GoertzelDetector Class Reference

Single-frequency Goertzel algorithm implementation for tone detection. The Goertzel algorithm is an efficient way to compute the magnitude of a specific frequency component in a signal. It's particularly useful for DTMF (touch-tone) detection and other single-frequency detection applications. More...

#include <GoerzelStream.h>

Public Member Functions
bool	begin (const GoertzelConfig &config)
	Initialize the Goertzel detector with configuration.
int	getBlockSize () const
	Get the block size.
const GoertzelConfig &	getConfig () const
	Get the current configuration.
float	getMagnitude () const
	Get the magnitude of the detected frequency.
float	getMagnitudeSquared () const
	Get the squared magnitude (more efficient if you don't need the actual magnitude)
void *	getReference ()
float	getTargetFrequency () const
	Get the target frequency.
bool	isDetected () const
	Check if the detected magnitude is above the configured threshold.
bool	isDetected (float threshold) const
	Check if the detected magnitude is above a threshold.
bool	processSample (float sample)
	Process a single sample.
void	reset ()
	Reset the detector state.
void	setReference (void *ref)

Protected Attributes
float	coeff = 0.0f
GoertzelConfig	config
float	magnitude = 0.0f
float	magnitude_squared = 0.0f
void *	reference = nullptr
float	s1 = 0.0f
float	s2 = 0.0f
int	sample_count = 0

Detailed Description

Single-frequency Goertzel algorithm implementation for tone detection. The Goertzel algorithm is an efficient way to compute the magnitude of a specific frequency component in a signal. It's particularly useful for DTMF (touch-tone) detection and other single-frequency detection applications.

This implementation expects normalized float samples in the range [-1.0, 1.0]. For different sample formats, use GoertzelStream which handles format conversion.

Author

pschatzmann

Copyright

GPLv3

Member Function Documentation

begin()

bool begin ( const GoertzelConfig &  config )

inline

Initialize the Goertzel detector with configuration.

Parameters

config

GoertzelConfig containing all parameters

getMagnitude()

float getMagnitude ( ) const

inline

Get the magnitude of the detected frequency.

Returns

Magnitude value

getMagnitudeSquared()

float getMagnitudeSquared ( ) const

inline

Get the squared magnitude (more efficient if you don't need the actual magnitude)

Returns

Squared magnitude value

isDetected() [1/2]

bool isDetected ( ) const

inline

Check if the detected magnitude is above the configured threshold.

Returns

True if magnitude is above configured threshold

isDetected() [2/2]

bool isDetected ( float  threshold ) const

inline

Check if the detected magnitude is above a threshold.

Parameters

threshold

Threshold value

Returns

True if magnitude is above threshold

processSample()

bool processSample ( float  sample )

inline

Process a single sample.

Parameters

sample

Input sample (normalized float in range [-1.0, 1.0])

Returns

True if block is complete and magnitude is available

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

• src/AudioTools/CoreAudio/GoerzelStream.h