The mobile phone recorded songs, and the file was later renamed. What does amr mean? What's the difference between this format and MP3 format?

Mobile devices generally use amr as a suffix to record files. The full names of adaptive multi-rate and adaptive multi-rate broadband are mainly used for audio of mobile devices. The compression ratio is relatively high, but the quality is poor compared with other compression formats. Because it is mostly used for voice and phone calls, the effect is still very good. Amr proposed by European Communication Standardization Committee is the most widely used voice standard in mobile communication system. Saving mobile phone recordings is a format recognized by major mobile phone manufacturers. Due to the small capacity of amr file, even a one-minute audio file can meet the current technical specification of China Mobile that the capacity of MMS should not exceed 50KB. Therefore, amr is the only format to load human voice into MMS. But due to the limitation of volume, amr is not optimistic about sound quality. Mp3 is a practical lossy audio compression coding, so as to obtain higher compression rate and smaller size. Compared with amr, mp3 files are larger and the corresponding sound quality is improved. The format conversion between amr and mp3 can be realized by software. If you are interested, you can convert several files, and you will naturally know the difference between the two files.