Gated, octave-safe, semitone-smoothed pitch tracking source. More...

#include <PitchFollower.h>

Public Member Functions
void	prepare (const AudioSpec &spec, int windowSize=0)
	Prepares the follower and the wrapped detector.

void	reset () noexcept
	Forgets the tracked pitch (parameters are kept). Allocation-free; call from the stream owner (it touches the same plain tracking state update() writes).

void	setRange (T minHz, T maxHz) noexcept
	Accepted pitch range in Hz (default 60 to 1200). Non-finite values are ignored (the old max() passed NaN through and closed the validity gate forever).

void	setConfidence (T threshold) noexcept
	Confidence threshold [0, 1] below which readings are ignored (default 0.85).

void	setGlide (T msPerOctave) noexcept
	Glide time in milliseconds per octave (default 60). 0 disables smoothing (the output snaps to each accepted reading). Non-finite values are ignored.

T	getMinHz () const noexcept
	Returns the lower bound of the accepted pitch range in Hz.

T	getMaxHz () const noexcept
	Returns the upper bound of the accepted pitch range in Hz.

T	getConfidenceThreshold () const noexcept
	Returns the confidence gating threshold [0, 1].

T	getGlide () const noexcept
	Returns the glide time in milliseconds per octave.

int	getWindowSize () const noexcept

T	getSmoothedHz () const noexcept

T	getRawHz () const noexcept

T	getConfidence () const noexcept

bool	isTracking () const noexcept

void	processBlock (AudioBufferView< const T > buffer) noexcept
	Feeds a block (any channel count); channels are averaged to mono.

void	pushSamples (std::span< const T > samples) noexcept
	Feeds mono samples directly (alternative to processBlock).

Detailed Description

template<FloatType T>
class dspark::PitchFollower< T >

Gated, octave-safe, semitone-smoothed pitch tracking source.

Template Parameters

T	Sample type (float or double).

Definition at line 75 of file PitchFollower.h.

Member Function Documentation

◆ getConfidence()

template<FloatType T>

T dspark::PitchFollower< T >::getConfidence ( ) const

inlinenoexcept

Returns: Detector confidence of the last raw reading [0, 1].

Definition at line 195 of file PitchFollower.h.

◆ getConfidenceThreshold()

template<FloatType T>

T dspark::PitchFollower< T >::getConfidenceThreshold ( ) const

inlinenoexcept

Returns the confidence gating threshold [0, 1].

Definition at line 172 of file PitchFollower.h.

◆ getGlide()

template<FloatType T>

T dspark::PitchFollower< T >::getGlide ( ) const

inlinenoexcept

Returns the glide time in milliseconds per octave.

Definition at line 175 of file PitchFollower.h.

◆ getMaxHz()

template<FloatType T>

T dspark::PitchFollower< T >::getMaxHz ( ) const

inlinenoexcept

Returns the upper bound of the accepted pitch range in Hz.

Definition at line 169 of file PitchFollower.h.

◆ getMinHz()

template<FloatType T>

T dspark::PitchFollower< T >::getMinHz ( ) const

inlinenoexcept

Returns the lower bound of the accepted pitch range in Hz.

Definition at line 166 of file PitchFollower.h.

◆ getRawHz()

template<FloatType T>

T dspark::PitchFollower< T >::getRawHz ( ) const

inlinenoexcept

Returns: Last raw detector reading in Hz (ungated - may be garbage).

Definition at line 192 of file PitchFollower.h.

◆ getSmoothedHz()

template<FloatType T>

T dspark::PitchFollower< T >::getSmoothedHz ( ) const

inlinenoexcept

Returns: Smoothed pitch in Hz; 0 until the first reliable reading.

Definition at line 186 of file PitchFollower.h.

◆ getWindowSize()

template<FloatType T>

int dspark::PitchFollower< T >::getWindowSize ( ) const

inlinenoexcept

Returns: The wrapped detector's analysis window in samples (the automatic choice unless prepare() was given an explicit one). The lowest trackable fundamental is sampleRate/(getWindowSize()/2 - 1).

