AVPlayer 视频播放

问题

AVPlayer 的使用和常见问题？

答案

基本使用

import AVKit

class PlayerViewController: UIViewController {
    private var player: AVPlayer?
    private var playerViewController: AVPlayerViewController?

    func playVideo(url: URL) {
        let playerItem = AVPlayerItem(url: url)
        player = AVPlayer(playerItem: playerItem)

        let playerVC = AVPlayerViewController()
        playerVC.player = player
        present(playerVC, animated: true) {
            self.player?.play()
        }
    }
}

自定义播放器

class CustomPlayerView: UIView {
    override class var layerClass: AnyClass { AVPlayerLayer.self }
    var playerLayer: AVPlayerLayer { layer as! AVPlayerLayer }

    private var player: AVPlayer?
    private var timeObserver: Any?

    func setup(url: URL) {
        let item = AVPlayerItem(url: url)
        player = AVPlayer(playerItem: item)
        playerLayer.player = player
        playerLayer.videoGravity = .resizeAspect

        // 播放进度监听
        timeObserver = player?.addPeriodicTimeObserver(
            forInterval: CMTime(seconds: 0.5, preferredTimescale: 600),
            queue: .main
        ) { [weak self] time in
            let seconds = CMTimeGetSeconds(time)
            // 更新进度条
        }

        // KVO 监听状态
        item.addObserver(self, forKeyPath: "status", options: .new, context: nil)
    }

    deinit {
        if let observer = timeObserver {
            player?.removeTimeObserver(observer)
        }
    }
}

常见场景

场景	方案
简单播放	AVPlayerViewController
自定义 UI	AVPlayer + AVPlayerLayer
列表视频	复用 AVPlayer，切换 AVPlayerItem
后台播放	开启 Background Modes: Audio
画中画	AVPictureInPictureController

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常见面试问题

Q1: AVPlayer 播放卡顿怎么排查？

答案：观察 playerItem.isPlaybackLikelyToKeepUp 和 loadedTimeRanges。常见原因：网络带宽不足、buffer 太小。可以用 preferredForwardBufferDuration 调整缓冲，或者使用 HLS 自适应码率。

相关链接

• Apple - AVPlayer