sd_ass: add a very simple and evil way to override ASS subtitle styles

--ass-style-override=force now attempts to override the 'Default' style.
May or may not work. In some situations it will work, but also mess up
seemingly unrelated things like signs typeset with ASS.

1 files changed, 27 insertions, 0 deletions

diff --git a/sub/sd_ass.c b/sub/sd_ass.c
index 8b6f1f1554..e4428516b9 100644
--- a/sub/sd_ass.c
+++ b/sub/sd_ass.c
@@ -128,6 +128,16 @@ static void decode(struct sd *sd, struct demux_packet *packet)
     event->Text = strdup(text);
 }
 
+static ASS_Style *find_style(ASS_Track *track, const char *name)
+{
+    for (int n = track->n_styles - 1; n >= 0; n--) {
+        const char *style_name = track->styles[n].Name;
+        if (style_name && strcasecmp(style_name, name) == 0)
+            return &track->styles[n];
+    }
+    return NULL;
+}
+
 static void get_bitmaps(struct sd *sd, struct mp_osd_res dim, double pts,
                         struct sub_bitmaps *res)
 {
@@ -137,6 +147,18 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res dim, double pts,
     if (pts == MP_NOPTS_VALUE || !sd->ass_renderer)
         return;
 
+    ASS_Style prev_default_style;
+    ASS_Style *default_style = NULL;
+    if (opts->ass_style_override == 2) {
+        default_style = find_style(ctx->ass_track, "Default");
+        if (default_style) {
+            prev_default_style = *default_style;
+            default_style->FontName = NULL; // don't free this
+            mp_ass_set_style(default_style, ctx->ass_track->PlayResY,
+                             opts->sub_text_style);
+        }
+    }
+
     ASS_Renderer *renderer = sd->ass_renderer;
     double scale = dim.display_par;
     if (!ctx->is_converted && (!opts->ass_style_override ||
@@ -166,6 +188,11 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res dim, double pts,
 
     if (!ctx->is_converted)
         mangle_colors(sd, res);
+
+    if (default_style) {
+        free(default_style->FontName);
+        *default_style = prev_default_style;
+    }
 }
 
 struct buf {