Script to extract youtube video sources

yt_sourcer.js

// https://www.youtube.com/watch?v=ZkZdMA5Ia7I
var stags = [];
stags.push.apply(stags, document.querySelectorAll('#player script'));

stags = stags
  .map(s => s.innerText)
  .filter(s => s.indexOf('url_encoded_fmt_stream_map') > -1)
  .map(s => s.split('url_encoded_fmt_stream_map')[1].split('"')[2].split(','))
  .map(s => s.map(decodeURIComponent).map(u => u.split("\\u0026")))
  .map(s => s.map(u => {
  var obj = {};
  u.forEach(entry => {
    const key = entry.split('=')[0];
    obj[key] = entry.replace(`${key}=`, '');
  });
  return obj;
}));

JSON.stringify(stags, null, ' ')

/*
[
 [
  {
   "type": "video/mp4;+codecs=\"avc1.64001F,+mp4a.40.2\"",
   "url": "https://r1---sn-hxugv4pcgx-woce.googlevideo.com/videoplayback?expire=1557430278&ei=pSvUXI3RPKyNxgKbrZ3gDA&ip=196.192.186.146&id=o-AO9YiavFGknz_TUZDn8LzHMERipzRSQQF5bdU2QkUxGK&itag=22&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-hxugv4pcgx-woce%2Csn-hfxc-wocl&ms=au%2Crdu&mv=m&pl=19&initcwndbps=546250&mime=video%2Fmp4&ratebypass=yes&dur=1550.883&lmt=1532910186376864&mt=1557408580&fvip=4&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cratebypass%2Cdur%2Clmt&sig=ALgxI2wwRQIgA854SE4Smkui465ttFYnmXMZOLY3Xf_cRbrkhXqjoMMCIQC1V94ZxH3kP8OEudf_0s4t_QDo0jAasZAK6RTNitF9vw%3D%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgArD-W3iQ1u9CLG16De5A7p1XF_H_FRQWtfkmKmASrsUCID6rJ6ghbENmQQ9PzKHch_vEHVCkufawfXPekMoZTFRh",
   "quality": "hd720",
   "itag": "22"
  },
  {
   "type": "video/webm;+codecs=\"vp8.0,+vorbis\"",
   "url": "https://r1---sn-hxugv4pcgx-woce.googlevideo.com/videoplayback?expire=1557430278&ei=pSvUXI3RPKyNxgKbrZ3gDA&ip=196.192.186.146&id=o-AO9YiavFGknz_TUZDn8LzHMERipzRSQQF5bdU2QkUxGK&itag=43&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-hxugv4pcgx-woce%2Csn-hfxc-wocl&ms=au%2Crdu&mv=m&pl=19&initcwndbps=546250&mime=video%2Fwebm&gir=yes&clen=143238550&ratebypass=yes&dur=0.000&lmt=1524321709993319&mt=1557408580&fvip=4&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cratebypass%2Cdur%2Clmt&sig=ALgxI2wwRQIgBc5QptTE6lEi30qPFOHP4VyOVVCdJXaB-KzUTGXgzIsCIQCVsJ05tLgq6Rt9adYyCtZtubzeVCFgKaVbEKSnGn1IAw%3D%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgArD-W3iQ1u9CLG16De5A7p1XF_H_FRQWtfkmKmASrsUCID6rJ6ghbENmQQ9PzKHch_vEHVCkufawfXPekMoZTFRh",
   "quality": "medium",
   "itag": "43"
  },
  {
   "type": "video/mp4;+codecs=\"avc1.42001E,+mp4a.40.2\"",
   "url": "https://r1---sn-hxugv4pcgx-woce.googlevideo.com/videoplayback?expire=1557430278&ei=pSvUXI3RPKyNxgKbrZ3gDA&ip=196.192.186.146&id=o-AO9YiavFGknz_TUZDn8LzHMERipzRSQQF5bdU2QkUxGK&itag=18&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-hxugv4pcgx-woce%2Csn-hfxc-wocl&ms=au%2Crdu&mv=m&pl=19&initcwndbps=546250&mime=video%2Fmp4&gir=yes&clen=96964919&ratebypass=yes&dur=1550.883&lmt=1524319451237085&mt=1557408580&fvip=4&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cratebypass%2Cdur%2Clmt&sig=ALgxI2wwRQIhAJXwnKClGK1_6CJWrLUTzg2B6Z3RnK2MTMLgV445fhxuAiB3-xaU4g3eJSYk5igJYnoHmueESlVmOhhEZ_ttM7Y7cA%3D%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgArD-W3iQ1u9CLG16De5A7p1XF_H_FRQWtfkmKmASrsUCID6rJ6ghbENmQQ9PzKHch_vEHVCkufawfXPekMoZTFRh",
   "quality": "medium",
   "itag": "18"
  }
 ]
]
*/

cool script but how do i call it or use it from html ?

@putout This is javascript that only serves to demonstrate how you'd unpack the information from the page. You can run it directly in your browser's console from the dev tools, but to include it in any sort of project you will have to make some changes.