krotos::SuperFluxOnsetDetection Class Reference

Performs Onset Detection with vibrato suppresion. More...

#include <SuperFluxOnsetDetection.h>

Public Member Functions
	SuperFluxOnsetDetection (std::vector< std::vector< float > > &logSpectrum, float sampleRate, int hopSize)
void	setParametersMS (float preMax, float postMax, float preAvg, float postAvg, float combWidth)
void	setDeltaPercentage (float deltaPrcnt)
std::vector< float >	trajectoryTracking (std::vector< std::vector< float > > logSpectrum)
std::vector< float >	calculateDetectionFunction (const std::vector< std::vector< float > > &logSpectrum, const std::vector< float > &maxLogSpectum)
std::vector< int >	peakPicking (std::vector< float > detectionFunction)
std::vector< int >	findOnsetsInSamples ()

Private Member Functions
float	halfWaveRect (float x)
std::vector< float >	movingMax (std::vector< float > detectionFunction)
std::vector< float >	movingMean (std::vector< float > detectionFunction)

Private Attributes
std::vector< std::vector< float > >	m_inputLogSpectrum
float	m_deltaPrcnt {0.0f}
int	m_preMaxFrames {0}
int	m_postMaxFrames {0}
int	m_preAvgFrames {0}
int	m_postAvgFrames {0}
int	m_combWidthFrames {0}
const int	mi = 2
int	m_numBands {0}
int	m_numFrames {0}
float	m_sampleRate {0.0f}
int	m_hopSize {0}

Detailed Description

Performs Onset Detection with vibrato suppresion.

This class implements the SuperFlux onset detection algorithm, which is an enhanced version of the universal spectral flux onset detection. It only considers the magnitude spectrogram, relying on detection of positive changes in the energy over time, but instead of calculating the difference between adjacent frames, it uses a trajectory tracking phase, incorporating a maximum filter for tracking. To facilitate trajectory tracking, the linear magnitude spectrogram has to be filtered with a filterBank with M=138 triangular filters with center frequencies alligned on the western music scale(Call MusicScaleFilterBak.h before). TODO: Online version (super simple), ComplexFlux (incorporates phase info as well.)

Constructor & Destructor Documentation

SuperFluxOnsetDetection()

krotos::SuperFluxOnsetDetection::SuperFluxOnsetDetection	(	std::vector< std::vector< float > > &	logSpectrum,
		float	sampleRate,
		int	hopSize )

Constructor

Parameters

logSpectrum	the filtered Spectrogram of the audiosignal in the form of [frames, bands]
sampleRate	the sampleRate of the audio signal ih Hz
hopSize	the hopSize of the STFT that initially was used on the signal to produce the spectrogram

Member Function Documentation

calculateDetectionFunction()

std::vector< float > krotos::SuperFluxOnsetDetection::calculateDetectionFunction	(	const std::vector< std::vector< float > > &	logSpectrum,
		const std::vector< float > &	maxLogSpectum )

Caclulates the Detection function vector using the trajectory tracking parameter mi.

Parameters

logSpectrum	the filtered Spectrogram of the audiosignal in the form of [frames, bands]
maxLogSpectrum	the maximum filtered Spectrogram

Returns

the Detection function vector

findOnsetsInSamples()

std::vector< int > krotos::SuperFluxOnsetDetection::findOnsetsInSamples

(

)

halfWaveRect()

float krotos::SuperFluxOnsetDetection::halfWaveRect ( float x )

inlineprivate

HalfWave Rectifier function.

movingMax()

std::vector< float > krotos::SuperFluxOnsetDetection::movingMax ( std::vector< float > detectionFunction )

private

Moving maximum.

movingMean()

std::vector< float > krotos::SuperFluxOnsetDetection::movingMean ( std::vector< float > detectionFunction )

private

Moving average.

peakPicking()

std::vector< int > krotos::SuperFluxOnsetDetection::peakPicking

(

std::vector< float >

detectionFunction

)

Peak picking stage.

Parameters

detectionFunction

the Detection function vector

Returns

onsetPositions in samples

setDeltaPercentage()

void krotos::SuperFluxOnsetDetection::setDeltaPercentage

(

float

deltaPrcnt

)

Set delta threshold parameter percentage.

setParametersMS()

void krotos::SuperFluxOnsetDetection::setParametersMS	(	float	preMax,
		float	postMax,
		float	preAvg,
		float	postAvg,
		float	combWidth )

Sets the peak picking parameters

Parameters

preMax	number of frames the moving max filter looks back in time
postMax	number of frames the moving max filter looks forward in time [set to 0 for online version]
preAvg	number of frames the moving avg filter looks forward in time
postAvg	number of frames the moving avg filter looks forward in time [set to 0 for online version]
combWidth	number of frames between two valid onsets

trajectoryTracking()

std::vector< float > krotos::SuperFluxOnsetDetection::trajectoryTracking

(

std::vector< std::vector< float > >

logSpectrum

)

Applies maximum filter on each frequency bin of the filtered spectrogram and its near neighbors, limited to each frame.

Parameters

logSpectrum

the filtered Spectrogram of the audiosignal in the form of [frames, bands] returns the maximum filtered Spectrogram

Member Data Documentation

m_combWidthFrames

int krotos::SuperFluxOnsetDetection::m_combWidthFrames {0}

private

m_deltaPrcnt

float krotos::SuperFluxOnsetDetection::m_deltaPrcnt {0.0f}

private

Peak picking parameters

m_hopSize

int krotos::SuperFluxOnsetDetection::m_hopSize {0}

private

m_inputLogSpectrum

std::vector<std::vector<float> > krotos::SuperFluxOnsetDetection::m_inputLogSpectrum

private

m_numBands

int krotos::SuperFluxOnsetDetection::m_numBands {0}

private

m_numFrames

int krotos::SuperFluxOnsetDetection::m_numFrames {0}

private

m_postAvgFrames

int krotos::SuperFluxOnsetDetection::m_postAvgFrames {0}

private

m_postMaxFrames

int krotos::SuperFluxOnsetDetection::m_postMaxFrames {0}

private

m_preAvgFrames

int krotos::SuperFluxOnsetDetection::m_preAvgFrames {0}

private

m_preMaxFrames

int krotos::SuperFluxOnsetDetection::m_preMaxFrames {0}

private

m_sampleRate

float krotos::SuperFluxOnsetDetection::m_sampleRate {0.0f}

private

mi

const int krotos::SuperFluxOnsetDetection::mi = 2

private

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

• krotos_dsp/utilities/onset_detection/SuperFluxOnsetDetection.h
• krotos_dsp/utilities/onset_detection/SuperFluxOnsetDetection.cpp