package { import flash.display.*; import flash.events.*; import flash.media.*; import flash.filters.*; public class Motion extends Sprite { private var bd:BitmapData; private var video:Video; private var bitmap:Bitmap; public function Motion(){ // (1) bd = new BitmapData(640, 480, false, 0x00000000); bitmap = new Bitmap(bd); addChild(bitmap); addEventListener(Event.ENTER_FRAME, onEnterFrame); // (