Memory Leakage During Full Screen Movie Playback in AVPlayerViewController

import UIKit
import AVKit
import AVFoundation

classMoviePlayViewController:UIViewController {

  varplayerViewController —AVPlayerViewController!

  override func viewDidLoad(){
    super.viewDidLoad()

    self.playerViewController=AVPlayerViewController()
    self.playerViewController.view.frame = CGRectMake(0,64,320,240)

    let path = NSBundle.mainBundle().pathForResource("hoge", ofType:"mp4")
    let url = NSURL (fileURLWithPath:path!)

    self.playerViewController.player=AVPlayer (URL: url)
    self.view.addSubview(self.playerViewController.view)
    self.addChildViewController (self.playerViewController)
    self.playerViewController.didMoveToParentViewController(self)
  }

  override funcdidReceiveMemoryWarning(){
    super.didReceiveMemoryWarning()
  }
}