可以使用CADisplayLink和CALayer的add方法来手动同步AVPlayerLayer和AVSynchronizedLayer的动画播放。以下是示例代码：

// 创建AVPlayer对象和AVPlayerLayer图层
AVPlayer *player = [AVPlayer playerWithURL:url];
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
playerLayer.frame = self.view.bounds;
[self.view.layer addSublayer:playerLayer];

// 创建CADisplayLink并添加到主线程循环中
CADisplayLink *displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(displayLinkDidFire:)];
[displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];

- (void)displayLinkDidFire:(CADisplayLink *)displayLink {
    // 更新AVSynchronizedLayer的时间偏移量
    CFTimeInterval playerTime = CMTimeGetSeconds(self.player.currentTime);
    self.syncLayer.timeOffset = playerTime - self.syncLayerPlayerTime;
}

// 创建AVSynchronizedLayer图层并添加到主AVPlayerLayer上
AVSynchronizedLayer *syncLayer = [AVSynchronizedLayer synchronizedLayerWithPlayerItem:self.player.currentItem];
[self.playerLayer addSublayer:syncLayer];
self.syncLayer = syncLayer;

// 将AVSynchronizedLayer图层的播放器时间偏移量设置为0
self.syncLayerPlayerTime = CMTimeGetSeconds(self.player.currentTime);
self.syncLayer.timeOffset = 0.0;

在displayLinkDidFire方法中，更新AVSynchronizedLayer的时间偏移量以与AVPlayerLayer保持同步。通过将AVSynchronizedLayer添加到AVPlayerLayer上，可以确保两个图层始终处于同步状态。