flex 摄像头操作

打开摄像头：
Camera camera = Camera.getCamera();
camera.setMode(240,180,15);
camera.setKeyFrameInterval(60);
camera.setQuality(144,85 );
Video video = new Video(camera.width*2, camera.height*2);
video.attachCamera(camera);
关闭摄像头：
camera = Camera.getCamera(null);
camera = null;
video.attachCamera(null);