diff --git a/.gitignore b/.gitignore
index b6066aa..bd82493 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,4 +48,4 @@ app.*.map.json
 /android/app/release
 /android/.kotlin
 
-CLAUDE.md
\ No newline at end of file
+CLAUDE.md
diff --git a/android/app/src/main/kotlin/com/dronex/rec/AppConstants.kt b/android/app/src/main/kotlin/com/dronex/rec/AppConstants.kt
index eca38e8..55732a9 100644
--- a/android/app/src/main/kotlin/com/dronex/rec/AppConstants.kt
+++ b/android/app/src/main/kotlin/com/dronex/rec/AppConstants.kt
@@ -1,10 +1,10 @@
 package com.dronex.rec
 
 object AppConstants {
-    const val PACKAGE_NAME = "com.dronex.rec"
-    const val PLATFORM_INFO_CHANNEL = "$PACKAGE_NAME/platform_info"
-    const val RECORDING_METHOD_CHANNEL = "$PACKAGE_NAME/recording"
-    const val RECORDING_EVENT_CHANNEL = "$PACKAGE_NAME/recording_events"
-    const val RECORDING_ACTION_START = "$PACKAGE_NAME.recording.START"
-    const val RECORDING_ACTION_STOP = "$PACKAGE_NAME.recording.STOP"
+    private const val CHANNEL_NAMESPACE = "app.record_tool"
+    const val PLATFORM_INFO_CHANNEL = "$CHANNEL_NAMESPACE/platform_info"
+    const val RECORDING_METHOD_CHANNEL = "$CHANNEL_NAMESPACE/recording"
+    const val RECORDING_EVENT_CHANNEL = "$CHANNEL_NAMESPACE/recording_events"
+    const val RECORDING_ACTION_START = "$CHANNEL_NAMESPACE.recording.START"
+    const val RECORDING_ACTION_STOP = "$CHANNEL_NAMESPACE.recording.STOP"
 }
diff --git a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingCameraController.kt b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingCameraController.kt
index 00f0d12..e5f09c7 100644
--- a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingCameraController.kt
+++ b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingCameraController.kt
@@ -3,9 +3,15 @@ package com.dronex.rec.recording
 import android.content.Context
 import android.hardware.camera2.CameraCharacteristics
 import android.hardware.camera2.CameraManager
+import android.hardware.camera2.CaptureRequest
+import android.os.Build
 import android.util.Log
+import androidx.camera.camera2.interop.Camera2CameraControl
 import androidx.camera.camera2.interop.Camera2CameraInfo
+import androidx.camera.camera2.interop.CaptureRequestOptions
+import androidx.camera.camera2.interop.ExperimentalCamera2Interop
 import androidx.camera.core.Camera
+import androidx.camera.core.CameraControl
 import androidx.camera.core.CameraSelector
 import androidx.camera.core.Preview
 import androidx.camera.lifecycle.ProcessCameraProvider
@@ -18,13 +24,18 @@ import androidx.camera.video.VideoRecordEvent
 import androidx.camera.view.PreviewView
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.LifecycleOwner
-import kotlin.math.atan
+import java.io.File
 import java.util.concurrent.Executor
+import java.util.concurrent.ExecutionException
+import java.util.concurrent.Executors
+import kotlin.math.atan
+import kotlin.math.round
 
 class RecordingCameraController(
         private val appContext: Context,
 ) {
     private val mainExecutor: Executor = ContextCompat.getMainExecutor(appContext)
+    private val ioExecutor = Executors.newSingleThreadExecutor()
 
     private var cameraProvider: ProcessCameraProvider? = null
     private var preview: Preview? = null
@@ -37,6 +48,12 @@ class RecordingCameraController(
     private var activeRecording: Recording? = null
     private var boundLifecycleOwner: LifecycleOwner? = null
     private var currentZoomRatio: Float = 1f
+    private var activeWithAudio: Boolean = true
+    private var activeDisplayName: String? = null
+    private var currentSegmentFile: File? = null
+    private val segmentFiles = mutableListOf<File>()
+    private var nextSegmentIndex: Int = 1
+    private var isSwitchingLens: Boolean = false
 
     var status: RecordingStatus = RecordingStatus(RecordingState.IDLE)
         private set
@@ -45,7 +62,9 @@ class RecordingCameraController(
 
     private var recordingStartedAt: Long = 0L
     private var latestOutputPath: String? = null
+    private var latestSegmentOutputPaths: List<String> = emptyList()
     private var pendingStopCallback: ((String?) -> Unit)? = null
+    private var pendingSegmentSwitch: PendingSegmentSwitch? = null
 
     fun bindPreview(
             lifecycleOwner: LifecycleOwner,
@@ -134,21 +153,55 @@ class RecordingCameraController(
             return
         }
 
+        if (activeRecording != null || isSwitchingLens) {
+            onStarted(false, "Already recording")
+            return
+        }
+
+        activeWithAudio = withAudio
+        activeDisplayName = displayName
+        segmentFiles.clear()
+        nextSegmentIndex = 1
+        latestOutputPath = null
+        latestSegmentOutputPaths = emptyList()
+
+        recordingStartedAt = System.currentTimeMillis()
+        updateStatus(
+                RecordingStatus(
+                        RecordingState.RECORDING,
+                        outputPath = latestOutputPath,
+                ),
+        )
+
+        startNewSegment(updateStatusOnStart = false, onStarted = onStarted)
+    }
+
+    private fun startNewSegment(
+            updateStatusOnStart: Boolean,
+            onStarted: (Boolean, String?) -> Unit,
+    ) {
+        val capture = videoCapture
+        if (capture == null || boundLifecycleOwner == null) {
+            onStarted(false, "Camera not ready")
+            return
+        }
         if (activeRecording != null) {
             onStarted(false, "Already recording")
             return
         }
 
-        val outputOptions =
-                RecordingOutputFactory.buildMediaStoreOutputOptions(
+        val segmentFile =
+                RecordingOutputFactory.createSegmentFile(
                         appContext,
-                        displayName,
+                        activeDisplayName,
+                        nextSegmentIndex++,
                 )
-        latestOutputPath = null
+        currentSegmentFile = segmentFile
+        val outputOptions = RecordingOutputFactory.buildSegmentOutputOptions(segmentFile)
 
         val pending =
                 capture.output.prepareRecording(appContext, outputOptions).apply {
-                    if (withAudio) {
+                    if (activeWithAudio) {
                         val granted =
                                 ContextCompat.checkSelfPermission(
                                         appContext,
@@ -160,48 +213,25 @@ class RecordingCameraController(
                     }
                 }
 
