dspark::ChordDetector< T > Class Template Reference

Monophonic-buffer chord recognition with confidence gating. More...

#include <ChordDetector.h>

Classes
struct	Result
	One detection result. More...

Public Types
enum class	ChordType : uint8_t {   None = 0 , Major , Minor , Diminished ,   Augmented , Sus2 , Sus4 , Dominant7 ,   Major7 , Minor7 , HalfDim7 }
	Recognized chord families. More...

Public Member Functions
void	prepare (const AudioSpec &spec, int windowSize=4096)
	Prepares the analysis pipeline.
void	reset () noexcept
	Clears the analysis ring and forgets the held chord.
void	setConfidenceThreshold (float threshold) noexcept
	Confidence below which the previous chord is held (default 0.55).
float	getConfidenceThreshold () const noexcept
void	processBlock (AudioBufferView< const T > buffer) noexcept
	Feeds a block (channels averaged to mono).
void	pushSamples (std::span< const T > samples) noexcept
	Feeds mono samples directly.
Result	getChord () const noexcept

Static Public Member Functions
static int	getChordName (const Result &result, char *dest, int size) noexcept
	Writes a human-readable chord name ("C", "F#m7", "Bbsus4"...).

Detailed Description

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

Monophonic-buffer chord recognition with confidence gating.

Template Parameters

T	Sample type (float or double).

Definition at line 59 of file ChordDetector.h.

Member Enumeration Documentation

ChordType

template<FloatType T>

enum class dspark::ChordDetector::ChordType : uint8_t

strong

Recognized chord families.

Enumerator
None
Major
Minor
Diminished
Augmented
Sus2
Sus4
Dominant7
Major7
Minor7
HalfDim7

Definition at line 63 of file ChordDetector.h.

Member Function Documentation

getChord()

template<FloatType T>

Result dspark::ChordDetector< T >::getChord ( ) const

inlinenoexcept

Returns

The current (possibly held) chord.

Definition at line 176 of file ChordDetector.h.

getChordName()

template<FloatType T>

static int dspark::ChordDetector< T >::getChordName ( const Result &  result, char *  dest, int  size  )

inlinestaticnoexcept

Writes a human-readable chord name ("C", "F#m7", "Bbsus4"...).

Parameters

result	Chord to name.
dest	Destination buffer.
size	Capacity of dest (8+ recommended).

Returns

Number of characters written (excluding the terminator).

Definition at line 188 of file ChordDetector.h.

getConfidenceThreshold()

template<FloatType T>

float dspark::ChordDetector< T >::getConfidenceThreshold ( ) const

inlinenoexcept

Returns

The current confidence-gating threshold.

Definition at line 140 of file ChordDetector.h.

prepare()

template<FloatType T>

void dspark::ChordDetector< T >::prepare ( const AudioSpec &  spec, int  windowSize = 4096  )

inline

Prepares the analysis pipeline.

Parameters

spec	Audio environment specification.
windowSize	Analysis window (default 4096: ~85 ms at 48 kHz).

Definition at line 84 of file ChordDetector.h.

processBlock()

template<FloatType T>

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

inlinenoexcept

Feeds a block (channels averaged to mono).

Definition at line 148 of file ChordDetector.h.

pushSamples()

template<FloatType T>

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

inlinenoexcept

Feeds mono samples directly.

Definition at line 166 of file ChordDetector.h.

reset()

template<FloatType T>

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

inlinenoexcept

Clears the analysis ring and forgets the held chord.

Allocation-free, but it rewrites the stream state: call it from the thread that owns the stream (or while processing is stopped), not concurrently with processBlock()/pushSamples().

Definition at line 118 of file ChordDetector.h.

setConfidenceThreshold()

template<FloatType T>

void dspark::ChordDetector< T >::setConfidenceThreshold ( float  threshold )

inlinenoexcept

Confidence below which the previous chord is held (default 0.55).

Callable from any thread. Non-finite values are ignored (a NaN would make every comparison false and freeze the detector on the held chord forever).

Definition at line 133 of file ChordDetector.h.

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

• Music/ChordDetector.h