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chrome-headlessHow to capture video using Chrome Remote Interface


We can record video by using screen cast interface to generate series of frames and then using ffmpeg to generate final video:

const chromeLauncher = require('chrome-launcher');
const CDP = require('chrome-remote-interface');
const fs = require('fs');

chromeLauncher.launch({ port: 9222, chromeFlags: [ '--window-size=1280,720', '--headless' ] }).then(function(chrome) {
  CDP(async (client) => {
    const {Page} = client;

    await Page.enable();
    await Page.navigate({url: 'https://github.com'});
    await Page.loadEventFired();
    await Page.startScreencast({format: 'png', everyNthFrame: 1});
    
    let counter = 0;
    while(counter < 25){
      const {data, metadata, sessionId} = await Page.screencastFrame();
      await Page.screencastFrameAck({sessionId: sessionId});
      
      fs.writeFileSync('screen-' + counter + '.png', Buffer.from(data, 'base64'));
      counter += 1;

      console.log(metadata.timestamp);
    }
    
    await client.close();
    chrome.kill();
  });
});ctrl + c
require('chrome-launcher')

Chrome-Launcher library to start/stop Chrome browser programmatically

require('chrome-remote-interface')

Chrome-Remote-Interface library to operate

Page.startScreencast

starts screen cast process in PNG format

Page.screencastFrame

get generated screen cast frame

fs.writeFileSync

save given screen frame buffer to file

'screen-' + counter + '.png'

use file name with counter variable to generate sequence of images

client.close

close remote debugging interface connection

chrome.kill()

close browser