TIPS: MPEG audio compression specifications

Http://www.sina.com.cn 2002/03/11 SCID-China Computer news

Text/Chen Yu The principle of MPEG (Moving Picture Experts Group) audio compression is very simple. The first is to use the encoding technology to re-encode and compress the source file (mostly in the wave format), and the second is to use data reduction, remove the insensitive parts of human hearing to narrow down the file size. Same as all compression formats, MPEG can also cause sound distortion. Therefore, different compression ratios are defined based on different needs, which is the origin of the Mpeg Compression format. The Mpeg Compression format is divided into three layers: MPEG audio layer-1, layer-2, and layer-3. Among them, we are most familiar with layer-3, also known as MP3. From this we can see that wave is a music file format that has not been compressed and is not distorted, but the file size is very large. Basically, it takes 10 MB to store music for one minute, therefore, the source file used as the Walkman is not suitable. Compared with the other two formats, the compression ratio of MP3 is larger, which can reach ~ The ratio of, while MP1 and MP2 are only and, respectively ~ Compression ratio. This determines that the file size in MP3 format is more suitable for walkman with small storage space.