mysql - Issue uploading WebM files using PHP -

i want able upload webm files on server simple upload script. able upload jpg's , png's server write them sql database, when using webm, file fails succesfully uploaded. however, create filename , redirect me file, doesn't exist. here section of code uploading webm files. appreciated.

                    if($file['type'] == "video/webm")                     {                         $seed = str_split('abcdefghijklmnopqrstuvwxyz'.'abcdefghijklmnopqrstuvwxyz'); // , other characters                         shuffle($seed);                         $rand = '';                         foreach (array_rand($seed, 6) $k)                          $rand .= $seed[$k];                         $filename = $rand.".webm";                         $dir = "uploads/".$filename;                          while(file_exists($dir))                         {                             $seed = str_split('abcdefghijklmnopqrstuvwxyz'.'abcdefghijklmnopqrstuvwxyz'); // , other characters                             shuffle($seed);                             $rand = '';                             foreach (array_rand($seed, 6) $k)                              $rand .= $seed[$k];                             $filename = $rand.".webm";                             $dir = "u/".$filename;                           }                             $host="localhost";                             $username="";                              $password="";                              $db_name="removed";                              $tbl_name="removed";                              $ipaddress = $_server['remote_addr'];                              mysql_connect("$host", "$username", "$password")or die("cannot connect server ");                              mysql_select_db("$db_name")or die("cannot select db");                              $datetime=date("y-m-d h:i:s");                             $sql="insert $tbl_name(filename, datetime)values('$filename', '$datetime')";                             $result=mysql_query($sql);                             mysql_close();                              move_uploaded_file($file['tmp_name'], $dir);                             header( 'location: u/'.$filename ) ;                       } 

i assume has way define filetype, can't find information on internet it. video/webm correct definition? don't know.

thanks.