Easy typescript camera

Version 1.1.2

This package helps you to add camera support to your web application easily and support front and rear camera out of the box.

npm install easy-ts-camera

This package is created based on easy-js-camera with some improvements and typescript support.

easy-js-camera link

Usage

Add your video and canvas as follow,

<video autoplay playsinline></video>
<canvas></canvas>

Import the Camera class as follow,

import ETC from 'easy-ts-camera';

To be able to access to all Video Inputs you first need to get the permission from the user.
Note: On some devices it is not needed to first get the permission but it is better to do that first since on some devices if the permission is not granted it doesn't return all the devices.

var video = document.getElementsByTagName('video')[0];
var canvas = document.getElementsByTagName('canvas')[0];
ETC.initWithUserCamera()
    .streamFrom(video)
    .drawInto(canvas)
    .getCameraAsync()
    .then(camera => {
        camera.startAsync()
    })
    .catch(error => {
        // Mostly happens if the user blocks the camera or the media devices are not supported
    });

Note: In order to make sure that the browser supports MediaDevices you can do as follow.

import { CameraUtils } from 'easy-ts-camera';

CameraUtils.isCameraSupported();

Camera object props

• devices: Contains an array of available VideoInput devices
• builder: An instance of the CameraBuilder class which contains the HtmlVideoELement and HtmlCanvasElement and also the MediaConstraints.
  • Builder now has a method to pick 4K resolution if available by the camera. call pick4KResolution before getting the camera.
  • Builder also supports the FullHD resolution. Please call this method before building camera.

Methods

• getDevicesAsync: Returns a promise which if is successfull will deliver an array of MediaDeviceInfo and if not will log an error.
• snap: This method will take a picture and will return the canvasElement so you can extract the picture as whatever format you like. Note: by default, this method will stop the camera. You can pass the stop as boolean to prevent this behavior.
• snapAsDataUrl: This method will take a picture and will return it as a dataUrl string.
• snapAsBlobAsync: This method will take a picture and will return a promise which on success will deliver a blob.
• startAsync: This method starts the camera and will return a promise.
• stop: This method is responsible for stoping the stream.
• switchAsync: This method switches the camera between front and rear. This method returns a promise. It is better that you disable the switch camera button while it is doing its job because on some phones with motorized selfie camera if the user press the button multiple times the camera will hang and will just stickout and no longer works unless he/she restarts the phone. Please Note that this method accept a boolean which is called tryAgain and it basically tries to access the rear camera. Sometime the rear camera is not accessible and on catch you can do something like below

  function switchCamera(tryAgain = false) {
      this.camera.switchAsync(tryAgain)
          .catch(() => {
              if(tryAgain) return; // This line prevents loops. Because the tryAgain may also fail
              this.switchCamera(true);
          });
  }

• multipleCameras: This method will check if there are more than one cameras are available. Useful when you want to show a switchCamera button