you should constraint the crop of scanning. #4
Description
I am using your source code and found out you are using full screen scanning. It makes a little bit odd as a user. you can set the variable rectOfInterest in AVCaptureMetadataOutput. Those changes make user feel that you are using the part of the crop for scanning.
I hardcore in my project output.rectOfInterest = CGRect(x: 0.3, y: 0.3, width: 0.55, height: 0.55)