Download Missing Last Chunk

PHP
1

I’m using the following script to download large file (>100Mb). It works well except that it seems to not ever save the final chunk. If the file is 149,499 on the server, it finishes its download at 145,996. Why? How do I get the last 2% or so to flush and complete the download? Thank much for your help.

FYI, this also happens the same on smaller files so its not stopping for time or file size issues.

 
$path = "the/file/path.mp4";

$headsize = get_headers($path,1);

$ext = str_from_last_occurrence($_vars['filepath'],".");

if ($ext=="mp3") { $type = "audio"; }
elseif ($ext=="mp4") { $type = "video"; }

function readfile_chunked($filename,$retbytes=true) {

	// Stream file
	$handle = fopen($filename, 'rb');
	$chunksize = 1*(1024*1024); // how many bytes per chunk
	$buffer = '';
	$cnt =0;

   if ($handle === false) {
       return false;
   }

   while (!feof($handle)) {
       $buffer = fread($handle, $chunksize);
       echo $buffer;
       ob_flush();
       flush();
       if ($retbytes) {
           $cnt += strlen($buffer);
       }
   }

   $status = fclose($handle);

   if ($retbytes && $status) {
       return $cnt; // return num. bytes delivered like readfile() does.
   }

   return $status;

}

header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate');
header("Content-type: ".$type."/".$ext);
header('Content-Length: ' . (string)($headsize['Content-Length']));
header('Content-Disposition: attachment; filename="'.str_from_last_occurrence($_vars['filepath'],"/").'"');
header("Content-Transfer-Encoding: binary");

readfile_chunked($path);

exit;