pvsfilter

pvsfilter — Multiply amplitudes of a pvoc stream by those of a second pvoc stream, with dynamic scaling.

Description

Multiply amplitudes of a pvoc stream by those of a second pvoc stream, with dynamic scaling.

Syntax

fsig pvsfilter fsigin, fsigfil, kdepth[, igain]

Performance

fsig -- output pv stream

fsigin -- input pv stream.

fsigfil -- filtering pvoc stream.

kdepth -- controls the depth of filtering of fsigin by fsigfil .

igain -- amplitude scaling (optional, defaults to 1).

Here the input pvoc stream amplitudes are modified by the filtering stream, keeping its frequencies intact. As usual, both signals have to be in the same format.

[Warning] 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

Example 667. Example

kfreq  expon 500, p3, 4000           ; 3-octave sweep
kdepth linseg 1, p3/2, 0.5, p3/2, 1  ; varying filter depth

asig  in                             ; input
afil  oscili  1, kfreq, 1            ; filter t-domain signal

fim   pvsanal  asig,1024,256,1024,0  ; pvoc analysis
fil   pvsanal  afil,1024,256,1024,0  
fou   pvsfilter fim, fil, kdepth     ; filter signal
aout  pvsynth  fou                   ; pvoc synthesis
        


In the example above the filter curve will depend on the spectral envelope of afil; in the simple case of a sinusoid, it will be equivalent to a narrowband band-pass filter.

Here is an example of the use of the pvsfilter opcode. It uses the file pvsfilter.csd.

Example 668. Example of the pvsfilter opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>
<CsOptions>
-odac
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 16
nchnls = 1
0dbfs = 1

;; example written by joachim heintz 2009

giSine		ftgen		0, 0, 4096, 10, 1
giBell		ftgen		0, 0, 4096, 9, .56, 1, 0, .57, .67, 0, .92, 1.8, 0, .93, 1.8, 0, 1.19, 2.67, 0, 1.7, 1.67, 0, 2, 1.46, 0, 2.74, 1.33, 0, 3, 1.33, 0, 3.76, 1, 0, 4.07, 1.33, 0; bell-like (after Risset)

instr 1
ipermut	=		p4; 1 = change order of soundfiles 
ifftsize	=		1024
ioverlap	=		ifftsize / 4
iwinsize	=		ifftsize
iwinshape	=		1; von-Hann window
Sfile1		=		"fox.wav"
ain1		soundin	Sfile1
kfreq		randomi	200, 300, 3
ain2		oscili		.2, kfreq, giBell
;ain2		oscili		.2, kfreq, giSine; try also this 
fftin1		pvsanal	ain1, ifftsize, ioverlap, iwinsize, iwinshape; fft-analysis of file 1
fftin2		pvsanal	ain2, ifftsize, ioverlap, iwinsize, iwinshape; fft-analysis of file 2
if ipermut == 1 then
fcross		pvsfilter	fftin2, fftin1, 1
else
fcross		pvsfilter	fftin1, fftin2, 1
endif
aout		pvsynth	fcross
		out		aout * 20
endin

</CsInstruments>
<CsScore>
i 1 0 2.757 0; frequencies from fox.wav, amplitudes multiplied by amplitudes of giBell
i 1 3 2.757 1; frequencies from giBell, amplitudes multiplied by amplitudes of fox.wav
e
</CsScore>
</CsoundSynthesizer>


See Also

pvsanal, pvsynth, pvsadsyn

Credits

Author: Victor Lazzarini
November 2004

New plugin in version 5

November 2004.