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