-        recordingStartedAt = System.currentTimeMillis()
-        updateStatus(
-                RecordingStatus(
-                        RecordingState.RECORDING,
-                        outputPath = latestOutputPath,
-                ),
-        )
+        if (updateStatusOnStart) {
+            updateStatus(
+                    RecordingStatus(
+                            RecordingState.RECORDING,
+                            outputPath = latestOutputPath,
+                            elapsedMillis = elapsedMillis(),
+                    ),
+            )
+        }
 
         activeRecording =
                 pending.start(mainExecutor) { event ->
                     when (event) {
                         is VideoRecordEvent.Start -> Unit
-                        is VideoRecordEvent.Finalize -> {
-                            activeRecording = null
-                            if (event.hasError()) {
-                                updateStatus(
-                                        RecordingStatus(
-                                                RecordingState.ERROR,
-                                                message = event.cause?.message
-                                                                ?: "Recording failed",
-                                        ),
-                                )
-                            } else {
-                                latestOutputPath = event.outputResults.outputUri.toString()
-                                updateStatus(
-                                        RecordingStatus(
-                                                RecordingState.PREVIEWING,
-                                                outputPath = latestOutputPath,
-                                                elapsedMillis =
-                                                        System.currentTimeMillis() -
-                                                                recordingStartedAt,
-                                        ),
-                                )
-                            }
-                            val stopCallback = pendingStopCallback
-                            pendingStopCallback = null
-                            stopCallback?.invoke(latestOutputPath)
-                        }
+                        is VideoRecordEvent.Finalize -> handleFinalize(event, segmentFile)
                     }
                 }
 
-        onStarted(true, latestOutputPath ?: "recording")
+        onStarted(true, segmentFile.absolutePath)
     }
 
     fun stopRecording(onStopped: (String?) -> Unit) {
@@ -210,12 +240,18 @@ class RecordingCameraController(
             onStopped(latestOutputPath)
             return
         }
+        if (isSwitchingLens) {
+            onStopped(null)
+            return
+        }
 
         pendingStopCallback = onStopped
+        val elapsed = elapsedMillis()
         updateStatus(
                 RecordingStatus(
                         RecordingState.STOPPING,
                         outputPath = latestOutputPath,
+                        elapsedMillis = elapsed,
                 ),
         )
 
@@ -223,27 +259,144 @@ class RecordingCameraController(
         activeRecording = null
     }
 
+    private fun handleFinalize(
+            event: VideoRecordEvent.Finalize,
+            segmentFile: File,
+    ) {
+        activeRecording = null
+        if (!event.hasError() && segmentFile.exists() && segmentFile.length() > 0L) {
+            segmentFiles.add(segmentFile)
+        }
+
+        val segmentSwitch = pendingSegmentSwitch
+        if (segmentSwitch != null) {
+            pendingSegmentSwitch = null
+            if (event.hasError()) {
+                isSwitchingLens = false
+                val message = event.cause?.message ?: "Recording segment failed"
+                updateStatus(RecordingStatus(RecordingState.ERROR, message = message))
+                segmentSwitch.onComplete(false, zoomCapabilitiesMap(), message)
+                return
+            }
+            continueSegmentSwitch(segmentSwitch)
+            return
+        }
+
+        val stopCallback = pendingStopCallback
+        pendingStopCallback = null
+        if (stopCallback == null) {
+            return
+        }
+
+        if (event.hasError()) {
+            val message = event.cause?.message ?: "Recording failed"
+            updateStatus(RecordingStatus(RecordingState.ERROR, message = message))
+            stopCallback.invoke(null)
+            return
+        }
+
+        finalizeRecordingOutput(stopCallback)
+    }
+
+    private fun finalizeRecordingOutput(stopCallback: (String?) -> Unit) {
+        val segments = segmentFiles.toList()
+        val displayName = activeDisplayName
+        ioExecutor.execute {
+            try {
+                val mergedFile = RecordingOutputFactory.createMergeFile(appContext, displayName)
+                RecordingSegmentMuxer.mergeOrCopy(segments, mergedFile)
+                val outputUri =
+                        RecordingOutputFactory.publishToMediaStore(
+                                appContext,
+                                displayName,
+                                mergedFile,
+                        )
+                latestOutputPath = outputUri
+                latestSegmentOutputPaths = emptyList()
+                cleanupSegmentFiles(segments + mergedFile)
+                mainExecutor.execute {
+                    val elapsed = System.currentTimeMillis() - recordingStartedAt
+                    updateStatus(
+                            RecordingStatus(
+                                    RecordingState.PREVIEWING,
+                                    outputPath = latestOutputPath,
+                                    elapsedMillis = elapsed,
+                            ),
+                    )
+                    stopCallback.invoke(latestOutputPath)
+                }
+            } catch (error: Exception) {
+                Log.e(TAG, "finalizeRecordingOutput failed", error)
+                val publishedParts = publishSegmentsAfterMergeFailure(segments, displayName)
+                latestOutputPath = publishedParts.firstOrNull()
+                latestSegmentOutputPaths = publishedParts
+                mainExecutor.execute {
+                    updateStatus(
+                            RecordingStatus(
+                                    RecordingState.ERROR,
+                                    outputPath = latestOutputPath,
+                                    message = error.message ?: "保存到文件夹失败",
+                            ),
+                    )
+                    stopCallback.invoke(latestOutputPath)
+                }
+            }
+        }
+    }
+
+    private fun publishSegmentsAfterMergeFailure(
+            segments: List<File>,
+            displayName: String?,
+    ): List<String> {
+        return segments.mapIndexedNotNull { index, segment ->
+            try {
+                RecordingOutputFactory.publishPartToMediaStore(
+                        appContext,
+                        displayName,
+                        segment,
+                        index + 1,
+                )
+            } catch (error: Exception) {
+                Log.e(TAG, "publish segment after merge failure failed", error)
+                null
+            }
+        }
+    }
+
+    private fun cleanupSegmentFiles(files: List<File>) {
+        files.forEach { file ->
+            try {
+                file.delete()
+            } catch (_: Exception) {
+            }
+        }
+    }
+
     fun zoomCapabilitiesMap(): Map<String, Any> {
         val zoomState = camera?.cameraInfo?.zoomState?.value
-        val logicalMin = zoomState?.minZoomRatio ?: 1f
-        // 兜底两路超广角来源：独立超广角镜头(0.6) 与 逻辑相机原生 <1.0 变焦范围，取更小者。
+        val cameraXMin = zoomState?.minZoomRatio ?: 1f
+        val cameraXMax = zoomState?.maxZoomRatio ?: 3f
+        val camera2Range = mainCameraZoomRatioRange()
+        val logicalMin = camera2Range?.lower?.let { minOf(cameraXMin, it) } ?: cameraXMin
+        val logicalMax = camera2Range?.upper?.let { maxOf(cameraXMax, it) } ?: cameraXMax
         val minZoom =
                 if (hasUltraWideCamera()) {
                     minOf(ultraWideZoomRatio, logicalMin)
                 } else {
                     logicalMin
                 }
-        val maxZoom = zoomState?.maxZoomRatio ?: 3f
+        val maxZoom = logicalMax
         val zoom =
                 if (currentLensMode == LensMode.ULTRA_WIDE) {
                     ultraWideZoomRatio
                 } else {
-                    (zoomState?.zoomRatio ?: currentZoomRatio).coerceIn(minZoom, maxZoom)
+                    currentZoomRatio.coerceIn(minZoom, maxZoom)
                 }
         currentZoomRatio = zoom
         Log.d(
                 TAG,
-                "zoomCapabilities hasUltraWide=${hasUltraWideCamera()} logicalMin=$logicalMin " +
+                "zoomCapabilities hasUltraWide=${hasUltraWideCamera()} cameraXMin=$cameraXMin " +
+                        "cameraXMax=$cameraXMax camera2Range=${camera2Range?.description()} " +
                         "ultraWideZoomRatio=$ultraWideZoomRatio minZoom=$minZoom maxZoom=$maxZoom zoom=$zoom",
         )
         return mapOf(
@@ -259,6 +412,10 @@ class RecordingCameraController(
     ) {
         val boundCamera = camera
         if (boundCamera == null) {
+            if (isSwitchingLens) {
+                onComplete(false, zoomCapabilitiesMap(), "Camera lens switch is already in progress")
+                return
+            }
             val clamped =
                     if (ratio < 1.0 && hasUltraWideCamera()) {
                         ultraWideZoomRatio
@@ -271,8 +428,11 @@ class RecordingCameraController(
         }
 
