Description

Shift the frequency components of a pv stream, stretching/compressing its spectrum.

Syntax

fsig pvshift fsigin, kshift, klowest[, ikeepform, igain]

Performance

fsig -- output pv stream

fsigin -- input pv stream

kshift -- shift amount (in Hz, positive or negative).

klowest -- lowest frequency to be shifted.

ikeepform -- attempt to keep input signal formants; 0: do not keep formants; 1: keep formants by imposing original amps; 2: keep formants by filtering using the original spec envelope (defaults to 0).

igain -- amplitude scaling (defaults to 1).

This opcode will shift the components of a pv stream, from a certain frequency upwards, up or down a fixed amount (in Hz). It can be used to transform a harmonic spectrum into an inharmonic one. The ikeepform flag can be used to try and preserve formants for possibly interesting and unusual spectral modifications.

	Warning
	It is unsafe to use the same f-variable for both input and output of pvs opcodes. Using the same one might lead to undefined behavior on some opcodes. Use a different one on the left and right sides of the opcode.

Examples

asig  in                                 ; get the signal in

fsig  pvsanal   asig, 1024, 256, 1024, 1 ; analyse it
ftps  pvshift   fsig, 100, 0             ; add 100 Hz to each component
atps  pvsynth   ftps                     ; synthesise it
        

Depending on the input, this will transform a pitched sound into an inharmonic, bell-like sound.

Credits

New plugin in version 5

Nivember 2004.