Check if a Buffer/Uint8Array is a m4a file.
$ npm install --save is-m4a
$ bower install --save is-m4a
$ component install hemanth/is-m4a
var readChunk = require('read-chunk'); // npm install read-chunk
var isM4a = require('is-m4a');
var buffer = readChunk('meow.m4a', 0, 8);
isM4a(buffer);
//=> true
var xhr = new XMLHttpRequest();
xhr.open('GET', 'meow.m4a');
xhr.responseType = 'arraybuffer';
xhr.onload = function () {
isM4a(new Uint8Array(this.response));
//=> true
};
xhr.send();
Accepts a Buffer (Node.js) or Uint8Array.
It only needs the first 4 bytes.
MIT © Hemanth.HM