Definition at line 181 of file PitchFollower.h.

◆ isTracking()

template<FloatType T>

bool dspark::PitchFollower< T >::isTracking ( ) const

inlinenoexcept

Returns: True while reliable readings arrived within the last 250 ms.

Definition at line 198 of file PitchFollower.h.

◆ prepare()

template<FloatType T>

void dspark::PitchFollower< T >::prepare	(	const AudioSpec &	spec,
		int	windowSize = `0`
	)

inline

Prepares the follower and the wrapped detector.

An invalid spec (non-finite or non-positive fields) is ignored, keeping the previous state.

Parameters

spec	Audio environment specification.
windowSize	Detector analysis window. Values <= 0 (the default) select PitchDetector's AUTOMATIC window: 2048 at 44.1/48 kHz, 4096 at 88.2/96 kHz, 8192 at 176.4/192 kHz. Explicit positive values are forwarded as given (with a hop of windowSize/4).

The tracked register is the detector's: the lowest reachable fundamental is sampleRate/(windowSize/2 - 1), so it depends on the RATIO, never on the count. The automatic window is good down to ~47 Hz at every rate from 44.1 to 192 kHz. A fixed 2048-sample window would instead stop at ~94 Hz at 96 kHz and ~188 Hz at 192 kHz: measured, a 55 Hz or 82 Hz sawtooth then never leaves getSmoothedHz() at 0 and isTracking() stays false, whatever setRange() says – the range gate cannot widen a register the detector cannot reach. For a lower floor pass an explicit window (doubling it halves the floor and doubles the analysis latency).

Definition at line 103 of file PitchFollower.h.

◆ processBlock()

template<FloatType T>

void dspark::PitchFollower< T >::processBlock ( AudioBufferView< const T > buffer )

inlinenoexcept

Feeds a block (any channel count); channels are averaged to mono.

Parameters

buffer Read-only audio block.

Definition at line 209 of file PitchFollower.h.

◆ pushSamples()

template<FloatType T>

void dspark::PitchFollower< T >::pushSamples ( std::span< const T > samples )

inlinenoexcept

Feeds mono samples directly (alternative to processBlock).

Parameters

samples Mono audio span.

Definition at line 245 of file PitchFollower.h.

◆ reset()

template<FloatType T>

void dspark::PitchFollower< T >::reset ( )

inlinenoexcept

Forgets the tracked pitch (parameters are kept). Allocation-free; call from the stream owner (it touches the same plain tracking state update() writes).

Definition at line 119 of file PitchFollower.h.

◆ setConfidence()

template<FloatType T>

void dspark::PitchFollower< T >::setConfidence ( T threshold )

inlinenoexcept

Confidence threshold [0, 1] below which readings are ignored (default 0.85).

Definition at line 148 of file PitchFollower.h.

◆ setGlide()

template<FloatType T>

void dspark::PitchFollower< T >::setGlide ( T msPerOctave )

inlinenoexcept

Glide time in milliseconds per octave (default 60). 0 disables smoothing (the output snaps to each accepted reading). Non-finite values are ignored.

Definition at line 159 of file PitchFollower.h.

◆ setRange()

template<FloatType T>

void dspark::PitchFollower< T >::setRange	(	T	minHz,
		T	maxHz
	)

inlinenoexcept

Accepted pitch range in Hz (default 60 to 1200). Non-finite values are ignored (the old max() passed NaN through and closed the validity gate forever).

Definition at line 138 of file PitchFollower.h.

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

PitchFollower.h

Public Member Functions

Detailed Description

Member Function Documentation

◆ getConfidence()

◆ getConfidenceThreshold()

◆ getGlide()

◆ getMaxHz()

◆ getMinHz()

◆ getRawHz()

◆ getSmoothedHz()

◆ getWindowSize()

◆ isTracking()

◆ prepare()

◆ processBlock()

◆ pushSamples()

◆ reset()

◆ setConfidence()

◆ setGlide()

◆ setRange()