CameraX 是否支持使用 Kotlin 录制视频？

Question

我已阅读 https://developer.android.com/training/camerax 上的 CameraX 概述。

我想录视频，CameraX支持录视频吗？

顺便说一句，Can I record video with CameraX (Android Jetpack)? 中的代码不适用于最新的camerax_version = "1.0.0-alpha06"

Answer 1

是的。您可以拥有视频用例。 请查看示例代码以启用视频用例，

https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-master-dev/camera/integration-tests/coretestapp/src/main/java/androidx/camera/integration/core/CameraXActivity.java#650

Answer 2

是的，CameraX 也支持录制视频。

我最近创建了演示。 请检查以下代码。

Java 文件

private const val REQUEST_CODE_PERMISSIONS = 10
private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO)
private val tag = MainActivity::class.java.simpleName



@SuppressLint("RestrictedApi, ClickableViewAccessibility")
class VideoCaptureActivity : AppCompatActivity(), LifecycleOwner {

    private lateinit var viewFinder: TextureView
    private lateinit var captureButton: ImageButton
    private lateinit var videoCapture: VideoCapture
    private var lensFacing = CameraX.LensFacing.BACK

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_video_capture)

        viewFinder = findViewById(R.id.view_finder)
        captureButton = findViewById(R.id.capture_button)

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

        val file = File(
            externalMediaDirs.first(),"${System.currentTimeMillis()}.mp4"
        )

        captureButton.setOnTouchListener { _, event ->
            if (event.action == MotionEvent.ACTION_DOWN) {
                captureButton.setBackgroundColor(Color.GREEN)
                videoCapture.startRecording(file, object : VideoCapture.OnVideoSavedListener {
                    override fun onVideoSaved(file: File?) {
                        Log.i(tag, "Video File : $file")
                    }

                    override fun onError(
                        useCaseError: VideoCapture.UseCaseError?,
                        message: String?,
                        cause: Throwable?
                    ) {
                        Log.i(tag, "Video Error: $message")
                    }
                })

            } else if (event.action == MotionEvent.ACTION_UP) {
                captureButton.setBackgroundColor(Color.RED)
                videoCapture.stopRecording()
                Log.i(tag, "Video File stopped")
            }
            false
        }
    }

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

    private fun allPermissionsGranted(): Boolean {
        for (permission in REQUIRED_PERMISSIONS) {
            if (ContextCompat.checkSelfPermission(
                    this, permission
                ) != PackageManager.PERMISSION_GRANTED
            ) {
                return false
            }
        }
        return true
    }

    private fun startCamera() {
        // Create configuration object for the viewfinder use case
        val previewConfig = PreviewConfig.Builder().apply {
            setLensFacing(lensFacing)
        }.build()
        // Build the viewfinder use case
        val preview = Preview(previewConfig)

        // Create a configuration object for the video use case
        val videoCaptureConfig = VideoCaptureConfig.Builder().apply {
            setTargetRotation(viewFinder.display.rotation)
            setLensFacing(lensFacing)
        }.build()
        videoCapture = VideoCapture(videoCaptureConfig)

        preview.setOnPreviewOutputUpdateListener {

            val parent = viewFinder.parent as ViewGroup
            parent.removeView(viewFinder)
            viewFinder.surfaceTexture = it.surfaceTexture
            parent.addView(viewFinder, 0)

        }

        // Bind use cases to lifecycle
        CameraX.bindToLifecycle(this, preview, videoCapture)
    }

    public final fun changeCamera(view : View) : Unit{
        lensFacing = if (CameraX.LensFacing.FRONT == lensFacing) {
            CameraX.LensFacing.BACK
        } else {
            CameraX.LensFacing.FRONT
        }
        try {
            // Only bind use cases if we can query a camera with this orientation
            CameraX.getCameraWithLensFacing(lensFacing)

            // Unbind all use cases and bind them again with the new lens facing configuration
            CameraX.unbindAll()
            startCamera()
        } catch (exc: Exception) {
            // Do nothing
        }
    }
}

布局文件

<?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=".activities.VideoCaptureActivity">

    <TextureView
        android:id="@+id/view_finder"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />


    <ImageButton
        android:id="@+id/capture_button"
        android:layout_width="72dp"
        android:layout_height="72dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="24dp"
        android:background="#F44336"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/view_finder"
        app:layout_constraintVertical_bias="0.923"
        app:srcCompat="@android:drawable/ic_menu_camera" />

    <ImageButton
        android:id="@+id/switch_button"
        android:layout_width="72dp"
        android:layout_height="72dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:onClick="changeCamera"
        android:layout_marginBottom="24dp"
        android:background="@color/colorPrimary"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.024"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/view_finder"
        app:layout_constraintVertical_bias="0.923"
        app:srcCompat="@android:drawable/ic_menu_revert" />

</androidx.constraintlayout.widget.ConstraintLayout>

我在gradle下面用过。

def camerax_version = "1.0.0-alpha03"
implementation "androidx.camera:camera-core:${camerax_version}"
implementation "androidx.camera:camera-camera2:${camerax_version}"