As a method of storing,processing and transporting sound,digital audio is widely used in many fields such as Digital Broadcast Audio,Internet Audio,multimedia communication etc.The efficient digital audio compression technologies have long been studied.The MPEG-1 audio standard is among them.
Now MP3 is a very popular Internet audio media,also suit for ISDN and satellite transmission use. By using MP3 audio coding,you may shrink down the original sound data from a CD by a factor of 12,without losing sound quality.Factors of 24 and even more still maintain a sound quality that is significantly better than what you get by just reducing the sampling rate and the resolution of your samples.So it is very important to research and realize this algorithm for us.
After analyzing and comparing the wideband audio algorithms based on subband coding,the paper mainly studies the MPEG-1 audio codec.First, it covers key technologies in wideband audio coding including auditory masking,Sub-Band Coding , Modified Discrete Cosine Transform and dynamic bit allocation.And then, it elaborates the algorithms of MPEG-1 audio compression and three independent layers of the MPEG-1 audio standard.Finally,it studies deeply in Layer Ⅲ(MP3) ,designs and achieves the MP3 algorithms of coding and decoding.
KEY WORDS MPEG-1,wideband audio,Sub-Band Coding,MP3