When handling file uploads its handy to check beforehand if the file fits insides the restrictions PHP sets in its ini file. To determine these the following functions are really handy:

function getShortInBytes($val) {
	$val = trim($val);
	$last = strtolower($val[strlen($val) - 1]);
	switch ($last) {
		case 'g':
			$val *= 1024;
		case 'm':
			$val *= 1024;
		case 'k':
			$val *= 1024;
	}
	return $val;
}

function getMaxFilesize() {
	$maxUpload = getShortInBytes(ini_get('upload_max_filesize'));
	$maxPost = getShortInBytes(ini_get('post_max_size'));
	if($maxPost<=$maxUpload){
		return $maxPost;
	}
	return $maxUpload;
}

With these you get the smallest possible filesize you can upload to the server. Make sure to also check the size when submitting:

$(function() {
    $('#videoFile').change(function() {
        if (this.files[0].size >= maxFileSize) {
            $(this).parents('.form-group').addClass('has-error').removeClass('has-success');
        }else{
            $(this).parents('.form-group').addClass('has-success').removeClass('has-error');
        }
    });

    //Prevent submission when not a valid file
    $('#submitCheck').on('submit', function(e) {
        if ($(this).find('.has-error').size() > 0) {
            e.preventDefault();
        }
    })
});