uint8_t *alpha,
uint32_t subtitle_color)
{
+ static const uint8_t level_map[4][4] = {
+ // this configuration (full range, lowest to highest) in tests
+ // seemed most common, so assume this
+ {0xff},
+ {0x00, 0xff},
+ {0x00, 0x80, 0xff},
+ {0x00, 0x55, 0xaa, 0xff},
+ };
uint8_t color_used[16];
int nb_opaque_colors, i, level, j, r, g, b;
if (nb_opaque_colors == 0)
return;
- j = nb_opaque_colors;
+ j = 0;
memset(color_used, 0, 16);
for(i = 0; i < 4; i++) {
if (alpha[i] != 0) {
if (!color_used[colormap[i]]) {
- level = (0xff * j) / nb_opaque_colors;
+ level = level_map[nb_opaque_colors][j];
r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
color_used[colormap[i]] = (i + 1);
- j--;
+ j++;
} else {
rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
((alpha[i] * 17) << 24);