Unable to take photo from webcam using HTML5 and getUserMedia() in Google Chrome on first page load

Question

Taking reference from this article on HTML5Rocks I am trying to build a utility to take photo from webcam.

Below is my HTML code snippet:

<button type="button" name="btnCapture" id="btnCapture">Start my camera</button><br />
<video autoplay="true" id="video" style="height:240px;width:320px"></video><canvas id="canvas" style="display: none; height:240px;width:320px"></canvas><br />
<img id="capturedImage" src="/blank.gif" style="height:240px;width:320px"><input type="hidden" id="hdnImageBase64" name="hdnImageBase64"><br />

On click of button btnCapture I start my webcam and clicking it again It captures the photo from webcam and puts it into the image capturedImage .

Below is my JavaScript code:

var video = document.getElementById("video");
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var localMediaStream = null;
var capturedImage = document.getElementById("capturedImage");
var buttonTextCapturePicture = "Say Cheese!";

function onFailSoHard(e) {
    if (e.code == 1) {
        alert("Something went wrong! Either your webcam is not connected or you denied access to it.");
    } else {
        alert("getUserMedia() not supported in your browser. Try using latest version of Google Chrome or Opera.");
    }
}

function snapshot() {
    if (localMediaStream) {
        try {
            ctx.drawImage(video, 0, 0);
            capturedImage.src = canvas.toDataURL("image/png");
            document.getElementById("hdnImageBase64").value = canvas.toDataURL("image/png");
        } catch (e) {
            alert("Something went wrong while capturing you. Try refreshing the page. " + e);
        }
    }
}

video.addEventListener("click", snapshot, false);

function sizeCanvas() {
    setTimeout( function() {
        canvas.width = video.videoWidth;
        canvas.height = video.videoHeight;
        capturedImage.height = video.videoHeight;
        capturedImage.width = video.videoWidth;
    }, 50);
}

var button = document.getElementById("btnCapture");
button.addEventListener("click", function(e) {
    if (localMediaStream) {
        snapshot();
        return;
    }
    if (navigator.getUserMedia) {
        navigator.getUserMedia("video", function(stream) {
            video.src = stream;
            localMediaStream = stream;
            sizeCanvas();
            button.textContent = buttonTextCapturePicture;
        }, onFailSoHard);
    } else if (navigator.webkitGetUserMedia) {
        navigator.webkitGetUserMedia({"video" : true}, function(stream) {
            video.src = window.webkitURL.createObjectURL(stream);
            localMediaStream = stream;
            sizeCanvas();
            button.textContent = buttonTextCapturePicture;
        }, onFailSoHard);
    } else {
        onFailSoHard({
            target : video
        });
    }
}, false);

When the button btnCapture is clickd first time it calls the function sizeCanvas() to set the canvas and image width & height to video's width & height (ie 320 & 240). When the button is clicked second time it take Base64 encoded snapshot from webcam using canvas.toDataURL and puts it into image capturedImage .

It works in Opera. But in Google Chrome it always fails the first time when page is loaded . But when the same page is refreshed it works. Trying to debug I found that the code canvas.toDataURL returns image Base64 as data:, for the first time due to which it is unable to draw image whih results in error of Resource interpreted as Image but transferred with MIME type text/plain: "data:,". in console. Also if I do not call the function sizeCanvas then it works first time but then the picture is not of the dimension I require and gets cropped.

Any ideas how I can make it work in Chrome the first time with sizeCanvas ?

Google Chrome: 24.0.1312.57 Opera: 12.11

Answer 1

LIVE DEMO

Works well in Chrome and FF.

(function() {

  var streaming = false,
      video        = document.querySelector('#video'),
      canvas       = document.querySelector('#canvas'),
      photo        = document.querySelector('#photo'),
      startbutton  = document.querySelector('#startbutton'),
      width = 320,
      height = 0;

  navigator.getMedia = ( navigator.getUserMedia ||
                         navigator.webkitGetUserMedia ||
                         navigator.mozGetUserMedia ||
                         navigator.msGetUserMedia);

  navigator.getMedia(
    {
      video: true,
      audio: false
    },
    function(stream) {
      if (navigator.mozGetUserMedia) {
        video.mozSrcObject = stream;
      } else {
        var vendorURL = window.URL || window.webkitURL;
        video.src = vendorURL.createObjectURL(stream);
      }
      video.play();
    },
    function(err) {
      console.log("An error occured! " + err);
    }
  );

This code I found here: LINK DEVELOPER MOZILLA

UPDATE: I updated my Live Demo to JSFiddle because getUserMedia() is no longer works on insecure origins. To use this feature, you should consider switching your application to a secure origin, such as HTTPS. See The Chromium Projects for more details.