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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