krotos::OnsetDetector Class Reference

A class calculating onset positions of signal based on a slope vector describing it's envelope. More...

#include <SlopEnvelopeOnsetdetection.h>

Public Member Functions
	OnsetDetector (float sampleRate)
std::vector< int >	calculateOnsetsGlobal (std::vector< float > slopeVector, std::vector< float > normalisedEnvelopeVector)
void	setThresholdPercentage (float thresholdPercentage)
void	setOnsetMiliSeconds (float onsetMiliSeconds)
void	setDecayLengthMiliSeconds (float decayLengthMiliSeconds)

Private Member Functions
std::pair< int, int >	detectAttackSegment (const std::vector< float > &slopeFrame, const std::vector< float > &normalisedEnvelopeFrame, float thresholdValue)

Private Attributes
float	m_threshold {0.0f}
int	m_onset {}
int	m_decayLength {}
float	m_epsilon = 1e-6f
float	m_sampleRate
bool	m_finishFlag {false}

Detailed Description

A class calculating onset positions of signal based on a slope vector describing it's envelope.

This class handles the segmentation process using an iterative scheme. Each time a new onset-attackPosition is found the segment is extracted and the detection process is repeated until the next is found. Segmentation results are heavily influenced by the values of the segmentation parameters. Play around to fine tune to your signal.

Constructor & Destructor Documentation

OnsetDetector()

krotos::OnsetDetector::OnsetDetector

(

float

sampleRate

)

Member Function Documentation

calculateOnsetsGlobal()

std::vector< int > krotos::OnsetDetector::calculateOnsetsGlobal	(	std::vector< float >	slopeVector,
		std::vector< float >	normalisedEnvelopeVector )

Contains the overall structure of the iterative routine. Terminates either if no more attacks-onsets are present in the signal or the whole signal has been consumed. Performs a search based on the slope Vector and assigns the normalised Envelope Vector to detectAttackSegment which is called iteratively.

Parameters

slopeVector	the slope of the envelope Vector
normalisedEnvelopeVector	the normalised envelope follower Vector

detectAttackSegment()

std::pair< int, int > krotos::OnsetDetector::detectAttackSegment ( const std::vector< float > & slopeFrame, const std::vector< float > & normalisedEnvelopeFrame, float thresholdValue )

private

Detects the first attack segment in a region of the signal and returns a pair of attackPosition and finishPositions to move the iteration forward.

setDecayLengthMiliSeconds()

void krotos::OnsetDetector::setDecayLengthMiliSeconds

(

float

decayLengthMiliSeconds

)

setOnsetMiliSeconds()

void krotos::OnsetDetector::setOnsetMiliSeconds

(

float

onsetMiliSeconds

)

setThresholdPercentage()

void krotos::OnsetDetector::setThresholdPercentage

(

float

thresholdPercentage

)

Setters for the 3 main segmentation Parameters.

Member Data Documentation

m_decayLength

int krotos::OnsetDetector::m_decayLength {}

private

m_epsilon

float krotos::OnsetDetector::m_epsilon = 1e-6f

private

m_finishFlag

bool krotos::OnsetDetector::m_finishFlag {false}

private

m_onset

int krotos::OnsetDetector::m_onset {}

private

m_sampleRate

float krotos::OnsetDetector::m_sampleRate

private

m_threshold

float krotos::OnsetDetector::m_threshold {0.0f}

private

Segmentation Parameters.

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

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