MPEG Audio Coding

This chapter examines the prevalence of motion picture experts group (MPEG) audio and digital audio compression (AC-3) in applications and plans. Before getting into the details of audio compression systems, however, it is important to understand a little bit about how the human auditory system works. The fundamental understanding of the operation of the ear/brain combination is that they act as a multi-channel real time analyser with varying sensitivities and bandwidths through the audio range. In the basic MPEG audio system, the input signal is broken up into uniform time segments, called "frames," based upon a certain number of samples. The chapter shows all of the principal parameters of MPEG audio in both its original MPEG-1 form and its extended MPEG-2 form. The MPEG-2 audio coding system is an extension of the system adopted for MPEG-1 and is both forward and backward compatible with it. Dolby AC-3 is the other important audio technique receiving wide application.