So I'm working on an app that requires QR scanner as a main feature. Previously I was using camerax-alpha06 with Firebase ML vision 24.0.3 and they were working fine for months, no customer complaints about scanning issues.
Then about two weeks ago I had to change Firebase ML vision to MLKit barcode scanning (related to the Crashlytics migration - out of topic) and now some of the users who could scan in the previous version now could not. Some sample devices be Samsung Tab A7 (Android 5.1.1) and Vivo 1919 (Android 10)
This is my build.gradle section that involves this feature
def camerax_version = "1.0.0-beta11"
implementation "androidx.camera:camera-core:${camerax_version}"
implementation "androidx.camera:camera-camera2:${camerax_version}"
implementation "androidx.camera:camera-lifecycle:${camerax_version}"
implementation "androidx.camera:camera-view:1.0.0-alpha18"
implementation "androidx.camera:camera-extensions:1.0.0-alpha18"
implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:16.1.2'
This is my camera handler file
class ScanQRCameraViewHandler(
private val fragment: ScanQRDialogFragment,
private val previewView: PreviewView
) {
private val displayLayout get() = previewView
companion object {
private const val RATIO_4_3_VALUE = 4.0 / 3.0
private const val RATIO_16_9_VALUE = 16.0 / 9.0
}
private val analyzer = GMSMLKitAnalyzer(onFoundQR = { extractedString ->
fragment.verifyExtractedString(extractedString)
}, onNotFoundQR = {
resetStateToAllowNewImageStream()
})
private var cameraProviderFuture: ListenableFuture<ProcessCameraProvider>? = null
private var camera: Camera? = null
private var isAnalyzing = false
internal fun resetStateToAllowNewImageStream() {
isAnalyzing = false
}
internal fun setTorceEnable(isEnabled: Boolean) {
camera?.cameraControl?.enableTorch(isEnabled)
}
internal fun initCameraProviderIfHasNot() {
if (cameraProviderFuture == null) {
fragment.context?.let {
cameraProviderFuture = ProcessCameraProvider.getInstance(it)
val executor = ContextCompat.getMainExecutor(it)
cameraProviderFuture?.addListener({
bindPreview(cameraProviderFuture?.get(), executor)
}, executor)
}
}
}
private fun bindPreview(cameraProvider: ProcessCameraProvider?, executor: Executor) {
val metrics = DisplayMetrics().also { displayLayout.display.getRealMetrics(it) }
val screenAspectRatio = aspectRatio(metrics.widthPixels, metrics.heightPixels)
val preview = initPreview(screenAspectRatio)
val imageAnalyzer = createImageAnalyzer()
val imageAnalysis = createImageAnalysis(executor, imageAnalyzer, screenAspectRatio)
val cameraSelector = createCameraSelector()
cameraProvider?.unbindAll()
camera = cameraProvider?.bindToLifecycle(
fragment as LifecycleOwner,
cameraSelector, imageAnalysis, preview
)
}
private fun createCameraSelector(): CameraSelector {
return CameraSelector.Builder()
.requireLensFacing(CameraSelector.LENS_FACING_BACK)
.build()
}
private fun createImageAnalysis(
executor: Executor, imageAnalyzer: ImageAnalysis.Analyzer, screenAspectRatio: Int
): ImageAnalysis {
val rotation = displayLayout.rotation
val imageAnalysis = ImageAnalysis.Builder()
// .setTargetRotation(rotation.toInt())
// .setTargetAspectRatio(screenAspectRatio)
.setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
.build()
imageAnalysis.setAnalyzer(executor, imageAnalyzer)
return imageAnalysis
}
private fun createImageAnalyzer(): ImageAnalysis.Analyzer {
return ImageAnalysis.Analyzer {
isAnalyzing = true
analyzer.analyze(it)
}
}
private fun initPreview(screenAspectRatio: Int): Preview {
val preview: Preview = Preview.Builder()
//.setTargetResolution(Size(840, 840))
// .setTargetAspectRatio(screenAspectRatio)
// .setTargetRotation(displayLayout.rotation.toInt())
.build()
preview.setSurfaceProvider(previewView.surfaceProvider)
return preview
}
fun unbindAll() {
cameraProviderFuture?.get()?.unbindAll()
}
private fun aspectRatio(width: Int, height: Int): Int {
val previewRatio = width.coerceAtLeast(height).toDouble() / width.coerceAtMost(height)
if (kotlin.math.abs(previewRatio - RATIO_4_3_VALUE) <= kotlin.math.abs(previewRatio - RATIO_16_9_VALUE)) {
return AspectRatio.RATIO_4_3
}
return AspectRatio.RATIO_16_9
}
}
And my analyzer
internal class GMSMLKitAnalyzer(
private val onFoundQR: (String) -> Unit,
private val onNotFoundQR: () -> Unit
) :
ImageAnalysis.Analyzer {
private val options = BarcodeScannerOptions.Builder()
.setBarcodeFormats(Barcode.FORMAT_QR_CODE).build()
@SuppressLint("UnsafeExperimentalUsageError")
override fun analyze(imageProxy: ImageProxy) {
imageProxy.image?.let { mediaImage ->
val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
val scanner = BarcodeScanning.getClient(options)
CoroutineScope(Dispatchers.Main).launch {
val result = scanner.process(image).await()
result.result?.let { barcodes ->
barcodes.find { it.rawValue != null }?.rawValue?.let {
onFoundQR(it)
} ?: run { onNotFoundQR() }
}
imageProxy.close()
}
} ?: imageProxy.close()
}
}
The commented out lines are what I've tried to add and didn't help, some even caused issues on other (used-to-be-working) devices.
I am unsure if I misconfigure anything or not, so I would like any suggestions that would help me find the solution.
Thank you
P.S. This is my first post so if I've done anything wrong or missed something please advise.
