move_upload_file not work for upload video - php

Question

I want to upload video (like mp4, wvm, flv) with form submit but move_file_upload() not working.
This is my code :
<?php
if (isset($_POST['submit'])) {
$errors = array();
$allowed_e = array('mp4', 'flv', 'wmv');
$file_name = $_FILES['video2']['name'];
$file_e = strtolower(pathinfo($file_name, PATHINFO_EXTENSION));
$file_s = $_FILES['video2']['size'];
$file_tmp = $_FILES['video2']['tmp_name'];
$t_name = #$_POST['topic_name'];
$content = #$_POST['content'];
$date = date("y-m-d");
if (in_array($file_e, $allowed_e) == false) {
$errors[] = 'ext not allowed';
}
if ($file_s > 20097152) {
$errors[] = 'File must be under 20mb';
}
if (empty($errors)) {
$rawBaseName = pathinfo($file_name, PATHINFO_FILENAME );
$extension = pathinfo($file_name, PATHINFO_EXTENSION );
$counter1 = 1;
$counter2 = 1;
while(file_exists('video/'.$file_name)) {
$file_name = $rawBaseName . $counter1 . $counter2 .'.' . $extension;
$counter1++;
$counter2++;}
move_uploaded_file($file_tmp, 'video/'.$file_name);
$video2_up = 'video/'.$file_name;
if ($posttopic = "INSERT INTO topics (topic_id, topic_name, topic_content, topic_creator, date, video)
VALUES ('', '".$t_name."', '".$content."', '".$_SESSION["username"]."', '".$date."', '".$video2_up."')" ){
$conn->exec($posttopic);
}header("Location: index.php");
}else{
foreach ($errors as $error) {
echo $error, '</br>';
}
}
}
?>
But when I remove that extension allowed and upload some image it works
please give me solution.

Answer 1

I think the problem is with the file size. Check your php.ini file and increase the limit for following php directives:
post_max_size = 20M
upload_max_filesize = 20M
After making the above changes, restart you web server.