问题描述
我正在通过以下方式在AVPlayer
中设置UIView
:
fileprivate func setUpAVPlayer(){
self.cardModel?.urlStrings?.forEach({ (urlString) in
guard let url = URL(string: urlString) else { return }
let asset = AVAsset(url: url)
let playerItem = AVPlayerItem(asset: asset,automaticallyLoadedAssetKeys: nil)
playerItem.addobserver(self,forKeyPath: #keyPath(AVPlayerItem.status),options: [.old,.new],context: nil)
self.playerItemArray.append(playerItem)
})
player = AVPlayer(playerItem: playerItemArray[0])
}
在layoutSubviews
中,我布置了显示播放器的playerLayer:
let playerLayer = AVPlayerLayer(player: player)
playerLayer.videoGravity = .resizeAspectFill
self.playerView.layer.insertSublayer(playerLayer,at: 0)
playerLayer.frame = playerView.bounds
在某个事件中,我更改了播放器的当前项目:
fileprivate func goToNextVideo(){
counter = counter+1
counter = min(playerItemArray.count-1,counter)
self.player?.replaceCurrentItem(with: self.playerItemArray[self.counter])
self.player?.seek(to: .zero)
self.player?.play()
}
当我更改项目时,过渡效果并不顺利,并且可以看到闪烁的view
下方。有些事情我不明白:
-
为什么要在开始时预加载所有
AVPlayerItems
(当我循环所有url字符串时),当它们成为AVPlayer的currentItem
时,我仍然必须等待它们被加载? -
出于什么考虑,我在网上搜索了闪烁效果,却没有找到解决方案,因此,每当更改Item时,我都会仔细检查
AVPlayer
的行为,并以此方式进行描述:
第一(白色)(下面的视图)
第三实际上显示了视频
这种行为真的很烦人,我想知道如何解决它。
解决方法
import UIKit
import GPUImage
import AVFoundation
class ViewController: UIViewController {
lazy var movie: GPUImageMovie = {
let movie = GPUImageMovie()
movie.yuvConversionSetup()
movie.addTarget(imageView)
return movie
}()
lazy var imageView: GPUImageView = {
let view = GPUImageView()
view.setBackgroundColorRed(1,green: 1,blue: 1,alpha: 1)
return view
}()
lazy var player: AVPlayer = {
let player = AVPlayer()
return player
}()
lazy var videoURLs: [URL] = {
return [
resource(filename: "video0.mp4"),resource(filename: "video1.mp4"),resource(filename: "video2.mp4"),resource(filename: "video3.mp4"),].compactMap({ $0 })
}()
lazy var button: UIButton = {
let button = UIButton()
button.setTitle("replaceCurrentItem",for: .normal)
button.setTitleColor(.gray,for: .normal)
button.addTarget(self,action: #selector(action(_:)),for: .touchUpInside)
return button
}()
var index = 0
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
view.addSubview(imageView)
view.addSubview(button)
imageView.frame = view.bounds
button.frame = CGRect(x: 0,y: view.bounds.maxY - 100,width: view.bounds.width,height: 44)
}
func resource(filename: String) -> URL? {
return Bundle.main.url(forResource: filename,withExtension: nil)
}
@objc func action(_ sender: UIButton) {
if let url = getVideoURL() {
player.pause()
movie.endProcessing()
movie.playerItem = AVPlayerItem(url: url)
player.replaceCurrentItem(with: movie.playerItem)
player.play()
movie.startProcessing()
}
}
func getVideoURL() -> URL? {
if videoURLs.indices.contains(index) {
let url = videoURLs[index]
index = (index + 1) % videoURLs.count
return url
} else {
return nil
}
}
}
Podfile:
platform :ios,'9.0'
source 'https://github.com/CocoaPods/Specs.git'
target 'Test' do
use_frameworks!
pod 'GPUImage'
end
当您调用 replaceCurrentItem
时,它将清理图像缓冲区,然后等待渲染下一帧。所以,关键是要保留屏幕上的最后一帧:您可以使用 AVPlayerLayer
获取帧并使用 OpenGL ES(或 Metal)渲染,而不是使用 AVPlayerItemVideoOutput
渲染视频帧.您还可以决定何时清理图像缓冲区。