diff --git a/flake.nix b/flake.nix
index c1f20d12..1025d2f0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -87,9 +87,6 @@
 
       # The order here is important(?).
       overlays = [
-        # Put my custom packages to be available.
-        self.overlays.default
-
         (final: prev: {
           inherit (inputs.firefox-addons.lib.${defaultSystem}) buildFirefoxXpiAddon;
           firefox-addons = final.callPackage ./pkgs/firefox-addons { };
@@ -103,7 +100,7 @@
 
         # Access to NUR.
         inputs.nur.overlay
-      ];
+      ] ++ (lib'.attrValues self.overlays);
 
       defaultSystem = "x86_64-linux";
 
@@ -385,7 +382,9 @@
         lib'.importModules (lib'.filesToAttr ./modules/home-manager);
 
       # In case somebody wants to use my stuff to be included in nixpkgs.
-      overlays.default = final: prev: import ./pkgs { pkgs = prev; };
+      overlays = import ./overlays // {
+        default = final: prev: import ./pkgs { pkgs = prev; };
+      };
 
       # My custom packages, available in here as well. Though, I mainly support
       # "x86_64-linux". I just want to try out supporting other systems.
diff --git a/overlays/default.nix b/overlays/default.nix
new file mode 100644
index 00000000..63cef0c7
--- /dev/null
+++ b/overlays/default.nix
@@ -0,0 +1,7 @@
+# A bunch of custom overlays. This is more suitable for larger and more
+# established packages that needed extensive customization. Take note each of
+# the values in the attribute set is a separate overlay function so you'll
+# simply have to append them as a list (i.e., `lib.attrValues`).
+{
+  ffmpeg-foodogsquared = import ./ffmpeg-foodogsquared;
+}
diff --git a/overlays/ffmpeg-foodogsquared/add-custom-filters.patch b/overlays/ffmpeg-foodogsquared/add-custom-filters.patch
new file mode 100644
index 00000000..b1323546
--- /dev/null
+++ b/overlays/ffmpeg-foodogsquared/add-custom-filters.patch
@@ -0,0 +1,26 @@
+diff --git a/libavfilter/Makefile b/libavfilter/Makefile
+index a90ca30ad7..c0fc73be46 100644
+--- a/libavfilter/Makefile
++++ b/libavfilter/Makefile
+@@ -367,6 +367,7 @@ OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
+ OBJS-$(CONFIG_ZMQ_FILTER)                    += f_zmq.o
+ OBJS-$(CONFIG_ZOOMPAN_FILTER)                += vf_zoompan.o
+ OBJS-$(CONFIG_ZSCALE_FILTER)                 += vf_zscale.o
++OBJS-$(CONFIG_GLTRANSITION_FILTER)           += vf_gltransition.o
++OBJS-$(CONFIG_SHADERTOY_FILTER)              += vf_shadertoy.o
+ 
+ OBJS-$(CONFIG_ALLRGB_FILTER)                 += vsrc_testsrc.o
+ OBJS-$(CONFIG_ALLYUV_FILTER)                 += vsrc_testsrc.o
+diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
+index 6eac828616..0570c1c2aa 100644
+--- a/libavfilter/allfilters.c
++++ b/libavfilter/allfilters.c
+@@ -357,6 +357,7 @@ extern AVFilter ff_vf_yadif;
+ extern const AVFilter ff_vf_zmq;
+ extern const AVFilter ff_vf_zoompan;
+ extern const AVFilter ff_vf_zscale;
++extern const AVFilter ff_vf_gltransition;
++extern const AVFilter ff_vf_shadertoy;
+
+ extern const AVFilter ff_vsrc_allrgb;
+ extern const AVFilter ff_vsrc_allyuv;
diff --git a/overlays/ffmpeg-foodogsquared/default.nix b/overlays/ffmpeg-foodogsquared/default.nix
new file mode 100644
index 00000000..8ed6e7c0
--- /dev/null
+++ b/overlays/ffmpeg-foodogsquared/default.nix
@@ -0,0 +1,29 @@
+final: prev:
+
+let
+  ffmpegGLTransitions = prev.fetchFromGitHub {
+    owner = "transitive-bullshit";
+    repo = "ffmpeg-gl-transition";
+    rev = "3639b521aafb30b185de281f94560f298a22d420";
+    hash = "";
+  };
+
+  ffmpegShadertoyFilter = prev.fetchFromGitLab {
+    owner = "kriwkrow";
+    repo = "ffmpeg_shadertoy_filter";
+    rev = "eb297df10a104cae2d4ef3f70188d1e84f104532";
+    hash = "";
+  };
+in
+{
+  ffmpeg-foodogsquared = prev.ffmpeg-full.overrideAttrs (finalAttrs: prevAttrs: {
+    pname = "ffmpeg-foodogsquared";
+    patches = prevAttrs.patches ++ [
+      ./add-custom-filters.patch
+    ];
+    postPatch = prevAttrs.postPatch + ''
+      cp ${ffmpegGLTransitions}/vf_gltransition.c $src/libavfilter
+      cp ${ffmpegShadertoyFilter}/vf_shadertoy.c $src/libavfilter
+    '';
+  });
+}