code-boxx/0-JS-WEBCAM.MD

## 0-JS-WEBCAM.MD

      
    Raw
  

              0-JS-WEBCAM.MD
            
          
    JAVASCRIPT TAKE PHOTO WITH WEBCAM


https://code-boxx.com/take-screenshots-javascript/
https://youtu.be/0stdKhGB7zQ

LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## save.php
<?php
// https://netcell.netlify.com/blog/2016/04/image-base64.html

// (A) BASE64 DECODE UPLOADED IMAGE
$data = explode(",", $_POST["snap"]);
$data = base64_decode($data[1]);

// (B) SAVE IMAGE
$file = fopen("snap.jpg", "w");
fwrite($file, $data);
fclose($file);
echo "OK";

## webcam.css
/* (A) ENTIRE PAGE */
* {
  font-family: Arial, Helvetica, sans-serif;
  box-sizing: border-box;
}
body, html {
  padding: 0; margin: 0;
  color: #fff;
  background: #101010;
}
body {
  max-width: 1000px;
  margin: 0 auto;
}
#cam-live, #cam-snaps, #cam-controls { width: 100%; }

/* (B) LIVE FEED VIDEO */
#cam-live {
  height: 500px;
  object-fit: cover;
}

/* (C) CONTROL BUTTONS */
#cam-controls { display: flex; }
#cam-controls input {
  flex-grow: 1;
  border: 0;
  color: #fff;
  background: #333;
  font-size: 32px;
  padding: 20px 0;
  cursor: pointer;
}

/* (D) SNAPSHOTS */
#cam-snaps {
  display: grid;
  grid-template-columns: repeat(4, 25%);
  min-height: 150px;
  background: #000;
}
#cam-snaps canvas {
  max-height: 150px;
  width: auto;
}


## webcam.html
<!DOCTYPE html>
<html>
  <head>
    <title>Webcam Capture Demo</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
    <!-- https://fonts.google.com/icons -->
    <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
    <link rel="stylesheet" href="webcam.css">
    <script defer src="webcam.js"></script>
  </head>
  <body>
    <!-- (A) VIDEO LIVE FEED -->
    <video id="cam-live" autoplay></video>

    <!-- (B) CONTROLS -->
    <div id="cam-controls">
      <input type="button" id="cam-take" class="material-icons"
             value="photo_camera" onclick="webcam.take()" disabled>
      <input type="button" id="cam-save" class="material-icons"
             value="download" onclick="webcam.save()" disabled>
      <input type="button" id="cam-upload" class="material-icons"
             value="upload" onclick="webcam.upload()" disabled>
    </div>

    <!-- (C) SNAPSHOTS -->
    <div id="cam-snaps"></div>
  </body>
</html>

## webcam.js
var webcam = {
  // (A) INITIALIZE - GET USER PERMISSION TO ACCESS CAMERA
  hVid : null, hSnaps :null,
  init : () => {
    navigator.mediaDevices.getUserMedia({ video: true })
    .then(stream => {
      // (A1) GET HTML ELEMENTS
      webcam.hVid = document.getElementById("cam-live"),
      webcam.hSnaps = document.getElementById("cam-snaps");

      // (A2) "LIVE FEED" WEB CAM TO <VIDEO>
      webcam.hVid.srcObject = stream;

      // (A3) ENABLE BUTTONS
      document.getElementById("cam-take").disabled = false;
      document.getElementById("cam-save").disabled = false;
      document.getElementById("cam-upload").disabled = false;
    })
    .catch(err => console.error(err));
  },

  // (B) SNAP VIDEO FRAME TO CANVAS
  snap : () => {
    // (B1) CREATE NEW CANVAS
    let cv = document.createElement("canvas"),
        cx = cv.getContext("2d");

    // (B2) CAPTURE VIDEO FRAME TO CANVAS
    cv.width = webcam.hVid.videoWidth;
    cv.height = webcam.hVid.videoHeight;
    cx.drawImage(webcam.hVid, 0, 0, webcam.hVid.videoWidth, webcam.hVid.videoHeight);

    // (B3) DONE
    return cv;
  },

  // (C) PUT SNAPSHOT INTO <DIV> WRAPPER
  take : () => webcam.hSnaps.appendChild(webcam.snap()),

  // (D) FORCE DOWNLOAD SNAPSHOT
  save : () => {
    // (D1) TAKE A SNAPSHOT, CREATE DOWNLOAD LINK
    let cv = webcam.snap(),
        a = document.createElement("a");
    a.href = cv.toDataURL("image/png");
    a.download = "snap.png";

    // (D2) "FORCE DOWNLOAD" - MAY NOT ALWAYS WORK!
    a.click(); a.remove(); cv.remove();

    // (D3) SAFER - LET USERS MANUAL CLICK
    // webcam.hSnaps.appendChild(a);
  },

  // (E) UPLOAD SNAPSHOT TO SERVER
  upload : () => {
    // (E1) APPEND SCREENSHOT TO DATA OBJECT
    var data = new FormData();
    data.append("snap", webcam.snap().toDataURL("image/jpeg", 0.6));

