krotos::SWIPE_PitchEstimation Class Reference

A Sawtooth waveform inspired pitch estimator for speech and music. Paper: https://www.researchgate.net/publication/23558616_A_sawtooth_waveform_inspired_pitch_estimator_for_speech_and_music. More...

#include <SWIPE_PitchEstimation.h>

Public Member Functions
	SWIPE_PitchEstimation (const float sampleRate, const float timeStep, const float log2PitchStep, const float ERBStep, const float normOverlap, const float strenThresh)
void	initVectors ()
std::pair< Eigen::VectorXf, Eigen::VectorXf >	calculatePitchStrengthPairs (std::vector< float > &signal)
Eigen::VectorXf	getTimes ()

Private Member Functions
Eigen::VectorXf	calculateLog2PitchCands (float log2PitchStep)
Eigen::VectorXf	calculatePitchCands (const Eigen::VectorXf &log2PitchCands)
std::pair< Eigen::VectorXf, Eigen::VectorXf >	selectCandidatesForWindowSize (size_t winSizeIDx)
Eigen::VectorXf	getERBsSubset (const Eigen::VectorXf &pitchCandsSubset)
Eigen::MatrixXf	pitchStrengthAllCandidates (const Eigen::VectorXf &ERBs, Eigen::MatrixXf &ERBsDistrValues, const Eigen::VectorXf &pitchCands)
Eigen::VectorXf	pitchStrengthOneCandidate (const Eigen::VectorXf &ERBS, const Eigen::MatrixXf &normERBsDistrValues, float pitchCand)
std::pair< Eigen::VectorXf, Eigen::VectorXf >	fineTunePitch (Eigen::MatrixXf globStrMatrix)
Eigen::VectorXi	primes (int n)
Eigen::MatrixXf	cumsum (const Eigen::MatrixXf &input)
Eigen::VectorXf	polyfit (const Eigen::VectorXf &x, const Eigen::VectorXf &y, int n)
Eigen::MatrixXf	computeN (const Eigen::MatrixXf &ERBsDistrValues)

Private Attributes
float	m_sampleRate {-1.0f}
float	m_timeStep {-1.0f}
float	m_log2PitchStep {-1.0f}
float	m_ERBStep {-1.0f}
float	m_normOverlap {-1.0f}
float	m_strenThresh {-1.0f}
Eigen::Vector2f	m_pitchLims
Eigen::VectorXf	m_times
Eigen::VectorXf	m_pitchCands
Eigen::VectorXf	m_winSizes
Eigen::VectorXf	m_log2DistWin1OptPitchAndPitchCands
Eigen::VectorXf	m_ERBs

Detailed Description

A Sawtooth waveform inspired pitch estimator for speech and music. Paper: https://www.researchgate.net/publication/23558616_A_sawtooth_waveform_inspired_pitch_estimator_for_speech_and_music.

Class representing the Harmonic Representation of an audio signal.

From the paper abstract:
Sawtooth Waveform Inspired Pitch Estimator (SWIPE) has been developed for
processing speech and music. SWIPE is shown to outperform existing algorithms on several
publicly available speech/musical-instruments databases and a disordered speech database.
SWIPE estimates the pitch as the fundamental frequency of the sawtooth waveform whose
spectrum best matches the spectrum of the input signal. A decaying cosine kernel provides an
extension to older frequency-based, sieve-type estimation algorithms by providing smooth peaks
with decaying amplitudes to correlate with the harmonics of the signal. An improvement on the
algorithm is achieved by using only the first and prime harmonics, which significantly reduces
subharmonic errors commonly found in other pitch estimation algorithms.

TODO: REPLACE ALL VECTORS AND MATRIX AS WELL AS LINEAR ALGEBRA OPERATIONS WITH EIGEN!!!.

This class evaluates a spectrogram of the audio signal, estimates the fundamental pitches for all hop times, and optimizes and corrects the fundamental frequencies while evaluating the inharmonicity coefficient. This process yields the frequencies of the rest of the harmonic partials and all their amplitudes using the spectrogram.

Constructor & Destructor Documentation

SWIPE_PitchEstimation()

krotos::SWIPE_PitchEstimation::SWIPE_PitchEstimation	(	const float	sampleRate,
		const float	timeStep,
		const float	log2PitchStep,
		const float	ERBStep,
		const float	normOverlap,
		const float	strenThresh )

Member Function Documentation

calculateLog2PitchCands()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::calculateLog2PitchCands ( float log2PitchStep )

private

Defines pitch candidates.

calculatePitchCands()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::calculatePitchCands ( const Eigen::VectorXf & log2PitchCands )

private

calculatePitchStrengthPairs()

std::pair< Eigen::VectorXf, Eigen::VectorXf > krotos::SWIPE_PitchEstimation::calculatePitchStrengthPairs

(

std::vector< float > &

signal

)

Estimates the pitch of the vector signal every timeStep seconds.

