NAME

       zretune - resample an audio file in order to change its pitch

SYNOPSIS

       zretune [options] input-file output-file

DESCRIPTION

       zretune  resamples  an  audio  file  by a the inverse of a ratio expressed in cents, without changing the
       nominal sample rate. The result is to change the musical pitch and lenght of the file. Input can  be  any
       audio  file  readable  by the libsndfile library. The output file type is either WAV, WAVEX, CAF, AIFF or
       FLAC.

OPTIONS

       --help Display a short help text.

       --cent pitch change in cents
              The number of cents by which the pitch is changed. The accepted  range  is  +/-  1200  cents,  the
              useful range in practice will be something like +/- 100 cents.

   Output file type
       --wav  Produce a WAV file, or for more than 2 channels, a WAVEX file.  This is the default.

       --amb  Produce a WAVEX file with the Ambisonic GUID. Such files should have the .amb filename extension.

       --caf  Produce a Core Audio file.

       --aiff Produce an AIFF file.

       --flac Produce a FLAC file.

   Output sample format
       --16bit
              Output  sample  format  is signed 16-bit. This option also enables the use of dithering, described
              below.

       --24bit
              Output sample format is 24-bit. This is the default.

       --float
              Output sample format is 32-bit floating point.

   Dithering
       --rec  Add white dithering noise with a rectangular distribution. This is the best option if  the  output
              data is going to processed again, but in that case it would be advisable to use 24-bit or float.

       --tri  Add filtered noise with a triangular distribution. Compared to the rectangular dither this reduces
              the noise density in the lower frequency range.

       --lips This uses the optimal error feedback filter described by Stanley Lipschitz. This is recommended is
              the output is the final distribution format, e.g. for a CD.

   Timing
       --pad  Insert  zero  valued  input  samples  at  the  start  and end so that the output includes the full
              symmetric filter response even for the first and last samples.

EXIT STATUS

       Zero in case there are no errors, non-zero otherwise.

AUTHOR

       Fons Adriaensen (fons (at) linuxaudio.org)