App保存所选的视频数据iOS

Question

所以我有这个应用程序，用户使用UIImagePickerController从相机胶卷加载视频，我的代码如下所示：

var videosPlaylist:NSMutableArray! = NSMutableArray()

func loadVideo()
{
    let picker = UIImagePickerController()
    picker.shouldAutorotate()
    picker.delegate = self
    picker.sourceType = .SavedPhotosAlbum
    picker.allowsEditing = false
    picker.videoQuality = .TypeHigh
    picker.mediaTypes = NSArray(object: kUTTypeMovie) as! [String]
    presentViewController(picker, animated: true, completion: nil)
}

然后在imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject])代码看起来像这样：

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) 
{
    let url:NSURL = NSURL(string: "\(info["UIImagePickerControllerMediaURL"]!)")!
    let videoURL = url
    if videosPlaylist.count > 0 //This way I get the user to save just one video to the array.
    {
        videosPlaylist.replaceObjectAtIndex(0, withObject: videoURL)
    }else if videosPlaylist.count == 0
    {
        videosPlaylist.addObject(videoURL)
    }
    dismissViewControllerAnimated(true, completion: nil)
}

现在的问题是，每次用户选择视频时，iPhone存储中的“文档和数据”都会不断增加。

如果我从未使用NSUserDefaults保存数据，如何停止应用保存视频数据？