Android CameraX を始めてみて

2024年1月20日

今日はコピペが多く大分楽しているなという顔をしている柴犬です。

概要

android スマホにインストールされていたカメラが壊れました。

これを機に、自分でAndroidStudioでカメラのコードを書いてインストールしてみることにしました。

androidstudio camera java kotlin というキーでWEBをググッても参考にできるHPがなかなか見つかりません。

最後と思って android camerax というキーでリクエストしたところトップに理想的なHPがみつかりました。

それがAndroidStudio公式HPの「CameraX の概要」です。　

https://developer.android.com/training/camerax?hl=ja

この中で特に「CameraX のスタートガイド」が、説明の仕方も丁寧で分かりやすく、レイアウトも見やすい整理されたもので、今後の私のブログに参考させていただきます。

内容も私の基礎とするべきものと感じました。

なので、コード類はほぼコピペですが記録します。

作って触ってみて、カメラ毎に保存先を変えることができたりカメラ毎にパラメータを変えることができるので、ベースがあれば楽にカスタマイズできると感じました。

AndroidManifest.xml

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-feature android:name="android.hardware.camera.any" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        android:maxSdkVersion="28" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Cameraapp"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity.kt

次のインポート文は

import com.android.example.cameraxapp.databinding.ActivityMainBinding

このようにパッケージ名に合わせて変更する必要があります。

import siba.inu.android.cameraapp.databinding.ActivityMainBinding

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package siba.inu.android.cameraapp

import android.Manifest
import android.content.ContentValues
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.provider.MediaStore
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.ImageCapture
import androidx.camera.video.Recorder
import androidx.camera.video.Recording
import androidx.camera.video.VideoCapture
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors
import android.widget.Toast
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.core.Preview
import androidx.camera.core.CameraSelector
import android.util.Log
import androidx.camera.core.ImageAnalysis
import androidx.camera.core.ImageCaptureException
import androidx.camera.core.ImageProxy
import androidx.camera.video.FallbackStrategy
import androidx.camera.video.MediaStoreOutputOptions
import androidx.camera.video.Quality
import androidx.camera.video.QualitySelector
import androidx.camera.video.VideoRecordEvent
import androidx.core.content.PermissionChecker
import siba.inu.android.cameraapp.databinding.ActivityMainBinding
import java.nio.ByteBuffer
import java.text.SimpleDateFormat
import java.util.Locale

typealias LumaListener = (luma: Double) -> Unit

class MainActivity : AppCompatActivity() {
    private lateinit var viewBinding: ActivityMainBinding

    private var imageCapture: ImageCapture? = null

    private var videoCapture: VideoCapture<Recorder>? = null
    private var recording: Recording? = null

    private lateinit var cameraExecutor: ExecutorService

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

        // Request camera permissions
        if (allPermissionsGranted()) {
            startCamera()
        } else {
            ActivityCompat.requestPermissions(
                this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
        }

        // Set up the listeners for take photo and video capture buttons
        viewBinding.imageCaptureButton.setOnClickListener { takePhoto() }
        viewBinding.videoCaptureButton.setOnClickListener { captureVideo() }

        cameraExecutor = Executors.newSingleThreadExecutor()
    }

    private fun takePhoto() {
        // Get a stable reference of the modifiable image capture use case
        val imageCapture = imageCapture ?: return

        // Create time stamped name and MediaStore entry.
        val name = SimpleDateFormat(FILENAME_FORMAT, Locale.US)
            .format(System.currentTimeMillis())
        val contentValues = ContentValues().apply {
            put(MediaStore.MediaColumns.DISPLAY_NAME, name)
            put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg")
            if(Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
                put(MediaStore.Images.Media.RELATIVE_PATH, "Pictures/CameraX-Image")
            }
        }

        // Create output options object which contains file + metadata
        val outputOptions = ImageCapture.OutputFileOptions
            .Builder(contentResolver,
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                contentValues)
            .build()

