Refactor and enable switching between cameras using physical id.

livekit-android-camerax/src/main/java/livekit/org/webrtc/CameraXCapturer.kt

@@ -23,6 +23,8 @@ import androidx.camera.camera2.interop.ExperimentalCamera2Interop
 import androidx.camera.core.Camera
 import androidx.camera.core.UseCase
 import androidx.lifecycle.LifecycleOwner
+import io.livekit.android.room.track.video.CameraCapturerUtils.CameraDeviceInfo
+import io.livekit.android.room.track.video.CameraCapturerUtils.findCamera
 import io.livekit.android.room.track.video.CameraCapturerWithSize
 import io.livekit.android.room.track.video.CameraEventsDispatchHandler
 import io.livekit.android.util.FlowObservable
@@ -32,13 +34,13 @@ import kotlinx.coroutines.flow.StateFlow
 
 @ExperimentalCamera2Interop
 internal class CameraXCapturer(
-    context: Context,
+    private val enumerator: CameraXEnumerator,
     private val lifecycleOwner: LifecycleOwner,
-    cameraName: String?,
+    private val cameraManager: CameraManager,
+    private var cameraDevice: CameraDeviceInfo,
     eventsHandler: CameraVideoCapturer.CameraEventsHandler?,
     private val useCases: Array<out UseCase> = emptyArray(),
-    var physicalCameraId: String? = null,
-) : CameraCapturer(cameraName, eventsHandler, CameraXEnumerator(context, lifecycleOwner)) {
+) : CameraCapturer(cameraDevice.deviceId, eventsHandler, enumerator) {
 
     @FlowObservable
     @get:FlowObservable
@@ -89,14 +91,21 @@ internal class CameraXCapturer(
             applicationContext,
             lifecycleOwner,
             surfaceTextureHelper,
-            cameraName,
+            cameraDevice,
             width,
             height,
             framerate,
             useCases,
-            physicalCameraId,
         )
     }
+
+    override fun switchCamera(switchEventsHandler: CameraVideoCapturer.CameraSwitchHandler?, cameraName: String?) {
+        val device = enumerator.findCamera(cameraManager, cameraName)
+        if (device == null) return
+
+        cameraDevice = device
+        super.switchCamera(switchEventsHandler, this.cameraName)
+    }
 }
 
 @ExperimentalCamera2Interop

livekit-android-camerax/src/main/java/livekit/org/webrtc/CameraXEnumerator.kt

@@ -20,12 +20,14 @@ import android.content.Context
 import android.graphics.Rect
 import android.graphics.SurfaceTexture
 import android.hardware.camera2.CameraCharacteristics
+import android.hardware.camera2.CameraManager
 import android.os.Build
 import android.os.Build.VERSION
 import androidx.camera.camera2.interop.Camera2CameraInfo
 import androidx.camera.camera2.interop.ExperimentalCamera2Interop
 import androidx.camera.core.UseCase
 import androidx.lifecycle.LifecycleOwner
+import io.livekit.android.room.track.video.CameraCapturerUtils.findCamera
 
 /**
  * @suppress
@@ -35,14 +37,15 @@ class CameraXEnumerator(
     context: Context,
     private val lifecycleOwner: LifecycleOwner,
     private val useCases: Array<out UseCase> = emptyArray(),
-    var physicalCameraId: String? = null,
+    private val cameraManager: CameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager,
 ) : Camera2Enumerator(context) {
 
     override fun createCapturer(
         deviceName: String?,
         eventsHandler: CameraVideoCapturer.CameraEventsHandler?,
     ): CameraVideoCapturer {
-        return CameraXCapturer(context, lifecycleOwner, deviceName, eventsHandler, useCases, physicalCameraId)
+        val deviceInfo = findCamera(cameraManager!!, deviceName, fallback = true)!!
+        return CameraXCapturer(this, lifecycleOwner, cameraManager!!, deviceInfo, eventsHandler, useCases)
     }
 
