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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /media/ffvpx/libavutil/lls.c | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavutil/lls.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/lls.c b/media/ffvpx/libavutil/lls.c new file mode 100644 index 0000000000..c1e038daf1 --- /dev/null +++ b/media/ffvpx/libavutil/lls.c @@ -0,0 +1,123 @@ +/* + * 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 "config.h" +#include "attributes.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); +#endif +} |