pvsbandr
Prev | Orchestra Opcodes and Operators | Next

## pvsbandr

pvsbandr — A band reject filter working in the spectral domain.

## Description

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

## Syntax

    fsig pvsbandr 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 rejected. 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 give an exponential curve

(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-reject filter with a spectral envelope shaped like

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

## Examples

Example 388. Example

    asig  in                                 ; get the signal in

    fsig  pvsanal   asig, 1024, 256, 1024, 1 ; analyse it
    ftps  pvsbandr  fsig, 200, 400, 1000, 2000 ; filter 300-1500Hz
    atps  pvsynth   ftps                     ; synthesise it

## Credits

Author: John ffitch
December 2007

Prev | Up | Next
pvsbandp | Home | pvsbin