Android CameraX Pro

Production-grade CameraX patterns for Android engineers who are done fighting Camera2 boilerplate. This skill helps you wire up Preview, ImageCapture, VideoCapture, and ImageAnalysis against a single lifecycle, then layer ML Kit detection overlays on top — with the lifecycle, threading, and coordinate-mapping details that usually take a few painful release cycles to get right.

When to use it

• You're adding a camera screen and want one correct lifecycle binding instead of leaked sessions on rotation.
• You need preview + photo capture + real-time analysis running at the same time (e.g. scan-a-barcode-while-previewing).
• You're drawing ML Kit results (barcodes, text blocks, face contours) and the boxes don't line up with the preview.
• You want HDR, low-light boost, or the Concurrent Camera API (front + back simultaneously) without guessing at device support.

How it works

The core is ProcessCameraProvider.getInstance(context), then bindToLifecycle(lifecycleOwner, cameraSelector, ...useCases). You build use cases with their builders — Preview.Builder, ImageCapture.Builder (set CAPTURE_MODE_MINIMIZE_LATENCY or MAXIMIZE_QUALITY), and VideoCapture.withOutput(Recorder). For analysis, ImageAnalysis.Builder().setBackpressureStrategy(STRATEGY_KEEP_ONLY_LATEST) feeds an Analyzer that hands the ImageProxy to ML Kit's InputImage.fromMediaImage(image, rotationDegrees).

Capability gates use CameraInfo: check ImageCapture.getImageCaptureCapabilities() for HDR via setDynamicRange, CameraInfo.isLowLightBoostSupported, and cameraProvider.getAvailableConcurrentCameraInfos() before binding a ConcurrentCamera. Overlay alignment is handled with a Matrix mapping from analysis image space to view space (the same transform MlKitAnalyzer produces when you bind it directly to the controller).

Usage

curl -fsSL --create-dirs -o ~/.claude/skills/android-camerax-pro/SKILL.md https://claudeskil.com/skills/android-camerax-pro/SKILL.md

val provider = ProcessCameraProvider.getInstance(ctx).await()
val preview = Preview.Builder().build()
    .also { it.surfaceProvider = previewView.surfaceProvider }
val capture = ImageCapture.Builder()
    .setCaptureMode(ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY).build()
val analysis = ImageAnalysis.Builder()
    .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST).build()
    .apply { setAnalyzer(executor, BarcodeAnalyzer(::onCodes)) }

provider.unbindAll()
provider.bindToLifecycle(owner, CameraSelector.DEFAULT_BACK_CAMERA,
    preview, capture, analysis)

Then ask: "add a face-contour overlay to my preview" or "make capture fall back when HDR isn't supported."

Tips & gotchas

• Always call unbindAll() before rebinding; re-binding the same use case throws.
• In your analyzer, imageProxy.close() is mandatory — skip it and the pipeline silently stalls after a few frames.
• Pass imageProxy.imageInfo.rotationDegrees into InputImage; hardcoding 0 is the usual cause of "detection works in portrait only."
• Not every device allows preview + capture + analysis together. Check isUseCasesCombinationSupported rather than catching the bind exception.

FAQ

CameraX or the camera-view controller? For most apps, LifecycleCameraController plus PreviewView is less code and gives you MlKitAnalyzer with automatic coordinate transforms. Drop to raw CameraProvider when you need fine-grained use-case control.

Compose support? Yes — wrap PreviewView in AndroidView, or use the camera-compose CameraXViewfinder. The binding logic is identical.

Why is my video missing audio? Recorder needs withAudioEnabled() plus the RECORD_AUDIO permission granted before start().