线程1：xcode 7.3

Question

我有一个应用视频的应用，然后显示预览。

拍摄视频并发送到预览的代码部分如下：

 if(!self.camera.isRecording) {
        self.segmentedControl.hidden = YES;
        self.flashButton.hidden = YES;
        self.switchButton.hidden = YES;

        self.snapButton.layer.borderColor = [UIColor redColor].CGColor;
        self.snapButton.backgroundColor = [[UIColor redColor] colorWithAlphaComponent:0.5];

        // start recording
        NSURL *outputURL = [[[self applicationDocumentsDirectory]
                             URLByAppendingPathComponent:@"test1"] URLByAppendingPathExtension:@"mov"];
        [self.camera startRecordingWithOutputUrl:outputURL];
    }
    else {
        self.segmentedControl.hidden = NO;
        self.flashButton.hidden = NO;
        self.switchButton.hidden = NO;

        self.snapButton.layer.borderColor = [UIColor whiteColor].CGColor;
        self.snapButton.backgroundColor = [[UIColor whiteColor] colorWithAlphaComponent:0.5];

        [self.camera stopRecording:^(LLSimpleCamera *camera, NSURL *outputFileUrl, NSError *error) {
            VideoViewController *vc = [[VideoViewController alloc] initWithVideoUrl:outputFileUrl];
            [self.navigationController pushViewController:vc animated:YES];
        }];
    }

然后，视频被发送到名为VideoViewController的活动：

 @import AVFoundation;

 @interface VideoViewController ()
 @property (strong, nonatomic) NSURL *videoUrl;
 @property (strong, nonatomic) AVPlayer *avPlayer;
 @property (strong, nonatomic) AVPlayerLayer *avPlayerLayer;
 @property (strong, nonatomic) UIButton *cancelButton;
 @property (strong, nonatomic) UIButton *sendButton;
 @end

 @implementation VideoViewController

 -(instancetype)initWithVideoUrl:(NSURL *)url {
     self = [super init];
     if(self) {
         _videoUrl = url;
     }

     return self;
 }

-(void)viewDidLoad {
[super viewDidLoad];

self.view.backgroundColor = [UIColor whiteColor];

// the video player
self.avPlayer = [AVPlayer playerWithURL:self.videoUrl];
self.avPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;

self.avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];
//self.avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(playerItemDidReachEnd:)
                                             name:AVPlayerItemDidPlayToEndTimeNotification
                                           object:[self.avPlayer currentItem]];

CGRect screenRect = [[UIScreen mainScreen] bounds];

self.avPlayerLayer.frame = CGRectMake(0, 0, screenRect.size.width, screenRect.size.height);
[self.view.layer addSublayer:self.avPlayerLayer];

根据xcode，错误在self.avPlayer = [AVPlayer playerWithURL:self.videoUrl];部分。当我构建项目时出现self VideoViewController * 0x146b91d0

我该怎么办才能解决这个错误？