X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Flls.c;h=bbcab6cf9fbb774076bf323326decdd05a45cc60;hb=0b311293891e44b8cb7c0a1f50f456ecd2e5d0d8;hp=aa9467dcee118f95a5e8e018b899699ef9e47303;hpb=b78e7197a81e193827cf2408fe25bc1f14843a72;p=ffmpeg diff --git a/libavutil/lls.c b/libavutil/lls.c index aa9467dcee1..bbcab6cf9fb 100644 --- a/libavutil/lls.c +++ b/libavutil/lls.c @@ -3,146 +3,170 @@ * * Copyright (c) 2006 Michael Niedermayer * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav 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, + * Libav 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 St, Fifth Floor, Boston, MA 02110-1301 USA + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** - * @file lls.c + * @file * linear least squares model */ #include #include +#include "version.h" #include "lls.h" -#ifdef TEST -#define av_log(a,b,...) printf(__VA_ARGS__) -#endif - -void av_init_lls(LLSModel *m, int indep_count){ +void avpriv_init_lls(LLSModel *m, int indep_count) +{ memset(m, 0, sizeof(LLSModel)); - - m->indep_count= indep_count; + m->indep_count = indep_count; } -void av_update_lls(LLSModel *m, double *var, double decay){ - int i,j; +void avpriv_update_lls(LLSModel *m, double *var, double decay) +{ + int i, j; - for(i=0; i<=m->indep_count; i++){ - for(j=i; j<=m->indep_count; j++){ + for (i = 0; i <= m->indep_count; i++) { + for (j = i; j <= m->indep_count; j++) { m->covariance[i][j] *= decay; - m->covariance[i][j] += var[i]*var[j]; + m->covariance[i][j] += var[i] * var[j]; } } } -void av_solve_lls(LLSModel *m, double threshold, int min_order){ - int i,j,k; - double (*factor)[MAX_VARS+1]= &m->covariance[1][0]; - double (*covar )[MAX_VARS+1]= &m->covariance[1][1]; - double *covar_y = m->covariance[0]; - int count= m->indep_count; - - for(i=0; i=0; 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]; +void avpriv_solve_lls(LLSModel *m, double threshold, unsigned short min_order) +{ + int i, j, k; + double (*factor)[MAX_VARS + 1] = (void *) &m->covariance[1][0]; + double (*covar) [MAX_VARS + 1] = (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 = i - 1; k >= 0; 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=0; k--) - sum -= factor[i][k]*m->coeff[0][k]; - m->coeff[0][i]= sum / factor[i][i]; + + for (i = 0; i < count; i++) { + double sum = covar_y[i + 1]; + + for (k = i - 1; k >= 0; 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]; + 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; kcoeff[j][k]*covar[k][i]; - m->variance[j] += m->coeff[j][i]*sum; + 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; } } } -double av_evaluate_lls(LLSModel *m, double *param, int order){ +double avpriv_evaluate_lls(LLSModel *m, double *param, int order) +{ int i; - double out= 0; + double out = 0; - for(i=0; i<=order; i++) - out+= param[i]*m->coeff[order][i]; + for (i = 0; i <= order; i++) + out += param[i] * m->coeff[order][i]; return out; } +#if FF_API_LLS_PRIVATE +void av_init_lls(LLSModel *m, int indep_count) +{ + avpriv_init_lls(m, indep_count); +} +void av_update_lls(LLSModel *m, double *param, double decay) +{ + avpriv_update_lls(m, param, decay); +} +void av_solve_lls(LLSModel *m, double threshold, int min_order) +{ + avpriv_solve_lls(m, threshold, min_order); +} +double av_evaluate_lls(LLSModel *m, double *param, int order) +{ + return avpriv_evaluate_lls(m, param, order); +} +#endif /* FF_API_LLS_PRIVATE */ + #ifdef TEST -#include #include +#include +#include "lfg.h" -int main(){ +int main(void) +{ LLSModel m; int i, order; + AVLFG lfg; - av_init_lls(&m, 3); + av_lfg_init(&lfg, 1); + avpriv_init_lls(&m, 3); - for(i=0; i<100; i++){ + for (i = 0; i < 100; i++) { double var[4]; - double eval, variance; -#if 0 - var[1] = rand() / (double)RAND_MAX; - var[2] = rand() / (double)RAND_MAX; - var[3] = rand() / (double)RAND_MAX; - - var[2]= var[1] + var[3]/2; - - var[0] = var[1] + var[2] + var[3] + var[1]*var[2]/100; -#else - var[0] = (rand() / (double)RAND_MAX - 0.5)*2; - var[1] = var[0] + rand() / (double)RAND_MAX - 0.5; - var[2] = var[1] + rand() / (double)RAND_MAX - 0.5; - var[3] = var[2] + rand() / (double)RAND_MAX - 0.5; -#endif - av_update_lls(&m, var, 0.99); - av_solve_lls(&m, 0.001, 0); - for(order=0; order<3; order++){ - eval= av_evaluate_lls(&m, var+1, order); - av_log(NULL, AV_LOG_DEBUG, "real:%f order:%d pred:%f var:%f coeffs:%f %f %f\n", - var[0], order, eval, sqrt(m.variance[order] / (i+1)), - m.coeff[order][0], m.coeff[order][1], m.coeff[order][2]); + double eval; + + var[0] = (av_lfg_get(&lfg) / (double) UINT_MAX - 0.5) * 2; + var[1] = var[0] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5; + var[2] = var[1] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5; + var[3] = var[2] + av_lfg_get(&lfg) / (double) UINT_MAX - 0.5; + avpriv_update_lls(&m, var, 0.99); + avpriv_solve_lls(&m, 0.001, 0); + for (order = 0; order < 3; order++) { + eval = avpriv_evaluate_lls(&m, var + 1, order); + printf("real:%9f order:%d pred:%9f var:%f coeffs:%f %9f %9f\n", + var[0], order, eval, sqrt(m.variance[order] / (i + 1)), + m.coeff[order][0], m.coeff[order][1], + m.coeff[order][2]); } } return 0;