Vision-Face-Quality-LivePhoto-Processing.swift

func processLivePhoto(livePhoto: PHLivePhoto)
    {
        let livePhotoResources = PHAssetResource.assetResources(for: livePhoto)
        guard let photoDir = generateFolderForLivePhotoResources() else{ return }
        for resource in livePhotoResources {
            
            if resource.type == PHAssetResourceType.pairedVideo {
                saveAssetResource(resource: resource, inDirectory: photoDir, buffer: nil, maybeError: nil)
            }
        }
    }
    
    func saveAssetResource(
        resource: PHAssetResource,
        inDirectory: NSURL,
        buffer: NSMutableData?, maybeError: Error?
    ) -> Void {
        guard maybeError == nil else {
            return
        }
        
        let maybeExt = UTTypeCopyPreferredTagWithClass(
            resource.uniformTypeIdentifier as CFString,
            kUTTagClassFilenameExtension
            )?.takeRetainedValue()
        
        guard let ext = maybeExt else {
            return
        }
        
        guard var fileUrl = inDirectory.appendingPathComponent(NSUUID().uuidString) else {
            print("file url error")
            return
        }
        
        fileUrl = fileUrl.appendingPathExtension(ext as String)
        
        if let buffer = buffer, buffer.write(to: fileUrl, atomically: true) {
            self.videoUrl = fileUrl
        } else {
            PHAssetResourceManager.default().writeData(for: resource, toFile: fileUrl, options: nil) { (error) in
                self.videoUrl = fileUrl
            }
        }
    }
    
    func generateFolderForLivePhotoResources() -> NSURL? {
        let photoDir = NSURL(
            fileURLWithPath: NSTemporaryDirectory(),
            isDirectory: true
        ).appendingPathComponent(NSUUID().uuidString)
        
        let fileManager = FileManager()
        let success : ()? = try? fileManager.createDirectory(
            at: photoDir!,
            withIntermediateDirectories: true,
            attributes: nil
        )
        
        return success != nil ? photoDir! as NSURL : nil
    }