Small ELBG optimization: use last pixel as a initial guess for the codebook

entry.

Originally committed as revision 21001 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vitor Sessak 2010-01-02 12:15:09 +00:00
parent aa13b573b4
commit 4e2c08c551

View File

@ -355,6 +355,7 @@ void ff_do_elbg(int *points, int dim, int numpoints, int *codebook,
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;
@ -380,14 +381,16 @@ void ff_do_elbg(int *points, int dim, int numpoints, int *codebook,
/* 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;