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Access Webcam with Flash

February 7th, 2009

I wanted a user to be able to upload pictures via their webcam. This post will show how to make a flash application using Flash 8 and actionscript 2 to have a website access a users webcam and take a picture and save it.

First off we need to import the following files:

 //This will allow us to create a photo
import flash.display.BitmapData;
// This is used to mirror the look of the webcam
import flash.geom.Matrix;
 //Used to interact with javascript
import flash.external.ExternalInterface;

This code is used to actually display the webcam on the screen except we’re setting the video visible to false.

video_vobj._visible = false;
var cam:Camera = Camera.get();
cam.setMode(300, 400, 28);

Occasionally when you reload the page the webcam displays a scrambled image or the last frame displayed. I rather not see anything if the camera isn’t ready which is why we set the video visible to false to begin. This next bit is a little hack to fix that problem.

var firstone:Boolean = true;
cam.onActivity = function(isActive:Boolean) {
  //clears the video screen so it won't display the scrambled screen or frozen frame.
        firstone = false;
        video_vobj._visible = true;

The position of the video.

var videoX:Number = video_vobj._x;
var videoY:Number = video_vobj._y;
var videoW:Number = video_vobj._width;
var videoH:Number = video_vobj._height;

In order for the website to access the webcam, a user must give the website permission.

If muted is true it means that the website currently doesn’t have access. By default flash will popup with a allow/deny dialog box but I prefer to display the settings dialog box. This is because the settings dialog box allows you to check a remember box so the website will always have access to the webcam unless you go into the settings and change it again. It also has a few other options like choosing a different webcam.

if(cam.muted == true){
      //Shows the setting dialog box with which tab to display passed to it.

This is a camera event that is triggered when access to the webcam has been granted or denied.

cam.onStatus = function(infoObj:Object) {
    switch (infoObj.code) {
    case 'Camera.Muted' :
    case 'Camera.Unmuted' :

First we’ll create a movie clip that will hold the button to take the picture.

var root:MovieClip = this;
root._x = 50;
root.createEmptyMovieClip("take", root.getNextHighestDepth());

I wanted to create a button that a user could click to take a picture. This could have just as easily been accomplished by adding a button in flash but I wanted to try it this way.

function createbutton(){
	take._x = 10;
	take._y = 435;
	var fillType:String = "linear";
	var colors:Array = [0xFAD4DB, 0xEC748B, 0xC13A59, 0xA81230];
	var alphas:Array = [100, 100, 100, 100];
	var ratios:Array = [0, 126, 127, 255];
	var matrix:Object = {matrixType:"box", x:0, y:0, w:80, h:30,
	take.createEmptyMovieClip("takebtn", reset.getNextHighestDepth());
	take.takebtn.lineStyle(0, 0x820F26, 60, true, "none", "square", "round");
	take.takebtn.beginGradientFill(fillType, colors, alphas, ratios, matrix);
	take.takebtn.lineTo(120, 0);
	take.takebtn.lineTo(120, 30);
	take.takebtn.lineTo(0, 30);
	take.takebtn.lineTo(0, 0);
	take.createTextField("labelText", take.getNextHighestDepth(), 0, 5,
         take._width, 24);
	take.labelText.text = "Take Picture";

Takes the inverse of the xscale in order to mirror the image.

video_vobj._x = video_vobj._width;
video_vobj._xscale = -video_vobj._xscale;

When you click the Take Picture button it triggers an event that will store the image that is currently on the screen
into this bitmap.

var screenS:BitmapData = new BitmapData(video_vobj._width, video_vobj._height,
                                       true, 0xff0000);

This function is called to reset everything to how it was at the start.

function resetflash(){

This is the code to actually creates the image. The screenS.draw function takes the video and matrix to draw a mirrored image.

take.onRelease = function() {
	var mymatrix:Matrix = new Matrix();
		mymatrix.d= 3.333*mymatrix.d;
		mymatrix.tx= video_vobj._width;
       screenS.draw(video_vobj, mymatrix);

I create a empty movie clip to hold and display the image. This makes it easy to remove the image by simply removing the movie clip. When I create one I pass the name and the depth. The root.getNextHighestDepth() makes sure that flash renders the movie clip in front of all the others.

root.createEmptyMovieClip("holder", root.getNextHighestDepth());
holder.attachBitmap(screenS, 1);
holder._x = videoX;
holder._y = videoY;
holder._width = videoW;
holder._height = videoH;

Here I create another button to reset everything to the start positions.

root.createEmptyMovieClip("reset", root.getNextHighestDepth());
reset._x = 10;
reset._y = 435;
var fillType:String = "linear";
var colors:Array = [0xFAD4DB, 0xEC748B, 0xC13A59, 0xA81230];
var alphas:Array = [100, 100, 100, 100];
var ratios:Array = [0, 126, 127, 255];
var matrix:Object = {matrixType:"box", x:0, y:0, w:80, h:30, r:90/180*Math.PI};
reset.createEmptyMovieClip("resetbtn", reset.getNextHighestDepth());
reset.resetbtn.lineStyle(0, 0x820F26, 60, true, "none", "square", "round");
reset.resetbtn.beginGradientFill(fillType, colors, alphas, ratios, matrix);
reset.resetbtn.lineTo(120, 0);
reset.resetbtn.lineTo(120, 30);
reset.resetbtn.lineTo(0, 30);
reset.resetbtn.lineTo(0, 0);
reset.createTextField("labelText", reset.getNextHighestDepth(), 0, 5,
   reset._width, 24);
reset.labelText.text = "Discard";

