'An AVPlayerItem cannot be associated with more than one instance of AVPlayer'

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醉酒成梦
醉酒成梦 2020-12-21 11:20

I know this question is all over Stack Overflow but still, most of them are old and not related with what I\'m going to ask here.

So I\'ve got an array with AV

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  • 2020-12-21 11:40

    It is required to check that the player item can be inserted into the player’s queue. Then add, remove or replace the player item based on the conditions as below:

    if player.canInsert(playerItem, after: nil) == true {
    
                player = AVQueuePlayer(playerItem: playerItem)
    
            } else {
    
                player.remove(self.playerItem)
    
                player.replaceCurrentItem(with: playerItem)
    }
    
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  • 2020-12-21 11:41

    From Apple documentation:

    Before add an item:

    canInsertItem(_:afterItem:)

    Returns a Boolean value that indicates whether a given player item can be inserted into the player’s queue.

    func canInsertItem(_ item: AVPlayerItem!, afterItem afterItem: AVPlayerItem!) -> Bool
    

    Adding an Item:

    insertItem(_:afterItem:)
    

    Places given player item after a specified item in the queue.

     func insertItem(_ item: AVPlayerItem!, afterItem afterItem: AVPlayerItem!)
    

    Removing an Item:

    removeItem(_:)

    Removes a given player item from the queue.

    func removeItem(_ item: AVPlayerItem!)

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  • 2020-12-21 11:51

    The way I solved this issue is that I kept a reference to AVAsset objects in an array and then mapped it to [AVPlayerItem] (the type that AVQUeuePlayer init accepts).

    To elaborate, we needed to make an audio recorder (code on github) that can be paused, so I used an AVQueuePlayer, but ran into the same issues as the OP, and the only clean solution is to recreate this player object with a new array.

    The relevant code in Swift 4.1:

    class RecordViewController: UIViewController {
    
        var audioRecorder: AVAudioRecorder?
    
        var audioChunks = [AVURLAsset]()
        var queuePlayer:  AVQueuePlayer?
    
    // irrelevant code omitted
    
        func stopRecorder() {
            self.audioRecorder?.stop()
            let assetURL  = self.audioRecorder!.url
    
            self.audioRecorder = nil
    
            let asset = AVURLAsset(url: assetURL)
            self.audioChunks.append(asset)
    
            let assetKeys = ["playable"]
            let playerItems = self.audioChunks.map {
                AVPlayerItem(asset: $0, automaticallyLoadedAssetKeys: assetKeys)
            }
    
            self.queuePlayer = AVQueuePlayer(items: playerItems)
            self.queuePlayer?.actionAtItemEnd = .advance
        }
    
        func startPlayer() {
            self.queuePlayer?.play()
        }
    
        func stopPlayer() {
            self.queuePlayer?.pause()
            self.queuePlayer = nil
        }
    }
    

    (In the end, AVAssetExportSession is used to stitch the chunks of audio back together, so storing AVAssets insead of AVPlayerItems was even more beneficial in the end.)

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  • 2020-12-21 11:51

    Using this code solved the problem for me:

    player?.pause()                     
    let playerItem = AVPlayerItem(asset: myAsset) 
    player = nil 
    player = AVPlayer()
    player?.replaceCurrentItem(with: playerItem)
    

    Instead of:

    player?.pause()                     
    player = nil player = AVPlayer()
    player?.replaceCurrentItem(with: availablePlayerItem) //
    availablePlayerItem is a playerItem which has been created before and
    played once with this AVPlayer
    

    Note: In both codes, the "player" is a global variable in my class which is:

    var player : AVPlayer? = nil

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  • 2020-12-21 11:55

    I initially initialized an AVPlayerItem inside a cell and added it to an AVPlayer (also inside the cell). I later presented a new vc and passed over that same cell's AVPlayerItem to a different AVPlayer inside the new vc and got a crash. To fix it I just made a copy of the playerItem using .copy() as? AVPlayerItem. A copy gives the new copy a different memory address from the original.

    cell:

    var cellPlayer: AVPlayer?
    var cellsPlayerItem: AVPlayerItem?
    
    cellsPlayerItem = AVPlayerItem(asset: AVAsset(url: url)) // cellsPlayerItem's memory address 0x1111111
    cellPlayer = AVPlayer(playerItem: cellsPlayerItem!)
    

    presented vc:

    var vcPlayer: AVPlayer?
    
    let playerItemCopy = cellsPlayerItem.copy() as? AVPlayerItem // playerItemCopy's memory address 0x2222222
    let vcPlayer = AVPlayer(playerItem: playerItemCopy)
    
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  • 2020-12-21 11:58

    The problem is that you're creating a new player object when you update the array of items with this line (in tableView:commitEditingStyle:forRowAtIndexPath:),

    audioPlayer = AVQueuePlayer(items: mediaArray)
    

    It seems that the player items are still associated with the original player when you do this. You should be able to delete that line, to make it work properly. Inserting or deleting items from mediaArray should be enough to do what you want; you don't need to create a new player.

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