FFmpeg
lls.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <limits.h>
20 #include <stdio.h>
21 
22 #include "libavutil/internal.h"
23 #include "libavutil/lfg.h"
24 #include "libavutil/lls.h"
25 
26 int main(void)
27 {
28  LLSModel m;
29  int i, order;
30  AVLFG lfg;
31 
32  av_lfg_init(&lfg, 1);
33  avpriv_init_lls(&m, 3);
34 
35  for (i = 0; i < 100; i++) {
36  LOCAL_ALIGNED(32, double, var, [4]);
37  double eval;
38 
39  var[0] = (av_lfg_get(&lfg) / (double) UINT_MAX - 0.5) * 2;
40  var[1] = var[0] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5;
41  var[2] = var[1] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5;
42  var[3] = var[2] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5;
43  m.update_lls(&m, var);
44  avpriv_solve_lls(&m, 0.001, 0);
45  for (order = 0; order < 3; order++) {
46  eval = m.evaluate_lls(&m, var + 1, order);
47  printf("real:%9f order:%d pred:%9f var:%f coeffs:%f %9f %9f\n",
48  var[0], order, eval, sqrt(m.variance[order] / (i + 1)),
49  m.coeff[order][0], m.coeff[order][1],
50  m.coeff[order][2]);
51  }
52  }
53  return 0;
54 }
Context structure for the Lagged Fibonacci PRNG.
Definition: lfg.h:33
Linear least squares model.
Definition: lls.h:38
double variance[MAX_VARS]
Definition: lls.h:41
int main(void)
Definition: lls.c:26
double(* evaluate_lls)(struct LLSModel *m, const double *var, int order)
Inner product of var[] and the LPC coefs.
Definition: lls.h:57
av_cold void avpriv_init_lls(LLSModel *m, int indep_count)
Definition: lls.c:115
common internal API header
void avpriv_solve_lls(LLSModel *m, double threshold, unsigned short min_order)
Definition: lls.c:47
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:53
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
void(* update_lls)(struct LLSModel *m, const double *var)
Take the outer-product of var[] with itself, and add to the covariance matrix.
Definition: lls.h:50
double coeff[32][32]
Definition: lls.h:40
#define LOCAL_ALIGNED(a, t, v,...)
Definition: internal.h:114
printf("static const uint8_t my_array[100] = {\n")
int i
Definition: input.c:406