    // (E2) UPLOAD SCREENSHOT TO SERVER
    fetch("save.php", { method:"post", body:data })
    .then(res => res.text())
    .then(txt => alert(txt));
  }
};
window.addEventListener("load", webcam.init);
	<?php
	// https://netcell.netlify.com/blog/2016/04/image-base64.html

	// (A) BASE64 DECODE UPLOADED IMAGE
	$data = explode(",", $_POST["snap"]);
	$data = base64_decode($data[1]);

	// (B) SAVE IMAGE
	$file = fopen("snap.jpg", "w");
	fwrite($file, $data);
	fclose($file);
	echo "OK";
	/* (A) ENTIRE PAGE */
	* {
	font-family: Arial, Helvetica, sans-serif;
	box-sizing: border-box;
	}
	body, html {
	padding: 0; margin: 0;
	color: #fff;
	background: #101010;
	}
	body {
	max-width: 1000px;
	margin: 0 auto;
	}
	#cam-live, #cam-snaps, #cam-controls { width: 100%; }

	/* (B) LIVE FEED VIDEO */
	#cam-live {
	height: 500px;
	object-fit: cover;
	}

	/* (C) CONTROL BUTTONS */
	#cam-controls { display: flex; }
	#cam-controls input {
	flex-grow: 1;
	border: 0;
	color: #fff;
	background: #333;
	font-size: 32px;
	padding: 20px 0;
	cursor: pointer;
	}

	/* (D) SNAPSHOTS */
	#cam-snaps {
	display: grid;
	grid-template-columns: repeat(4, 25%);
	min-height: 150px;
	background: #000;
	}
	#cam-snaps canvas {
	max-height: 150px;
	width: auto;
	}
	<!DOCTYPE html>
	<html>
	<head>
	<title>Webcam Capture Demo</title>
	<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
	<!-- https://fonts.google.com/icons -->
	<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
	<link rel="stylesheet" href="webcam.css">
	<script defer src="webcam.js"></script>
	</head>
	<body>
	<!-- (A) VIDEO LIVE FEED -->
	<video id="cam-live" autoplay></video>

	<!-- (B) CONTROLS -->
	<div id="cam-controls">
	<input type="button" id="cam-take" class="material-icons"
	value="photo_camera" onclick="webcam.take()" disabled>
	<input type="button" id="cam-save" class="material-icons"
	value="download" onclick="webcam.save()" disabled>
	<input type="button" id="cam-upload" class="material-icons"
	value="upload" onclick="webcam.upload()" disabled>
	</div>

	<!-- (C) SNAPSHOTS -->
	<div id="cam-snaps"></div>
	</body>
	</html>
	var webcam = {
	// (A) INITIALIZE - GET USER PERMISSION TO ACCESS CAMERA
	hVid : null, hSnaps :null,
	init : () => {
	navigator.mediaDevices.getUserMedia({ video: true })
	.then(stream => {
	// (A1) GET HTML ELEMENTS
	webcam.hVid = document.getElementById("cam-live"),
	webcam.hSnaps = document.getElementById("cam-snaps");

	// (A2) "LIVE FEED" WEB CAM TO <VIDEO>
	webcam.hVid.srcObject = stream;

	// (A3) ENABLE BUTTONS
	document.getElementById("cam-take").disabled = false;
	document.getElementById("cam-save").disabled = false;
	document.getElementById("cam-upload").disabled = false;
	})
	.catch(err => console.error(err));
	},

	// (B) SNAP VIDEO FRAME TO CANVAS
	snap : () => {
	// (B1) CREATE NEW CANVAS
	let cv = document.createElement("canvas"),
	cx = cv.getContext("2d");

	// (B2) CAPTURE VIDEO FRAME TO CANVAS
	cv.width = webcam.hVid.videoWidth;
	cv.height = webcam.hVid.videoHeight;
	cx.drawImage(webcam.hVid, 0, 0, webcam.hVid.videoWidth, webcam.hVid.videoHeight);

	// (B3) DONE
	return cv;
	},

	// (C) PUT SNAPSHOT INTO <DIV> WRAPPER
	take : () => webcam.hSnaps.appendChild(webcam.snap()),

	// (D) FORCE DOWNLOAD SNAPSHOT
	save : () => {
	// (D1) TAKE A SNAPSHOT, CREATE DOWNLOAD LINK
	let cv = webcam.snap(),
	a = document.createElement("a");
	a.href = cv.toDataURL("image/png");
	a.download = "snap.png";

	// (D2) "FORCE DOWNLOAD" - MAY NOT ALWAYS WORK!
	a.click(); a.remove(); cv.remove();

	// (D3) SAFER - LET USERS MANUAL CLICK
	// webcam.hSnaps.appendChild(a);
	},

	// (E) UPLOAD SNAPSHOT TO SERVER
	upload : () => {
	// (E1) APPEND SCREENSHOT TO DATA OBJECT
	var data = new FormData();
	data.append("snap", webcam.snap().toDataURL("image/jpeg", 0.6));

	// (E2) UPLOAD SCREENSHOT TO SERVER
	fetch("save.php", { method:"post", body:data })
	.then(res => res.text())
	.then(txt => alert(txt));
	}
	};
	window.addEventListener("load", webcam.init);