         if (ratio < 1.0 && hasUltraWideCamera()) {
-            switchToUltraWide(onComplete)
-            return
+            val logicalRange = mainCameraZoomRatioRange()
+            if (logicalRange == null || !logicalRange.contains(ratio.toFloat())) {
+                switchToUltraWide(onComplete)
+                return
+            }
         }
 
         if (currentLensMode == LensMode.ULTRA_WIDE) {
@@ -281,18 +441,36 @@ class RecordingCameraController(
         }
 
         val zoomState = boundCamera.cameraInfo.zoomState.value
-        val minZoom = zoomState?.minZoomRatio ?: 1f
-        val maxZoom = zoomState?.maxZoomRatio ?: clampedMaxZoom()
+        val camera2Range = mainCameraZoomRatioRange()
+        val minZoom = camera2Range?.lower ?: zoomState?.minZoomRatio ?: 1f
+        val maxZoom = camera2Range?.upper ?: zoomState?.maxZoomRatio ?: clampedMaxZoom()
         val nextZoom = ratio.toFloat().coerceIn(minZoom, maxZoom)
         currentZoomRatio = nextZoom
 
-        val future = boundCamera.cameraControl.setZoomRatio(nextZoom)
+        val future =
+                if (
+                        Build.VERSION.SDK_INT >= Build.VERSION_CODES.R &&
+                                camera2Range?.contains(nextZoom) == true
+                ) {
+                    applyCamera2ZoomRatio(boundCamera, nextZoom)
+                } else {
+                    boundCamera.cameraControl.setZoomRatio(nextZoom)
+                }
         future.addListener(
                 {
                     try {
                         future.get()
-                        onComplete(true, zoomCapabilitiesMap(), null)
+                        val capabilities = zoomCapabilitiesMap()
+                        logSetZoomResult(ratio, nextZoom, capabilities)
+                        onComplete(true, capabilities, null)
                     } catch (error: Exception) {
+                        if (isSupersededCamera2ZoomRequest(error)) {
+                            Log.d(TAG, "setZoomRatio superseded by newer Camera2 options")
+                            val capabilities = zoomCapabilitiesMap()
+                            logSetZoomResult(ratio, nextZoom, capabilities)
+                            onComplete(true, capabilities, null)
+                            return@addListener
+                        }
                         Log.e(TAG, "setZoomRatio failed", error)
                         onComplete(false, zoomCapabilitiesMap(), error.message)
                     }
@@ -304,12 +482,20 @@ class RecordingCameraController(
     fun unbind() {
         activeRecording?.stop()
         activeRecording = null
+        pendingSegmentSwitch = null
+        pendingStopCallback = null
+        isSwitchingLens = false
         cameraProvider?.unbindAll()
         cameraProvider = null
         preview = null
         videoCapture = null
         camera = null
         boundLifecycleOwner = null
+        currentSegmentFile = null
+        cleanupSegmentFiles(segmentFiles)
+        segmentFiles.clear()
+        nextSegmentIndex = 1
+        activeDisplayName = null
         currentLensMode = LensMode.MAIN
         currentZoomRatio = 1f
         ultraWideZoomRatio = DEFAULT_ULTRA_WIDE_ZOOM_RATIO
@@ -321,6 +507,8 @@ class RecordingCameraController(
         return System.currentTimeMillis() - recordingStartedAt
     }
 
+    fun segmentOutputPaths(): List<String> = latestSegmentOutputPaths
+
     private fun updateStatus(next: RecordingStatus) {
         status = next
         statusListener?.invoke(next)
@@ -334,10 +522,18 @@ class RecordingCameraController(
             return
         }
         val zoomState = boundCamera.cameraInfo.zoomState.value
-        val minZoom = zoomState?.minZoomRatio ?: 1f
-        val maxZoom = zoomState?.maxZoomRatio ?: clampedMaxZoom()
+        val camera2Range = mainCameraZoomRatioRange()
+        val minZoom = camera2Range?.lower ?: zoomState?.minZoomRatio ?: 1f
+        val maxZoom = camera2Range?.upper ?: zoomState?.maxZoomRatio ?: clampedMaxZoom()
         currentZoomRatio = currentZoomRatio.coerceIn(minZoom, maxZoom)
-        boundCamera.cameraControl.setZoomRatio(currentZoomRatio)
+        if (
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.R &&
+                        camera2Range?.contains(currentZoomRatio) == true
+        ) {
+            applyCamera2ZoomRatio(boundCamera, currentZoomRatio)
+        } else {
+            boundCamera.cameraControl.setZoomRatio(currentZoomRatio)
+        }
     }
 
     private fun clampedMaxZoom(): Float {
@@ -345,9 +541,11 @@ class RecordingCameraController(
     }
 
     private fun discoverBackCameras(provider: ProcessCameraProvider) {
+        val manager = appContext.getSystemService(Context.CAMERA_SERVICE) as CameraManager
         if (mainCameraId == null) {
             mainCameraId = cameraIdForSelector(provider, CameraSelector.DEFAULT_BACK_CAMERA)
         }
+        logPublicCameraDiagnostics(provider, manager, mainCameraId)
         val ultraWideCamera = findUltraWideCamera(provider, mainCameraId)
         ultraWideCameraId = ultraWideCamera?.cameraId
         ultraWideZoomRatio = ultraWideCamera?.zoomRatio ?: DEFAULT_ULTRA_WIDE_ZOOM_RATIO
@@ -383,6 +581,13 @@ class RecordingCameraController(
         val candidates =
                 manager.cameraIdList
                         .mapNotNull { cameraId -> backCameraProfile(manager, cameraId) }
+                        .onEach { profile ->
+                            Log.d(
+                                    TAG,
+                                    "backCamera ${profile.description()} " +
+                                            "bindable=${provider.hasCameraSafely(selectorForCameraId(profile.cameraId))}",
+                            )
+                        }
                         .filter { it.cameraId != excludedCameraId }
                         .filter { provider.hasCameraSafely(selectorForCameraId(it.cameraId)) }
                         .sortedWith(
@@ -391,11 +596,16 @@ class RecordingCameraController(
                         )
 
         val mainProfile = excludedCameraId?.let { backCameraProfile(manager, it) }
-        val widest = candidates.firstOrNull() ?: return null
+        val widest =
+                candidates.firstOrNull()
+                        ?: run {
+                            logPhysicalOnlyUltraWideDiagnostics(manager, mainProfile, excludedCameraId)
+                            return null
+                        }
         val candidatesDesc =
-                candidates.joinToString { "id=${it.cameraId} fov=${it.horizontalFov} focal=${it.minFocalLength}" }
+                candidates.joinToString { it.description() }
         val mainDesc =
-                mainProfile?.let { "id=${it.cameraId} fov=${it.horizontalFov} focal=${it.minFocalLength}" }
+                mainProfile?.description()
         Log.d(TAG, "ultraWide candidates=[$candidatesDesc] main=$mainDesc")
         if (mainProfile == null) {
             return UltraWideCamera(widest.cameraId, DEFAULT_ULTRA_WIDE_ZOOM_RATIO)
@@ -410,10 +620,98 @@ class RecordingCameraController(
                         "(fovFactor=$ULTRA_WIDE_FOV_FACTOR focalFactor=$ULTRA_WIDE_FOCAL_FACTOR)",
         )
         if (!meaningfullyWider) {
+            logPhysicalOnlyUltraWideDiagnostics(manager, mainProfile, excludedCameraId)
             return null
         }
 
