protected function fread($bytes) {
    if ($this->data_string_flag) {
      $this->data_string_position += $bytes;
      return substr($this->data_string, $this->data_string_position - $bytes, $bytes);
    }
    if ($bytes == 0) {
      return '';
    } elseif ($bytes < 0) {
      throw new getid3_exception('cannot fread('.$bytes.' from '.$this->getid3_handler::ftell().')', 10);
    }
    $pos = $this->getid3_handler::ftell() + $bytes;
    if (!getid3_lib::intValueSupported($pos)) {
      throw new getid3_exception('cannot fread('.$bytes.' from '.$this->getid3_handler::ftell().') because beyond PHP filesystem limit', 10);
    }

    //return fread($this->getid3->fp, $bytes);
    /*
		* https://www.getid3.org/phpBB3/viewtopic.php?t=1930
		* "I found out that the root cause for the problem was how getID3 uses the PHP system function fread().
		* It seems to assume that fread() would always return as many bytes as were requested.
		* However, according the PHP manual (http://php.net/manual/en/function.fread.php), this is the case only with regular local files, but not e.g. with Linux pipes.
		* The call may return only part of the requested data and a new call is needed to get more."
		*/
    $contents = '';
    do {
      //if (($this->getid3->memory_limit > 0) && ($bytes > $this->getid3->memory_limit)) {
      if (($this->getid3->memory_limit > 0) && (($bytes / $this->getid3->memory_limit) > 0.99)) { // enable a more-fuzzy match to prevent close misses generating errors like "PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 33554464 bytes)"
        throw new getid3_exception('cannot fread('.$bytes.' from '.$this->getid3_handler::ftell().') that is more than available PHP memory ('.$this->getid3->memory_limit.')', 10);
      }
      $part = fread($this->getid3->fp, $bytes);
      $partLength  = strlen($part);
      $bytes      -= $partLength;
      $contents   .= $part;
    } while (($bytes > 0) && ($partLength > 0));
    return $contents;
  }