Get file to download directly

download.php

<?php 
if(!empty($_GET['file'])) { 
   $filename = filter_input(INPUT_GET, 'file', FILTER_SANITIZE_STRING);

   if(strpos(basename($filename), 'jpg') !== false) {
      $basename = "/content/images/full/";
   }else if(strpos(basename($filename), 'mp4') !== false) {
      $basename = "/content/videos/full/";
   }else{
      $basename = "/file/";
   }
   $filepath = realpath(dirname(__FILE__)).$basename.$filename; // don't accept other directories 
   //echo $filepath;
   $mime = mime_content_type($filepath);
   $fp = @fopen($filepath, "rb"); 
   if ($fp) 
   { 
      header("Content-type: {$mime}"); 
      header("Content-Length: " . filesize($filepath)); 
      header("Content-Disposition: attachment; filename=$filename"); 
      header('Content-Transfer-Encoding: binary'); 
      header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
      fpassthru($fp); 
      exit; 
   } else {
      echo "file does not exist";
   }
} else {
   header("HTTP/1.0 404 Not Found");    
   echo "string";
}