-        return UltraWideCamera(widest.cameraId, DEFAULT_ULTRA_WIDE_ZOOM_RATIO)
+        return UltraWideCamera(widest.cameraId, estimateUltraWideZoomRatio(widest, mainProfile))
+    }
+
+    private fun logPublicCameraDiagnostics(
+            provider: ProcessCameraProvider,
+            manager: CameraManager,
+            mainCameraId: String?,
+    ) {
+        Log.d(TAG, "publicCameraIds=[${manager.cameraIdList.joinToString()}] mainCameraId=$mainCameraId")
+        manager.cameraIdList.forEach { cameraId ->
+            try {
+                val characteristics = manager.getCameraCharacteristics(cameraId)
+                val bindable = provider.hasCameraSafely(selectorForCameraId(cameraId))
+                val physicalIds = physicalCameraIds(characteristics)
+                Log.d(
+                        TAG,
+                        "publicCamera id=$cameraId facing=${lensFacingDescription(characteristics)} " +
+                                "physicalIds=[${physicalIds.joinToString()}] " +
+                                "capabilities=[${capabilitiesDescription(characteristics)}] " +
+                                "zoomRange=${zoomRatioRangeFromCharacteristics(characteristics)?.description()} " +
+                                "focals=${focalLengthsDescription(characteristics)} " +
+                                "sensor=${sensorSizeDescription(characteristics)} bindable=$bindable",
+                )
+                if (cameraId == mainCameraId) {
+                    logMainPhysicalCameraDiagnostics(manager, cameraId, physicalIds)
+                }
+            } catch (error: Exception) {
+                Log.w(TAG, "publicCamera diagnostics failed for cameraId=$cameraId", error)
+            }
+        }
+    }
+
+    private fun logMainPhysicalCameraDiagnostics(
+            manager: CameraManager,
+            mainCameraId: String,
+            physicalIds: Set<String>,
+    ) {
+        Log.d(TAG, "mainCamera id=$mainCameraId physicalIds=[${physicalIds.joinToString()}]")
+        physicalIds.forEach { physicalId ->
+            try {
+                val characteristics = manager.getCameraCharacteristics(physicalId)
+                Log.d(
+                        TAG,
+                        "mainPhysicalCamera id=$physicalId facing=${lensFacingDescription(characteristics)} " +
+                                "zoomRange=${zoomRatioRangeFromCharacteristics(characteristics)?.description()} " +
+                                "focals=${focalLengthsDescription(characteristics)} " +
+                                "sensor=${sensorSizeDescription(characteristics)}",
+                )
+            } catch (error: Exception) {
+                Log.w(TAG, "mainPhysicalCamera diagnostics failed for physicalId=$physicalId", error)
+            }
+        }
+    }
+
+    private fun logPhysicalOnlyUltraWideDiagnostics(
+            manager: CameraManager,
+            mainProfile: CameraProfile?,
+            mainCameraId: String?,
+    ) {
+        if (mainProfile == null || mainCameraId == null) {
+            return
+        }
+        val characteristics =
+                try {
+                    manager.getCameraCharacteristics(mainCameraId)
+                } catch (error: Exception) {
+                    Log.w(TAG, "physicalOnlyUltraWide diagnostics failed for mainCameraId=$mainCameraId", error)
+                    return
+                }
+        val physicalProfiles =
+                physicalCameraIds(characteristics)
+                        .mapNotNull { physicalId -> backCameraProfile(manager, physicalId) }
+                        .filter { it.cameraId != mainCameraId }
+                        .sortedBy { it.minFocalLength }
+        val widestPhysical = physicalProfiles.firstOrNull()
+        if (widestPhysical == null) {
+            Log.d(TAG, "physicalOnlyUltraWide none main=${mainProfile.description()}")
+            return
+        }
+        val meaningfullyWider =
+                widestPhysical.horizontalFov > mainProfile.horizontalFov * ULTRA_WIDE_FOV_FACTOR ||
+                        widestPhysical.minFocalLength < mainProfile.minFocalLength * ULTRA_WIDE_FOCAL_FACTOR
+        Log.d(
+                TAG,
+                "physicalOnlyUltraWide widest=${widestPhysical.description()} " +
+                        "main=${mainProfile.description()} meaningfullyWider=$meaningfullyWider " +
+                        "exposedAsBindableCamera=false action=diagnostic_only",
+        )
     }
 
     private fun backCameraProfile(
@@ -435,13 +733,168 @@ class RecordingCameraController(
             val minFocalLength = focalLengths.minOrNull() ?: return null
             val horizontalFov =
                     2.0 * atan((physicalSize.width / (2.0f * minFocalLength)).toDouble())
-            CameraProfile(cameraId, minFocalLength, horizontalFov)
+            CameraProfile(
+                    cameraId,
+                    minFocalLength,
+                    horizontalFov,
+                    zoomRatioRangeFromCharacteristics(characteristics),
+            )
         } catch (error: Exception) {
             Log.w(TAG, "backCameraProfile failed for cameraId=$cameraId", error)
             null
         }
     }
 
