test-file-name.php

/*mile test */
function make_filename_hash($filename) {
    if( isset($_REQUEST['post_id']) ) {
        $post_id =  (int)$_REQUEST['post_id'];
    }else{
        $post_id=0;
    }

    $info = pathinfo($filename);
    $ext  = empty($info['extension']) ? '' : '.' . $info['extension'];
    $name = "imported";

    if($post_id>0){
        return get_the_title($post_id)."_".$name . $ext;
    }else{
        return $name . $ext;
    }
}
add_filter('sanitize_file_name', 'make_filename_hash', 10);