Question

仅当我使用updatedMetadataObjectForMetadataObject来调整previewLayer时，问题是不稳定的（每次更新时两个大小之间的大小跳转）大小。

    for(AVMetadataObject *metadataObject in metadataObjects) {
        if([metadataObject.type isEqualToString:AVMetadataObjectTypeFace]) {
            // Take an image of the face and pass to CoreImage for detection


            AVMetadataObject *metadataObjectR=[previewLayer transformedMetadataObjectForMetadataObject:metadataObject];


            previewLayer.bounds = CGRectMake(previewLayer.bounds.origin.x,previewLayer.bounds.origin.y, metadataObjectR.bounds.size.width,metadataObjectR.bounds.size.height);

创建previewLayer的代码（previewViewLayer是CALayer）

[captureSession addInput:vInput];
[captureSession setSessionPreset:AVCaptureSessionPresetPhoto];

previewViewLayer = [self.view layer];
[previewViewLayer setBackgroundColor:(__bridge CGColorRef _Nullable)([UIColor blackColor])];
previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:captureSession];
[previewLayer setFrame:[previewViewLayer bounds]];
[previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[previewViewLayer addSublayer:previewLayer];

Answer 1

我不知道你想做什么。函数transformationMetadataObjectForMetadataObject，返回在previewLayer坐标中的metaDataObject，所以它的边界是metaDataObject的框架。但是你用这个框架来设置previewLayer的界限。预览层的框架不应该改变，因为它用于预览相机。你应该使用新的metaDataObject界限来改变图层的框架来指示面部。 / p>

Objective C transformedMetadataObjectForMetadataObject在我用它来调整预览图层大小时会产生不稳定的大小

1 个答案: