I was stuck in the same problem for a bit of time. Since it is a big answer, it may bore you but I hope it will help you. Here is my answer in Swift 3.
Theory:
Firstly, you have to make a video with your image array. A lot of solutions are available regarding this problem. Just search a bit, hope you will get one. If not, see my code below.
Secondly, you might know that a CALayer can be added over a video. If not, search a bit how to add CALayer over a video.
Thirdly, you have to know, how to animate a CALayer. Core Animation will do the job for you. A huge collection of sample codes are available regarding this. Search for it.
Now you have a CALayer and you know how to animate it. Lastly, you have to add this animated CALayer in your video.
Code:
1.Create a video with your array of images
let outputSize = CGSize(width: 1920, height: 1280)
let imagesPerSecond: TimeInterval = 3 //each image will be stay for 3 secs
var selectedPhotosArray = [UIImage]()
var imageArrayToVideoURL = NSURL()
let audioIsEnabled: Bool = false //if your video has no sound
var asset: AVAsset!
func buildVideoFromImageArray() {
for image in 0..<5 {
selectedPhotosArray.append(UIImage(named: "(image + 1).JPG")!) //name of the images: 1.JPG, 2.JPG, 3.JPG, 4.JPG, 5.JPG
}
imageArrayToVideoURL = NSURL(fileURLWithPath: NSHomeDirectory() + "/Documents/video1.MP4")
removeFileAtURLIfExists(url: imageArrayToVideoURL)
guard let videoWriter = try? AVAssetWriter(outputURL: imageArrayToVideoURL as URL, fileType: AVFileTypeMPEG4) else {
fatalError("AVAssetWriter error")
}
let outputSettings = [AVVideoCodecKey : AVVideoCodecH264, AVVideoWidthKey : NSNumber(value: Float(outputSize.width)), AVVideoHeightKey : NSNumber(value: Float(outputSize.height))] as [String : Any]
guard videoWriter.canApply(outputSettings: outputSettings, forMediaType: AVMediaTypeVideo) else {
fatalError("Negative : Can't apply the Output settings...")
}
let videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: outputSettings)
let sourcePixelBufferAttributesDictionary = [kCVPixelBufferPixelFormatTypeKey as String : NSNumber(value: kCVPixelFormatType_32ARGB), kCVPixelBufferWidthKey as String: NSNumber(value: Float(outputSize.width)), kCVPixelBufferHeightKey as String: NSNumber(value: Float(outputSize.height))]
let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput, sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
if videoWriter.canAdd(videoWriterInput) {
videoWriter.add(videoWriterInput)
}
if videoWriter.startWriting() {
let zeroTime = CMTimeMake(Int64(imagesPerSecond),Int32(1))
videoWriter.startSession(atSourceTime: zeroTime)
assert(pixelBufferAdaptor.pixelBufferPool != nil)
let media_queue = DispatchQueue(label: "mediaInputQueue")
videoWriterInput.requestMediaDataWhenReady(on: media_queue, using: { () -> Void in
let fps: Int32 = 1
let framePerSecond: Int64 = Int64(self.imagesPerSecond)
let frameDuration = CMTimeMake(Int64(self.imagesPerSecond), fps)
var frameCount: Int64 = 0
var appendSucceeded = true
while (!self.selectedPhotosArray.isEmpty) {
if (videoWriterInput.isReadyForMoreMediaData) {
let nextPhoto = self.selectedPhotosArray.remove(at: 0)
let lastFrameTime = CMTimeMake(frameCount * framePerSecond, fps)
let presentationTime = frameCount == 0 ? lastFrameTime : CMTimeAdd(lastFrameTime, frameDuration)
var pixelBuffer: CVPixelBuffer? = nil
let status: CVReturn = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferAdaptor.pixelBufferPool!, &pixelBuffer)
if let pixelBuffer = pixelBuffer, status == 0 {
let managedPixelBuffer = pixelBuffer
CVPixelBufferLockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
let data = CVPixelBufferGetBaseAddress(managedPixelBuffer)
let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
let context = CGContext(data: data, width: Int(self.outputSize.width), height: Int(self.outputSize.height), bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(managedPixelBuffer), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue)
context!.clear(CGRect(x: 0, y: 0, width: CGFloat(self.outputSize.width), height: CGFloat(self.outputSize.height)))
let horizontalRatio = CGFloat(self.outputSize.width) / nextPhoto.size.width
let verticalRatio = CGFloat(self.outputSize.height) / nextPhoto.size.height
//let aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill
let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit
let newSize: CGSize = CGSize(width: nextPhoto.size.width * aspectRatio, height: nextPhoto.size.height * aspectRatio)
let x = newSize.width < self.outputSize.width ? (self.outputSize.width - newSize.width) / 2 : 0
let y = newSize.height < self.outputSize.height ? (self.outputSize.height - newSize.height) / 2 : 0
context?.draw(nextPhoto.cgImage!, in: CGRect(x: x, y: y, width: newSize.width, height: newSize.height))
CVPixelBufferUnlockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
appendSucceeded = pixelBufferAdaptor.append(pixelBuffer, withPresentationTime: presentationTime)
} else {
print("Failed to allocate pixel buffer")
appendSucceeded = false
}
}
if !appendSucceeded {
break
}
frameCount += 1
}
videoWriterInput.markAsFinished()
videoWriter.finishWriting { () -> Void in
print("-----video1 url = (self.imageArrayToVideoURL)")
self.asset = AVAsset(url: self.imageArrayToVideoURL as URL)
self.exportVideoWithAnimation()
}
})
}
}
func removeFileAtURLIfExists(url: NSURL) {
if let filePath = url.path {
let fileManager = FileManager.default
if fileManager.fileExists(atPath: filePath) {
do{
try fileManager.removeItem(atPath: filePath)
} catch let error as NSError {
print("Couldn't remove existing destination file: (error)")
}
}
}
}
2.Add animation to the created video (Please read all the commented sections carefully. I think some issues will get clear by reading those.)
