gistfile1.c

#include "kiss_fft.h"
#include "kiss_fftr.h"

#define FRAMES_PER_BUFFER 2048

kiss_fft_cpx freq_data[FRAMES_PER_BUFFER];
kiss_fft_scalar audio_data[FRAMES_PER_BUFFER];
kiss_fftr_cfg fft_cfg;


void init() {
	fft_cfg = kiss_fftr_alloc( FRAMES_PER_BUFFER , 0, 0, 0);
}

void audio_callback() {
	// Update audio_data, apply window if required?
	kiss_fftr(fft_cfg, audio_data, freq_data);
	// frequency data should be the magnitude (.r * .r + .i * .i) of freq_data[0 .. FRAMES_PER_BUFFER / 2] (where FRAMES_PER_BUFFER / 2 == nyquist frequency)
}