sub: add --sub-gray option to display image subs in grayscale

MPlayer/mplayer2 still show DVD subtitles in gray. Depending on who you
ask, this can be considered a bug or a feature. Include rendering in
gray as explicit feature, so the user can decide what is better.

This affects all indexed sub bitmaps entering the OSD rendering path.
Currently, this means all image subs are affected by this option, but
nothing else.

1 files changed, 5 insertions, 2 deletions

diff --git a/sub/sub.c b/sub/sub.c
index 66ee6ea42c..0dae442aee 100644
--- a/sub/sub.c
+++ b/sub/sub.c
@@ -221,11 +221,14 @@ static void render_object(struct osd_state *osd, struct osd_object *obj,
 
     bool cached = false; // do we have a copy of all the image data?
 
+    if (out_imgs->format == SUBBITMAP_INDEXED && opts->sub_gray)
+        cached |= osd_conv_idx_to_gray(obj->cache[0], out_imgs);
+
     if (formats[SUBBITMAP_RGBA] && out_imgs->format == SUBBITMAP_INDEXED)
-        cached |= osd_conv_idx_to_rgba(obj->cache[0], out_imgs);
+        cached |= osd_conv_idx_to_rgba(obj->cache[1], out_imgs);
 
     if (out_imgs->format == SUBBITMAP_RGBA && opts->sub_gauss != 0.0f)
-        cached |= osd_conv_blur_rgba(obj->cache[1], out_imgs, opts->sub_gauss);
+        cached |= osd_conv_blur_rgba(obj->cache[2], out_imgs, opts->sub_gauss);
 
     if (cached)
         obj->cached = *out_imgs;