flash摄像头拍照实现原理分析

最近一段时间，由于网站的需要，做了一个在线拍照的flash，刚开始的时候也是什么都不懂，对flash也是了解点皮毛，经过不断的在网上查阅资料。经过一周的努力，终于被我搞定了。
主要用到Camera类，MovieClip 类，BitmapData类，LoadVars类，如果要实现这个功能，必须先去了解这几个类
实现的过程如下。
1，先在库中新建一个视频元件，把视频元件拖放到场景中，取名为my_video，新建一个按纽元件，取名为btn_print.
2，加入以下代码实现视频的播放
myCam = Camera.get();
myCam.setMode(266,200,10);
my_video.attachVideo(myCam);
3 ，以下代码实现图片的获得和上传
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.ColorTransform;
class PrintScreen {

public var addListener:Function
public var broadcastMessage:Function

private var id: Number;
public var record:LoadVars;

function PrintScreen(){
AsBroadcaster.initialize( this );
}
public function print(mc:MovieClip, w:Number, h:Number){
broadcastMessage("onStart", mc);
w = Math.floor(w);
h = Math.floor(h);
var bmp:BitmapData = new BitmapData(w, h, false);
record = new LoadVars();
record.width = w
record.height = h
record.cols = 0
record.rows = 0
bmp.draw(mc);
id = setInterval(copysource, 1, this, mc, bmp);
}

private function copysource(scope, movie, bit){
var pixel:Number
var str_pixel:String
scope.record["px" + scope.record.rows] = new Array();
for(var a = 0; a < bit.width; a++){
pixel = bit.getPixel(a, scope.record.rows )
str_pixel = pixel.toString(16)
scope.record["px" + scope.record.rows].push(str_pixel)
}

scope.record.rows += 1
if(scope.record.rows >= bit.height){
clearInterval(scope.id)
bit.dispose();
}
}
}
4 以下代码在服务器段接受数据，生成图片(jsp版)
String width = request.getParameter("width");
String height = request.getParameter("height");
int w = Integer.parseInt(width);
int h = Integer.parseInt(height);
try {
OutputStream fos = response.getOutputStream();
BufferedImage bf = new BufferedImage(w, h,
BufferedImage.TYPE_INT_RGB);
for (int i = 0; i < bf.getHeight(); i++) {
String data = request.getParameter("px" + i);
String[] ds = data.split(",");
for (int j = 0; j < bf.getWidth(); j++) {
int d = Integer.parseInt(ds[j], 16);
bf.setRGB(j, i, d);
}
}
ImageWriter writer = null;
ImageTypeSpecifier type = ImageTypeSpecifier
.createFromRenderedImage(bf);
Iterator iter = ImageIO.getImageWriters(type, "jpg");
if (iter.hasNext()) {
writer = (ImageWriter) iter.next();
}
if (writer == null) {
return null;
}
IIOImage iioImage = new IIOImage(bf, null, null);
ImageWriteParam param = writer.getDefaultWriteParam();
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionQuality(0.2f);
// save to file
ImageOutputStream outputStream2 = ImageIO
.createImageOutputStream(response.getOutputStream());
writer.setOutput(outputStream2);
writer.write(null, iioImage, param);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("w = " + w + ",h=" + h);
response.setContentType("image/jpeg");
return null;