Swift memory management problem when taking pictures - ios

Question

I am making an iOS app that takes pictures, makes boomerang videos and makes gifs. For the boomerang what I do is take 16 pictures and put them on an array and then I add them again on the reverse order to male the boomerang effect, which makes a total of 31 images, because I don’t repeat the last one. I convert this array to a video, using the code below:
func writeImagesAsMovie(_ allImages: [UIImage], videoPath: String, videoSize: CGSize, videoFPS: Int32, completion: #escaping (Bool) -> ()) -> Bool{
guard let assetWriter = try? AVAssetWriter(outputURL: URL(string: videoPath)!, fileType: AVFileType.mp4) else {
fatalError("AVVideoCodecType.h264 error")
}
let outputSettings = [AVVideoCodecKey : AVVideoCodecType.h264, AVVideoWidthKey : NSNumber(value: Float(videoSize.width)), AVVideoHeightKey : NSNumber(value: Float(videoSize.height))] as [String : Any]
guard assetWriter.canApply(outputSettings: outputSettings, forMediaType: AVMediaType.video) else {
fatalError("Negative : Can't apply the Output settings...")
}
let writerInput = AVAssetWriterInput(mediaType: AVMediaType.video, outputSettings: outputSettings)
let sourcePixelBufferAttributesDictionary = [kCVPixelBufferPixelFormatTypeKey as String : NSNumber(value: kCVPixelFormatType_32ARGB), kCVPixelBufferWidthKey as String: NSNumber(value: Float(videoSize.width)), kCVPixelBufferHeightKey as String: NSNumber(value: Float(videoSize.height))]
let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: writerInput, sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
if assetWriter.canAdd(writerInput) {
assetWriter.add(writerInput)
}
// Start writing session
if assetWriter.startWriting() {
assetWriter.startSession(atSourceTime: CMTime.zero)
// -- Create queue for <requestMediaDataWhenReadyOnQueue>
assert(pixelBufferAdaptor.pixelBufferPool != nil)
let mediaQueue = DispatchQueue(label: "mediaInputQueue", attributes: [])
// -- Set video parameters
let frameDuration = CMTimeMake(value: 1, timescale: videoFPS)
var frameCount = 0
// -- Add images to video
let numImages = allImages.count
writerInput.requestMediaDataWhenReady(on: mediaQueue, using: { [unowned self]() -> Void in
// Append unadded images to video but only while input ready
while (writerInput.isReadyForMoreMediaData && frameCount < numImages) {
let lastFrameTime = CMTimeMake(value: Int64(frameCount), timescale: videoFPS)
let presentationTime = frameCount == 0 ? lastFrameTime : CMTimeAdd(lastFrameTime, frameDuration)
if !self.appendPixelBufferForImageAtURL(allImages[frameCount], pixelBufferAdaptor: pixelBufferAdaptor, presentationTime: presentationTime) {
print("Error converting images to video: AVAssetWriterInputPixelBufferAdapter failed to append pixel buffer")
return
}
frameCount += 1
}
// No more images to add? End video.
if (frameCount >= numImages) {
writerInput.markAsFinished()
assetWriter.finishWriting {
if (assetWriter.error != nil) {
print("Error converting images to video: \(String(describing: assetWriter.error))")
} else {
print("Converted images to movie # \(videoPath)")
completion(true)
}
}
}
})
}
return true
}
func createAssetWriter(_ path: String, size: CGSize) -> AVAssetWriter? {
// Convert <path> to NSURL object
let pathURL = URL(fileURLWithPath: path)
// Return new asset writer or nil
do {
// Create asset writer
let newWriter = try AVAssetWriter(outputURL: pathURL, fileType: AVFileType.mp4)
// Define settings for video input
let videoSettings: [String : AnyObject] = [
AVVideoCodecKey : AVVideoCodecType.h264 as AnyObject,
AVVideoWidthKey : size.width as AnyObject,
AVVideoHeightKey : size.height as AnyObject,
]
// Add video input to writer
let assetWriterVideoInput = AVAssetWriterInput(mediaType: AVMediaType.video, outputSettings: videoSettings)
newWriter.add(assetWriterVideoInput)
// Return writer
print("Created asset writer for \(size.width)x\(size.height) video")
return newWriter
} catch {
print("Error creating asset writer: \(error)")
return nil
}
}
func appendPixelBufferForImageAtURL(_ image: UIImage, pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor, presentationTime: CMTime) -> Bool {
var appendSucceeded = false
autoreleasepool {
if let pixelBufferPool = pixelBufferAdaptor.pixelBufferPool {
let pixelBufferPointer = UnsafeMutablePointer<CVPixelBuffer?>.allocate(capacity:1)
let status: CVReturn = CVPixelBufferPoolCreatePixelBuffer(
kCFAllocatorDefault,
pixelBufferPool,
pixelBufferPointer
)
if let pixelBuffer = pixelBufferPointer.pointee , status == 0 {
fillPixelBufferFromImage(image, pixelBuffer: pixelBuffer)
appendSucceeded = pixelBufferAdaptor.append(pixelBuffer, withPresentationTime: presentationTime)
pixelBufferPointer.deinitialize(count: 1)
} else {
NSLog("Error: Failed to allocate pixel buffer from pool")
}
//capacity: 1
pixelBufferPointer.deallocate()
}
}
return appendSucceeded
}
func fillPixelBufferFromImage(_ image: UIImage, pixelBuffer: CVPixelBuffer) {
CVPixelBufferLockBaseAddress(pixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer)
let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
// Create CGBitmapContext
let context = CGContext(
data: pixelData,
width: Int(image.size.width),
height: Int(image.size.height),
bitsPerComponent: 8,
bytesPerRow: CVPixelBufferGetBytesPerRow(pixelBuffer),
space: rgbColorSpace,
bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue
)!
