Frame Duration time - UIImage array to movie - ios

Question

I have successfully completed the part "Export UIImage array as movie" through this code. In the exported video every image is shown for 1 second. But I need, every image will be shown for 5 seconds in the exported video.
What is the minimal change I need to do so ?
Here is my code...
var outputSize = CGSize(width: 1920, height: 1280)
func build(outputSize outputSize: CGSize) {
let fileManager = NSFileManager.defaultManager()
let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
guard let documentDirectory: NSURL = urls.first else {
fatalError("documentDir Error")
}
let videoOutputURL = documentDirectory.URLByAppendingPathComponent("OutputVideo.mp4")
if NSFileManager.defaultManager().fileExistsAtPath(videoOutputURL!.path!) {
do {
try NSFileManager.defaultManager().removeItemAtPath(videoOutputURL!.path!)
} catch {
fatalError("Unable to delete file: \(error) : \(#function).")
}
}
guard let videoWriter = try? AVAssetWriter(URL: videoOutputURL!, fileType: AVFileTypeMPEG4) else {
fatalError("AVAssetWriter error")
}
let outputSettings = [AVVideoCodecKey : AVVideoCodecH264, AVVideoWidthKey : NSNumber(float: Float(outputSize.width)), AVVideoHeightKey : NSNumber(float: Float(outputSize.height))]
guard videoWriter.canApplyOutputSettings(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(unsignedInt: kCVPixelFormatType_32ARGB), kCVPixelBufferWidthKey as String: NSNumber(float: Float(outputSize.width)), kCVPixelBufferHeightKey as String: NSNumber(float: Float(outputSize.height))]
let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput, sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
if videoWriter.canAddInput(videoWriterInput) {
videoWriter.addInput(videoWriterInput)
}
if videoWriter.startWriting() {
videoWriter.startSessionAtSourceTime(kCMTimeZero)
assert(pixelBufferAdaptor.pixelBufferPool != nil)
let media_queue = dispatch_queue_create("mediaInputQueue", nil)
videoWriterInput.requestMediaDataWhenReadyOnQueue(media_queue, usingBlock: { () -> Void in
let fps: Int32 = 1
let frameDuration = CMTimeMake(1, fps)
var frameCount: Int64 = 0
var appendSucceeded = true
while (!self.choosenPhotos.isEmpty) {
if (videoWriterInput.readyForMoreMediaData) {
let nextPhoto = self.choosenPhotos.removeAtIndex(0)
let lastFrameTime = CMTimeMake(frameCount, 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 where status == 0 {
let managedPixelBuffer = pixelBuffer
CVPixelBufferLockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
let data = CVPixelBufferGetBaseAddress(managedPixelBuffer)
let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
let context = CGBitmapContextCreate(data, Int(self.outputSize.width), Int(self.outputSize.height), 8, CVPixelBufferGetBytesPerRow(managedPixelBuffer), rgbColorSpace, CGImageAlphaInfo.PremultipliedFirst.rawValue)
CGContextClearRect(context!, CGRectMake(0, 0, CGFloat(self.outputSize.width), CGFloat(self.outputSize.height)))
let horizontalRatio = CGFloat(self.outputSize.width) / nextPhoto.size.width
let verticalRatio = CGFloat(self.outputSize.height) / nextPhoto.size.height
let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit
let newSize:CGSize = CGSizeMake(nextPhoto.size.width * aspectRatio, 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
CGContextDrawImage(context!, CGRectMake(x, y, newSize.width, newSize.height), nextPhoto.CGImage!)
CVPixelBufferUnlockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
appendSucceeded = pixelBufferAdaptor.appendPixelBuffer(pixelBuffer, withPresentationTime: presentationTime)
} else {
print("Failed to allocate pixel buffer")
appendSucceeded = false
}
}
if !appendSucceeded {
break
}
frameCount += 1
}
videoWriterInput.markAsFinished()
videoWriter.finishWritingWithCompletionHandler { () -> Void in
print("FINISHED!!!!!")
}
})
}
}

Answer 1

Just change:
let frameDuration = CMTimeMake(5, fps)
And change this line from:
let lastFrameTime = CMTimeMake(frameCount, fps)
To
let lastFrameTime = CMTimeMake(frameCount*5, fps)
Or
let lastFrameTime = frameDuration
Hope this helps.

Answer 2

let lastFrameTime = CMTimeMake(frameCount * 5, fps)
let presentationTime = frameCount == 0 ? lastFrameTime : CMTimeAdd(lastFrameTime, frameDuration)
CMTime t2 = CMTimeMake(2, 1); // 2 seconds It represent value/timeScale.