func exportVideoWithAnimation() {
let composition = AVMutableComposition()
let track = asset?.tracks(withMediaType: AVMediaTypeVideo)
let videoTrack:AVAssetTrack = track![0] as AVAssetTrack
let timerange = CMTimeRangeMake(kCMTimeZero, (asset?.duration)!)
let compositionVideoTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
do {
try compositionVideoTrack.insertTimeRange(timerange, of: videoTrack, at: kCMTimeZero)
compositionVideoTrack.preferredTransform = videoTrack.preferredTransform
} catch {
print(error)
}
//if your video has sound, you don’t need to check this
if audioIsEnabled {
let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
for audioTrack in (asset?.tracks(withMediaType: AVMediaTypeAudio))! {
do {
try compositionAudioTrack.insertTimeRange(audioTrack.timeRange, of: audioTrack, at: kCMTimeZero)
} catch {
print(error)
}
}
}
let size = videoTrack.naturalSize
let videolayer = CALayer()
videolayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
let parentlayer = CALayer()
parentlayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
parentlayer.addSublayer(videolayer)
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//this is the animation part
var time = [0.00001, 3, 6, 9, 12] //I used this time array to determine the start time of a frame animation. Each frame will stay for 3 secs, thats why their difference is 3
var imgarray = [UIImage]()
for image in 0..<5 {
imgarray.append(UIImage(named: "(image + 1).JPG")!)
let nextPhoto = imgarray[image]
let horizontalRatio = CGFloat(self.outputSize.width) / nextPhoto.size.width
let verticalRatio = CGFloat(self.outputSize.height) / nextPhoto.size.height
let aspectRatio = min(horizontalRatio, verticalRatio)
let newSize: CGSize = CGSize(width: nextPhoto.size.width * aspectRatio, height: nextPhoto.size.height * aspectRatio)
let x = newSize.width < self.outputSize.width ? (self.outputSize.width - newSize.width) / 2 : 0
let y = newSize.height < self.outputSize.height ? (self.outputSize.height - newSize.height) / 2 : 0
///I showed 10 animations here. You can uncomment any of this and export a video to see the result.
///#1. left->right///
let blackLayer = CALayer()
blackLayer.frame = CGRect(x: -videoTrack.naturalSize.width, y: 0, width: videoTrack.naturalSize.width, height: videoTrack.naturalSize.height)
blackLayer.backgroundColor = UIColor.black.cgColor
let imageLayer = CALayer()
imageLayer.frame = CGRect(x: x, y: y, width: newSize.width, height: newSize.height)
imageLayer.contents = imgarray[image].cgImage
blackLayer.addSublayer(imageLayer)
let animation = CABasicAnimation()
animation.keyPath = "position.x"
animation.fromValue = -videoTrack.naturalSize.width
animation.toValue = 2 * (videoTrack.naturalSize.width)
animation.duration = 3
animation.beginTime = CFTimeInterval(time[image])
animation.fillMode = kCAFillModeForwards
animation.isRemovedOnCompletion = false
blackLayer.add(animation, forKey: "basic")
///#2. right->left///
// let blackLayer = CALayer()
// blackLayer.frame = CGRect(x: 2 * videoTrack.naturalSize.width, y: 0, width: videoTrack.naturalSize.width, height: videoTrack.naturalSize.height)
// blackLayer.back
