record-page v1.0.1

record-page

Library for recording web page as high resolution video with specified frame rate using Headless Chrome.

Uses virtual time budgeting under the hood. Produces smooth video as each frame, before capture, is given enough time to flush all changes to the screen.

Note: Library uses HeadlessExperimental domain of Chrome DevTools Protocol, as the name indicates it's experimental, so it may stop working with future Chrome updates. Confirmed to work correctly on Chrome 80.

Install

$ npm install record-page

Requirements

• Chrome launcher needs to be able to start Chrome instance.

• ffmpeg is required to be installed in order to render video files (also available as a command ffmpeg).

Usage

const record = require('record-page');

(async () => {
  await record({
    url: 'https://animejs.com/',
    maxFramesCount: 150,
  });
  console.log('Finished, video.mp4 generated!');
})();

Frames recording can be stopped by defining maxFramesCount parameter or calling window.RECORDING_STOP() function in page context.

Docs

Config

url

Type: string Required

URL of page to be recorded.

filename

Type: string Default: 'video'

Result file filename.

framesDir

Type: string Default: 'frames'

Name of directory where video frames will be saved.

framesPerSecond

Type: number Default: 30

Frame rate at which frames will be saved and then video generated.

maxFramesCount

Type: number

Defines after how many frames should recording stop.

width

Type: number Default: 1920

Window width.

height

Type: number Default: 1080

Window height;

delay

Type: number Default: 0

Delay recording by given ms duration. Applied right after page load.

shouldWaitForRecordStart

Type: boolean Default: false

If false then recording will start immediately, otherwise only after window.RECORDING_START() will be called in page context.

shouldApplyReflow

Type: boolean Default: true

In order for frame changes to be flushed and visible on screenshot in most cases forced reflow should be applied. If set to true then page is forced to reflow in requestAnimationFrame callback (it doesn't hurt performance as virtual time is used here).

expression

Type: string

Expression to be evaluated in page context. Useful for interactions with page.

audio

Type: object

Defines audio configuration applied when rendering video.

{
  path: string,
  loop: boolean,
  // in seconds
  fadeInDuration: number,
  fadeOutDuration: number,
}

chrome

Type: object

Chrome launch options.

{
  headless?: boolean,
  port?: number,
  debug?: boolean,
  flags?: string[],
}

onInit

Type: callback

Callback executed after client is initialized. chrome-remote-interface client is passed as an argument.

Roadmap

• easier interactions with page (maybe with Puppeteer?)
• more precise handling when recording stops
• allow modifying params passed to ffmpeg
• testing