An Overview of the MPEG/audio Compression Algorithm

This paper gives a summary of the MPEG/audio compression algorithm. This algorithm was developed by the Motion Picture Experts Group (MPEG), as an International Organization for Standardization standard for the high fidelity compression of digital audio. The MPEG/audio compression standard is one part of a multiple part standard that addresses the compression of video (11172-2), the compression of audio (11172-3), and the synchronization of the audio, video, and related data streams (11172-1) to an aggregate bit rate of about 1.5 Mbit/sec. The MPEG/audio standard also can be used for audio-only applications to compress high fidelity audio data at much lower bit rates. While the MPEG/audio compression algorithm is lossy, often it can provide `transparent', perceptually lossless, compression even with compression factors of 6-to-1 or more. The algorithm works by exploiting the perceptual weaknesses of the human ear. This paper also will cover the basics of psychoacoustic modeling and the methods used by the MPEG/audio algorithm to compress audio data with least perceptible degradation.