{pkgs, ...}:
pkgs.writeShellApplication {
  name = "convertMkv";

  runtimeInputs = with pkgs; [
    ffmpeg-full
  ];

  text = ''
    extension="$1"
    file="$2"

    new_file="''${file%."$extension"}.mkv"

    ffmpeg -i "$file" -c copy "$new_file" &&
    rm "$file"
  '';
}