Parameters

signal

signal in time vector representation

Returns

first vector is the vector of pitch estimates

second vector is the strength of every pitch estimate TODO:: Rewrite after high level refactor to return Eigen pair

computeN()

Eigen::MatrixXf krotos::SWIPE_PitchEstimation::computeN ( const Eigen::MatrixXf & ERBsDistrValues )

private

cumsum()

Eigen::MatrixXf krotos::SWIPE_PitchEstimation::cumsum ( const Eigen::MatrixXf & input )

private

fineTunePitch()

std::pair< Eigen::VectorXf, Eigen::VectorXf > krotos::SWIPE_PitchEstimation::fineTunePitch ( Eigen::MatrixXf globStrMatrix )

private

The pitch is fine-tuned using parabolic interpolation with a resolution of 1 cent

getERBsSubset()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::getERBsSubset ( const Eigen::VectorXf & pitchCandsSubset )

private

Used to compute loudness at ERBs uniformly-spaced frequencies.

getTimes()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::getTimes ( )

inline

Returns the vector of times at which the pitch was estimated.

Returns

vector of times

initVectors()

void krotos::SWIPE_PitchEstimation::initVectors

(

)

Initialize vectors for intermediate calculations. Called in the constructor after initial parameters have been setup.

pitchStrengthAllCandidates()

Eigen::MatrixXf krotos::SWIPE_PitchEstimation::pitchStrengthAllCandidates ( const Eigen::VectorXf & ERBs, Eigen::MatrixXf & ERBsDistrValues, const Eigen::VectorXf & pitchCands )

private

pitchStrengthOneCandidate()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::pitchStrengthOneCandidate ( const Eigen::VectorXf & ERBS, const Eigen::MatrixXf & normERBsDistrValues, float pitchCand )

private

polyfit()

Eigen::VectorXf krotos::SWIPE_PitchEstimation::polyfit ( const Eigen::VectorXf & x, const Eigen::VectorXf & y, int n )

private

Polynomial curve fitting.

Parameters

x	Query points.These correspond to the fitted function values contained in y
y	Fitted values at query points. The values in y correspond to the query points contained in x
n	Degree of polynomial fit

Returns

Coefficients for a polynomial p(x) of degree n that is a best fit (in a least-squares sense) for the data in y The coefficients in p are in descending powers, and the length of p is n+1

primes()

Eigen::VectorXi krotos::SWIPE_PitchEstimation::primes ( int n )

private

Vector/Linear algebra operations. TODO Move somewhere to be reused

selectCandidatesForWindowSize()

std::pair< Eigen::VectorXf, Eigen::VectorXf > krotos::SWIPE_PitchEstimation::selectCandidatesForWindowSize ( size_t winSizeIDx )

private

Select candidates that use a specific window size.

Member Data Documentation

m_ERBs

Eigen::VectorXf krotos::SWIPE_PitchEstimation::m_ERBs

private

m_ERBStep

float krotos::SWIPE_PitchEstimation::m_ERBStep {-1.0f}

private

m_log2DistWin1OptPitchAndPitchCands

Eigen::VectorXf krotos::SWIPE_PitchEstimation::m_log2DistWin1OptPitchAndPitchCands

private

m_log2PitchStep

float krotos::SWIPE_PitchEstimation::m_log2PitchStep {-1.0f}

private

m_normOverlap

float krotos::SWIPE_PitchEstimation::m_normOverlap {-1.0f}

private

m_pitchCands

Eigen::VectorXf krotos::SWIPE_PitchEstimation::m_pitchCands

private

m_pitchLims

Eigen::Vector2f krotos::SWIPE_PitchEstimation::m_pitchLims

private

The pitch is searched within the range m_pitchLims(in Hertz)

m_sampleRate

float krotos::SWIPE_PitchEstimation::m_sampleRate {-1.0f}

private

m_strenThresh

float krotos::SWIPE_PitchEstimation::m_strenThresh {-1.0f}

private

m_times

Eigen::VectorXf krotos::SWIPE_PitchEstimation::m_times

private

m_timeStep

float krotos::SWIPE_PitchEstimation::m_timeStep {-1.0f}

private

m_winSizes

Eigen::VectorXf krotos::SWIPE_PitchEstimation::m_winSizes

private

---

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

• krotos_dsp/utilities/analysis_modules/frequency_domain_analysis/SWIPE_PitchEstimation.h
• krotos_dsp/utilities/analysis_modules/frequency_domain_analysis/SWIPE_PitchEstimation.cpp