camera-samples: CameraX Back and front camera can't preview at same time ?

previewBack.setSurfaceProvider(viewBack.surfaceProvider)
previewFront.setSurfaceProvider(viewFront.surfaceProvider)
val cameraBack = cameraProvider.bindToLifecycle(this, cameraSelectorBack, previewBack)
val cameraFront = cameraProvider.bindToLifecycle(this, cameraSelectorFront, previewFront)

 java.lang.IllegalArgumentException: Multiple LifecycleCameras with use cases are registered to the same LifecycleOwner.
        at androidx.camera.lifecycle.LifecycleCameraRepository.bindToLifecycleCamera(LifecycleCameraRepository.java:269)
        at androidx.camera.lifecycle.ProcessCameraProvider.bindToLifecycle(ProcessCameraProvider.java:423)
        at androidx.camera.lifecycle.ProcessCameraProvider.bindToLifecycle(ProcessCameraProvider.java:274)

About this issue

Original URL
State: closed
Created 3 years ago
Comments: 16 (4 by maintainers)

Most upvoted comments

Hii guy’s use - cameraProvider.unbindAll() // Unbind use cases before rebinding,

btnSwitchCamera.setOnClickListener {

        if (cameraSelector == CameraSelector.DEFAULT_FRONT_CAMERA && cameraProvider.hasCamera(
                CameraSelector.DEFAULT_BACK_CAMERA)) {

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

            cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA
            val preview = Preview.Builder().build().also {
                it.setSurfaceProvider(viewFinder.createSurfaceProvider())
            }
            cameraProvider.bindToLifecycle(this, cameraSelector, preview)
            
        } else if (cameraSelector == CameraSelector.DEFAULT_BACK_CAMERA && cameraProvider.hasCamera(
                CameraSelector.DEFAULT_FRONT_CAMERA)) {

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

            cameraSelector = CameraSelector.DEFAULT_FRONT_CAMERA
            val preview = Preview.Builder().build().also {
                it.setSurfaceProvider(viewFinder.createSurfaceProvider())
            }
            cameraProvider.bindToLifecycle(this, cameraSelector, preview)
        }

    }

DroidDevTaiyab on May 11, 2021

Hi lodgkk,

Version 1.3.0-alpha06 is the latest version supporting both front and back cameras simultaneously. https://developer.android.com/jetpack/androidx/releases/camera#1.3.0-alpha06

This is the javadoc for main api: https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-main/camera/camera-lifecycle/src/main/java/androidx/camera/lifecycle/ProcessCameraProvider.java#759

This is the sample app to show a front + back camera previews in Picture-in-Picutre layout or Side-by-Side layout: https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-main/camera/integration-tests/coretestapp/src/main/java/androidx/camera/integration/core/ConcurrentCameraActivity.java#239

Let us know if any other questions.

kailianc on May 11, 2023