tone_detect.h File Reference

Go to the source code of this file.

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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