mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-13 10:44:59 +00:00
96d616052b
* commit 'd12b5b2f135aade4099f4b26b0fe678656158c13': build: Split test programs off into separate files Some conversions done by: James Almer <jamrial@gmail.com> Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
|
|
* linear least squares model
|
|
*
|
|
* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* linear least squares model
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include <string.h>
|
|
|
|
#include "attributes.h"
|
|
#include "internal.h"
|
|
#include "version.h"
|
|
#include "lls.h"
|
|
|
|
static void update_lls(LLSModel *m, const double *var)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i <= m->indep_count; i++) {
|
|
for (j = i; j <= m->indep_count; j++) {
|
|
m->covariance[i][j] += var[i] * var[j];
|
|
}
|
|
}
|
|
}
|
|
|
|
void avpriv_solve_lls(LLSModel *m, double threshold, unsigned short min_order)
|
|
{
|
|
int i, j, k;
|
|
double (*factor)[MAX_VARS_ALIGN] = (void *) &m->covariance[1][0];
|
|
double (*covar) [MAX_VARS_ALIGN] = (void *) &m->covariance[1][1];
|
|
double *covar_y = m->covariance[0];
|
|
int count = m->indep_count;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
for (j = i; j < count; j++) {
|
|
double sum = covar[i][j];
|
|
|
|
for (k = 0; k <= i-1; k++)
|
|
sum -= factor[i][k] * factor[j][k];
|
|
|
|
if (i == j) {
|
|
if (sum < threshold)
|
|
sum = 1.0;
|
|
factor[i][i] = sqrt(sum);
|
|
} else {
|
|
factor[j][i] = sum / factor[i][i];
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
double sum = covar_y[i + 1];
|
|
|
|
for (k = 0; k <= i-1; k++)
|
|
sum -= factor[i][k] * m->coeff[0][k];
|
|
|
|
m->coeff[0][i] = sum / factor[i][i];
|
|
}
|
|
|
|
for (j = count - 1; j >= min_order; j--) {
|
|
for (i = j; i >= 0; i--) {
|
|
double sum = m->coeff[0][i];
|
|
|
|
for (k = i + 1; k <= j; k++)
|
|
sum -= factor[k][i] * m->coeff[j][k];
|
|
|
|
m->coeff[j][i] = sum / factor[i][i];
|
|
}
|
|
|
|
m->variance[j] = covar_y[0];
|
|
|
|
for (i = 0; i <= j; i++) {
|
|
double sum = m->coeff[j][i] * covar[i][i] - 2 * covar_y[i + 1];
|
|
|
|
for (k = 0; k < i; k++)
|
|
sum += 2 * m->coeff[j][k] * covar[k][i];
|
|
|
|
m->variance[j] += m->coeff[j][i] * sum;
|
|
}
|
|
}
|
|
}
|
|
|
|
static double evaluate_lls(LLSModel *m, const double *param, int order)
|
|
{
|
|
int i;
|
|
double out = 0;
|
|
|
|
for (i = 0; i <= order; i++)
|
|
out += param[i] * m->coeff[order][i];
|
|
|
|
return out;
|
|
}
|
|
|
|
av_cold void avpriv_init_lls(LLSModel *m, int indep_count)
|
|
{
|
|
memset(m, 0, sizeof(LLSModel));
|
|
m->indep_count = indep_count;
|
|
m->update_lls = update_lls;
|
|
m->evaluate_lls = evaluate_lls;
|
|
if (ARCH_X86)
|
|
ff_init_lls_x86(m);
|
|
}
|