UIScrollView中的多个AVPlayers - 仅显示其中的16个 [英] Multiple AVPlayers in a UIScrollView - only 16 of them are shown
问题描述
我正在开发一个视频库，我有一个ScrollView，里面有多个视图，每个视图都有一个AVPlayer - 到目前为止，它是非常标准的。请注意，所有AVPlayer都预装了他们的视频，等待播放。
I'm developing a video gallery, I have a ScrollView with multiple views inside of it, each view has a single AVPlayer - so far it's pretty standard I guess. Note that all of the AVPlayers are pre-loaded with their video, waiting to be played.
当我在图库中有很多项目（视频）时，会出现问题。在任何给定时间 - 只显示其中的16个，从开始到结束，其余显示黑屏。
如果我正在撤销物品的顺序 - 显示新的另外16个，其余的则显示黑屏。
The problem occurs when I have many items (videos) in the gallery. At any given time - only 16 of them are shown, from start to end, the rest shows a black screen. If I'm reversing the order of the items - the other 16 from the new side are shown, and the rest shows a black screen too.
另外，如果我去另一个屏幕，然后回到画廊 - 一切都变黑了，没有任何显示。
Additionally, if I go to another screen and then come back to the gallery - everything becomes black and nothing shown.
如果我用随机颜色背景替换玩家每个视图 - 显示所有视图。所以我认为问题在于玩家而不是视图本身。
If i'm replacing the players with a random color background for each view - all of the views are shown. So I assume the problem is with the players and not with the views themselves.
根据Xcode我的应用只使用~7-10％CPU和~10-11 MB因此它看起来不像是一个性能问题 - 更像是并发有效AVPlayers的限制，但我找不到任何有关它的信息。
According to Xcode my app only use ~7-10% CPU and ~10-11 MB of RAM so it doesn't looks like a performance problem - more like a limitation of concurrent active AVPlayers but I couldn't find any information regarding that.
有没有人有有什么建议么？这让我发疯了。
Does anyone have any suggestions? this is driving me crazy.
提前致谢！
推荐答案
我在不同的环境中遇到了与你相同的问题（我有一个加载视频的tableview，它在16次点击后停止工作）。
I was running into the same problem as you in a different context (I had a tableview that loaded a video and it stopped working after 16 clicks).
这些是一些帮助我的线程：
These were some of the threads that helped me out:
AVPlayerItem失败，AVStatusFailed和错误代码无法解码
基本上可以创建16个avplayers / avplayerlayers的硬限制。如果你试图超过这个，你会得到不稳定的行为。
Essentially theres a hard limit of 16 avplayers/avplayerlayers that can be created. If you try to exceed this you get wonky behaviour.
在您的特定情况下，您必须创建一个包含16个视频的缓冲区并删除/添加它们，因为它们在滚动视图中不再可见。我建议将缓冲区降低（如8）导致16导致最新的iphone型号出现严重滞后。
In your particular case you will have to create a buffer of 16 videos and remove/add them as they no longer become visible on the scrollview. I would recommend making the buffer lower (like 8) cause 16 causes some serious lag on the latest iphone model.
要删除播放器，请使用以下代码：
To remove the player use this code:
player.pause()
player = nil
playerLayer.removeFromSuperlayer()
确保播放器是一个变量（不要使用let）并且它是一个可选类型。
Make sure the player is a variable (dont use let) and that it is an optional type.
var player : AVPlayer? = AVPlayer(url: videoURL as URL)
希望这会有所帮助
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