Question

我使用UIImagePicker只从我的库中挑选视频，并将媒体类型设置为：

imagePicker.mediaTypes = [kUTTypeMovie as String]

我注意到，当图书馆出现时，即使我只期待视频，如果图片库中有实时照片，但Bounce或Loop效果也会显示。如果我拍摄同一张照片并将其效果切换为Live或Long Exposure，则它将不再显示在库中。如果我将其重新切换回Bounce或Loop，则会重新显示。

我已经尝试了.photoLibrary和.savedPhotosAlbum，同样的事情发生了。

我问的原因是因为我想让他们不在图书馆里，而我只想要挑选xxx秒或更多的视频。

为什么这些效果类型会显示在图片选择器库中，即使我只选择视频？
为什么只显示Loop和Bounce，但Long Exposure和Live没有？
如何阻止他们？

也许这是一个单独的问题，但由于它与相同的Live和Bounce照片问题相关，我添加了它。我注意到如果我在AVPlayer中放置一个来自Live或Bounce照片的网址，如果我转到后台然后回来，当应用重新进入前景，它只发生在那两个效果（不应该是可用的）。当应用程序进入后台时，我使用此方法Remove AVPlayerLayer正确删除了AVPlayerLayer，但是当在播放器内部初始化效果类型的url时，它仍在前台暂时冻结（app无响应）

代码：

import MobileCoreServices
import AVFoundation

class ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate{

var playerItem: AVPlayerItem?
var player: AVPlayer?
var playerLayer: AVPlayerLayer?
var currentPlayTime: CMTime?
let imagePicker = UIImagePickerController()

override func viewDidLoad() {
    super.viewDidLoad()

    imagePickerController.delegate = self

    NotificationCenter.default.addObserver(self, selector: #selector(appHasEnteredBackground), name: Notification.Name.UIApplicationWillResignActive, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(appWillEnterForeground), name: Notification.Name.UIApplicationWillEnterForeground, object: nil)
}

override func viewDidLayoutSubviews() {
    // I have a UIView Outlet for the AVPlayerLayer named viewForPlayerLayer.

    guard let playerLayer = playerLayer else { return }
    playerLayer.videoGravity = .resizeAspectFill
    viewForPlayerLayer.layer.insertSublayer(playerLayer, at: 0)
    playerLayer.frame = viewForPlayerLayer.bounds
    playerLayer.masksToBounds = true

}

@IBAction fileprivate func showLibraryButtonTapped(_ sender: UIButton) {

    imagePicker.sourceType = UIImagePickerControllerSourceType.photoLibrary // .savedPhotosAlbum also tried 
    imagePicker.mediaTypes = [kUTTypeMovie as String]
    imagePicker.videoMaximumDuration = 60
    present(imagePicker, animated: true, completion: nil)
}

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

    if let url = info[UIImagePickerControllerMediaURL] as? URL{

          let asset = AVAsset(url: url)
          playerItem = AVPlayerItem(asset: asset)
          player = AVPlayer(playerItem: playerItem!)
          playerLayer = AVPlayerLayer(player: player)
          player?.play()
    }
    imagePicker.dismiss(animated: true, completion: nil)
}

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    imagePicker.dismiss(animated: true, completion: nil)
}

@objc fileprivate func appHasEnteredBackground() {

    currentPlayTime = player.currentTime()

    if player.isPlaying{
        player.pause()
    }

    playerLayer = nil
}

@objc fileprivate func appWillEnterForeground(){

    if let player = player, let currentPlayTime = currentPlayTime{

        playerLayer = AVPlayerLayer(player: player)

        player.seek(to: currentPlayTime, toleranceBefore: kCMTimeZero, toleranceAfter: kCMTimeZero)
    }
}

}

Answer 1

如果您要求显示视频，则无法阻止出现在选择器中的循环/反弹实时照片视频，因为它们是视频。但是，如果用户在委托方法中选择，则可以检测到一个。为此，UIImagePickerControllerMediaType的细粒度不够。相反，获取照片库授权并获取UIImagePickerControllerPHAsset密钥返回的PHAsset，并检查其playbackStyle。这将得出你想要的区别。

https://developer.apple.com/documentation/photos/phasset.playbackstyle

.videoLooping是一张反弹或缩放实时照片。

为什么imagePickerController.mediaTypes = [kUTTypeMovie as String]包括实时照片作为视频的反弹或循环效果？

1 个答案: