add flake

flake.nix

@@ -0,0 +1,20 @@
+{
+  description = "pixelflut video/image player (ffmpeg-python + C renderer)";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-26.05";
+
+  outputs = {
+    self,
+    nixpkgs,
+  }: let
+    pkgs = nixpkgs.legacyPackages.x86_64-linux;
+  in {
+    devShells.x86_64-linux.default = pkgs.mkShell {
+      packages = [
+        (pkgs.python3.withPackages (ps: [ps.ffmpeg-python]))
+        pkgs.ffmpeg
+        pkgs.gcc13
+      ];
+    };
+  };
+}