        // Set up image capture listener, which is triggered after photo has
        // been taken
        imageCapture.takePicture(
            outputOptions,
            ContextCompat.getMainExecutor(this),
            object : ImageCapture.OnImageSavedCallback {
                override fun onError(exc: ImageCaptureException) {
                    Log.e(TAG, "Photo capture failed: ${exc.message}", exc)
                }

                override fun
                        onImageSaved(output: ImageCapture.OutputFileResults){
                    val msg = "Photo capture succeeded: ${output.savedUri}"
                    Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
                    Log.d(TAG, msg)
                }
            }
        )
    }

    // Implements VideoCapture use case, including start and stop capturing.
    private fun captureVideo() {
        val videoCapture = this.videoCapture ?: return

        viewBinding.videoCaptureButton.isEnabled = false

        val curRecording = recording
        if (curRecording != null) {
            // Stop the current recording session.
            curRecording.stop()
            recording = null
            return
        }

        // create and start a new recording session
        val name = SimpleDateFormat(FILENAME_FORMAT, Locale.US)
            .format(System.currentTimeMillis())
        val contentValues = ContentValues().apply {
            put(MediaStore.MediaColumns.DISPLAY_NAME, name)
            put(MediaStore.MediaColumns.MIME_TYPE, "video/mp4")
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
                put(MediaStore.Video.Media.RELATIVE_PATH, "Movies/CameraX-Video")
            }
        }

        val mediaStoreOutputOptions = MediaStoreOutputOptions
            .Builder(contentResolver, MediaStore.Video.Media.EXTERNAL_CONTENT_URI)
            .setContentValues(contentValues)
            .build()
        recording = videoCapture.output
            .prepareRecording(this, mediaStoreOutputOptions)
            .apply {
                if (PermissionChecker.checkSelfPermission(this@MainActivity,
                        Manifest.permission.RECORD_AUDIO) ==
                    PermissionChecker.PERMISSION_GRANTED)
                {
                    withAudioEnabled()
                }
            }
            .start(ContextCompat.getMainExecutor(this)) { recordEvent ->
                when(recordEvent) {
                    is VideoRecordEvent.Start -> {
                        viewBinding.videoCaptureButton.apply {
                            text = getString(R.string.stop_capture)
                            isEnabled = true
                        }
                    }
                    is VideoRecordEvent.Finalize -> {
                        if (!recordEvent.hasError()) {
                            val msg = "Video capture succeeded: " +
                                    "${recordEvent.outputResults.outputUri}"
                            Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT)
                                .show()
                            Log.d(TAG, msg)
                        } else {
                            recording?.close()
                            recording = null
                            Log.e(TAG, "Video capture ends with error: " +
                                    "${recordEvent.error}")
                        }
                        viewBinding.videoCaptureButton.apply {
                            text = getString(R.string.start_capture)
                            isEnabled = true
                        }
                    }
                }
            }
    }

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

        cameraProviderFuture.addListener({
            // Used to bind the lifecycle of cameras to the lifecycle owner
            val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

            // Preview
            val preview = Preview.Builder()
                .build()
                .also {
                    it.setSurfaceProvider(viewBinding.viewFinder.surfaceProvider)
                }
            val recorder = Recorder.Builder()
                .setQualitySelector(QualitySelector.from(Quality.HIGHEST,
                    FallbackStrategy.higherQualityOrLowerThan(Quality.SD)))
                .build()
            videoCapture = VideoCapture.withOutput(recorder)

            imageCapture = ImageCapture.Builder().build()

            /*
            val imageAnalyzer = ImageAnalysis.Builder().build()
                .also {
                    setAnalyzer(
                        cameraExecutor,
                        LuminosityAnalyzer { luma ->
                            Log.d(TAG, "Average luminosity: $luma")
                        }
                    )
                }
            */

            // Select back camera as a default
            val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

            try {
                // Unbind use cases before rebinding
                cameraProvider.unbindAll()

                // Bind use cases to camera
                cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview, imageCapture, videoCapture)

            } 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()
    }

    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()
    }

    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()
            }
        }
    }