+    private fun mainCameraZoomRatioRange(): ZoomRatioRange? {
+        val cameraId = mainCameraId ?: activeCameraId()
+        return zoomRatioRangeForCamera(cameraId)
+    }
+
+    private fun activeCameraId(): String? {
+        val boundCamera = camera ?: return null
+        return try {
+            Camera2CameraInfo.from(boundCamera.cameraInfo).cameraId
+        } catch (error: Exception) {
+            null
+        }
+    }
+
+    private fun zoomRatioRangeForCamera(cameraId: String?): ZoomRatioRange? {
+        if (cameraId == null) return null
+        return try {
+            val manager = appContext.getSystemService(Context.CAMERA_SERVICE) as CameraManager
+            zoomRatioRangeFromCharacteristics(manager.getCameraCharacteristics(cameraId))
+        } catch (error: Exception) {
+            Log.w(TAG, "zoomRatioRangeForCamera failed for cameraId=$cameraId", error)
+            null
+        }
+    }
+
+    private fun zoomRatioRangeFromCharacteristics(
+            characteristics: CameraCharacteristics,
+    ): ZoomRatioRange? {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
+            return null
+        }
+        val range = characteristics.get(CameraCharacteristics.CONTROL_ZOOM_RATIO_RANGE)
+                ?: return null
+        return ZoomRatioRange(range.lower, range.upper)
+    }
+
+    private fun physicalCameraIds(characteristics: CameraCharacteristics): Set<String> {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
+            return emptySet()
+        }
+        return characteristics.physicalCameraIds
+    }
+
+    private fun lensFacingDescription(characteristics: CameraCharacteristics): String {
+        return when (val facing = characteristics.get(CameraCharacteristics.LENS_FACING)) {
+            CameraCharacteristics.LENS_FACING_BACK -> "BACK"
+            CameraCharacteristics.LENS_FACING_FRONT -> "FRONT"
+            CameraCharacteristics.LENS_FACING_EXTERNAL -> "EXTERNAL"
+            null -> "null"
+            else -> "UNKNOWN($facing)"
+        }
+    }
+
+    private fun capabilitiesDescription(characteristics: CameraCharacteristics): String {
+        val capabilities =
+                characteristics.get(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES)
+                        ?: return "null"
+        return capabilities.joinToString { capabilityDescription(it) }
+    }
+
+    private fun capabilityDescription(capability: Int): String {
+        return when (capability) {
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE ->
+                    "BACKWARD_COMPATIBLE"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_MANUAL_SENSOR -> "MANUAL_SENSOR"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_MANUAL_POST_PROCESSING ->
+                    "MANUAL_POST_PROCESSING"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_RAW -> "RAW"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_PRIVATE_REPROCESSING ->
+                    "PRIVATE_REPROCESSING"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_READ_SENSOR_SETTINGS ->
+                    "READ_SENSOR_SETTINGS"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_BURST_CAPTURE -> "BURST_CAPTURE"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_YUV_REPROCESSING ->
+                    "YUV_REPROCESSING"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_DEPTH_OUTPUT -> "DEPTH_OUTPUT"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_CONSTRAINED_HIGH_SPEED_VIDEO ->
+                    "CONSTRAINED_HIGH_SPEED_VIDEO"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_MOTION_TRACKING -> "MOTION_TRACKING"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA ->
+                    "LOGICAL_MULTI_CAMERA"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_MONOCHROME -> "MONOCHROME"
+            CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_SECURE_IMAGE_DATA -> "SECURE_IMAGE_DATA"
+            else -> "UNKNOWN($capability)"
+        }
+    }
+
+    private fun focalLengthsDescription(characteristics: CameraCharacteristics): String {
+        val focalLengths =
+                characteristics.get(CameraCharacteristics.LENS_INFO_AVAILABLE_FOCAL_LENGTHS)
+                        ?: return "null"
+        return focalLengths.joinToString(prefix = "[", postfix = "]")
+    }
+
+    private fun sensorSizeDescription(characteristics: CameraCharacteristics): String {
+        val size = characteristics.get(CameraCharacteristics.SENSOR_INFO_PHYSICAL_SIZE)
+                ?: return "null"
+        return "${size.width}x${size.height}"
+    }
+
+    private fun estimateUltraWideZoomRatio(
+            ultraWide: CameraProfile,
+            main: CameraProfile,
+    ): Float {
+        if (main.minFocalLength <= 0f) {
+            return DEFAULT_ULTRA_WIDE_ZOOM_RATIO
+        }
+        val rawRatio = ultraWide.minFocalLength / main.minFocalLength
+        val roundedRatio = round(rawRatio * 10f) / 10f
+        return roundedRatio.coerceIn(MIN_ULTRA_WIDE_ZOOM_RATIO, MAX_ULTRA_WIDE_ZOOM_RATIO)
+    }
+
+    @androidx.annotation.OptIn(ExperimentalCamera2Interop::class)
+    private fun applyCamera2ZoomRatio(
+            boundCamera: Camera,
+            zoomRatio: Float,
+    ) =
+            Camera2CameraControl.from(boundCamera.cameraControl)
+                    .setCaptureRequestOptions(
+                            CaptureRequestOptions.Builder()
+                                    .setCaptureRequestOption(
+                                            CaptureRequest.CONTROL_ZOOM_RATIO,
+                                            zoomRatio,
+                                    )
+                                    .build(),
+                    )
+
+    private fun isSupersededCamera2ZoomRequest(error: Exception): Boolean {
+        val cause =
+                if (error is ExecutionException) {
+                    error.cause
+                } else {
+                    error
+                }
+        return cause is CameraControl.OperationCanceledException &&
+                cause.message?.contains("updated with new options") == true
+    }
+
+    private fun logSetZoomResult(
+            requestedRatio: Double,
+            nextZoom: Float,
+            capabilities: Map<String, Any>,
+    ) {
+        Log.d(
+                TAG,
+                "setZoomRatio result requestedRatio=$requestedRatio nextZoom=$nextZoom " +
+                        "currentZoomRatio=$currentZoomRatio returnedZoom=${capabilities["zoomRatio"]}",
+        )
+    }
+
     private fun selectorForCurrentLensMode(): CameraSelector {
         val cameraId =
                 if (currentLensMode == LensMode.ULTRA_WIDE) {
@@ -496,7 +949,11 @@ class RecordingCameraController(
             return
         }
         if (activeRecording != null) {
-            onComplete(false, zoomCapabilitiesMap(), "Cannot switch physical camera while recording")
+            switchRecordingSegmentToLens(
+                    LensMode.ULTRA_WIDE,
+                    ultraWideZoomRatio.toDouble(),
+                    onComplete,
+            )
             return
         }
         val provider = cameraProvider
@@ -530,7 +987,7 @@ class RecordingCameraController(
             onComplete: (Boolean, Map<String, Any>, String?) -> Unit,
     ) {
         if (activeRecording != null) {
-            onComplete(false, zoomCapabilitiesMap(), "Cannot switch physical camera while recording")
+            switchRecordingSegmentToLens(LensMode.MAIN, ratio, onComplete)
             return
         }
         val provider = cameraProvider
@@ -554,6 +1011,62 @@ class RecordingCameraController(
         return ultraWideCameraId != null
     }
 
+    private fun switchRecordingSegmentToLens(
+            targetLensMode: LensMode,
+            targetRatio: Double,
+            onComplete: (Boolean, Map<String, Any>, String?) -> Unit,
+    ) {
+        val recording = activeRecording
+        if (recording == null) {
+            onComplete(false, zoomCapabilitiesMap(), "Recording is not active")
+            return
+        }
+        if (isSwitchingLens || pendingSegmentSwitch != null) {
+            onComplete(false, zoomCapabilitiesMap(), "Camera lens switch is already in progress")
+            return
+        }
+        pendingSegmentSwitch = PendingSegmentSwitch(targetLensMode, targetRatio, onComplete)
+        isSwitchingLens = true
+        recording.stop()
+        activeRecording = null
+    }
+
+    private fun continueSegmentSwitch(request: PendingSegmentSwitch) {
+        val provider = cameraProvider
+        val lifecycleOwner = boundLifecycleOwner
+        if (provider == null || lifecycleOwner == null) {
+            isSwitchingLens = false
+            request.onComplete(false, zoomCapabilitiesMap(), "Camera is not ready")
+            return
+        }
+
+        try {
+            currentLensMode = request.targetLensMode
+            currentZoomRatio =
+                    if (request.targetLensMode == LensMode.ULTRA_WIDE) {
+                        ultraWideZoomRatio
+                    } else {
+                        request.targetRatio.toFloat().coerceAtLeast(1f)
+                    }
+            bindUseCases(provider, lifecycleOwner, selectorForCurrentLensMode())
+            applyCurrentZoom()
+            startNewSegment(updateStatusOnStart = true) { started, message ->
+                isSwitchingLens = false
+                if (started) {
+                    request.onComplete(true, zoomCapabilitiesMap(), null)
+                } else {
+                    updateStatus(RecordingStatus(RecordingState.ERROR, message = message))
+                    request.onComplete(false, zoomCapabilitiesMap(), message)
+                }
+            }
+        } catch (error: Exception) {
+            Log.e(TAG, "continueSegmentSwitch failed", error)
+            isSwitchingLens = false
+            updateStatus(RecordingStatus(RecordingState.ERROR, message = error.message))
+            request.onComplete(false, zoomCapabilitiesMap(), error.message)
+        }
+    }
+
     private fun ProcessCameraProvider.hasCameraSafely(selector: CameraSelector): Boolean {
         return try {
             hasCamera(selector)
@@ -571,16 +1084,43 @@ class RecordingCameraController(
             val cameraId: String,
             val minFocalLength: Float,
             val horizontalFov: Double,
-    )
+            val zoomRatioRange: ZoomRatioRange?,
+    ) {
+        fun description(): String {
+            return "id=$cameraId fov=$horizontalFov focal=$minFocalLength " +
+                    "zoomRange=${zoomRatioRange?.description()}"
+        }
+    }
+
+    private data class ZoomRatioRange(
+            val lower: Float,
+            val upper: Float,
+    ) {
+        fun contains(ratio: Float): Boolean {
+            return ratio >= lower && ratio <= upper
+        }
+
+        fun description(): String {
+            return "$lower..$upper"
+        }
+    }
 
