Overview of Beta stage of CameraX. You can taste api and test cases of CameraX beta, and this include several code snippet which is essential.

1. Beyond Alpha, CameraX
Wonyoung Choi
@TORU_0239

2. CameraX

3. Overview
• Lifecycle-aware component
• Backward compatibility till L
• Use-case based approaches
• Resolving device-compatibility issues

4. •10 stages of Alpha
•3 stages of Beta
Versions

5. Use Cases
• Preview
• Image Analysis
• Image Capture

6. Preview

7. Preview
• New Preview Layout
• Possibility of customising TextureView

8. <androidx.camera.view.PreviewView
android:id="@+id/viewFinder"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>

9. val viewFinder = view.findViewById(R.id.viewFinder)
val preview = Preview.Builder()
.setTargetAspectRatio(screenAspectRatio)
.setTargetRotation(rotation)
.build()
preview.setSurfaceProvider(viewFinder.previewSurfaceProvider)

10. class CameraXApp:Application(), CameraXConfig.Provider{
override fun getCameraXConfig(): CameraXConfig {
return Camera2Config.defaultConfig()
}
}
Revised in beta-02

11. val viewFinder = view.findViewById(R.id.viewFinder)
val preview = Preview.Builder()
.setTargetAspectRatio(screenAspectRatio)
.setTargetRotation(rotation)
.build()
preview.setSurfaceProvider(viewFinder.previewSurfaceProvider)
preview.setSurfaceProvider(preview.createSurfaceProvider(camera.cameraInfo))
Revised in beta-02

12. Image Analysis

13. val imageAnalyzer = ImageAnalysis.Builder()
.setTargetResolution(Size(720, 1280))
// non-blocking mode can be enabled by this line
.setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
.build()

14. imageAnalyzer.setAnalyzer(executor,
ImageAnalysis.Analyzer { image ->
// put your code
}
)

15. Image Capture

16. val imageCapture = ImageCapture.Builder()
.setCaptureMode(imageCaptureMode)
.setTargetAspectRatio(screenAspectRatio)
.setTargetRotation(viewFinder.display.rotation)
.build()

17. AspectRatio Constant:
AspectRatio.RATIO_16_9
AspectRatio.RATIO_4_3
ImageCaptureMode Constant:
ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY
ImageCapture.CAPTURE_MODE_MAXIMIZE_QUALITY

18. •Taking Picture!
Interact

19. val outputOptions = ImageCapture.OutputFileOptions.Builder(File(...))
val metaData = ImageCapture.Metadata().apply {
isReversedHorizontal =
(lensFacing == CameraSelector.LENS_FACING_FRONT)
}
val outputOptions = ImageCapture.OutputFileOptions.Builder(file)
.setMetadata(metaData)
.build()

20. imageCapture.takePicture(outputOptions, executor,
object:ImageCapture.OnImageSavedCallback {
override fun onImageSaved(results: ImageCapture.OutputFileResults) {
// put your code
}
override fun onError(exception: ImageCaptureException) {
// put your code
}
})
}

21. New APIs in Beta

22. •Initialisation
•Picking a camera
•Camera control
New APIs in Beta

23. •A new class, ProcessCameraProvider
•Using concurrency api for initialisation
Initialisation

24. val cameraProviderFuture = ProcessCameraProvider.getInstance(context)
cameraProviderFuture.addListener(Runnable {
val cameraProvider:ProcessCameraProvider =
cameraProviderFuture.get()
... // discuss later
}, executor)
Initialisation

25. •A new class, CameraSelector
•Picks the most suitable one based on option given.
Picking a camera

26. val cameraSelector = CameraSelector.Builder()
.requireLensFacing(lensFacing)
.build()
lensFacing:
CameraSelector.LENS_FACING_BACK
CameraSelector.LENS_FACING_FRONT
Picking a camera

27. •CameraControl, CameraInfo
•An object returned a!er binding to lifecycle
•Querying and modifying ce"ain aspects of the camera
Camera controls

28. val camera = cameraProvider.bindToLifecycle(…)
val info:CameraInfo = camera.cameraInfo
val control:CameraControl = camera.cameraControl
Camera controls

29. control.enableTorch(Boolean)
control.setLinearZoom(Float)
control.setZoomRatio(Float)
control.startFocusAndMetering(FocusMeteringAction)
control.cancelFocusAndMetering()

30. val degree:Int = cameraInfo.sensorRotationDegrees
val torch:LiveData<Int> = cameraInfo.torchState
val zoom:LiveData<ZoomState> = cameraInfo.zoomState
val flash:Boolean = cameraInfo.hasFlashUnit()

31. •Only one line required!
•Has been changed in Beta
How to bind to lifecycle

32. val camera = cameraProvider.bindToLifecycle
(
viewLifecycleOwner,
cameraSelector,
preview,
imageCapture,
imageAnalyzer
)
How to bind to lifecycle

33. cameraProvider.unbindAll()
How to unbind to lifecycle

34. Fu!her Discussion

35. Advanced Features
•Tap to focus
•Pinch zoom
•Zoom slider
•Torch enable/disable

36. Vendor Extensions
•Visual e#ects such as Bokeh or HDR
•Only for speci$c devices by manufacturers

37. QA

38. Thank You!
Wonyoung Choi
@TORU_0239