}

private class LuminosityAnalyzer(private val listener: LumaListener) : ImageAnalysis.Analyzer {

    private fun ByteBuffer.toByteArray(): ByteArray {
        rewind()    // Rewind the buffer to zero
        val data = ByteArray(remaining())
        get(data)   // Copy the buffer into a byte array
        return data // Return the byte array
    }

    override fun analyze(image: ImageProxy) {

        val buffer = image.planes[0].buffer
        val data = buffer.toByteArray()
        val pixels = data.map { it.toInt() and 0xFF }
        val luma = pixels.average()

        listener(luma)

        image.close()
    }
}

res/layout/activity_main.xml

HPのまるっとコピーです。

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<?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
        android:id="@+id/viewFinder"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <Button
        android:id="@+id/image_capture_button"
        android:layout_width="110dp"
        android:layout_height="110dp"
        android:layout_marginBottom="50dp"
        android:layout_marginEnd="50dp"
        android:elevation="2dp"
        android:text="@string/take_photo"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintEnd_toStartOf="@id/vertical_centerline" />

    <Button
        android:id="@+id/video_capture_button"
        android:layout_width="110dp"
        android:layout_height="110dp"
        android:layout_marginBottom="50dp"
        android:layout_marginStart="50dp"
        android:elevation="2dp"
        android:text="@string/start_capture"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@id/vertical_centerline" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/vertical_centerline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent=".50" />

</androidx.constraintlayout.widget.ConstraintLayout>

res/values/strings

HPのまるっとコピーです。

copy

<resources>
    <string name="app_name">CameraXApp</string>
    <string name="take_photo">Take Photo</string>
    <string name="start_capture">Start Capture</string>
    <string name="stop_capture">Stop Capture</string>
</resources>

build.gradle.kts（Module :app）

HPでは次のコードでしたがエラーとなりました。

  def camerax_version = "1.1.0-beta01"
  implementation "androidx.camera:camera-core:${camerax_version}"
  implementation "androidx.camera:camera-camera2:${camerax_version}"
  implementation "androidx.camera:camera-lifecycle:${camerax_version}"
  implementation "androidx.camera:camera-video:${camerax_version}"

  implementation "androidx.camera:camera-view:${camerax_version}"
  implementation "androidx.camera:camera-extensions:${camerax_version}"

次のようなコードにしました。

    var camerax_version = "1.1.0-beta01"
    implementation("androidx.camera:camera-core:${camerax_version}")
    implementation("androidx.camera:camera-camera2:${camerax_version}")
    implementation("androidx.camera:camera-lifecycle:${camerax_version}")
    implementation("androidx.camera:camera-video:${camerax_version}")

    implementation("androidx.camera:camera-view:${camerax_version}")
    implementation("androidx.camera:camera-extensions:${camerax_version}")

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plugins {
    id("com.android.application")
    id("org.jetbrains.kotlin.android")
}

android {
    namespace = "siba.inu.android.cameraapp"
    compileSdk = 34

    defaultConfig {
        applicationId = "siba.inu.android.cameraapp"
        minSdk = 26
        targetSdk = 33
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
    buildFeatures {
        viewBinding = true
    }

}

dependencies {

    implementation("androidx.core:core-ktx:1.9.0")
    implementation("androidx.appcompat:appcompat:1.6.1")
    implementation("com.google.android.material:material:1.11.0")
    implementation("androidx.constraintlayout:constraintlayout:2.1.4")
    testImplementation("junit:junit:4.13.2")
    androidTestImplementation("androidx.test.ext:junit:1.1.5")
    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
    var camerax_version = "1.1.0-beta01"
    implementation("androidx.camera:camera-core:${camerax_version}")
    implementation("androidx.camera:camera-camera2:${camerax_version}")
    implementation("androidx.camera:camera-lifecycle:${camerax_version}")
    implementation("androidx.camera:camera-video:${camerax_version}")

    implementation("androidx.camera:camera-view:${camerax_version}")
    implementation("androidx.camera:camera-extensions:${camerax_version}")
}