     private data class UltraWideCamera(
             val cameraId: String,
             val zoomRatio: Float,
     )
 
+    private data class PendingSegmentSwitch(
+            val targetLensMode: LensMode,
+            val targetRatio: Double,
+            val onComplete: (Boolean, Map<String, Any>, String?) -> Unit,
+    )
+
     companion object {
         private const val TAG = "RecordingCamera"
         private const val DEFAULT_ULTRA_WIDE_ZOOM_RATIO = 0.6f
+        private const val MIN_ULTRA_WIDE_ZOOM_RATIO = 0.3f
+        private const val MAX_ULTRA_WIDE_ZOOM_RATIO = 0.99f
         // 适度放宽判定宽容度，覆盖更多机型(更小的 FOV/焦距差异也视为超广角)。
         private const val ULTRA_WIDE_FOV_FACTOR = 1.04
         private const val ULTRA_WIDE_FOCAL_FACTOR = 0.96
diff --git a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingOutputFactory.kt b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingOutputFactory.kt
index 7eabb4c..f5f25ad 100644
--- a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingOutputFactory.kt
+++ b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingOutputFactory.kt
@@ -4,7 +4,9 @@ import android.content.ContentValues
 import android.content.Context
 import android.os.Build
 import android.provider.MediaStore
-import androidx.camera.video.MediaStoreOutputOptions
+import androidx.camera.video.FileOutputOptions
+import java.io.File
+import java.io.FileInputStream
 import java.text.SimpleDateFormat
 import java.util.Date
 import java.util.Locale
@@ -13,10 +15,37 @@ object RecordingOutputFactory {
     private const val RELATIVE_PATH = "Movies/飞行极控录像工作台"
     private const val MIME_TYPE = "video/mp4"
 
-    fun buildMediaStoreOutputOptions(
+    fun buildSegmentOutputOptions(segmentFile: File): FileOutputOptions {
+        return FileOutputOptions.Builder(segmentFile).build()
+    }
+
+    fun createSegmentFile(
             context: Context,
             displayName: String?,
-    ): MediaStoreOutputOptions {
+            index: Int,
+    ): File {
+        val directory = File(context.cacheDir, "recording_segments")
+        if (!directory.exists()) {
+            directory.mkdirs()
+        }
+        val baseName = resolveFileName(displayName).removeSuffix(".mp4")
+        return File(directory, "${baseName}_${System.currentTimeMillis()}_part$index.mp4")
+    }
+
+    fun createMergeFile(context: Context, displayName: String?): File {
+        val directory = File(context.cacheDir, "recording_segments")
+        if (!directory.exists()) {
+            directory.mkdirs()
+        }
+        val baseName = resolveFileName(displayName).removeSuffix(".mp4")
+        return File(directory, "${baseName}_${System.currentTimeMillis()}_merged.mp4")
+    }
+
+    fun publishToMediaStore(
+            context: Context,
+            displayName: String?,
+            sourceFile: File,
+    ): String? {
         val fileName = resolveFileName(displayName)
         val contentValues =
                 ContentValues().apply {
@@ -24,15 +53,42 @@ object RecordingOutputFactory {
                     put(MediaStore.MediaColumns.MIME_TYPE, MIME_TYPE)
                     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                         put(MediaStore.Video.Media.RELATIVE_PATH, RELATIVE_PATH)
+                        put(MediaStore.Video.Media.IS_PENDING, 1)
                     }
                 }
 
-        return MediaStoreOutputOptions.Builder(
-                        context.contentResolver,
-                        MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
-                )
-                .setContentValues(contentValues)
-                .build()
+        val resolver = context.contentResolver
+        val uri =
+                resolver.insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, contentValues)
+                        ?: return null
+        try {
+            val outputStream =
+                    resolver.openOutputStream(uri)
+                            ?: throw IllegalStateException("Cannot open MediaStore output stream")
+            outputStream.use { output ->
+                FileInputStream(sourceFile).use { input -> input.copyTo(output) }
+            }
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                val publishedValues =
+                        ContentValues().apply { put(MediaStore.Video.Media.IS_PENDING, 0) }
+                resolver.update(uri, publishedValues, null, null)
+            }
+            return uri.toString()
+        } catch (error: Exception) {
+            resolver.delete(uri, null, null)
+            throw error
+        }
+    }
+
+    fun publishPartToMediaStore(
+            context: Context,
+            displayName: String?,
+            sourceFile: File,
+            partIndex: Int,
+    ): String? {
+        val resolvedName = resolveFileName(displayName)
+        val partName = resolvedName.replace(".mp4", "_part$partIndex.mp4")
+        return publishToMediaStore(context, partName, sourceFile)
     }
 
