The second parameter in move_uploaded_file() needs to be the full path (you can use [man]realpath/man to help get the path to the current directory). I'd also suggest capturing the output of the move_uploaded_file function. It can return true or false depending upon if the file is moved.
The reason your videos end up in the wrong spot is because you're moving them to a folder that is the files name in the directory where this script is.
From the looks of it, your path should be something like:
$file_path1 = $_SERVER['DOCUMENT_ROOT'].'/html/video/'.$file_Name;
$file_path2 = $_SERVER['DOCUMENT_ROOT'].'/html/video/thumb/'.$file2_Name;
Note that you also should make sure you use the paths above as part of the recursive directory creation function you have.