     companion object {

livekit-android-camerax/src/main/java/livekit/org/webrtc/CameraXHelper.kt

@@ -18,7 +18,6 @@ package livekit.org.webrtc
 
 import android.content.Context
 import android.hardware.camera2.CameraManager
-import android.os.Build
 import androidx.camera.camera2.interop.ExperimentalCamera2Interop
 import androidx.camera.core.UseCase
 import androidx.lifecycle.Lifecycle
@@ -63,15 +62,10 @@ class CameraXHelper {
             ): VideoCapturer {
                 val enumerator = provideEnumerator(context)
                 val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
-                val deviceId = options.deviceId
-                var targetDeviceName: String? = null
-                if (deviceId != null) {
-                    targetDeviceName = findCameraById(cameraManager, deviceId)
-                }
-                if (targetDeviceName == null) {
-                    // Fallback to enumerator.findCamera which can't find camera by physical id but it will choose the closest one.
-                    targetDeviceName = enumerator.findCamera(deviceId, options.position)
-                }
+
+                val targetDevice = enumerator.findCamera(cameraManager, options.deviceId, options.position)
+                val targetDeviceName = targetDevice?.physicalId ?: targetDevice?.deviceId
+
                 val targetVideoCapturer = enumerator.createCapturer(targetDeviceName, eventsHandler) as CameraXCapturer
 
                 return CameraXCapturerWithSize(
@@ -85,23 +79,6 @@ class CameraXHelper {
             override fun isSupported(context: Context): Boolean {
                 return Camera2Enumerator.isSupported(context) && lifecycleOwner.lifecycle.currentState.isAtLeast(Lifecycle.State.INITIALIZED)
             }
-
-            private fun findCameraById(cameraManager: CameraManager, deviceId: String): String? {
-                for (id in cameraManager.cameraIdList) {
-                    if (id == deviceId) return id // This means the provided id is logical id.
-
-                    val characteristics = cameraManager.getCameraCharacteristics(id)
-                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
-                        val ids = characteristics.physicalCameraIds
-                        if (ids.contains(deviceId)) {
-                            // This means the provided id is physical id.
-                            enumerator?.physicalCameraId = deviceId
-                            return id // This is its logical id.
-                        }
-                    }
-                }
-                return null
-            }
         }
 
         private fun getSupportedFormats(

livekit-android-camerax/src/main/java/livekit/org/webrtc/CameraXSession.kt

@@ -42,6 +42,7 @@ import androidx.camera.core.resolutionselector.ResolutionStrategy
 import androidx.camera.lifecycle.ProcessCameraProvider
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.LifecycleOwner
+import io.livekit.android.room.track.video.CameraCapturerUtils
 import livekit.org.webrtc.CameraEnumerationAndroid.CaptureFormat
 import java.util.concurrent.Executor
 import java.util.concurrent.TimeUnit
@@ -57,12 +58,11 @@ internal constructor(
     private val context: Context,
     private val lifecycleOwner: LifecycleOwner,
     private val surfaceTextureHelper: SurfaceTextureHelper,
-    private val cameraId: String,
+    private val cameraDevice: CameraCapturerUtils.CameraDeviceInfo,
     private val width: Int,
     private val height: Int,
     private val frameRate: Int,
     private val useCases: Array<out UseCase> = emptyArray(),
-    var physicalCameraId: String? = null,
 ) : CameraSession {
 
     private var state = SessionState.RUNNING
@@ -120,7 +120,7 @@ internal constructor(
     }
 
     override fun stop() {
-        Logging.d(TAG, "Stop cameraX session on camera $cameraId")
+        Logging.d(TAG, "Stop cameraX session on camera $cameraDevice")
         checkIsOnCameraThread()
         if (state != SessionState.STOPPED) {
             val stopStartTime = System.nanoTime()
@@ -133,7 +133,7 @@ internal constructor(
 
     private fun openCamera() {
         checkIsOnCameraThread()
-        Logging.d(TAG, "Opening camera $cameraId")
+        Logging.d(TAG, "Opening camera $cameraDevice")
         events.onCameraOpening()
         val cameraProviderFuture = ProcessCameraProvider.getInstance(context)
         val helperExecutor = Executor { command ->
@@ -160,7 +160,7 @@ internal constructor(
 