     fun resolveFileName(displayName: String?): String {
diff --git a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingPlatformHandler.kt b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingPlatformHandler.kt
index 8226430..9bf22f2 100644
--- a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingPlatformHandler.kt
+++ b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingPlatformHandler.kt
@@ -196,6 +196,7 @@ class RecordingPlatformHandler(
                         "outputPath" to path,
                         "status" to controller.status.toMap(),
                         "fileSaved" to fileSaved,
+                        "segmentOutputPaths" to controller.segmentOutputPaths(),
                 )
         if (!fileSaved) {
             payload["fileErrorMessage"] = controller.status.message ?: "保存到文件夹失败"
diff --git a/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingSegmentMuxer.kt b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingSegmentMuxer.kt
new file mode 100644
index 0000000..83b9c18
--- /dev/null
+++ b/android/app/src/main/kotlin/com/dronex/rec/recording/RecordingSegmentMuxer.kt
@@ -0,0 +1,174 @@
+package com.dronex.rec.recording
+
+import android.media.MediaCodec
+import android.media.MediaExtractor
+import android.media.MediaFormat
+import android.media.MediaMuxer
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.nio.ByteBuffer
+
+object RecordingSegmentMuxer {
+    fun mergeOrCopy(
+            segments: List<File>,
+            outputFile: File,
+    ) {
+        val validSegments = segments.filter { it.exists() && it.length() > 0L }
+        require(validSegments.isNotEmpty()) { "No recording segments were generated" }
+        if (validSegments.size == 1) {
+            copyFile(validSegments.first(), outputFile)
+            return
+        }
+
+        MediaMuxer(outputFile.absolutePath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4).use {
+                muxer ->
+            val firstTracks = readTrackFormats(validSegments.first())
+            val videoTrack = firstTracks.video?.let { muxer.addTrack(it) }
+            val audioTrack = firstTracks.audio?.let { muxer.addTrack(it) }
+            require(videoTrack != null) { "No video track in recording segment" }
+
+            muxer.start()
+            var offsetUs = 0L
+            validSegments.forEach { segment ->
+                val durationUs =
+                        copySegmentTracks(
+                                segment = segment,
+                                muxer = muxer,
+                                videoOutputTrack = videoTrack,
+                                audioOutputTrack = audioTrack,
+                                offsetUs = offsetUs,
+                        )
+                offsetUs += durationUs + 1L
+            }
+        }
+    }
+
+    private fun copyFile(source: File, target: File) {
+        FileInputStream(source).use { input ->
+            FileOutputStream(target).use { output -> input.copyTo(output) }
+        }
+    }
+
+    private fun readTrackFormats(file: File): TrackFormats {
+        val extractor = MediaExtractor()
+        extractor.setDataSource(file.absolutePath)
+        try {
+            var video: MediaFormat? = null
+            var audio: MediaFormat? = null
+            for (index in 0 until extractor.trackCount) {
+                val format = extractor.getTrackFormat(index)
+                val mime = format.getString(MediaFormat.KEY_MIME).orEmpty()
+                when {
+                    mime.startsWith("video/") && video == null -> video = format
+                    mime.startsWith("audio/") && audio == null -> audio = format
+                }
+            }
+            return TrackFormats(video = video, audio = audio)
+        } finally {
+            extractor.release()
+        }
+    }
+
+    private fun copySegmentTracks(
+            segment: File,
+            muxer: MediaMuxer,
+            videoOutputTrack: Int,
+            audioOutputTrack: Int?,
+            offsetUs: Long,
+    ): Long {
+        var segmentDurationUs = 0L
+        segmentDurationUs =
+                maxOf(
+                        segmentDurationUs,
+                        copyTrack(segment, muxer, "video/", videoOutputTrack, offsetUs),
+                )
+        if (audioOutputTrack != null) {
+            segmentDurationUs =
+                    maxOf(
+                            segmentDurationUs,
+                            copyTrack(segment, muxer, "audio/", audioOutputTrack, offsetUs),
+                    )
+        }
+        return segmentDurationUs
+    }
+
+    private fun copyTrack(
+            segment: File,
+            muxer: MediaMuxer,
+            mimePrefix: String,
+            outputTrack: Int,
+            offsetUs: Long,
+    ): Long {
+        val extractor = MediaExtractor()
+        extractor.setDataSource(segment.absolutePath)
+        try {
+            val inputTrack = findTrack(extractor, mimePrefix) ?: return 0L
+            extractor.selectTrack(inputTrack)
+            val bufferSize = trackBufferSize(extractor.getTrackFormat(inputTrack))
+            val buffer = ByteBuffer.allocate(bufferSize)
+            val info = MediaCodec.BufferInfo()
+            var firstSampleTimeUs: Long? = null
+            var lastSampleTimeUs = 0L
+
+            while (true) {
+                buffer.clear()
+                val sampleSize = extractor.readSampleData(buffer, 0)
+                if (sampleSize < 0) break
+
+                val sampleTimeUs = extractor.sampleTime
+                val baseTimeUs = firstSampleTimeUs ?: sampleTimeUs.also { firstSampleTimeUs = it }
+                val normalizedTimeUs = (sampleTimeUs - baseTimeUs).coerceAtLeast(0L)
+                info.set(
+                        0,
+                        sampleSize,
+                        offsetUs + normalizedTimeUs,
+                        extractor.sampleFlags,
+                )
+                muxer.writeSampleData(outputTrack, buffer, info)
+                lastSampleTimeUs = normalizedTimeUs
+                extractor.advance()
+            }
+            return lastSampleTimeUs
+        } finally {
+            extractor.release()
+        }
+    }
+
+    private fun findTrack(extractor: MediaExtractor, mimePrefix: String): Int? {
+        for (index in 0 until extractor.trackCount) {
+            val mime = extractor.getTrackFormat(index).getString(MediaFormat.KEY_MIME).orEmpty()
+            if (mime.startsWith(mimePrefix)) {
+                return index
+            }
+        }
+        return null
+    }
+
+    private fun trackBufferSize(format: MediaFormat): Int {
+        return if (format.containsKey(MediaFormat.KEY_MAX_INPUT_SIZE)) {
+            format.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE).coerceAtLeast(DEFAULT_BUFFER_SIZE)
+        } else {
+            DEFAULT_BUFFER_SIZE
+        }
+    }
+
+    private data class TrackFormats(
+            val video: MediaFormat?,
+            val audio: MediaFormat?,
+    )
+
+    private const val DEFAULT_BUFFER_SIZE = 2 * 1024 * 1024
+}
+
+private inline fun MediaMuxer.use(block: (MediaMuxer) -> Unit) {
+    try {
+        block(this)
+    } finally {
+        try {
+            stop()
+        } catch (_: Exception) {
+        }
+        release()
+    }
+}
diff --git a/ios/Runner/PlatformInfoPlugin.swift b/ios/Runner/PlatformInfoPlugin.swift
index a6ee22d..f219908 100644
--- a/ios/Runner/PlatformInfoPlugin.swift
+++ b/ios/Runner/PlatformInfoPlugin.swift
@@ -4,7 +4,7 @@ import UIKit
 final class PlatformInfoPlugin: NSObject, FlutterPlugin {
   static func register(with registrar: FlutterPluginRegistrar) {
     let channel = FlutterMethodChannel(
-      name: "com.dronex.rec/platform_info",
+      name: "app.record_tool/platform_info",
       binaryMessenger: registrar.messenger()
     )
     let plugin = PlatformInfoPlugin()
diff --git a/ios/Runner/RecordingPlugin.swift b/ios/Runner/RecordingPlugin.swift
index 83b3353..6b8e53b 100644
--- a/ios/Runner/RecordingPlugin.swift
+++ b/ios/Runner/RecordingPlugin.swift
@@ -633,9 +633,9 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
 }
 
 private enum RecordingChannelNames {
-  static let packageName = "com.dronex.rec"
-  static let method = "\(packageName)/recording"
-  static let events = "\(packageName)/recording_events"
+  static let namespace = "app.record_tool"
+  static let method = "\(namespace)/recording"
+  static let events = "\(namespace)/recording_events"
 }
 
 final class RecordingPlugin: NSObject, FlutterPlugin, FlutterStreamHandler {
diff --git a/lib/core/platform/app_platform_info.dart b/lib/core/platform/app_platform_info.dart
index f1aa85c..3f70f66 100644
--- a/lib/core/platform/app_platform_info.dart
+++ b/lib/core/platform/app_platform_info.dart
@@ -60,7 +60,7 @@ class AppPlatformInfo {
   AppPlatformInfo._();
 
