zooming live webcam video streaming

Dear all
I had integrated a web cam using New Video (Action Script controlled) Object from the library menu and gave the instance name as webcamVideo
and had used the following code code get live webcam video steaming

import flash.display.MovieClip;
import flash.media.Camera;
import flash.media.Video;

var camera:Camera = Camera.getCamera();
camera.setMode(800, 600, 30, false);

all i need is to give a zoom in and zoom out on two button for the live streaming video very much similar to what we get with default software of every webcam.

Plz help me out