Hi Guys

Sometime might be same to me you need that uploaded file name must be unquie or untamper so that you can use this snip code to resolve your issue.

<?php
function vv_video_file_conflict_file_insert($file) {
  // Here in split file uri into chuncks because i want to implement this code
  // for specific directory of the files
  //  public://videos/original/job/---here-are-my-files
  $expload = explode('/', $file->uri);
  if($expload['2'] == 'videos' && $expload['3'] == 'original' && $expload['4'] == 'job'  ) {
    $newuri = vv_video_file_conflict_rename_with_unique($file->uri);
    file_move( $file, $newuri, FILE_EXISTS_REPLACE);
    $file->filename = $name;
  }
}

function vv_video_file_conflict_rename_with_unique($uri) {
     $expload = explode('/', $uri);
     $fname = end($expload);
     $without_ext = preg_replace('/\.[a-z0-9]+$/', '', $fname);
     if(preg_match('/\.[a-z0-9]+$/', $fname, $match)) {
       $new_name = $without_ext.uniqid('_unique_id_').'_'.mt_rand();
       $expload[count($expload) - 1] = $new_name.$match[0];
       $newuri = join( '/', $expload);
       return $newuri;
     }
 
}
?>

Supposed you uploads a file with name test.flv then code rename its uri to something like this test_unique_id_525795a9144a5_1308199621.flv.
without code: public://videos/original/job/test.flv
with code: public://videos/original/job/test_unique_id_525795a9144a5_1308199621.flv