Camera2

Cmaera2 is the android official package that makes developers being able to develop various camera characteristics in detail.
See more information => https://developer.android.com/media/camera/camera2

Prerequisite

You could see preview on your app( if not, this site will help you =>https://github.com/googlearchive/android-Camera2Basic/blob/master/kotlinApp/Application/src/main/java/com/example/android/camera2basic/Camera2BasicFragment.kt)

How to request changing camera params?

All of camera prams are changed by using CaptureRequestBuilder that could be retrieved by CameraDevice. CameraDevice is the main object that have all features of Android camera device).

Steps

In this example, I will change white balance and adjust focus as auto focus.

You can get the instance of CameraDevice from cameraDeviceSessionCallback.
The following example really helped for me.

camera-samples/HdrViewfinder/Application/src/main/java/com/example/android/hdrviewfinder/CameraOps.java at 96cbc7d8014d72470c4b70ca76adfdc332d60123 · android/camera-samples

Multiple samples showing the best practices in camera APIs on Android. - android/camera-samples

github.com

１. retrive CameraRequestBuilder from cameraDeive

val captureRequestBuilder = cameraDevice?.createCaptureRequest(CameraDevice.TEMPLATE_MANUAL)

２. Set repoeating request that you want to change your camera parameters

            captureRequestBuilder?.run {
                addTarget(surfaceView!!.holder.surface)
                set(CaptureRequest.CONTROL_AWB_MODE, CameraMetadata.CONTROL_AWB_MODE_OFF)
                set(CaptureRequest.COLOR_CORRECTION_MODE, CameraMetadata.COLOR_CORRECTION_MODE_TRANSFORM_MATRIX)
                set(CaptureRequest.COLOR_CORRECTION_GAINS, getRggbChannelVector(to))
                set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE)
                CameraManagerWrapper.cameraOps.cameraCaptureSession?.setRepeatingRequest(
                    this.build(),
                    CameraManagerWrapper.cameraOps.captureCallbackListener,
                    null,
                )
                CameraManagerWrapper.cameraOps.captureRequestBuilder = captureRequestBuilder
            }

You can set the second parameter in the setRepeatingRequest. But I reccoment to set it due to save the camera parameter's context. And you can get latest camera parameters from CaptureResult(TotalCaptureResult)::get()

                CameraManagerWrapper.cameraOps.cameraCaptureSession?.setRepeatingRequest(
                    this.build(),
                    CameraManagerWrapper.cameraOps.captureCallbackListener,//⭐️ here
                    null,
                )