1zretune(1)                       USER COMMANDS                      zretune(1)
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NAME

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

9       zretune [options] input-file output-file
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DESCRIPTION

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

19       --help Display a short help text.
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21       --cent pitch change in cents
22              The  number of cents by which the pitch is changed. The accepted
23              range is +/- 1200 cents, the useful range in  practice  will  be
24              something like +/- 100 cents.
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26   Output file type
27       --wav  Produce  a  WAV file, or for more than 2 channels, a WAVEX file.
28              This is the default.
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30       --amb  Produce a WAVEX file with the Ambisonic GUID. Such files  should
31              have the .amb filename extension.
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33       --caf  Produce a Core Audio file.
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35       --aiff Produce an AIFF file.
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37       --flac Produce a FLAC file.
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39   Output sample format
40       --16bit
41              Output  sample format is signed 16-bit. This option also enables
42              the use of dithering, described below.
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44       --24bit
45              Output sample format is 24-bit. This is the default.
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47       --float
48              Output sample format is 32-bit floating point.
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50   Dithering
51       --rec  Add white dithering noise with a rectangular distribution.  This
52              is  the  best  option  if  the output data is going to processed
53              again, but in that case it would be advisable to use  24-bit  or
54              float.
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56       --tri  Add  filtered  noise with a triangular distribution. Compared to
57              the rectangular dither this reduces the  noise  density  in  the
58              lower frequency range.
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60       --lips This uses the optimal error feedback filter described by Stanley
61              Lipschitz. This is recommended is the output is the  final  dis‐
62              tribution format, e.g. for a CD.
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64   Timing
65       --pad  Insert  zero  valued  input samples at the start and end so that
66              the output includes the full symmetric filter response even  for
67              the first and last samples.
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EXIT STATUS

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

73       Fons Adriaensen (fons (at) linuxaudio.org)
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77version 0.0.1                      Sept 2012                        zretune(1)