NAME

       soundstretch - audio processing utility

SYNOPSIS

       soundstretch infile.wav outfile.wav [options]

DESCRIPTION

       SoundStretch  is  a  simple  command-line  application  that  can  change tempo, pitch and
       playback rates of WAV sound files. This program is intended primarily to  demonstrate  how
       the  "SoundTouch"  library can be used to process sound in your own program, but it can as
       well be used for processing sound files.

USAGE

       SoundStretch Usage syntax:

       "infile.wav"    Name of the input sound data  file  (in  .WAV  audio  file  format).  Give
       "stdin" as filename to use standard input pipe.

       "outfile.wav"    Name of the output sound file where the resulting sound is saved (in .WAV
       audio file format). This parameter may be omitted if you don't want  to  save  the  output
       (e.g. when only calculating BPM rate with '-bpm' switch). Give "stdout" as filename to use
       standard output pipe.

       [options]       Are one or more control options.

OPTIONS

       Available control options are:

       -tempo=n Change the sound tempo by n percents (n = -95.0 .. +5000.0 %)

       -pitch=n Change the sound pitch by n semitones (n = -60.0 .. + 60.0 semitones)

       -rate=n Change the sound playback rate by n percents (n = -95.0 .. +5000.0 %)

       -bpm=n Detect the Beats-Per-Minute (BPM) rate of the sound and adjust the  tempo  to  meet
       'n'  BPMs.  When  this  switch  is  applied,  the  " -tempo" switch is ignored. If "=n" is
       omitted, i.e. switch " -bpm" is used alone, then the BPM rate is estimated and  displayed,
       but tempo not adjusted according to the BPM value.

       -quick Use quicker tempo change algorithm. Gains speed but loses sound quality.

       -naa  Don't  use  anti-alias  filtering  in sample rate transposing. Gains speed but loses
       sound quality.

       -license Displays the program license text (LGPL)

NOTES

       * To use standard  input/output  pipes  for  processing,  give  "stdin"  and  "stdout"  as
       input/output  filenames  correspondingly. The standard input/output pipes will still carry
       the audio data in .wav audio file format.

       * The numerical switches allow both integer (e.g.  "  -tempo=123")  and  decimal  (e.g.  "
       -tempo=123.45") numbers.

       * The " -naa" and/or " -quick" switches can be used to reduce CPU usage while compromising
       some sound quality

       * The BPM detection algorithm works by detecting repeating bass or drum  patterns  at  low
       frequencies  of  <250Hz.  A  lower-than-expected BPM figure may be reported for music with
       uneven or complex bass patterns.

EXAMPLES

       Example 1

       The following command increases tempo of the sound file "originalfile.wav"  by  12.5%  and
       stores result to file "destinationfile.wav":

            soundstretch originalfile.wav destinationfile.wav -tempo=12.5

       Example 2

       The  following command decreases the sound pitch (key) of the sound file "orig.wav" by two
       semitones and stores the result to file "dest.wav":

            soundstretch orig.wav dest.wav -pitch= -2

       Example 3

       The following command processes the file "orig.wav" by decreasing the sound tempo by 25.3%
       and  increasing  the  sound  pitch  (key)  by  1.5 semitones. Resulting .wav audio data is
       directed to standard output pipe:

            soundstretch orig.wav stdout -tempo= -25.3 -pitch=1.5

       Example 4

       The following command detects the BPM rate of the file "orig.wav" and adjusts the tempo to
       match 100 beats per minute. Result is stored to file "dest.wav":

            soundstretch orig.wav dest.wav -bpm=100

       Example 5

       The following command reads .wav sound data from standard input pipe and estimates the BPM
       rate:

            soundstretch stdin -bpm

NOTES

       Converted from the README.html that comes with SoundTouch.

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