ios - 使用 GPUImagePicture 和自定义 LUT 进行 GPUImageVideoCamera 实时预览

Question

我正在将 Swift 3 与 GPUImage 结合使用。我有一个名为:lut_lookup.png 的 LUT 图像文件，我已成功地将其与 GPUImage 一起在静态图像上使用，并且它使用 LUT 滤镜应用并显示结果。

我现在尝试将相同的 LUT 滤镜应用到实时摄像机 View ，但我似乎无法让它工作。它基本上甚至不显示相机。

我在下面提供了我的代码，任何帮助将不胜感激。这可能是我错过/做错的一些简单的事情，但我似乎无法发现它。

import UIKit
import GPUImage

class LiveCameraVC: UIViewController
{

// MARK: - Variables

let videoCamera: GPUImageVideoCamera? = {
    if let videoCamera = GPUImageVideoCamera(sessionPreset: AVCaptureSessionPreset640x480, cameraPosition: .back) {
        videoCamera.outputImageOrientation = .portrait
        videoCamera.horizontallyMirrorFrontFacingCamera = false
        videoCamera.horizontallyMirrorRearFacingCamera = false
        return videoCamera
    } else {
        print("GPUImageVideoCamera Nil")
        return nil
    }
}()

let filter: GPUImageLookupFilter = {
    let filter = GPUImageLookupFilter()
    filter.intensity = 1.0
    return filter
}()

// MARK: - UI

let modifiedImageView: GPUImageView = {
    let imageView = GPUImageView.newAutoLayout()
    imageView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill;
    imageView.isUserInteractionEnabled = true
    return imageView
}()

// MARK: - Life Cycle

override func viewDidLoad() {
    super.viewDidLoad()

    let tapGesture:UITapGestureRecognizer = UITapGestureRecognizer().bk_init { [unowned self] (sender:UIGestureRecognizer?, state:UIGestureRecognizerState, location:CGPoint) in

        print("Tapped")
        self.performLut()

        } as! UITapGestureRecognizer
    modifiedImageView.addGestureRecognizer(tapGesture)
}

override func loadView() {
    super.loadView()

    self.view.addSubview(modifiedImageView)
    modifiedImageView.autoPinEdgesToSuperviewEdges()
}

// MARK: - Private

private func performLut() {
    print("performLut")
    if let videoCamera = videoCamera {
        if let lookupImageSource = GPUImagePicture(image: UIImage(named:"lut_lookup")) {
            videoCamera.addTarget(filter, atTextureLocation: 0)
            lookupImageSource.addTarget(filter, atTextureLocation: 1)
            filter.addTarget(modifiedImageView)
            videoCamera.startCapture()
        } else {
            print("videoCamera Nil")
        }
    } else {
        print("GPUImageVideoCamera Nil")
    }
}
}

谢谢

Answer 1

解决了。我将代码更改为:

let imagePicture: GPUImagePicture? = {
    if let imagePicture = GPUImagePicture(image: UIImage(named:"lut_lookup")) {
        return imagePicture
    } else {
        print("GPUImagePicture Nil")
        return nil
    }
}()


private func performLut() {
    if let videoCamera = videoCamera {
        if let imagePicture = imagePicture {
            videoCamera.addTarget(filter)
            imagePicture.addTarget(filter)
            imagePicture.processImage()
            filter.addTarget(modifiedImageView)
            videoCamera.startCapture()
        }
    }
}

希望这对某人有帮助!