Youtube FullScreen Video Screenshot - Bookmarklet

yt-fs-video-screenshot.js

javascript:(function(){
  try{
    function exitFS(){
      let d=document;
      (d.exitFullscreen||d.webkitExitFullscreen||d.mozCancelFullScreen||d.msExitFullscreen)?.call(d);
    }
    function requestFS(el){
      (el.requestFullscreen||el.webkitRequestFullscreen||el.mozRequestFullScreen||el.msRequestFullscreen)?.call(el);
    }

    var v=document.querySelector("video");
    if(!v){alert("No video found!");return;}

    if(confirm("Enter fullscreen mode before capturing?")){
      requestFS(v);
      setTimeout(capture,400);
    } else {
      capture();
    }

    function capture(){
      var c=document.createElement("canvas");
      c.width=v.videoWidth;
      c.height=v.videoHeight;
      var x=c.getContext("2d");
      x.drawImage(v,0,0,c.width,c.height);
      var a=document.createElement("a");
      a.href=c.toDataURL("image/jpeg");
      a.download="video_screenshot_"+Date.now()+".jpg";
      a.click();
      exitFS();
    }

  }catch(e){alert("Screenshot error: "+e);}
})();