@@ -40,6 +40,8 @@ struct color_ref {
/* Store a range of colors */
struct range_box {
uint32_t color; // average color
+ int major_axis; // best axis candidate for cutting the box
+ uint64_t weight; // sum of all the weights of the colors
int64_t variance; // overall variance of the box (how much the colors are spread)
int start; // index in PaletteGenContext->refs
int len; // number of referenced colors
@@ -143,6 +145,35 @@ static av_always_inline int diff(const uint32_t a, const uint32_t b)
return dr*dr + dg*dg + db*db;
}
+static void compute_box_stats(PaletteGenContext *s, struct range_box *box)
+{
+ int rr, gr, br;
+
+ /* compute the box weight (sum all the weights of the colors in the
+ * range) and its boundings */
+ uint8_t min[3] = {0xff, 0xff, 0xff};
+ uint8_t max[3] = {0x00, 0x00, 0x00};
+ box->weight = 0;
+ for (int i = box->start; i < box->start + box->len; i++) {
+ const struct color_ref *ref = s->refs[i];
+ const uint32_t rgb = ref->color;
+ const uint8_t r = rgb >> 16 & 0xff, g = rgb >> 8 & 0xff, b = rgb & 0xff;
+ min[0] = FFMIN(r, min[0]), max[0] = FFMAX(r, max[0]);
+ min[1] = FFMIN(g, min[1]), max[1] = FFMAX(g, max[1]);
+ min[2] = FFMIN(b, min[2]), max[2] = FFMAX(b, max[2]);
+ box->weight += ref->count;
+ }
+
+ /* define the axis to sort by according to the widest range of colors */
+ rr = max[0] - min[0];
+ gr = max[1] - min[1];
+ br = max[2] - min[2];
+ box->major_axis = 1; // pick green by default (the color the eye is the most sensitive to)
+ if (br >= rr && br >= gr) box->major_axis = 2;
+ if (rr >= gr && rr >= br) box->major_axis = 0;
+ if (gr >= rr && gr >= br) box->major_axis = 1; // prefer green again
+}
+
/**
* Find the next box to split: pick the one with the highest variance
*/
@@ -324,35 +355,16 @@ static AVFrame *get_palette_frame(AVFilterContext *ctx)
s->nb_boxes = 1;
while (box && box->len > 1) {
- int i, rr, gr, br, longest;
- uint64_t median, box_weight = 0;
-
- /* compute the box weight (sum all the weights of the colors in the
- * range) and its boundings */
- uint8_t min[3] = {0xff, 0xff, 0xff};
- uint8_t max[3] = {0x00, 0x00, 0x00};
- for (i = box->start; i < box->start + box->len; i++) {
- const struct color_ref *ref = s->refs[i];
- const uint32_t rgb = ref->color;
- const uint8_t r = rgb >> 16 & 0xff, g = rgb >> 8 & 0xff, b = rgb & 0xff;
- min[0] = FFMIN(r, min[0]), max[0] = FFMAX(r, max[0]);
- min[1] = FFMIN(g, min[1]), max[1] = FFMAX(g, max[1]);
- min[2] = FFMIN(b, min[2]), max[2] = FFMAX(b, max[2]);
- box_weight += ref->count;
- }
+ int i, longest;
+ uint64_t median, box_weight;
- /* define the axis to sort by according to the widest range of colors */
- rr = max[0] - min[0];
- gr = max[1] - min[1];
- br = max[2] - min[2];
- longest = 1; // pick green by default (the color the eye is the most sensitive to)
- if (br >= rr && br >= gr) longest = 2;
- if (rr >= gr && rr >= br) longest = 0;
- if (gr >= rr && gr >= br) longest = 1; // prefer green again
+ compute_box_stats(s, box);
+ longest = box->major_axis;
+ box_weight = box->weight;
- ff_dlog(ctx, "box #%02X [%6d..%-6d] (%6d) w:%-6"PRIu64" ranges:[%2x %2x %2x] sort by %c (already sorted:%c) ",
+ ff_dlog(ctx, "box #%02X [%6d..%-6d] (%6d) w:%-6"PRIu64" sort by %c (already sorted:%c) ",
box_id, box->start, box->start + box->len - 1, box->len, box_weight,
- rr, gr, br, "rgb"[longest], box->sorted_by == longest ? 'y':'n');
+ "rgb"[longest], box->sorted_by == longest ? 'y':'n');
/* sort the range by its longest axis if it's not already sorted */
if (box->sorted_by != longest) {