PSMVocoder Class Reference

The PSMVocoder object implements a phase vocoder pitch shifter. Phase locking and peak tracking are optional. More...

#include <fxobjects.h>

Inheritance diagram for PSMVocoder:

Public Member Functions
virtual bool	reset (double _sampleRate)
virtual bool	canProcessAudioFrame ()
void	setPitchShift (double semitones)
int	findPreviousNearestPeak (int peakIndex)
void	findPeaksAndRegionsOfInfluence ()
virtual double	processAudioSample (double input)
PSMVocoderParameters	getParameters ()
void	setParameters (const PSMVocoderParameters &params)
Public Member Functions inherited from IAudioSignalProcessor
virtual bool	reset (double _sampleRate)=0
virtual double	processAudioSample (double xn)=0
virtual bool	canProcessAudioFrame ()=0
virtual void	setSampleRate (double _sampleRate)
virtual void	enableAuxInput (bool enableAuxInput)
virtual double	processAuxInputAudioSample (double xn)
virtual bool	processAudioFrame (const float *inputFrame, float *outputFrame, uint32_t inputChannels, uint32_t outputChannels)

Protected Attributes
PSMVocoderParameters	parameters
	object parameters
PhaseVocoder	vocoder
	vocoder to perform PSM
double	alphaStretchRatio = 1.0
	alpha stretch ratio = hs/ha
const double	hs = PSM_FFT_LEN / 4
	hs = N/4 — 75% overlap
double	ha = PSM_FFT_LEN / 4
	ha = N/4 — 75% overlap
double	phi [PSM_FFT_LEN] = { 0.0 }
	array of phase values for classic algorithm
double	psi [PSM_FFT_LEN] = { 0.0 }
	array of phase correction values for classic algorithm
BinData	binData [PSM_FFT_LEN]
	array of BinData structures for current FFT frame
BinData	binDataPrevious [PSM_FFT_LEN]
	array of BinData structures for previous FFT frame
int	peakBins [PSM_FFT_LEN] = { -1 }
	array of current peak bin index values (-1 = not peak)
int	peakBinsPrevious [PSM_FFT_LEN] = { -1 }
	array of previous peak bin index values (-1 = not peak)
double *	windowBuff = nullptr
	buffer for window
double *	outputBuff = nullptr
	buffer for resampled output
double	windowCorrection = 0.0
	window correction value
unsigned int	outputBufferLength = 0
	lenght of resampled output array

Detailed Description

The PSMVocoder object implements a phase vocoder pitch shifter. Phase locking and peak tracking are optional.

Audio I/O:

• Processes mono input to mono output.

Control I/F:

• Use PSMVocoderParameters structure to get/set object params.

Author

Will Pirkle http://www.willpirkle.com

Remarks

This object is included in Designing Audio Effects Plugins in C++ 2nd Ed. by Will Pirkle

Version

Revision : 1.0

Date

Date : 2018 / 09 / 7

Member Function Documentation

canProcessAudioFrame()

virtual bool PSMVocoder::canProcessAudioFrame ( )

inlinevirtual

return false: this object only processes samples

Implements IAudioSignalProcessor.

findPeaksAndRegionsOfInfluence()

void PSMVocoder::findPeaksAndRegionsOfInfluence ( )

inline

identify peak bins and tag their respective regions of influence

findPreviousNearestPeak()

int PSMVocoder::findPreviousNearestPeak ( int  peakIndex )

inline

find bin index of nearest peak bin in previous FFT frame

getParameters()

PSMVocoderParameters PSMVocoder::getParameters ( )

inline

get parameters: note use of custom structure for passing param data

Returns

PSMVocoderParameters custom data structure

processAudioSample()

virtual double PSMVocoder::processAudioSample ( double  input )

inlinevirtual

process input sample through PSM vocoder

Parameters

xn

input

Returns

the processed sample

Implements IAudioSignalProcessor.

reset()

virtual bool PSMVocoder::reset ( double  _sampleRate )

inlinevirtual

reset members to initialized state

Implements IAudioSignalProcessor.

setParameters()

void PSMVocoder::setParameters ( const PSMVocoderParameters &  params )

inline

set parameters: note use of custom structure for passing param data

Parameters

PSMVocoderParameters

custom data structure

setPitchShift()

void PSMVocoder::setPitchShift ( double  semitones )

inline

set the pitch shift in semitones (note that this can be fractional too)

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The documentation for this class was generated from the following file:

• C:/RackAFX_v7/ASPIK_Doxygen/PluginObjects/fxobjects.h