Add Gif to CALayer for Video Overlay

Gif-CALayer.swift

func startGifAnimation(with url: URL?, in layer: CALayer?) {
        let animation: CAKeyframeAnimation? = animationForGif(with: url)
        if let animation = animation {
            layer?.add(animation, forKey: "contents")
        }
    }
    
func animationForGif(with url: URL?) -> CAKeyframeAnimation? {

    let animation = CAKeyframeAnimation(keyPath: "contents")

    var frames = [CGImage]()
    var delayTimes = [NSNumber]()

    var totalTime: Float = 0.0
//        var gifWidth: Float
//        var gifHeight: Float

    let gifSource = CGImageSourceCreateWithURL(url! as CFURL, nil)
    // get frame count
    let frameCount = CGImageSourceGetCount(gifSource!)
    for i in 0..<frameCount {
        // get each frame
        let frame = CGImageSourceCreateImageAtIndex(gifSource!, i, nil)
        if let frame = frame {
            frames.append(frame)
        }

        // get gif info with each frame
        var dict = CGImageSourceCopyPropertiesAtIndex(gifSource!, i, nil) as? [CFString: AnyObject]

        // get gif size
        //gifWidth = (dict?[kCGImagePropertyPixelWidth] as? NSNumber)?.floatValue ?? 0.0
        //gifHeight = (dict?[kCGImagePropertyPixelHeight] as? NSNumber)?.floatValue ?? 0.0

        let gifDict = dict?[kCGImagePropertyGIFDictionary]
        if let value = gifDict?[kCGImagePropertyGIFDelayTime] as? NSNumber {
            delayTimes.append(value)
        }

        totalTime = totalTime + (((gifDict?[kCGImagePropertyGIFDelayTime] as? NSNumber)?.floatValue)!)

    }

    var times = [AnyHashable](repeating: 0, count: 3)
    var currentTime: Float = 0
    let count: Int = delayTimes.count
    for i in 0..<count {
        times.append(NSNumber(value: Float((currentTime / totalTime))))
        currentTime += Float(delayTimes[i])
    }

    var images = [AnyHashable](repeating: 0, count: 3)
    for i in 0..<count {
        images.append(frames[i])
    }

    animation.keyTimes = times as? [NSNumber]
    animation.values = images
    animation.timingFunction = CAMediaTimingFunction(name: .linear)
    animation.duration = CFTimeInterval(totalTime)
    animation.repeatCount = Float.infinity

    animation.beginTime = AVCoreAnimationBeginTimeAtZero
    animation.isRemovedOnCompletion = false

    return animation

}