Aztec Barcode cant read binary data

Hello,


I am trying to encode and decode binary data in an 2D readable Barcode (e.g Aztec).

Unfortunately I cant get it running and I couldn't find something that helped me.


Since iOS 11 it should be possible to create barcodes with binary content due to this apple release notes: https://developer.apple.com/library/archive/releasenotes/General/WhatsNewIniOS/Articles/iOS_11_0.html

"Added APIs to AV Foundation, Core Image, and SiriKit to support detection, decoding, and creation of barcodes with binary content."


To generate an Aztec Code image, I used the following code snippet:

let binaryData = Data([UInt8](arrayLiteral: 0x01, 0x02, 0x03, 0x04, 0x05, 0x06))
guard let filter = CIFilter(name: "CIAztecCodeGenerator") else {
                return nil
        }

 filter.setValue(binaryData, forKey: "inputMessage")

 guard let image = filter.outputImage else {
        return nil
 }


I now can use the image and show it in an UIImageView. It shows a nice Aztec code.


But I have a problem, when decoding the Aztec code back to binary. I am using the the iphone camera and a AVCaptureSession with an AVMetadataOutput. The detection of the aztec code works fine, but in the delegate function, I am not able to retrieve the actually binary data

func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        captureSession.stopRunning()

        if let metadataObject = metadataObjects.first {
            
           guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return }
           guard let descriptor = readableObject.descriptor as? CIAztecCodeDescriptor else {return}
             
            // here I dont get the correct raw bytes (0x01 -0x06)
            // Instead I only get this: e8864298f0000000
            let rawBytes = descriptor.errorCorrectedPayload
            print(rawBytes)
            let dataString = rawBytes.hex
            print("dataString: \(dataString)")

            guard let stringValue = readableObject.stringValue else { return }
          
        }
}


I am not able to get the correct raw bytes (0x01, 0x02, 0x03, 0x04, 0x05, 0x06). The "stringValue" is empty, because the encoded bytes are binary data and are not a valid string.

Are the raw bytes (e8864298f0000000) somehow encrypted or encoded in a special format?


Best regards

Julian

Replies

Hello,

Can you resolve it?

Best regards

Dayron