你如何在 Swift 中循环播放 AVPlayer？

Question

一个简单的问题，由于某种原因，我似乎找不到答案。

如何在 Swift 中循环 AVPlayer？

numberOfLoops = -1 仅适用于 AVAudioPlayer

我确实需要它在没有任何延迟/黑色闪光等的情况下循环播放。这就是我不使用 MPMoviePlayerViewController 的原因。

感谢您的帮助。

代码：

    let url_1 = NSURL.fileURLWithPath(outputFilePath_1)

    let asset_1 = AVAsset.assetWithURL(url_1) as? AVAsset
    let playerItem_1 = AVPlayerItem(asset: asset_1)

    let player_1 = AVPlayer(playerItem: self.playerItem_1)

    let playerLayer_1 = AVPlayerLayer(player: self.player_1)

    playerLayer_1!.frame = self.view.frame

    self.view.layer.addSublayer(self.playerLayer_1)

    player_1!.play()

Answer 1

Swift 5 (iOS 10.0+)

var playerLooper: AVPlayerLooper! // should be defined in class
var queuePlayer: AVQueuePlayer!
...

let asset: AVAsset = ... // AVAsset with its 'duration' property value loaded
let playerItem = AVPlayerItem(asset: asset)
self.queuePlayer = AVQueuePlayer(playerItem: playerItem)

// Create a new player looper with the queue player and template item
self.playerLooper = AVPlayerLooper(player: queuePlayer, templateItem: playerItem)

以下所有内容均适用于任何 iOS 版本。但是，对于

斯威夫特 4

var player: AVPlayer!

...

NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: self.player.currentItem, queue: .main) { [weak self] _ in
    self?.player?.seek(to: CMTime.zero)
    self?.player?.play()
}

斯威夫特 3

NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: self.player.currentItem, queue: .main) { [weak self] _ in
    self?.player?.seek(to: kCMTimeZero)
    self?.player?.play()
}

斯威夫特 2

配置 AVPlayerItem 并创建播放器后：

var player: AVPlayer!

...

// Invoke after player is created and AVPlayerItem is specified
NSNotificationCenter.defaultCenter().addObserver(self,
    selector: "playerItemDidReachEnd:",
    name: AVPlayerItemDidPlayToEndTimeNotification,
    object: self.player.currentItem)

...
 
func playerItemDidReachEnd(notification: NSNotification) {
    self.player.seekToTime(kCMTimeZero)
    self.player.play()
}

别忘了import AVFoundation

Answer 2

从 iOS 10 开始，无需使用通知来循环播放视频，只需使用 AVPlayerLooper，就像这样：

let asset = AVAsset(url: videoURL)
let item = AVPlayerItem(asset: asset)
let player = AVQueuePlayer(playerItem: item)
videoLooper = AVPlayerLooper(player: player, templateItem: item)

确保这个循环器是在函数范围之外创建的，以防它在函数返回时停止。

Answer 3

@Christopher Pickslay 为 Swift 4 更新了答案：

func loopVideo(videoPlayer: AVPlayer) {
    NotificationCenter.default.addObserver(forName: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: nil, queue: nil) { notification in
        videoPlayer.seek(to: CMTime.zero)
        videoPlayer.play()
    }
}

但是，正如我在他的回答下面提到的，如果您有多个玩家，请务必将该对象指定为 AVPlayer 的玩家项目。

Answer 4

或者，您可以使用基于块的 NSNotificationCenter API：

func loopVideo(videoPlayer: AVPlayer) {
    NSNotificationCenter.defaultCenter().addObserverForName(AVPlayerItemDidPlayToEndTimeNotification, object: nil, queue: nil) { notification in
        videoPlayer.seekToTime(kCMTimeZero)
        videoPlayer.play()
    }
}

Answer 5

好的，我已经解决了。感谢 Msencenb 用 Objective C 的答案为我指明了正确的方向。

player_1?.actionAtItemEnd = .None

//set a listener for when the video ends   
NSNotificationCenter.defaultCenter().addObserver(self,
        selector: "restartVideoFromBeginning",
        name: AVPlayerItemDidPlayToEndTimeNotification,
        object: player_1?.currentItem)


//function to restart the video
func restartVideoFromBeginning()  {

    //create a CMTime for zero seconds so we can go back to the beginning
    let seconds : Int64 = 0
    let preferredTimeScale : Int32 = 1
    let seekTime : CMTime = CMTimeMake(seconds, preferredTimeScale)

    player_1!.seekToTime(seekTime)

    player_1!.play()

}

Answer 6

我已经设法在 swift 3 中为 OSX 创建了一个无缝的视频循环。它应该可以在 iOS 上运行，并且在 swift 2 上也几乎没有修改。

var player : AVQueuePlayer!

// Looping video initial call
internal func selectVideoWithLoop(url : URL)
{
    let asset = AVAsset(url: url)
    player.pause()
    let playerItem1 = AVPlayerItem(asset: asset)
    let playerItem2 = AVPlayerItem(asset: asset)
    player.removeAllItems()
    player.replaceCurrentItem(with: playerItem1)
    player.insert(playerItem2, after: playerItem1)
    player.actionAtItemEnd = AVPlayerActionAtItemEnd.advance
    player.play()

    let selector = #selector(ViewController.playerItemDidReachEnd(notification:))
    let name = NSNotification.Name.AVPlayerItemDidPlayToEndTime
    // removing old observer and adding it again for sequential calls. 
    // Might not be necessary, but I like to unregister old notifications.
    NotificationCenter.default.removeObserver(self, name: name, object: nil)
    NotificationCenter.default.addObserver(self, selector: selector, name: name, object: nil)
}

// Loop video with threadmill pattern
// Called by NotificationCenter, don't call directly
func playerItemDidReachEnd(notification: Notification)
{
    let item = player.currentItem!
    player.remove(item)
    item.seek(to: kCMTimeZero)
    player.insert(item, after: nil)
}

当你想改变视频时，只需再次使用不同的 url 调用 selectVideoWithLoop 即可。

Answer 7

斯威夫特 3.0：

首先检查视频终点：-

NotificationCenter.default.addObserver(self, selector: #selector(LoginViewController.playerItemDidReachEnd), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: self.player?.currentItem)



func videoDidReachEnd() {

        //now use seek to make current playback time to the specified time in this case (O)
        let duration : Int64 = 0 (can be Int32 also)
        let preferredTimeScale : Int32 = 1
        let seekTime : CMTime = CMTimeMake(duration, preferredTimeScale)
        player!.seek(to: seekTime)
        player!.play()
    }

Answer 8

斯威夫特 5.5：

func loopVideo(videoPlayer: AVPlayer) {
  NotificationCenter.default.addObserver(forName: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: nil, queue: nil) { notification in
    videoPlayer.seek(to: .zero)
    videoPlayer.play()
  }
}