#include “speex/speex_preprocess.h”

#define MAX_FRAME_SIZE 2000

int denoise_enabled = 1;
int agc_enabled = 1;
SpeexPreprocessState *preprocess = NULL;
Short input[MAX_FRAME_SIZE];
spx_int32_t frame_size;
bool moreFrames = true;

preprocess = speex_preprocess_state_init(frame_size, rate);
speex_preprocess_ctl(preprocess, SPEEX_PREPROCESS_SET_DENOISE, &denoise_enabled);
speex_preprocess_ctl(preprocess, SPEEX_PREPROCESS_SET_AGC, &agc_enabled);

while(moreFrames)
{
	//...
	speex_preprocess(preprocess, input_frame, NULL);
	//...
}