CODEWITHSUNDEEP
javascripthtmlimagevideo
FullMetalScientist
FullMetalScientist

Reputation: 71

How to take a photo of an <img> video stream? HTML5 Javascript

When using <video id="videoID"> </video> (HTML),

you can use canvas = document.getElementById('canvas') in the script (Javascript)

and videoID.play() or videoID.pause().

If my video is streaming from a URL (as webcams do) as an <img src="http://ip_address/stream"> tag, I can't use the .play() or .pause() functions. Can I still use: 

    canvas = document.getElementById('canvas');

    var context = acontainer.getContext('2d');
    context.drawImage(acontainer, 0, 0, width, height);
    var data = acontainer.toDataURL('image/jpeg');
    photo.setAttribute('src', data);

The goal is to get a picture of the video stream when I click - so I have a mouse click event that does the above.

How can I do this?

More info: This page has URL http://ip_address and video stream has URL http://ip_address/stream. The video stream is <img> -lots of jpeg images being streamed- within a <div> container, e.g. Code looks like- 

    <!DOCTYPE html>
    <html>
    <head>
    ...
    <style>
    ...
    </style>
    </head>
    <body>
        <div id="container">
            <img src=...>
        </div>
    <script>
        container.addEventListener("click", function(element){}, false);
    ...
    </script>
    </body>
    </html>

EDIT: This question is not a duplicate as I'm not asking how to stream to a html canvas. Rather, I already have a stream displaying in a container and I want to take a photo of it and have it appear in a canvas - so the stream and photo appear on the same page.

Upvotes: 2

Views: 5473

Answers (1)

guest271314
guest271314

Reputation: 1

Set .getContext("2d") should be called on canvas element, not acontainer; pass img reference as first parameter to .drawImage() instead of acontainer; .toDataURL() should be called on canvas element, not acontainer.

var blue = "data:image/png;charset=binary;base64,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";

var red = "data:image/png;charset=binary;base64,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";

var green = "data:image/png;charset=binary;base64,iVBORw0KGgoAAAANSUhEUgAAAScAAADBCAYAAACNMHZqAAAABHNCSVQICAgIfAhkiAAAApJJREFUeJzt1DEBwCAQwMCnynEOBrqT4U5BpqzZcwYg5nsdAPDHnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUgyJyDJnIAkcwKSzAlIMicgyZyAJHMCkswJSDInIMmcgCRzApLMCUi6PDoDAbyCsn8AAAAASUVORK5CYII=";

var arr = [red, blue, green];

var img = document.querySelector("img");

var button = document.querySelector("button");

var containerImg = document.querySelector("div > img");

var canvas = document.createElement("canvas");

canvas.width = canvas.height = 100;

var ctx = canvas.getContext("2d");

var i = 0;

button.addEventListener("click", function() {
  ctx.drawImage(img, 0, 0)
  containerImg.src = canvas.toDataURL();
});

setInterval(function() {
  img.src = arr[i];
  i = ++i % arr.length;
}, 100);
<button>capture image</button><br><br>
<img width="100" height="100" alt="stream"/>
<br><br>
<div>
  <img width="100" height="100" alt="capture"/>
</div>

Upvotes: 1

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