#ifndef _VAD_H

#define _VAD_H

#include <stdio.h>

/* TODO: add the needed states */

typedef enum {ST_UNDEF=0, ST_SILENCE, ST_VOICE, ST_INIT} VAD_STATE;

/* Return a string label associated to each state */

const char *state2str(VAD_STATE st);

/* TODO: add the variables needed to control the VAD

(counts, thresholds, etc.) */

typedef struct {

VAD_STATE state;

float sampling_rate;

unsigned int frame_length;

float last_feature; /* for debuggin purposes */

} VAD_DATA;

/* Call this function before using VAD:

It should return allocated and initialized values of vad_data

sampling_rate: ... the sampling rate */

VAD_DATA *vad_open(float sampling_rate);

/* vad works frame by frame.

This function returns the frame size so that the program knows how

many samples have to be provided */

unsigned int vad_frame_size(VAD_DATA *);

/* Main function. For each 'time', compute the new state

It returns:

ST_UNDEF (0) : undefined; it needs more frames to take decission

ST_SILENCE (1) : silence

ST_VOICE (2) : voice

x: input frame

It is assumed the length is frame_length */

VAD_STATE vad(VAD_DATA *vad_data, float *x);

/* Free memory

Returns the state of the last (undecided) states. */

VAD_STATE vad_close(VAD_DATA *vad_data);

/* Print actual state of vad, for debug purposes */

void vad_show_state(const VAD_DATA *, FILE *);

#endif