sub: pack libass bitmaps directly in sd_ass.c and osd_libass.c

Change all producer of libass images to packing the bitmaps into a
single larger bitmap directly when they're output. This is supposed to
help working towards refcounted sub bitmaps.

This will reduce performance for VOs like vo_xv, but not for vo_opengl.
vo_opengl simply will pick up the pre-packed sub bitmaps, and skip
packing them again. vo_xv will copy and pack the sub bitmaps
unnecessarily - but if we want sub bitmap refcounting, they'd have to be
copied anyway.

The packing code cannot be removed yet from vo_opengl, because there are
certain corner cases that still produce unpackad other sub bitmaps.
Actual refcounting will also require more work.

1 files changed, 22 insertions, 11 deletions

diff --git a/sub/osd_libass.c b/sub/osd_libass.c
index 6a2efa6603..f940b6117f 100644
--- a/sub/osd_libass.c
+++ b/sub/osd_libass.c
@@ -90,7 +90,6 @@ void osd_destroy_backend(struct osd_state *osd)
     for (int n = 0; n < MAX_OSD_PARTS; n++) {
         struct osd_object *obj = osd->objs[n];
         destroy_ass_renderer(&obj->ass);
-        talloc_free(obj->parts_cache.parts);
         for (int i = 0; i < obj->num_externals; i++)
             destroy_external(&obj->externals[i]);
         obj->num_externals = 0;
@@ -501,7 +500,7 @@ void osd_set_external(struct osd_state *osd, void *id, int res_x, int res_y,
         entry->res_x = res_x;
         entry->res_y = res_y;
         update_external(osd, obj, entry);
-        obj->parts_cache.change_id = 1;
+        obj->changed = true;
         osd_changed_unlocked(osd, obj->type);
     }
 
@@ -510,14 +509,19 @@ done:
 }
 
 static void append_ass(struct ass_state *ass, struct mp_osd_res *res,
-                       struct sub_bitmaps *imgs)
+                       ASS_Image **img_list, bool *changed)
 {
-    if (!ass->render || !ass->track)
+    if (!ass->render || !ass->track) {
+        *img_list = NULL;
         return;
+    }
 
     ass_set_frame_size(ass->render, res->w, res->h);
     ass_set_aspect_ratio(ass->render, res->display_par, 1.0);
-    mp_ass_render_frame(ass->render, ass->track, 0, imgs);
+
+    int ass_changed;
+    *img_list = ass_render_frame(ass->render, ass->track, 0, &ass_changed);
+    *changed |= ass_changed;
 }
 
 void osd_object_get_bitmaps(struct osd_state *osd, struct osd_object *obj,
@@ -526,12 +530,19 @@ void osd_object_get_bitmaps(struct osd_state *osd, struct osd_object *obj,
     if (obj->force_redraw && obj->type == OSDTYPE_OSD)
         update_osd(osd, obj);
 
-    append_ass(&obj->ass, &obj->vo_res, &obj->parts_cache);
-    for (int n = 0; n < obj->num_externals; n++)
-        append_ass(&obj->externals[n].ass, &obj->vo_res, &obj->parts_cache);
+    if (!obj->ass_packer)
+        obj->ass_packer = mp_ass_packer_alloc(obj);
+
+    MP_TARRAY_GROW(obj, obj->ass_imgs, obj->num_externals + 1);
+
+    append_ass(&obj->ass, &obj->vo_res, &obj->ass_imgs[0], &obj->changed);
+    for (int n = 0; n < obj->num_externals; n++) {
+        append_ass(&obj->externals[n].ass, &obj->vo_res, &obj->ass_imgs[n + 1],
+                   &obj->changed);
+    }
 
-    *out_imgs = obj->parts_cache;
+    mp_ass_packer_pack(obj->ass_packer, obj->ass_imgs, obj->num_externals + 1,
+                       obj->changed, SUBBITMAP_LIBASS, out_imgs);
 
-    obj->parts_cache.change_id = 0;
-    obj->parts_cache.num_parts = 0;
+    obj->changed = false;
 }