                 // Select camera by ID
                 val cameraSelector = CameraSelector.Builder()
-                    .addCameraFilter { cameraInfo -> cameraInfo.filter { Camera2CameraInfo.from(it).cameraId == cameraId } }
+                    .addCameraFilter { cameraInfo -> cameraInfo.filter { Camera2CameraInfo.from(it).cameraId == cameraDevice.deviceId } }
                     .build()
 
                 try {
@@ -209,7 +209,7 @@ internal constructor(
     private fun <T> ExtendableBuilder<T>.applyCameraSettings(): ExtendableBuilder<T> {
         val cameraExtender = Camera2Interop.Extender(this)
 
-        physicalCameraId?.let { physicalId ->
+        cameraDevice.physicalId?.let { physicalId ->
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
                 cameraExtender.setPhysicalCameraId(physicalId)
             }
@@ -275,7 +275,7 @@ internal constructor(
     }
 
     private fun obtainCameraConfiguration() {
-        val camera = cameraProvider.availableCameraInfos.map { Camera2CameraInfo.from(it) }.first { it.cameraId == cameraId }
+        val camera = cameraProvider.availableCameraInfos.map { Camera2CameraInfo.from(it) }.first { it.cameraId == cameraDevice.deviceId }
 
         cameraOrientation = camera.getCameraCharacteristic(CameraCharacteristics.SENSOR_ORIENTATION) ?: -1
         isCameraFrontFacing = camera.getCameraCharacteristic(CameraCharacteristics.LENS_FACING) == CameraMetadata.LENS_FACING_FRONT

livekit-android-sdk/src/main/java/io/livekit/android/room/track/LocalVideoTrack.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 LiveKit, Inc.
+ * Copyright 2023-2025 LiveKit, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package io.livekit.android.room.track
 import android.Manifest
 import android.content.Context
 import android.content.pm.PackageManager
+import android.hardware.camera2.CameraManager
 import androidx.core.content.ContextCompat
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
@@ -27,9 +28,9 @@ import io.livekit.android.memory.CloseableManager
 import io.livekit.android.memory.SurfaceTextureHelperCloser
 import io.livekit.android.room.DefaultsManager
 import io.livekit.android.room.track.video.CameraCapturerUtils
+import io.livekit.android.room.track.video.CameraCapturerUtils.CameraDeviceInfo
 import io.livekit.android.room.track.video.CameraCapturerUtils.createCameraEnumerator
 import io.livekit.android.room.track.video.CameraCapturerUtils.findCamera
-import io.livekit.android.room.track.video.CameraCapturerUtils.getCameraPosition
 import io.livekit.android.room.track.video.CameraCapturerWithSize
 import io.livekit.android.room.track.video.CaptureDispatchObserver
 import io.livekit.android.room.track.video.ScaleCropVideoProcessor
@@ -179,26 +180,29 @@ constructor(
             return
         }
 
-        var targetDeviceId: String? = null
+        var targetDevice: CameraDeviceInfo? = null
         val enumerator = createCameraEnumerator(context)
+        val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
         if (deviceId != null || position != null) {
-            targetDeviceId = enumerator.findCamera(deviceId, position, fallback = false)
+            targetDevice = enumerator.findCamera(cameraManager, deviceId, position, fallback = false)
         }
 
-        if (targetDeviceId == null) {
+        if (targetDevice == null) {
             val deviceNames = enumerator.deviceNames
             if (deviceNames.size < 2) {
                 LKLog.w { "No available cameras to switch to!" }
                 return
             }
             val currentIndex = deviceNames.indexOf(options.deviceId)
-            targetDeviceId = deviceNames[(currentIndex + 1) % deviceNames.size]
+            val targetDeviceId = deviceNames[(currentIndex + 1) % deviceNames.size]
+            targetDevice = enumerator.findCamera(cameraManager, targetDeviceId, fallback = false)
         }
 
+        val targetDeviceId = targetDevice?.physicalId ?: targetDevice?.deviceId
         fun updateCameraOptions() {
             val newOptions = options.copy(
                 deviceId = targetDeviceId,
-                position = enumerator.getCameraPosition(targetDeviceId),
+                position = targetDevice?.position,
             )
             options = newOptions
         }
@@ -243,7 +247,7 @@ constructor(
                 LKLog.w { "switching camera failed: $errorDescription" }
             }
         }
-        if (targetDeviceId == null) {
+        if (targetDevice == null) {
             LKLog.w { "No target camera found!" }
             return
         } else {