerably. A known software implementation of this codec is CelestialTech's AudioLib. Later, it was considerably improved and renamed to ePAC (enhanced Perceptual Audio Coder) by Lucent, available in the AudioVeda music library manager.[citation needed]
See also
References
- S2CID 59104987.