HACK: dvdsubdec: try to improve default dvd subtitle color guessing

1 files changed, 9 insertions, 33 deletions

diff --git a/libavcodec/dvdsubdec.c b/libavcodec/dvdsubdec.c
index e18113c20c..1ff80f2ce5 100644
--- a/libavcodec/dvdsubdec.c
+++ b/libavcodec/dvdsubdec.c
@@ -147,16 +147,12 @@ static void guess_palette(DVDSubContext* ctx,
                           uint32_t *rgba_palette,
                           uint32_t subtitle_color)
 {
-    static const uint8_t level_map[4][4] = {
+    static const uint8_t level_map[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},
+        0x00, 0xe0, 0x80, 0x20
     };
-    uint8_t color_used[16] = { 0 };
-    int nb_opaque_colors, i, level, j, r, g, b;
+    int i, level, r, g, b;
     uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
 
     if(ctx->has_palette) {
@@ -169,33 +165,13 @@ static void guess_palette(DVDSubContext* ctx,
     for(i = 0; i < 4; i++)
         rgba_palette[i] = 0;
 
-    nb_opaque_colors = 0;
-    for(i = 0; i < 4; i++) {
-        if (alpha[i] != 0 && !color_used[colormap[i]]) {
-            color_used[colormap[i]] = 1;
-            nb_opaque_colors++;
-        }
-    }
-
-    if (nb_opaque_colors == 0)
-        return;
-
-    j = 0;
-    memset(color_used, 0, 16);
     for(i = 0; i < 4; i++) {
         if (alpha[i] != 0) {
-            if (!color_used[colormap[i]])  {
-                level = level_map[nb_opaque_colors - 1][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] * 17U) << 24);
-                color_used[colormap[i]] = (i + 1);
-                j++;
-            } else {
-                rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
-                                    ((alpha[i] * 17U) << 24);
-            }
+            level = level_map[i];
+            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] * 17U) << 24);
         }
     }
 }
@@ -400,7 +376,7 @@ static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
                 } else {
                     sub_header->rects[0]->nb_colors = 4;
                     guess_palette(ctx, (uint32_t*)sub_header->rects[0]->data[1],
-                                  0xffff00);
+                                  0xffffff);
                 }
                 sub_header->rects[0]->x = x1;
                 sub_header->rects[0]->y = y1;