Audio compression

Abstract

In the past decades, human beings have a great improvement over technology, and audio compression is one of them. Audio compression allows an audio file to be obtained by minimum resources such as storage and downloading time. The efficiency is good enough for the past. However, the world is changing and the requirement for audio compression is also changed. The hardware development in these few years causes the rapidly drop in computer memory prices. Customer can have an 80GBytes hard disk with only $700. Now, no one cares how many bytes are used to store a song, user only care is the quality. Besides, the downloading speed also has a new evolution. Broadband is common nowadays, the network capacity of 3 Mega byte per person can be seen anywhere. Therefore, the desire for the audio file in small size with fair quality is significantly decreased. All these changes in the requirement of audio compression causing compression with high quality become a must. The existing compression methods include PCM, DPCM, and ADPCM, especially the outstanding compression quality of MPEG audio series (MPEG1-layer3, ACC). Most of them can achieve a fair quality with reasonable resources. However, the better people has, the much better people wants, the desire for a better compression becomes stronger. This project aims to develop a methodology for getting a very high quality audio file with reasonable amount of resources by performing a series of pre-processing programs before audio compression.