Source : Free On-Line Dictionary of Computing

MPEG-1 audio layer 1
     
         (MP1) A simple 32-{subband}
        {audio compressor} using a {floating point} representation for
        subband samples.  Resolution and scale factor are stored for
        groups of 12 subsamples.  MP1 is only used for {Philips} DCC
        {Digital Compact cassette} with data rates of 384 kbps.
     
        (2001-12-02)