如何获取AVPlayer中视频实际播放区域的尺寸与坐标？

我使用AVPlayer播放分辨率为720x1280的视频，由于不同手机的分辨率存在差异，请问如何获取视频在手机上的实际播放区域坐标或尺寸？同时，如何获取下图中橙色线条标注区域（黑边）的尺寸或坐标？

现有代码 #

let url = URL(fileURLWithPath: path)
let playerItem: AVPlayerItem = AVPlayerItem(url: url)
player = AVPlayer(playerItem: playerItem)
playerLayer = AVPlayerLayer(player: player)
playerLayer!.frame = viewPlayer.bounds
viewPlayer.layer.addSublayer(playerLayer!)
player!.play()

print("playerLayer videoRect: \(String(describing: playerLayer?.videoRect.width))")
print("playerLayer bounds: \(String(describing: playerLayer?.bounds))")
print("playerLayer frame: \(String(describing: playerLayer?.frame))")

let size = videoTrack.naturalSize // 视频原始尺寸720x1280

播放效果示意图 #

竖屏播放（橙色标注为上下黑边）：

横屏播放（橙色标注为左右黑边）：

解决方案 #

1. 获取视频实际播放区域 #

AVPlayerLayer的videoRect属性直接对应视频内容在layer内的实际显示区域。必须等视频加载完成后再获取，否则会得到无效值。

实现步骤

• 监听AVPlayerItem的status状态，确认视频已准备好播放
• 拿到videoRect后，可根据需求转换为屏幕坐标系或父视图坐标系的区域

代码示例

// 监听AVPlayerItem的加载状态
playerItem.addObserver(self, forKeyPath: "status", options: [.new], context: nil)

// 处理监听回调
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    guard keyPath == "status", let item = object as? AVPlayerItem else { return }
    
    if item.status == .readyToPlay {
        // 此时videoRect已可用
        guard let videoRect = playerLayer?.videoRect else { return }
        print("视频播放区域（相对于playerLayer）：\(videoRect)")
        
        // 转换为屏幕坐标系的区域
        if let window = view.window {
            let screenRect = playerLayer!.convert(videoRect, to: window)
            print("视频播放区域（屏幕坐标系）：\(screenRect)")
        }
    }
}

// 记得在deinit中移除监听
deinit {
    playerItem.removeObserver(self, forKeyPath: "status")
}

也可以直接监听playerLayer的videoRect属性变化，实时获取最新区域：

playerLayer?.addObserver(self, forKeyPath: "videoRect", options: [.new], context: nil)

2. 获取橙色标注的黑边区域 #

橙色标注的是playerLayer中未被视频填充的黑边区域，可通过playerLayer.bounds减去videoRect计算得出：

代码示例

guard let playerLayer = playerLayer, let videoRect = playerLayer.videoRect else { return }
let layerBounds = playerLayer.bounds

// 竖屏时的上下黑边
let topBarHeight = (layerBounds.height - videoRect.height) / 2
let topBarRect = CGRect(x: 0, y: 0, width: layerBounds.width, height: topBarHeight)
let bottomBarRect = CGRect(x: 0, y: videoRect.maxY, width: layerBounds.width, height: topBarHeight)
print("上黑边区域：\(topBarRect)，下黑边区域：\(bottomBarRect)")

// 横屏时的左右黑边
let leftBarWidth = (layerBounds.width - videoRect.width) / 2
let leftBarRect = CGRect(x: 0, y: 0, width: leftBarWidth, height: layerBounds.height)
let rightBarRect = CGRect(x: videoRect.maxX, y: 0, width: leftBarWidth, height: layerBounds.height)
print("左黑边区域：\(leftBarRect)，右黑边区域：\(rightBarRect)")

注意事项 #

• 屏幕旋转或viewPlayer的frame变化时，需重新计算区域，可在viewDidLayoutSubviews方法中执行计算逻辑
• 若使用自动布局，确保playerLayer的frame随viewPlayer同步更新

内容的提问来源于stack exchange，提问作者patient