After iPadOS 17.4, AVCaptureMetadataOutput no longer detects QR codes on some devices.

Same here too.

We also found that on some specific iPads running iPadOS 17.4, even with the "Scan QR Codes" in Settings -> Camera is on, we still can't use the native camera app to scan QR codes, there is no response from Camera app.

I don't know the solution yet, but I found a workaround without using AVCaptureMetadataOutput.
This workaround has been confirmed to work properly on iPad (7th Gen).

WORKAROUND:

1. Set AVCaptureVideoDataOutput to the output of AVCaptureSession instead of AVCaptureMetadataOutput.

    captureSession.beginConfiguration()

    // Add video input.
    ...

    // Set AVCaptureVideoDataOutput to the output of AVCaptureSession.
    let videodataOutput = AVCaptureVideoDataOutput()
    if captureSession.canAddOutput(videodataOutput) {
        captureSession.addOutput(videodataOutput)
        // Set AVCaptureVideoDataOutputSampleBufferDelegate implemented object.
        videodataOutput.setSampleBufferDelegate(delegate, queue: videoDataOutputQueue)
    }

    captureSession.commitConfiguration()

    sessionQueue.async {
        self.session.startRunning()
    }

1. Detect the barcode of the sampleBuffer received by the delegate using the Vision.framework

extension CameraViewController: AVCaptureVideoDataOutputSampleBufferDelegate {

    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {

        // convert sampleBuffer to CVImageBuffer.
        guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }

        let handler = VNSequenceRequestHandler()
        let barcodesDetectionRequest = VNDetectBarcodesRequest { (request, error) in

            if let error = error {
                // handle error.
                NSLog("Error: %@", error.localizedDescription)
                return
            }

            guard let results = request.results else { return }            
            for result in results {
                if let barcode = result as? VNBarcodeObservation, validBarcodeTypes.contains(barcode.symbology),
                   let capturedCode = barcode.payloadStringValue {

                    NSLog("captured Code: %@", capturedCode)
                }
            }
        }

        // If necessary, specify the barcode type you want to detect.
        barcodesDetectionRequest.symbologies = [.qr, .code128]

        try? handler.perform([barcodesDetectionRequest], on: imageBuffer)
    }
}

We also have the same stuation. In our case, that happens only when we scan QR code with 6 and 7th Gen iPads. With 8th or more Gen iPads, it dosen't happen. We hope this problem is going to be solved soon.

+1

Upgrade 17.4.1 will be fine

I don't have access to any of the affected devices, but my customer says he installed 17.4.1, and our app still is not able to scan barcodes. Anyone else?

iOS 17.4.1 still has the issue for barcodes (QR code issue was resolved). No official notification from Apple though. There's a Stack Overflow about this too: https://stackoverflow.com/questions/78128010/ipados-17-4-avcapturemetadataoutput-delegate-not-called-qrscanner

Thank you all for replying.

Upgrading to iPadOS 17.4.1 only fixed scanning QR codes, and upgrading to iPadOS 17.5 beta seems to fix scanning other barcodes as well.