pvsbandp
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## pvsbandp

pvsbandp — A band pass filter working in the spectral domain.

## Description

Filter the pvoc frames, passing bins whose frequency is within a band, and with linear interpolation for transitional bands.

## Syntax

    fsig pvsbandp fsigin, xlowcut, xlowfull, \
          xhighfull, xhighcut[, ktype]

## Performance

fsig -- output pv stream

fsigin -- input pv stream.

xlowcut, xlowfull, xhighfull, xhighcut -- define a trapezium shape for the band that is passed. The a-rate versions only apply to the sliding case.

ktype -- specifies the shape of the transitional band. If at the default value of zero the shape is as below, with linear transition in amplitude. Other values yield and exponential shape:

(1 - exp( r*type )) / (1 - exp(type))

This includes a linear dB shape when ktype is log(10) or about 2.30.

The opcode performs a band-pass filter with a spectral envelope shaped like

klowfull __________________________ khighfull
/ \
/ \
/ \
/ \
/ \
________/ \______________
klowcut khighcut

## Examples

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

Example 630. Example of the pvsbandp opcode.

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

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

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

    ;; example written by joachim heintz 2009

    instr 1
    Sfile		=		"fox.wav"
    klowcut = 100
    klowfull = 200
    khighfull = 1900
    khighcut = 2000
    ain		soundin	Sfile
    fftin		pvsanal	ain, 1024, 256, 1024, 1; fft-analysis of the audio-signal
    fftbp		pvsbandp	fftin, klowcut, klowfull, khighfull, khighcut ; band pass
    abp		pvsynth	fftbp; resynthesis
    		out		abp
    endin

    </CsInstruments>
    <CsScore>
    i 1 0 3
    e
    </CsScore>
    </CsoundSynthesizer>

## See Also

pvsanal, pvsynth, pvsadsyn, pvsbandr

## Credits

Author: John ffitch
December 2007

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