为预览图层设置边框会导致边框设置不正确

Question

我在使用 PBJVision 时遇到了一些问题。

我将它集成到一个 Swift 项目中，当我尝试设置预览图层的框架时，它导致框架不一致：

我有这个代码：

var _previewLayer: AVCaptureVideoPreviewLayer = PBJVision.sharedInstance().previewLayer
@IBOutlet weak var previewView: UIView! // this is the white view in the back

let bounds = self.previewView.layer.bounds
_previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
_previewLayer.bounds = bounds
_previewLayer.position = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds))
previewView.layer.addSublayer(_previewLayer)

Answer 1

您是否尝试过在 previewView 布置其子视图时调整 _previewLayer 的框架大小？

为您的 previewView 子类 UIView，为您的 AVCaptureVideoPreviewLayer 设置属性，并将其框架设置为与您的视图边界匹配：

class PreviewView: UIView {

    let previewLayer: AVCaptureVideoPreviewLayer?

    override func layoutSubviews() {
        self.previewLayer?.frame = self.bounds;
    }
}

Answer 2

我遇到了同样的问题。

我尝试了@rkyr 的建议（在viewDidLayoutSubviews 方法中设置框架），但没有成功。我也想在不添加子类的情况下修复它。

我能够通过 2 个更改修复它： - 确保 previewLayer 被定义为 AVCaptureVideoPreviewLayer（CALayer 的子类）而不是 CALayer，这是我的情况

var previewLayer: AVCaptureVideoPreviewLayer? // :CALayer

确保图层的frame设置好，图层session的所有设置都设置好后添加到视图中：这段代码有效：

captureSession = AVCaptureSession()
let captureDevice = AVCaptureDevice.default(for: AVMediaType.video)
do {
    let input = try AVCaptureDeviceInput(device: captureDevice!)
    captureSession?.addInput(input)
} catch {
    onErrorCloseAndReturn(error: error)
}
let dataOutput = AVCaptureVideoDataOutput()
dataOutput.videoSettings = [((kCVPixelBufferPixelFormatTypeKey as NSString) as String): NSNumber(value: kCVPixelFormatType_32BGRA)]
dataOutput.alwaysDiscardsLateVideoFrames = true
if captureSession!.canAddOutput(dataOutput) {
    captureSession?.addOutput(dataOutput)
}
captureSession?.commitConfiguration()
let queue = DispatchQueue(label: "captureQueue")
dataOutput.setSampleBufferDelegate(self, queue: queue)
captureSession?.startRunning()

previewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
previewLayer?.frame = self.view.layer.bounds
self.view.layer.addSublayer(previewLayer!)

我希望它有帮助...e

为预览图层设置边框会导致边框设置不正确

Setting the frame for the preview layer results in incorrect frame settings

ios

swift

pbjvision