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/*
* Copyright (C) 2012 Jamie Bullock
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#include "xtract/libxtract.h"
#include <stdio.h>
#include <stdlib.h>
#define BLOCKSIZE 1024
#define SAMPLERATE 44100
#define PERIOD 100
#define MFCC_FREQ_BANDS 13
#define MFCC_FREQ_MIN 20
#define MFCC_FREQ_MAX 20000
int main(void)
{
float mean = 0.f;
float input[BLOCKSIZE];
float spectrum[BLOCKSIZE];
float mfccs[MFCC_FREQ_BANDS * sizeof(float)];
float argf[4];
int n;
xtract_mel_filter mel_filters;
/* fill the input array with a sawtooth wave */
for(n = 0; n < BLOCKSIZE; ++n)
{
input[n] = ((n % PERIOD) / (float)PERIOD) - .5;
}
/* get the mean of the input */
xtract[XTRACT_MEAN]((void *)&input, BLOCKSIZE, NULL, (void *)&mean);
printf("\nInput mean = %.2f\n\n", mean);
/* get the spectrum */
argf[0] = SAMPLERATE / (float)BLOCKSIZE;
argf[1] = XTRACT_MAGNITUDE_SPECTRUM;
argf[2] = 0.f; /* No DC component */
argf[3] = 0.f; /* No Normalisation */
xtract_init_fft(BLOCKSIZE, XTRACT_SPECTRUM);
xtract[XTRACT_SPECTRUM]((void *)&input, BLOCKSIZE, &argf[0], (void *)&spectrum[0]);
/* print the spectral bins */
printf("\nSpectral bins:\n");
for(n = 0; n < (BLOCKSIZE >> 1); ++n){
printf("freq: %.1f\tamp: %.6f\n", spectrum[n + (BLOCKSIZE >> 1)], spectrum[n]);
}
printf("\n");
/* compute the MFCCs */
mel_filters.n_filters = MFCC_FREQ_BANDS;
mel_filters.filters = malloc(MFCC_FREQ_BANDS * sizeof(float *));
for(n = 0; n < MFCC_FREQ_BANDS; ++n)
{
mel_filters.filters[n] = malloc(BLOCKSIZE * sizeof(float));
}
xtract_init_mfcc(BLOCKSIZE >> 1, SAMPLERATE >> 1, XTRACT_EQUAL_GAIN, MFCC_FREQ_MIN, MFCC_FREQ_MAX, mel_filters.n_filters, mel_filters.filters);
xtract_mfcc(spectrum, BLOCKSIZE >> 1, &mel_filters, mfccs);
/* print the MFCCs */
printf("MFCCs:\n");
for(n = 0; n < MFCC_FREQ_BANDS; ++n)
{
printf("band: %d\t", n);
if(n < 10) {
printf("\t");
}
printf("coeff: %f\n", mfccs[n]);
}
/* cleanup */
for(n = 0; n < MFCC_FREQ_BANDS; ++n)
{
free(mel_filters.filters[n]);
}
free(mel_filters.filters);
return 0;
}
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