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/*
* moosynth.c
*
* Work out how to synthesize a cow
*
* (c) 2008 Thomas White <taw27@srcf.ucam.org>
*
* This file is part of OpenMooCow - accelerometer moobox simulator
*
* OpenMooCow is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OpenMooCow is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenMooCow. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fftw3.h>
#include <math.h>
int main(int argc, char *argv[]) {
FILE *fh;
double *data;
fftw_complex *ft;
struct stat statbuf;
fftw_plan plan;
int samples;
int16_t *sdata;
int i, max_fq, c;
double max_am, next_max_am, max_ph;
const int ncomp = 20;
int components[ncomp];
if ( argc != 2 ) {
fprintf(stderr, "Syntax: %s <file.pcm>\n", argv[0]);
return 1;
}
/* Determine size of data */
if ( stat(argv[1], &statbuf) == -1 ) {
fprintf(stderr, "Couldn't stat file '%s'\n", argv[1]);
return 1;
}
samples = statbuf.st_size/2; /* Two bytes per sample, one channel */
printf("File size: %lli bytes\n", (long long int)statbuf.st_size);
/* Read the data in */
fh = fopen(argv[1], "rb");
if ( fh == NULL ) {
fprintf(stderr, "Couldn't open file '%s'\n", argv[1]);
return 1;
}
sdata = malloc(samples*2);
fread(sdata, 2, samples, fh);
fclose(fh);
data = fftw_malloc(samples*sizeof(double));
ft = fftw_malloc(samples*sizeof(fftw_complex));
for ( i=0; i<samples; i++ ) {
data[i] = sdata[i];
}
plan = fftw_plan_dft_r2c_1d(samples, data, ft, FFTW_ESTIMATE);
fftw_execute(plan);
printf("DC component: %f %f\n", ft[0][0], ft[0][1]);
next_max_am = +1000000000.0;
for ( c=0; c<ncomp-1; c++ ) {
max_am = 0.0;
max_ph = 0.0;
max_fq = 0;
for ( i=1; i<samples/2; i++ ) {
double re, im, am, ph;
re = ft[i][0];
im = ft[i][1];
am = sqrt(re*re + im*im);
ph = atan2(im, re);
// printf("Frequency: %i Hz : %f %f\n", (44100/samples)*i, am, 180*(ph/M_PI));
if ( (am > max_am) && (am < next_max_am) ) {
max_am = am;
max_fq = i;
max_ph = ph;
}
}
printf("%2i %6i Hz %14.2f %+7.1f\n", c+1, (44100/samples)*max_fq, max_am, 180*(max_ph/M_PI));
components[c] = max_fq;
next_max_am = max_am;
}
for ( i=0; i<samples/2; i++ ) {
int c;
int found = 0;
for ( c=0; c<ncomp-1; c++ ) {
if ( components[c] == i ) found = 1;
}
if ( !found ) {
ft[i][0] = 0.0;
ft[i][1] = 0.0;
}
}
plan = fftw_plan_dft_c2r_1d(samples, ft, data, FFTW_ESTIMATE);
fftw_execute(plan);
for ( i=0; i<samples; i++ ) {
sdata[i] = (data[i])/(samples*2);
}
fh = fopen("filtered.pcm", "wb");
fwrite(sdata, 2, samples, fh);
fclose(fh);
return 0;
}
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