How get a buffer object from input type=file in html5 like fs readFile in nodejs

Question

//html5

let file = document.getElementById('input').files[0];
console.log(file);

//nodejs

const md5 = require('md5')
const fs = require('fs')
fs.readFile('xxx.mp4', (err, data) => {
  console.log(data);
});

i want get the same value between md(file) and md(data).
how escape the object file to buffer? How get a buffer object from input type=file in html5 like fs readFile in nodejs

thanks!!!