function is_ani($filename)
{
        $filecontents=file_get_contents($filename);

        $str_loc=0;
        $count=0;
        while ($count < 2) # There is no point in continuing after we find a 2nd frame
        {

                $where1=strpos($filecontents,"\x00\x21\xF9\x04",$str_loc);
                if ($where1 === FALSE)
                {
                        break;
                }
                else
                {
                        $str_loc=$where1+1;
                        $where2=strpos($filecontents,"\x00\x2C",$str_loc);
                        if ($where2 === FALSE)
                        {
                                break;
                        }
                        else
                        {
                                if ($where1+8 == $where2)
                                {
                                        $count++;
                                }
                                $str_loc=$where2+1;
                        }
                }
        }

        if ($count > 1)
        {
                return(true);

        }
        else
        {
                return(false);
        }
}