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sfpv − Applies a phase vocoder to a soundfile. |
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sfpv [-d n][-c n][-C n][-L n][-t n][-o outputSoundfile][-S s] inputSoundfile |
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sfpv Applies a phase vocoder to a soundfile. This program is primarily used for changing the pitch of a sound without changing its duration, or for changing the duration of a sound without changing its pitch. |
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−d n |
Desired duration of output sound in seconds. |
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−c n |
Change of pitch in cents (where 100 cents is equal to a semi-tone). |
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−C n |
Change of ending pitch in cents. The "-c" option sets the initial change of pitch in cents, and the "-C" option sets the final change of pitch in cents. |
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-L n |
Length of the FFT window, in samples. The default value is 4096. (This probably never has to be changed.) |
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-t n |
Amplitude threshold. All amplitudes that are below this threshold are ignored, speeding up the phase vocoder significantly. (This probably never has to be changed.) |
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-o outputSoundfile |
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Where to put the resulting sound. |
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-S dur |
Add "dur" seconds of silence to the end of the sound. |
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sfpv -d 10 soundfile |
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Stretch (or shrink) the duration of soundfile to be 10 seconds long without changing its pitch. The output is placed in the default output soundfile sfpvout.wav . |
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sfpv -c +100 snd1.wav |
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Raise the pitch of snd1.wav by 100 cents. Place the output in sfpvout.wav . |
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sfpv -c -100 -C +100 snd1.wav |
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At the beginning of the sound, shift the pitch by -100 cents, and keep raising the pitch, until by the end of the sound it is +100 above the original. Put the output in sfpvout.wav . |
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This program will only work with WAVE, AIFF, AIFC, and the old NeXT/Sun "snd" format soundfiles, that are 16-bit PCM encoded, with only 1 channel. |
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Arun Chandra <arunc@evergreen.edu> sfpv is free software. |