zita-retune (1)
NAME
zita-retune - resample an audio file in order to change its pitchSYNOPSIS
zita-retune <options> <input file> <output file>.DESCRIPTION
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.
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.
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.
SEE ALSO
Some examples of dithering are available here: www.kokkinizita.net/linuxaudio/dithering.html
AUTHOR
zita-retune was written by Fons Adriaensen <fons@kokkinizita.net>.This manual page was written by Jaromír Mikeš <mira.mikes@seznam.cz> for the Debian project (but may be used by others).