MPC (audio compression format)
MPC (also known as Musepack or MPEGPlus/MP+) is a lossy audio compression format, similar in function to MPEG-1 Layer II Audio, also known as Musicam.
Unlike MPEG Layer II it uses:
- subband-wise selectable M/S encoding (like MPEG-AAC)
- Huffman coding (like MPEG Layer III, MPEG AAC, ...)
- noise substitution techniques as used in ATSC A-52 and MPEG-4 AAC V2
- pure variable bitrate between 3 and 1300 kbit/s (when needed)
The psycho-acoustic model of MPC is based on MPEG ISO model 2, but is extended by CVD (clear voice detection). The quantization algorithm of the MPC encoder performs spectral shaping of the noise, called adaptive noise shaping (ANS), in order to overcome the low frequency resolution of the polyphase quadrature filter bands.
Its proponents claim that MPC is the best available lossy codec for high-quality music compression, at bitrates of 160kbit/s and upwards.
I.e it is possible to encode a piece of music so that it is indistinguishable from the original at a lower bitrate with MPC than with e.g. MP3 or Ogg Vorbis.
Development of MPC was initiated in 1997 by Andree Buschmann and later taken over by Frank Klemm.
