Swift - GPUImageStillCamera

import UIKit
import GPUImage

class ViewController: UIViewController {

fileprivate var camera : GPUImageStillCamera!
fileprivate var filter : GPUImageBrightnessFilter!

var isFirst : Bool = true

override func viewDidLoad() {
    super.viewDidLoad()
}

@IBAction func startCapturing() {
    if isFirst {
        // 1.创建GPUImage中的相机 100 : 1
        let camera = GPUImageStillCamera(sessionPreset: AVCaptureSessionPresetHigh, cameraPosition: .front)
        camera?.outputImageOrientation = .portrait
        self.camera = camera
        
        // 2.添加滤镜
        let filter = GPUImageBrightnessFilter()
        camera?.addTarget(filter)
        self.filter = filter
        
        // 3.创建GPUImageView对象
        let gpuImageView = GPUImageView(frame: view.bounds)
        view.insertSubview(gpuImageView, at: 0)
        filter.addTarget(gpuImageView)
        
        isFirst = false
    }
    
    // 4.开始采集
    camera?.startCapture()
}

@IBAction func stopCapturing() {
    camera.stopCapture()
}

@IBAction func rotateCamera() {
    camera.rotateCamera()
}

@IBAction func takePhoto() {
    camera.capturePhotoAsImageProcessedUp(toFilter: filter) { (image :  UIImage?, error : Error?) in
        UIImageWriteToSavedPhotosAlbum(image!, nil, nil, nil)
    }
}

}