Webcam Component for React

react-webcam

Webcam component for React. See http://caniuse.com/#feat=stream for browser compatibility.

Note: Browsers will throw an error if the page is loaded from insecure origin. I.e. Use https.

Installation

npm install react-webcam

Demo

https://codepen.io/mozmorris/pen/JLZdoP

Usage

import React from "react";
import Webcam from "react-webcam";

const WebcamComponent = () => <Webcam />;

Props

The props here are specific to this component but one can pass any prop to the underlying video tag eg className or style

prop	type	default	notes
audio	boolean	true	enable/disable audio
audioConstraints	object		MediaStreamConstraint(s) for the audio
forceScreenshotSourceSize	boolean	false	uses size of underlying source video stream (and thus ignores other size related props)
imageSmoothing	boolean	true	pixel smoothing of the screenshot taken
mirrored	boolean	false	show camera preview and get the screenshot mirrored
minScreenshotHeight	number		min height of screenshot
minScreenshotWidth	number		min width of screenshot
onUserMedia	function	noop	callback for when component receives a media stream
onUserMediaError	function	noop	callback for when component can’t receive a media stream with MediaStreamError param
screenshotFormat	string	‘image/webp’	format of screenshot
screenshotQuality	number	0.92	quality of screenshot(0 to 1)
videoConstraints	object		MediaStreamConstraints(s) for the video

Methods

getScreenshot - Returns a base64 encoded string of the current webcam image. Example:

https://codepen.io/mozmorris/pen/gOOoqpw

You may also pass in an optional dimensions object:

getScreenshot({width: 1920, height: 1080});

The Constraints

We can build a constraints object by passing it to the videoConstraints prop. This gets passed into getUserMedia method. Please take a look at the MDN docs to get an understanding how this works.

https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia https://developer.mozilla.org/en-US/docs/Web/API/Media_Streams_API/Constraints

As an example take a look at this CodePen demo https://codepen.io/mozmorris/pen/GRpEQwK?editors=0010 which shows how to build a custom aspect ratio for the video.

const videoConstraints = {
  width: 1280,
  height: 720,
  facingMode: "user"
};

const WebcamCapture = () => {
  const webcamRef = React.useRef(null);

  const capture = React.useCallback(
    () => {
      const imageSrc = webcamRef.current.getScreenshot();
    },
    [webcamRef]
  );

  return (
    <>
      <Webcam
        audio={false}
        height={720}
        ref={webcamRef}
        screenshotFormat="image/jpeg"
        width={1280}
        videoConstraints={videoConstraints}
      />
      <button onClick={capture}>Capture photo</button>
    </>
  );
};

Capturing video

It is posible to capture video with <Webcam /> using the MediaStream Recording API.

You can find an exammple https://codepen.io/mozmorris/pen/yLYKzyp?editors=0010.

Choosing a camera

User/Selfie/forward facing camera

class WebcamCapture extends React.Component {
  render() {
    const videoConstraints = {
      facingMode: "user"
    };

    return <Webcam videoConstraints={videoConstraints} />;
  }
}

Environment/Facing-Out camera

class WebcamCapture extends React.Component {
  render() {
    const videoConstraints = {
      facingMode: { exact: "environment" }
    };

    return <Webcam videoConstraints={videoConstraints} />;
  }
}

For more information on facingMode, please see the MDN web docs https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackConstraints/facingMode

Show all cameras by deviceId

const WebcamCapture = () => {
  const [deviceId, setDeviceId] = React.useState({});
  const [devices, setDevices] = React.useState([]);

  const handleDevices = React.useCallback(
    mediaDevices =>
      setDevices(mediaDevices.filter(({ kind }) => kind === "videoinput")),
    [setDevices]
  );

  React.useEffect(
    () => {
      navigator.mediaDevices.enumerateDevices().then(handleDevices);
    },
    [handleDevices]
  );

  return (
    <>
      {devices.map((device, key) => (
          <div>
            <Webcam audio={false} videoConstraints={{ deviceId: device.deviceId }} />
            {device.label || `Device ${key + 1}`}
          </div>

        ))}
    </>
  );
};

Recording a stream

https://codepen.io/mozmorris/pen/yLYKzyp?editors=0011

Using within an iframe

The Webcam component will fail to load when used inside a cross-origin iframe in newer version of Chrome (> 64). In order to overcome this security restriction a special allow attribute needs to be added to the iframe tag specifying microphone and camera as the required permissions like in the below example:

<iframe src="https://my-website.com/page-with-webcam" allow="camera; microphone;"/>

Download Details:

Author: mozmorris

Live Demo: https://codepen.io/mozmorris/pen/JLZdoP

GitHub: https://github.com/mozmorris/react-webcam

#react #reactjs #javascript