tone_detect.h File Reference

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Classes
struct	goertzel_descriptor_t
struct	goertzel_state_t
Functions
void	make_goertzel_descriptor (goertzel_descriptor_t *t, float freq, int samples)
	Create a descriptor for use with either a Goertzel transform.
goertzel_state_t *	goertzel_init (goertzel_state_t *s, goertzel_descriptor_t *t)
	Initialise the state of a Goertzel transform.
void	goertzel_reset (goertzel_state_t *s)
	Reset the state of a Goertzel transform.
int	goertzel_update (goertzel_state_t *s, const int16_t amp[], int samples)
	Update the state of a Goertzel transform.
float	goertzel_result (goertzel_state_t *s)
	Evaluate the final result of a Goertzel transform.

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Detailed Description

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Function Documentation

goertzel_state_t* goertzel_init (  goertzel_state_t *  s, goertzel_descriptor_t *  t )

Initialise the state of a Goertzel transform. Parameters: s  The Goertzel context. If NULL, a context is allocated with malloc. t  The Goertzel descriptor. Returns: A pointer to the Goertzel state.

void goertzel_reset (  goertzel_state_t *  s  )

Reset the state of a Goertzel transform. Parameters: s  The Goertzel context. t  The Goertzel descriptor. Returns: A pointer to the Goertzel state.

float goertzel_result (  goertzel_state_t *  s  )

Evaluate the final result of a Goertzel transform. Parameters: s  The Goertzel context Returns: The result of the transform.

int goertzel_update (  goertzel_state_t *  s, const int16_t  amp[], int  samples )

Update the state of a Goertzel transform. Parameters: s  The Goertzel context amp  The samples to be transformed samples  The number of samples Returns: The number of samples unprocessed

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