'Security violation' problem when using canvas.toDataURL() to get a video frame data

Hi all,
I want to test the webcam feature in Opera (Opera desktop for Windows, http://labs.opera.com/news/2011/10/19/) and i tried to get the video frame data, so i can save it in local storage, but i meet a 'Security violation' problem when using canvas.toDataURL(). How can i get the camera frame data, thanks for your advice:)

The JS code as bellow:

var scaleFactor = 0.30;
var video = document.getElementsByTagName('video')[0],
heading = document.getElementsByTagName('h1')[0];

if(navigator.getUserMedia) {
navigator.getUserMedia('video', successCallback, errorCallback);
function successCallback( stream ) {
video.src = stream;
}
function errorCallback( error ) {
heading.textContent =
"An error occurred: [CODE " + error.code + "]";
}
} else {
heading.textContent =
"Native web camera streaming is not supported in this browser!";
}


function capture(video, scaleFactor) {
if(scaleFactor == null){
scaleFactor = 1;
}
var w = Math.floor(video.videoWidth * scaleFactor);
var h = Math.floor(video.videoHeight * scaleFactor);
var canvas = document.createElement('canvas');
canvas.width = w;
canvas.height = h;

var ctx = canvas.getContext('2d');
ctx.drawImage(video, 0, 0, w, h);

//for test
var canvas_test = document.getElementById('myCanvas');
var ctx_test = canvas_test.getContext('2d');
ctx_test.drawImage(video, 0, 0, canvas_test.width, canvas_test.height);

var frameData = canvas_test.toDataURL('image/png'); //Uncaught exception: ReferenceError: Security violation

//.....

return canvas;
}

function shoot(){
var canvas = capture(video, scaleFactor);
}

I get the same error.
Any clue on this?

got the same error.
I searched a lot, only some clue about image, but not solution to this problem.
http://blog.chromium.org/2011/07/using-cross-domain-images-in-webgl-and.html

They tried this:

• Type in about:config into the address bar

• Go to Security Prefs and tick ”Allow Camera To Canvas Copy”

That should work.

This DID work. Thank you!

Originally posted by ramkira:

They tried this:

• Type in about:config into the address bar

• Go to Security Prefs and tick ”Allow Camera To Canvas Copy”

That should work.