Flatpak: add fix ass subtitles smooth scaling patch

Fix for ass subtitles jittering animations. More info in my GStreamer MR:
https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1822

pkgs/flatpak/gstreamer-1.0/gst-plugins-bad-assrender-smooth-scaling.patch

@@ -0,0 +1,30 @@
+From 1c8538d8f8c2181106d626d67784af6db094036e Mon Sep 17 00:00:00 2001
+From: Rafostar <rafostar.github@gmail.com>
+Date: Thu, 19 Nov 2020 18:03:11 +0100
+Subject: [PATCH] assrender: fix smooth scaling by disabling hinting
+
+When ass hinting value is set to anything other than NONE,
+subtitles cannot use smooth scaling, thus all animations will jitter.
+
+The libass author warns about possibility of breaking some scripts when it is enabled,
+so lets do what is recommended and disable it to get the smooth scaling working.
+---
+ ext/assrender/gstassrender.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/ext/assrender/gstassrender.c b/ext/assrender/gstassrender.c
+index e99458bf29..111987b9d8 100644
+--- a/ext/assrender/gstassrender.c
++++ b/ext/assrender/gstassrender.c
+@@ -916,7 +916,7 @@ gst_ass_render_negotiate (GstAssRender * render, GstCaps * caps)
+     ass_set_pixel_aspect (render->ass_renderer,
+         (gdouble) render->info.par_n / (gdouble) render->info.par_d);
+     ass_set_font_scale (render->ass_renderer, 1.0);
+-    ass_set_hinting (render->ass_renderer, ASS_HINTING_LIGHT);
++    ass_set_hinting (render->ass_renderer, ASS_HINTING_NONE);
+ 
+     ass_set_fonts (render->ass_renderer, "Arial", "sans-serif", 1, NULL, 1);
+     ass_set_fonts (render->ass_renderer, NULL, "Sans", 1, NULL, 1);
+-- 
+GitLab
+

pkgs/flatpak/gstreamer-1.0/gst-plugins-bad.json

@@ -36,6 +36,10 @@
         {
             "type": "patch",
             "path": "gst-plugins-bad-vah264dec-fix-seeking-errors.patch"
+        },
+        {
+            "type": "patch",
+            "path": "gst-plugins-bad-assrender-smooth-scaling.patch"
         }
     ]
 }