!752

static int window =
  8; // erratic
  //100; // stable
  //20; // compromise?

p {
  final DialogIO io = findBot("Music");
  final JPanel panel = singleColorPanel(Color.black);
  showFrame(panel);
  installTimer(panel, 100, r {
    S s = io.ask("pcm data " + window);
    if (eq(s, "null")) ret;
    byte[] pcm = (byte[]) safeUnstructure(s);
    if (pcm != null) {
      Color color = levelToColor(pcmToLevel(pcm));
      panel.setBackground(color);
    }
  });
}

static Color levelToColor(float l) {
  ret new Color(0, l, 0);
}