/*
* Copyright (C) 2007 Vitor Sessak <vitor1001@gmail.com>
*
- * 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file cbook_gen.c
+ * @file
* Codebook Generator using the ELBG algorithm
*/
#include <string.h>
-#include "libavutil/random.h"
+#include "libavutil/lfg.h"
#include "elbg.h"
#include "avcodec.h"
int *utility_inc;
int *nearest_cb;
int *points;
- AVRandomState *rand_state;
+ AVLFG *rand_state;
+ int *scratchbuf;
} elbg_data;
static inline int distance_limited(int *a, int *b, int dim, int limit)
{
int i=0;
/* Using linear search, do binary if it ever turns to be speed critical */
- int r = av_random(elbg->rand_state)%(elbg->utility_inc[elbg->numCB-1]-1) + 1;
+ int r = av_lfg_get(elbg->rand_state)%elbg->utility_inc[elbg->numCB-1] + 1;
while (elbg->utility_inc[i] < r)
i++;
/**
* Implementation of the simple LBG algorithm for just two codebooks
*/
-static int simple_lbg(int dim,
+static int simple_lbg(elbg_data *elbg,
+ int dim,
int *centroid[3],
int newutility[3],
int *points,
{
int i, idx;
int numpoints[2] = {0,0};
- int newcentroid[2][dim];
+ int *newcentroid[2] = {
+ elbg->scratchbuf + 3*dim,
+ elbg->scratchbuf + 4*dim
+ };
cell *tempcell;
- memset(newcentroid, 0, sizeof(newcentroid));
+ memset(newcentroid[0], 0, 2 * dim * sizeof(*newcentroid[0]));
newutility[0] =
newutility[1] = 0;
int *newcentroid_p)
{
cell *tempcell;
- int min[elbg->dim];
- int max[elbg->dim];
+ int *min = newcentroid_i;
+ int *max = newcentroid_p;
int i;
for (i=0; i< elbg->dim; i++) {
}
for (i=0; i<elbg->dim; i++) {
- newcentroid_i[i] = min[i] + (max[i] - min[i])/3;
- newcentroid_p[i] = min[i] + (2*(max[i] - min[i]))/3;
+ int ni = min[i] + (max[i] - min[i])/3;
+ int np = min[i] + (2*(max[i] - min[i]))/3;
+ newcentroid_i[i] = ni;
+ newcentroid_p[i] = np;
}
}
* and update elbg->error, elbg->utility and elbg->nearest_cb.
*
* @param elbg Internal elbg data
- * @param indexes {luc (low utility cell, huc (high utility cell), cluc (closest cell to low utility cell)}
+ * @param idx {luc (low utility cell, huc (high utility cell), cluc (closest cell to low utility cell)}
*/
static void try_shift_candidate(elbg_data *elbg, int idx[3])
{
int j, k, olderror=0, newerror, cont=0;
int newutility[3];
- int newcentroid[3][elbg->dim];
- int *newcentroid_ptrs[3];
+ int *newcentroid[3] = {
+ elbg->scratchbuf,
+ elbg->scratchbuf + elbg->dim,
+ elbg->scratchbuf + 2*elbg->dim
+ };
cell *tempcell;
- newcentroid_ptrs[0] = newcentroid[0];
- newcentroid_ptrs[1] = newcentroid[1];
- newcentroid_ptrs[2] = newcentroid[2];
-
for (j=0; j<3; j++)
olderror += elbg->utility[idx[j]];
newerror = newutility[2];
- newerror += simple_lbg(elbg->dim, newcentroid_ptrs, newutility, elbg->points,
+ newerror += simple_lbg(elbg, elbg->dim, newcentroid, newutility, elbg->points,
elbg->cells[idx[1]]);
if (olderror > newerror) {
- shift_codebook(elbg, idx, newcentroid_ptrs);
+ shift_codebook(elbg, idx, newcentroid);
elbg->error += newerror - olderror;
if (elbg->utility_inc[elbg->numCB-1] == 0)
return;
+ idx[1] = get_high_utility_cell(elbg);
idx[2] = get_closest_codebook(elbg, idx[0]);
- do {
- idx[1] = get_high_utility_cell(elbg);
- } while (idx[1] == idx[0] || idx[1] == idx[2]);
- try_shift_candidate(elbg, idx);
+ if (idx[1] != idx[0] && idx[1] != idx[2])
+ try_shift_candidate(elbg, idx);
}
}
void ff_init_elbg(int *points, int dim, int numpoints, int *codebook,
int numCB, int max_steps, int *closest_cb,
- AVRandomState *rand_state)
+ AVLFG *rand_state)
{
int i, k;
void ff_do_elbg(int *points, int dim, int numpoints, int *codebook,
int numCB, int max_steps, int *closest_cb,
- AVRandomState *rand_state)
+ AVLFG *rand_state)
{
int dist;
elbg_data elbg_d;
int *size_part = av_malloc(numCB*sizeof(int));
cell *list_buffer = av_malloc(numpoints*sizeof(cell));
cell *free_cells;
+ int best_dist, best_idx = 0;
elbg->error = INT_MAX;
elbg->dim = dim;
elbg->nearest_cb = closest_cb;
elbg->points = points;
elbg->utility_inc = av_malloc(numCB*sizeof(int));
+ elbg->scratchbuf = av_malloc(5*dim*sizeof(int));
elbg->rand_state = rand_state;
/* This loop evaluate the actual Voronoi partition. It is the most
costly part of the algorithm. */
for (i=0; i < numpoints; i++) {
- dist_cb[i] = INT_MAX;
+ best_dist = distance_limited(elbg->points + i*elbg->dim, elbg->codebook + best_idx*elbg->dim, dim, INT_MAX);
for (k=0; k < elbg->numCB; k++) {
- dist = distance_limited(elbg->points + i*elbg->dim, elbg->codebook + k*elbg->dim, dim, dist_cb[i]);
- if (dist < dist_cb[i]) {
- dist_cb[i] = dist;
- elbg->nearest_cb[i] = k;
+ dist = distance_limited(elbg->points + i*elbg->dim, elbg->codebook + k*elbg->dim, dim, best_dist);
+ if (dist < best_dist) {
+ best_dist = dist;
+ best_idx = k;
}
}
+ elbg->nearest_cb[i] = best_idx;
+ dist_cb[i] = best_dist;
elbg->error += dist_cb[i];
elbg->utility[elbg->nearest_cb[i]] += dist_cb[i];
free_cells->index = i;
av_free(list_buffer);
av_free(elbg->cells);
av_free(elbg->utility_inc);
+ av_free(elbg->scratchbuf);
}
projects / ffmpeg / blobdiff