Here I create another button in order to save the image.

root.createEmptyMovieClip("myButton1", root.getNextHighestDepth());
myButton1._x = 150;
myButton1._y = 435;
var fillType:String = "linear";
var colors:Array = [0xFAD4DB, 0xEC748B, 0xC13A59, 0xA81230];
var alphas:Array = [100, 100, 100, 100];
var ratios:Array = [0, 126, 127, 255];
var matrix:Object = {matrixType:"box", x:0, y:0, w:80, h:30, r:90/180*Math.PI};
myButton1.createEmptyMovieClip("buttonBkg", myButton1.getNextHighestDepth());
myButton1.buttonBkg.lineStyle(0, 0x820F26, 60, true, "none",
   "square", "round");
myButton1.buttonBkg.beginGradientFill(fillType, colors, alphas,
   ratios, matrix);
myButton1.buttonBkg.lineTo(120, 0);
myButton1.buttonBkg.lineTo(120, 30);
myButton1.buttonBkg.lineTo(0, 30);
myButton1.buttonBkg.lineTo(0, 0);
myButton1.createTextField("labelText", myButton1.getNextHighestDepth(),
  0, 5, myButton1._width, 24);
myButton1.labelText.text = "Save Image";

reset.onRelease = resetflash;

This is the event that will trigger the image to begin saving. I first create a movie clip to display a red film over the picture and text to display the progress of the picture. It then creates a SaveImage object. This object is defined in SaveImage.as which is a file you’ll have to create.

myButton1.onRelease = function(){
		tbo.text= screenS.width;
		root.createEmptyMovieClip("loader", root.getNextHighestDepth());
		loader._x = 0;
		loader._y = 0;
		loader.beginFill(0xFF0000, 50);
		loader.lineTo(300, 0);
		loader.lineTo(300, 400);
		loader.lineTo(0, 400);
		loader.lineTo(0, 400);

		loader.createTextField("my_txt", 1, 0, 150, 300, 100);
		var my_fmt:TextFormat = new TextFormat();
		my_fmt.color = 0xFFFFFF;
		loader.my_txt.text = "Progress";

		var si:SaveImage = new SaveImage();
		si.addListener( listener ); // assign a listener
		si.print(root, 0, 0, video_vobj._width, video_vobj._height) // copy the root


I create a listener object that I added to si (SaveImage object). This is used to view the progress of the picture being saved and also when it is completed.

var listener:Object = new Object();

listener.onProgress = function(target:MovieClip, loaded:Number, total:Number){
var perc = Math.round((loaded/total)*100)
	var my_fmt:TextFormat = new TextFormat();
	my_fmt.color = 0xFFFFFF;
       loader.my_txt.text = "computing "+perc+"%";

When the image is finished copying the data it sends it to some server file for processing via the sendAndLoad function. It then takes whatever was returned from the file and stores it in result_lv. When data is put into that LoadVars object an event onData is triggered. The src variable is what is returned and in this case is the name of the image I created. I then call my javascript function with the ExternalInterface.call which will display the image.

listener.onComplete = function(target:MovieClip, load_var:LoadVars){
	var result_lv:LoadVars = new LoadVars();
       result_lv.onData = function(src:String) {
		var retText = src;
		ExternalInterface.call("showimg", retText);
    load_var.sendAndLoad("yourfile.php", result_lv, "POST");

This next part is to make the SaveImage.as file. Everthing will be in class SaveImage. You can’t have more than one class in a .as file. The first part is to define some variables.

 class SaveImage {
    public var addListener:Function
    public var broadcastMessage:Function
    private var id:   Number;
    public  var record:LoadVars;

This function initializes the object and makes it an event broadcaster. This allows us to create custom event handling mechanisms. The listener object we added earlier will now receive notification anytime we call the broadcastMessage() method.

    function SaveImage(){
        AsBroadcaster.initialize( this );

This is the function we called to begin copying the image data. We store it in the LoadVars object “record”. Then we call the setInterval function that calls copysource.

    public function print(mc:MovieClip, x:Number, y:Number, w:Number, h:Number){
        if(x == undefined) x = 0;
        if(y == undefined) y = 0;
        if(w == undefined) w = mc._width;
        if(h == undefined) h = mc._height;
        record = new LoadVars();
        record.width  = w
        record.height = h
        record.cols   = 0
        record.rows   = 0
        id = setInterval(copysource, 5, this, _root.video_vobj, _root.screenS);

This function is the one that is actually copying all the image data pixel by pixel. Instead of looping through all of it at once I do it row by row by using the setInterval function. I do this so I can show the progress which is displayed when I call broadcastMessage(“onProgress”). After it is completed I call the clearInterval(this.id) so it wont call the funtion anymore.

    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)
            if(pixel == 0xFFFFFF) str_pixel = "";   // don't send blank pixel
            scope.record["px" + scope.record.rows].push(str_pixel)

        scope.broadcastMessage("onProgress", movie, scope.record.rows, bit.height)
        scope.record.rows += 1
        if(scope.record.rows >= bit.height){
            scope.broadcastMessage("onComplete", movie, scope.record)

Here is the php code I use to process the post variables.

View PHP code

View All Flash Code

View Example

Here is the .fla and .as files

Flash Files

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