{...}: {
  config.programs.mpv = {
    enable = true;
    bindings = let
      volume-step = "5";
      speed-step = "0.125";
      seek-step = "5";
    in {
      # supported commands https://raw.githubusercontent.com/mpv-player/mpv/master/etc/input.conf
      WHEEL_UP = "add volume +${volume-step}";
      WHEEL_DOWN = "add volume -${volume-step}";
      RIGHT = "seek +${seek-step}";
      LEFT = "seek -${seek-step}";
      UP = "add volume +${volume-step}";
      DOWN = "add volume -${volume-step}";
      "Alt+h" = "vf toggle hflip";
      "Alt+v" = "vf toggle vflip";
      ">" = "add speed +${speed-step}";
      "<" = "add speed -${speed-step}";
      BS = "set speed 1.0";
    };
  };
}