如何在AVCaptureVideoPreviewLayer上显示叠加层

Question

我需要在AVCaptureVideoPreviewLayer上显示图像(帧)覆盖.我怎样才能做到这一点？

-(void) viewDidAppear:(BOOL)animated
{
    AVCaptureSession *session = [[AVCaptureSession alloc] init];
    session.sessionPreset = AVCaptureSessionPresetPhoto;
    [session commitConfiguration];

    CALayer *viewLayer = self.vImagePreview.layer;
    NSLog(@"viewLayer = %@", viewLayer);

    AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

    captureVideoPreviewLayer.frame = self.vImagePreview.bounds;
    [self.vImagePreview.layer addSublayer:captureVideoPreviewLayer];

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    NSError *error = nil;
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    if (!input) {
        // Handle the error appropriately.
        NSLog(@"ERROR: trying to open camera: %@", error);
    }
    [session addInput:input];

    _stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [_stillImageOutput setOutputSettings:outputSettings];

    [session addOutput:_stillImageOutput];

    [session startRunning];

}

在视频输出图层上添加新视图不起作用.预览图层显示在所有视图的顶部.

我的视图层次结构

• 的MainView
  • OverlayView的
  • VideoOutputView

Answer 1

尽管这个问题是在N年前提出的,但我想分享我的确切答案.几分钟后,我能够理解古吉明说的话.实际上,解决方案可以通过编程方式完成.但是如果您在XIB或Storyboard中进行操作,请检查此类层次结构.不要将任何子视图放到您的CameraPreviewView(其图层将是相机的uiview).

Answer 2

通过以编程方式创建所有视图来解决（没有故事板）