CSE-Media/core/submit/video.add.php

<?php 

if(isset($_FILES["videoFile"]["tmp_name"])){
    $idVideo = fichier::add($_FILES["videoFile"], $_POST);
    if($idVideo != FALSE) {
        echo json_encode(['id' => $idVideo]);
        exit();
    }
} else {
    header("Location: /");
    exit();
}