android - Android CameraX 如何实现广角/缩小

Question

我尝试使用CameraX api为我的应用内相机实现广角选项，但遇到了一个问题 -CameraControl.setZoomRatio允许在ZoomState.getMinZoomRatio()和之间设置缩放ZoomState.getMaxZoomRatio()，在我测试过的手机minZoomRatio上1.0f。同一部手机支持缩小到0.5f系统摄像头。

当前片段我如何初始化相机：

private var camera: Camera? = null
private var imageCapture: ImageCapture? = null

private fun startCamera() {
    val cameraProviderFuture = ProcessCameraProvider.getInstance(this)

    cameraProviderFuture.addListener({
            val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

            val preview = Preview.Builder()
                .build()
                .also {
                    it.setSurfaceProvider(binding.viewFinder.surfaceProvider)
                }

            imageCapture = ImageCapture.Builder()
                .setFlashMode(ImageCapture.FLASH_MODE_AUTO)
                .build()

            val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

            try {
                cameraProvider.unbindAll()

                camera = cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview, imageCapture
                )
                viewModel.onCameraStarted()
            } catch (exc: Exception) {
                Timber.e(exc)
            }
        },
        ContextCompat.getMainExecutor(this)
    )
}

当前捏到缩放实现：

val scaleGestureDetector = ScaleGestureDetector(this,
    object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
        override fun onScale(detector: ScaleGestureDetector): Boolean {
            val camera = camera ?: return false
            val zoomState = camera.cameraInfo.zoomState.value ?: return false
            val scale = zoomState.zoomRatio * detector.scaleFactor
            val finalScale =
                scale.coerceIn(MIN_ZOOM, MAX_ZOOM).coerceIn(zoomState.minZoomRatio, zoomState.maxZoomRatio)
            camera.cameraControl.setZoomRatio(finalScale)
            return true
        }
    })

binding.viewFinder.setOnTouchListener { view, event ->
    view.performClick()
    scaleGestureDetector.onTouchEvent(event)
    return@setOnTouchListener true
}

我的问题是可以使用CameraX api使用广角相机（或实现0.5f变焦），还是我必须使用Camera2重写整个实现。

标签： androidkotlinandroid-camera2android-camerax