Android CameraX dual camera

안드로이드 X로 좀 찾아보다가 1.3.0 베타에 듀얼카메라가 업데이트된걸 찾았다.

https://developer.android.com/jetpack/androidx/releases/camera?hl=ko#1.3.0-alpha06

원래는 후면 wide, ultra-wide 카메라를 두 개 동시에 사용하려고 찾은건데 전면과 후면 카메라만 일단 동시에 사용할 수 있다고 한다.

package com.example.android_stereo_vision_opencv

import android.Manifest
import android.annotation.SuppressLint
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.CameraSelector
import androidx.camera.core.ConcurrentCamera.SingleCameraConfig
import androidx.camera.core.ImageCapture
import androidx.camera.core.Preview
import androidx.camera.core.UseCaseGroup
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.example.android_stereo_vision_opencv.databinding.ActivityMainBinding
import com.google.firebase.crashlytics.buildtools.reloc.com.google.common.collect.ImmutableList
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors


var primaryCameraSelector: CameraSelector? = null
var secondaryCameraSelector: CameraSelector? = null

class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding
    private lateinit var cameraExecutor: ExecutorService
    private var imageCapture: ImageCapture? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        if (allPermissionsGranted()) {
            cameraExecutor = Executors.newSingleThreadExecutor()
            startCamera()
        } else {
            ActivityCompat.requestPermissions(
                this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
        }
    }

    @SuppressLint("RestrictedApi")
    private fun startCamera() {
        val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
        cameraProviderFuture.addListener({
            val cameraProvider = cameraProviderFuture.get()

            // 동시에 사용 가능한 카메라 조합을 확인
            val availableCameraPairs = cameraProvider.availableConcurrentCameraInfos

            Log.d("test", availableCameraPairs.toString())


            if (availableCameraPairs.isEmpty()) {
                Log.e(TAG, "No concurrent cameras available.")
                return@addListener
            }

            primaryCameraSelector = availableCameraPairs[1][0].cameraSelector
            secondaryCameraSelector = availableCameraPairs[1][1].cameraSelector


            // 두 카메라에 대한 미리보기 설정
            val primaryPreview = Preview.Builder().build().also {
                it.setSurfaceProvider(binding.previewUw.surfaceProvider)
            }
            val secondaryPreview = Preview.Builder().build().also {
                it.setSurfaceProvider(binding.previewWide.surfaceProvider)
            }


            try {
                // 기존의 카메라 바인딩을 해제
                cameraProvider.unbindAll()

                val primary = SingleCameraConfig(
                    primaryCameraSelector!!,
                    UseCaseGroup.Builder()
                        .addUseCase(primaryPreview)
                        .build(),
                    this
                )



                val secondary = SingleCameraConfig(
                    secondaryCameraSelector!!,
                    UseCaseGroup.Builder()
                        .addUseCase(secondaryPreview)
                        .build(),
                    this
                )

                cameraProvider.bindToLifecycle(ImmutableList.of(primary, secondary));

            } catch (exc: Exception) {
                Log.e(TAG, "Use case binding failed", exc)
            }
        }, ContextCompat.getMainExecutor(this))
    }


    private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
        ContextCompat.checkSelfPermission(
            baseContext, it) == PackageManager.PERMISSION_GRANTED
    }

    override fun onDestroy() {
        super.onDestroy()
        cameraExecutor.shutdown()
    }

    override fun onRequestPermissionsResult(
        requestCode: Int, permissions: Array<String>, grantResults:
        IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == REQUEST_CODE_PERMISSIONS) {
            if (allPermissionsGranted()) {
                startCamera()
            } else {
                Toast.makeText(this,
                    "Permissions not granted by the user.",
                    Toast.LENGTH_SHORT).show()
                finish()
            }
        }
    }

    companion object {
        private const val TAG = "CameraXApp"
        private const val FILENAME_FORMAT = "yyyy-MM-dd-HH-mm-ss-SSS"
        private const val REQUEST_CODE_PERMISSIONS = 10
        private val REQUIRED_PERMISSIONS =
            mutableListOf (
                Manifest.permission.CAMERA,
                Manifest.permission.RECORD_AUDIO
            ).apply {
                if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
                    add(Manifest.permission.WRITE_EXTERNAL_STORAGE)
                }
            }.toTypedArray()
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.camera.view.PreviewView
        app:scaleType="fitCenter"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@id/preview_uw"
        android:id="@+id/preview_wide"
        android:layout_width="match_parent"
        android:layout_height="0dp"/>

    <androidx.camera.view.PreviewView
        app:scaleType="fitCenter"
        app:layout_constraintTop_toBottomOf="@id/preview_wide"
        app:layout_constraintBottom_toTopOf="@id/iv_depth_map"
        android:id="@+id/preview_uw"
        android:layout_width="match_parent"
        android:layout_height="0dp"/>

    <ImageView
        app:layout_constraintTop_toBottomOf="@id/preview_uw"
        app:layout_constraintBottom_toBottomOf="parent"
        android:id="@+id/iv_depth_map"
        android:layout_width="match_parent"
        android:layout_height="0dp"/>

    <androidx.constraintlayout.widget.ConstraintLayout
        app:layout_constraintTop_toTopOf="parent"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <Button
            android:textSize="12sp"
            android:id="@+id/btn_wide_camera"
            android:layout_margin="5dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="광각 카메라" />

        <Button
            android:textSize="12sp"
            android:id="@+id/btn_uw_camera"
            android:layout_margin="5dp"
            app:layout_constraintStart_toEndOf="@id/btn_wide_camera"
            app:layout_constraintTop_toTopOf="parent"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="초광각 카메라" />

        <Button
            android:textSize="12sp"
            android:id="@+id/btn_depth_estimation"
            android:layout_margin="5dp"
            app:layout_constraintStart_toEndOf="@id/btn_uw_camera"
            app:layout_constraintTop_toTopOf="parent"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="깊이 추정" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

위 코드는 cameraX를 사용해서 전면과 후면의 카메라를 동시에 사용할 수있는 코드이다.

CameraX 나오기 전이라면 Camera2로 두 카메라를 연결할 때 세션관리를 같이 해줘야하는데 CameraX가 이런 부분은 전부 없애버려서 간단하게 코드를 작성할 수 있었다.