MPC is one of the files of the Audio category. This unlicensed file format is intended to store audio information. The MPC format (i.e. Musepack Compressed Audio File) was created by Musepack. Musepack is a lossy compression scheme developed by German programmer Andree Buschmann. He started creating the codec in 1997. At that time he had the name MP +. The developer was not satisfied with the existing quality of MP3 coding. The algorithm is based on MP2 (MPEG-1 Layer 2), where there are 32 frequency bands, but with significant improvements. Over the past years, it has undergone revision and has become much better. It is currently at a more advanced stage, which contains highly optimized and unpatented source code. The MPC encoding quality at high bitrates (160 Kbps and more) is much higher than the quality that MP3 provides. During coding, a different psychoacoustic compression algorithm is used. In MPC, frequencies that ignore MP3 encoders do not disappear. The specificity of MPC is the fine tuning of psychoacoustics. This provides the ability to operate with pure VBR encoding (variable bit rate encoding). The main task of Musepack is to obtain the highest transparency of sound.
AMR is a sound file format with a specific focus. Created a long time ago, before the advent of MP3. some sources call the developer Ericsson. The name of the format is an abbreviation for Adaptive Multi Rate. Sound files of this format are intended for mobile devices and in GSM cellular networks. Using this format provides a small file size due to the technology of signal coding in the speech frequency range. Effectively compressing audio recordings of human speech makes this format often used in voice recorders on mobile phones, for voice recordings, and for MMS messages.