zita-retune - resample an audio file in order to change its pitch
zita-retune <options> <input file> <output file>.
zita-retune 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 length of the file. Input
can be any audio file readable by the libsndfile library. The output
file type is either WAV or CAF.
--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.
Output sample format
Output sample format is signed 16-bit. This option also enables
the use of dithering, described below.
Output sample format is 24-bit. This is the default.
Output sample format is 32-bit floating point.
--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
--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.
--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.
Zero in case there are no errors, non-zero otherwise.
Some examples of dithering are available here:
zita-retune was written by Fons Adriaensen <email@example.com>.
This manual page was written by Jaromír Mikeš <firstname.lastname@example.org>
for the Debian project (but may be used by others).
September 2012 ZITA-RETUNE(1)