为什么上传取消，服务器关闭连接

我正在上传一个14兆字节的视频文件，这是我的配置：

ini_set("max_execution_time", "180");
ini_set("upload_max_filesize", "300M");
ini_set("post_max_size", "300M");
ini_set("memory_limit", "300M");

我已经把它放在index.php文件和我的.htaccess:中了

addDefaultCharset UTF-8
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /
RewriteCond $1 !^(index'.php|uploads|robots'.txt|favicon'.ico)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

所以问题是，当我上传视频文件时，在状态栏中，我看到百分比增加了1%、2%、3%、4%、5%、6%、7%、8%、9%、10%、11%、12%、13$、14%、15%。。。等等。

当它达到19-20%时，它取消到0%，然后再次开始增加1%、2%、3%，我不明白为什么会发生这种情况？有人能给我解释一下吗？你吃过这样的东西吗？如何解决这个问题？，这个文件大约有14兆字节。。。。

<form action="" method="post" enctype="multipart/form-data">
<p>title</p>
<input type="text" name="title">
<p>video file</p>
<input type="file" name="video">
<p>cover file</p>
<input type="file" name="pic">
<p>description</p>
<textarea name="short_desc" style="width: 500px; height: 150px;"></textarea>
<p><input type="submit" value="add video" name="add"></p>
</form>

这是html上传表单…

这是codeIgniter:中的上传方法

public function add_video()
{
    if(!$this->is_admin){return false;}
    if(!$this->input->post('add')){
    $data['content'] = $this->load->view(ADMIN.'video/add', null, true);
    $this->load->view(ADMIN.'layout', $data);
    }
    else
    {
        $num = 1;
        if(is_dir("./uploads/videos/video".$num))
        {
            while(true)
            {
                $num++;
                if(!is_dir("./uploads/videos/video".$num))
                {
                    mkdir("./uploads/videos/video".$num);
                    break;
                }
            }
        }
        else
        {
            mkdir("./uploads/videos/video".$num);
        }

    $config['upload_path'] = "./uploads/videos/video".$num;
    $config['allowed_types'] = 'mov|mpeg|mp3|mp4|avi|flv';;
    $config['max_size'] = '0';
    $config['max_width']  = '0';
    $config['max_height']  = '0';
    $this->load->library('upload', $config);
    if ($this->upload->do_upload('video'))
    {
         $data = array('upload_data' => $this->upload->data());
         $file_name = $data['upload_data']['file_name'];
         $video_path = "./uploads/videos/video".$num.'/'.$file_name;
         $config['allowed_types'] = 'jpg|png|gif|bmp';
         $this->upload->initialize($config);
         if ($this->upload->do_upload('pic'))
         {
             $data = array('upload_data' => $this->upload->data());
             $file_name = $data['upload_data']['file_name'];
             $config['image_library'] = 'gd2';
             $config['source_image'] = "./uploads/videos/video".$num.'/'.$file_name;
             $config['create_thumb'] = FALSE;
             $config['maintain_ratio'] = FALSE;
             $config['width'] = 150;
             $config['height'] = 100;
             $this->load->library('image_lib', $config); 
             $this->image_lib->resize();
             $image_path = $config['source_image'];

         }
         else
         {
            redirect(base_url().'admin/add_video');
         }
    }
    else
    {
        redirect(base_url().'admin/add_video');
    }
    $data = array();
    $data['title'] = $this->input->post('title');
    $data['short_desc'] = strip_tags($this->input->post('short_desc'));
    $data['video_path'] = $video_path;
    $data['image_path'] = $image_path;
    $data['date'] = date('y-m-d h:i:s');
    $this->load->model('video_model');
    $this->video_model->add($data);
    redirect(base_url().'admin/add_video');

    }
}

很抱歉有太多的代码，但你能在这里找到一些导致这个问题的bug吗？