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pvsblur

Average the amp/freq time functions of each analysis channel for a specified time (truncated to number of frames).

As a side-effect the input pvoc stream will be delayed by that amount.

Syntax

fsig pvsblur fsigin, kblurtime, imaxdel

Performance

fsig -- output pv stream

fsigin -- input pv stream.

kblurtime -- time in secs during which windows will be averaged .

imaxdel -- maximum delay time, used for allocating memory used in the averaging operation.

This opcode will blur a pvstream by smoothing the amplitude and frequency time functions (a type of low-pass filtering); the amount of blur will depend on the length of the averaging period, larger blurtimes will result in a more pronounced effect.

⚠ 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

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

Example of the _pvsblur_ opcode.
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 <CsoundSynthesizer>
 <CsOptions>
 ; Select audio/midi flags here according to platform
 ; Audio out   Audio in
 -odac       ;;;RT audio out
 ; For Non-realtime ouput leave only the line below:
 ; -o pvsblur.wav -W ;;; for file output any platform
 </CsOptions>
 <CsInstruments>

 sr = 44100
 ksmps = 32
 nchnls = 2
 0dbfs  = 1

 ;; example written by joachim heintz 2009

 instr 1
 ifftsize       = 1024
 ioverlap       = ifftsize / 4
 iwinsize       = ifftsize
 iwinshape      = 1               ; von-Hann window
 Sfile  = "fox.wav"
 ain            soundin Sfile
 fftin  pvsanal ain, ifftsize, ioverlap, iwinsize, iwinshape; fft-analysis of the audio-signal
 fftblur        pvsblur fftin, p4, 1; blur
 aout           pvsynth fftblur; resynthesis
                outs    aout, aout
 endin

 </CsInstruments>
 <CsScore>
 i 1 0 3    0
 i 1 3 3   .1
 i 1 6 3.5 .5
 e
 </CsScore>
 </CsoundSynthesizer>

See also

Tools for Real-time Spectral Processing (pvs opcodes)

Credits

Author: Victor Lazzarini
November 2004

New plugin in version 5

November 2004.