AVPlayer 帧动画-解网

问：

我正在开发一个应用程序，其中包括播放带有每帧动画的视频的功能。您可以看到此类功能的示例。

我已经尝试添加到子层并遇到一些麻烦。CAKeyFrameAnimationAVSynchronizedLayer

我也已经尝试过用预渲染视频，它运行良好。但它非常缓慢。渲染此类视频最多需要 3 分钟。AVAssetExportSession

也许还有其他方法可以做到这一点？

更新：

这就是我实现动画的方式：AVSynchronizedLayer

let fullScreenAnimationLayer = CALayer()
fullScreenAnimationLayer.frame = videoRect
fullScreenAnimationLayer.geometryFlipped = true

values: [NSValue] = [], times: [NSNumber] = []

// fill values array with positions of face center for each frame
values.append(NSValue(CATransform3D: t))

// fill times with corresoinding time for each frame
times.append(NSNumber(double: (Double(j) / fps) / videoDuration)) // where fps = 25 (according to video file fps)

...

let transform = CAKeyframeAnimation(keyPath: "transform")
transform.duration = videoDuration
transform.calculationMode = kCAAnimationDiscrete
transform.beginTime = AVCoreAnimationBeginTimeAtZero
transform.values = values
transform.keyTimes = times
transform.removedOnCompletion = false
transform.fillMode = kCAFillModeForwards
fullScreenAnimationLayer.addAnimation(transform, forKey: "a_transform")

...

if let syncLayer = AVSynchronizedLayer(playerItem: player.currentItem) {
    syncLayer.frame = CGRect(origin: CGPointZero, size: videoView.bounds.size)
    syncLayer.addSublayer(fullScreenAnimationLayer)
    videoView.layer.addSublayer(syncLayer)
}

iOS Swift 视频 AVFafoundation

AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:blahURL options:nil];
AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:urlAsset];
AVPlayer *player = [AVPlayer playerWithPlayerItem:playerItem];
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
playerLayer.frame = yourFrame;

UIView *videoView = [UIView new];
[videoView addSublayer:playerLayer];

然后

为 videoView 提供动画

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AVPlayer 帧动画

AVPlayer frame animation

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