// Draw image into context
let drawCGRect = CGRect(x:0, y:0, width:image.size.width, height:image.size.height)
var drawRect = NSCoder.string(for: drawCGRect);
let ciImage = CIImage(image: image)
let cgImage = convertCIImageToCGImage(inputImage: ciImage!)
context.draw(cgImage!, in: CGRect(x: 0.0,y: 0.0,width: image.size.width,height: image.size.height))
CVPixelBufferUnlockBaseAddress(pixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
}
func convertCIImageToCGImage(inputImage: CIImage) -> CGImage! {
let context = CIContext(options: nil)
if context != nil {
return context.createCGImage(inputImage, from: inputImage.extent)
}
return nil
}
My problem is with memory management, my app crashes after I do 3 or 4 boomerangs. I don’t know what else to do, I tried a lot of the memory management tips that are out there. I am using autoreleasepool, and weak and unowned self when I can. There is also no warning of memory leak anywhere. I notice that after I make the boomerang, there is always like an extra 100 mb that seams to never be released. Like the app starts at 70 mb, when is making the boomerang it gets to 800 mb, after is done it goes to 200 mb and stays there. If I do another boomerang it goes now to 900 mb, after is done it goes to 300 mb and now this is the new minimum. It goes like this until there is no more memory available and the app crashes while making a new boomerang.
I don't think the problem is with my conversion to video for the boomerang, because this constant accumulation of memory also happens with the normal pictures and gifs but in lesser quantity so the app never accumulates enough to crash.
I am also removing everything after I am done using. I empty the image array of the boomerang and I set all UIImages to null, I saw somewhere that that could help, but it didn't change anything. I don't know if the pictures that are taken are kept stored somewhere on the system that I need to remove.
This is the code for taking the pictures:
#objc func takePhoto(_ sender: Any?) {
TapToStart.alpha = 0
contador.alpha = 1
if deviceOrientation == .portrait {
lookHereView.alpha = 1
}
reescolherMoldura.isEnabled = false
var videoOrientation = AVCaptureVideoOrientation.portrait
if moldura.larguraFoto > moldura.alturaFoto{
videoOrientation = AVCaptureVideoOrientation.landscapeRight
}
stillImageOutput!.connection(with: .video)?.videoOrientation = videoOrientation
let settings = AVCapturePhotoSettings(format: [AVVideoCodecKey: AVVideoCodecType.jpeg])
let gesture = previewView.gestureRecognizers
previewView.removeGestureRecognizer(gesture![0])
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
self.contador.text = "2"
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
self.contador.text = "1"
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
self.contador.alpha = 0
self.stillImageOutput!.capturePhoto(with: settings, delegate: self)
}
}
}
}
func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
guard let imageData = photo.fileDataRepresentation()
else { return }
if tipoDeFoto == "normal" {
tirarFotoNormal(imageData: imageData)
}
else if tipoDeFoto == "gif" {
tirarGif(imageData: imageData)
}
else if tipoDeFoto == "boomerang" {
tirarBoomerang(imageData: imageData)
}
}
I don't know what else to try, any help is appreciated.
Edit
Checking the instruments more carefully I realised that the app is keeping all of the pictures I take in memory. I am removing all references to the images as soon as I am done with them. So I assume that AVCapturePhotoOutput is keeping them in the memory and never releasing it. Is there a way to clear this from memory?
The function that calls to make the boomerang and to use the writeImagesAsMovie func:
func tirarBoomerang(imageData: Data){
UIGraphicsBeginImageContextWithOptions(previewView.frame.size, false, 0.0)
previewView.superview!.layer.render(in: UIGraphicsGetCurrentContext()!)
let foto = UIImage(data: imageData)!
let cropedPhoto = cropToBounds(image: foto, width: Double(moldura.larguraFoto), height: Double(moldura.alturaFoto))
let resultImage = blendImages(cropedPhoto, molduraImagem!)
fotosBoomerangArray.append(resultImage!)
numFotosLabel.text = "\(fotosBoomerangArray.count)/16"
if fotosBoomerangArray.count == 16 {
for (index, fotoBoomerang) in fotosBoomerangArray.enumerated().reversed() {
if index == 15{
continue
}
autoreleasepool {
fotosBoomerangArray.append(fotoBoomerang)
}
}
SVProgressHUD.show(withStatus: "Aguarde")
SVProgressHUD.setDefaultStyle(.dark)
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let fileURL = documentsURL.appendingPathComponent("\(public_id!.description).mp4")
let sizeVideo = CGSize(width: moldura.larguraMoldura, height: moldura.alturaMoldura)
imageToVideo.writeImagesAsMovie(fotosBoomerangArray, videoPath: fileURL.absoluteString, videoSize: sizeVideo, videoFPS: 30) { [weak self](success) in
DispatchQueue.main.async {
SVProgressHUD.dismiss()
self!.irParaPreview()
}
}
}
else {
fotoNumero += 1
let settings = AVCapturePhotoSettings(format: [AVVideoCodecKey: AVVideoCodecType.jpeg])
self.stillImageOutput!.capturePhoto(with: settings, delegate: self)
}
}