capture-video-frame

A micro-library for taking screenshots from a running HTML5 video. Built to work together with getUserMedia.js

Installation

$ npm install --save capture-video-frame

Example

HTML:

<video id="my-video" autoplay>
  <source src="movie.mp4" type="video/mp4" />
</video>
 
<img id="my-screenshot" />

JavaScript:

import captureVideoFrame from "capture-video-frame.js";
 
// When you want to record the image
const frame = captureVideoFrame("my-video-id", "png");
 
// Show the image
const img = document.getElementById("my-screenshot");
img.setAttribute("src", frame.dataUri);
 
// Upload the image...
const formData = new FormData();
formData.append("file", frame.blob, `my-screenshot.${frame.format}`);
 
// ...with plain JS
const request = new XMLHttpRequest();
request.open("POST", "/api/upload", true);
request.setRequestHeader(
  "Content-Type",
  "application/multipart/form-data; charset=UTF-8"
);
request.send(formData);
 
// ...or with jQuery
$.ajax({
  url: "/api/upload",
  method: "POST",
  data: formData,
  processData: false,
  contentType: false,
});

Browser support

Tested on current Chrome and Firefox.

API

captureVideoFrame(source, format, quality)

Parameters

source (element or string, mandatory) Source video. If string, id of the element.

format (string, optional) Output image format. Can be either png or jpeg. png is the default.

quality (number, optional) A Number between 0 and 1 indicating image quality if the requested type is image/jpeg or image/webp. The default value is 0.92.

Return value

• Object with blob, dataUri, and format properties if the capture succeeded
• false if the capture failed.

Image blob can be easily uploaded to the server using XHR2 FormData API.

Image data URI can be easily set as <img> src attribute to show the captured image.

License

MIT