video-thumb-generator

Generate/capture screenshots from videos on the fly over HTML5

This library will let you grab screenshots from video tracks that supported by modern web browsers and will give you standard images (ObjectURL or base64 DataURL)

Demo

https://imshaikot.github.io/video-thumb-generator/

Installation

$ npm install video-thumb-generator --save

OR umd builds are also available

<script src="https://unpkg.com/video-thumb-generator/umd/VideoToThumb.min.js"></script>

Getting Started

This is a tiny library to get screenshots from video tracks either from your local filesytem OR same-origin based URL.

// Using ES6
import VideoToThumb from 'video-thumb-generator'; // This is a default export, so you don't have to worry about the import name
 
// Not using ES6
var VideoToThumb = require('video-thumb-generator');

Example and API

The constructor accepts 3 types of value as its parameter.

1. HTML5 File Object (Ex. dataTransfer.files[0])
2. Any existing/active HTML Video element's DOM object/instance (Ex. document.getElementById('video'))
3. Same origin video URL as string. (Ex. 'http://mydomain.com/video.avi')

const videoToThumb = new VideoToThumb(file.files[0]); // OR you could pass instantiate new VideoToThumb('http://mydomain.com/video.mp4') OR maybe new VideoToThumb(document.getElementById('video'))

The instance of VideoToThumb contains a bunch of method (which are chained) but to get strated you have to call the load() method before any other chained method being called

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load(); // This will start the process

After the .load() being called then you're free to call other methods. Like .positions([]) method - this method will accept a parameter as an Array of the positions (in second) of video duration where you want to capture the screenshots. The Defualt value is [1]

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.positions([223, 555, 632, 104]);

In order to set the returned screenshots size - you can call .size([320, 240]) - default is [320, 240]

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.positions([223, 555, 632, 104])
.size([480, 360]); // 480x360 pixel

You can also customize the screenshot coordinates by calling xy([0, 0]) this method. This method will decide from which coordinate to start capturing the snapshots.

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.positions([223, 555, 632, 104])
.xy([0, 0])
.size([480, 360]);

Another method type() - this method to tell whether you want the image to be returned as base64 dataURL OR HTML5 objectURL - default 'objectURL'

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.xy([0, 0])
.size([480, 360])
.positions([223, 555, 632, 104])
.type('base64')

In order to track errors during the process (media, canvas or input) - this method will help you to track and this method accept a parameter of errorCallback Caution: Few Media Errors are still silent and won't reach the error callback (I'll work to get it done)

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.xy([0, 0])
.size([480, 360])
.positions([223, 555, 632, 104])
.type('base64')
.error(function(err) {
  console.log(JSON.stringify(err));
})

And finally the done(callback) method. Remember the load() method to start and now done to end the process and your job done. This method accept a parameters successCallback. The success callback returns the successive screenshots that have been taken as an array.

const videoToThumb = new VideoToThumb(file.files[0]);
videoToThumb
.load()
.xy([0, 0])
.size([480, 360])
.positions([223, 555, 632, 104])
.type('base64')
.error(function(err) {
  console.log(JSON.stringify(err));
})
.done(function(imgs) {
  imgs.forEach(function(img) {
    var elem = new Image();
    elem.src = img;
    document.body.appendChild(elem);
  })
})

Note: All methods are chained, that means every method returns the same instance/context and that means you can call any method in any order but load() method must be called at the top and done() at the bottom, unless you want some silent errors ;)

Warnings: few errors are still silent and won't reach the error callback. Feel free to make pull request.

LICENSE

MIT