   static const MethodChannel _channel = MethodChannel(
-    'com.dronex.rec/platform_info',
+    'app.record_tool/platform_info',
   );
 
   static Future<AppPackageInfo> packageInfo() async {
diff --git a/lib/features/recording/model/model_recording_session.dart b/lib/features/recording/model/model_recording_session.dart
index 9a06e2c..5e25176 100644
--- a/lib/features/recording/model/model_recording_session.dart
+++ b/lib/features/recording/model/model_recording_session.dart
@@ -7,6 +7,7 @@ class RecordingSessionState {
     this.isTouchLocked = true,
     this.isPreviewReady = false,
     this.isStartingRecording = false,
+    this.isSwitchingLens = false,
     this.hasDndAccess = false,
     this.isBatteryOptimizedIgnored = true,
     this.notificationsGranted = true,
@@ -19,12 +20,14 @@ class RecordingSessionState {
     this.errorMessage,
     this.permissionWarning,
     this.fileSaveFailed = false,
+    this.segmentOutputPaths = const [],
   });
 
   final RecordingStatus status;
   final bool isTouchLocked;
   final bool isPreviewReady;
   final bool isStartingRecording;
+  final bool isSwitchingLens;
   final bool hasDndAccess;
   final bool isBatteryOptimizedIgnored;
   final bool notificationsGranted;
@@ -37,6 +40,7 @@ class RecordingSessionState {
   final String? errorMessage;
   final String? permissionWarning;
   final bool fileSaveFailed;
+  final List<String> segmentOutputPaths;
 
   bool get isRecording => status.isRecording;
 
@@ -53,6 +57,7 @@ class RecordingSessionState {
     bool? isTouchLocked,
     bool? isPreviewReady,
     bool? isStartingRecording,
+    bool? isSwitchingLens,
     bool? hasDndAccess,
     bool? isBatteryOptimizedIgnored,
     bool? notificationsGranted,
@@ -65,6 +70,7 @@ class RecordingSessionState {
     String? errorMessage,
     String? permissionWarning,
     bool? fileSaveFailed,
+    List<String>? segmentOutputPaths,
     bool clearPermissionWarning = false,
     bool clearLastSaved = false,
   }) {
@@ -73,6 +79,7 @@ class RecordingSessionState {
       isTouchLocked: isTouchLocked ?? this.isTouchLocked,
       isPreviewReady: isPreviewReady ?? this.isPreviewReady,
       isStartingRecording: isStartingRecording ?? this.isStartingRecording,
+      isSwitchingLens: isSwitchingLens ?? this.isSwitchingLens,
       hasDndAccess: hasDndAccess ?? this.hasDndAccess,
       isBatteryOptimizedIgnored:
           isBatteryOptimizedIgnored ?? this.isBatteryOptimizedIgnored,
@@ -90,6 +97,7 @@ class RecordingSessionState {
           ? null
           : (permissionWarning ?? this.permissionWarning),
       fileSaveFailed: fileSaveFailed ?? this.fileSaveFailed,
+      segmentOutputPaths: segmentOutputPaths ?? this.segmentOutputPaths,
     );
   }
 }
diff --git a/lib/features/recording/pages/page_record.dart b/lib/features/recording/pages/page_record.dart
index 7841308..803e28a 100644
--- a/lib/features/recording/pages/page_record.dart
+++ b/lib/features/recording/pages/page_record.dart
@@ -173,7 +173,11 @@ class _RecordingPageState extends ConsumerState<RecordingPage> {
     if (!mounted) return;
     final latest = ref.read(recordingViewModelProvider).session;
     if (latest.fileSaveFailed) {
-      AppToast.show(latest.errorMessage ?? '保存到文件夹失败，请检查文件保存权限');
+      if (latest.segmentOutputPaths.isNotEmpty) {
+        AppToast.show('视频合并失败，已为你保存分段文件，可在相册中查看');
+      } else {
+        AppToast.show(latest.errorMessage ?? '保存到文件夹失败，请检查文件保存权限');
+      }
       return;
     }
     await _showRecordingSavedDialogIfNeeded();
@@ -374,6 +378,7 @@ class _RecordingHudLayer extends ConsumerWidget {
           m.session.notificationsGranted,
           m.session.isRecording,
           m.session.isStartingRecording,
+          m.session.isSwitchingLens,
           m.session.isTouchLocked,
           m.session.zoomRatio,
           m.session.minZoomRatio,
@@ -391,6 +396,7 @@ class _RecordingHudLayer extends ConsumerWidget {
       notificationsGranted,
       isRecording,
       isStartingRecording,
+      isSwitchingLens,
       isTouchLocked,
       zoomRatio,
       minZoomRatio,
@@ -408,6 +414,7 @@ class _RecordingHudLayer extends ConsumerWidget {
       notificationsGranted: notificationsGranted,
       isRecording: isRecording,
       isStartingRecording: isStartingRecording,
+      isSwitchingLens: isSwitchingLens,
       isTouchLocked: isTouchLocked,
       zoomRatio: zoomRatio,
       minZoomRatio: minZoomRatio,
diff --git a/lib/features/recording/platform/recording_channel_names.dart b/lib/features/recording/platform/recording_channel_names.dart
index e0293da..4d07f93 100644
--- a/lib/features/recording/platform/recording_channel_names.dart
+++ b/lib/features/recording/platform/recording_channel_names.dart
@@ -1,5 +1,5 @@
 abstract final class RecordingChannelNames {
-  static const packageName = 'com.dronex.rec';
-  static const method = '$packageName/recording';
-  static const events = '$packageName/recording_events';
+  static const namespace = 'app.record_tool';
+  static const method = '$namespace/recording';
+  static const events = '$namespace/recording_events';
 }
diff --git a/lib/features/recording/platform/recording_platform.dart b/lib/features/recording/platform/recording_platform.dart
index 6bfa443..ecf6d88 100644
--- a/lib/features/recording/platform/recording_platform.dart
+++ b/lib/features/recording/platform/recording_platform.dart
@@ -207,12 +207,14 @@ class RecordingStopResult {
     required this.status,
     this.fileSaved = true,
     this.fileErrorMessage,
+    this.segmentOutputPaths = const [],
   });
 
   final String? outputPath;
   final RecordingStatus status;
   final bool fileSaved;
   final String? fileErrorMessage;
+  final List<String> segmentOutputPaths;
 
   factory RecordingStopResult.fromMap(Map<String, dynamic>? result) {
     return RecordingStopResult(
@@ -222,6 +224,11 @@ class RecordingStopResult {
       ),
       fileSaved: result?['fileSaved'] as bool? ?? true,
       fileErrorMessage: result?['fileErrorMessage'] as String?,
+      segmentOutputPaths:
+          (result?['segmentOutputPaths'] as List?)?.whereType<String>().toList(
+            growable: false,
+          ) ??
+          const [],
     );
   }
 }
diff --git a/lib/features/recording/view-model/view_model_recording.dart b/lib/features/recording/view-model/view_model_recording.dart
index 39276e8..d4fe6e6 100644
--- a/lib/features/recording/view-model/view_model_recording.dart
+++ b/lib/features/recording/view-model/view_model_recording.dart
@@ -349,10 +349,14 @@ class RecordingViewModel extends Notifier<RecordingModel> {
   /// 设置相机倍距，原生层会返回设备实际应用后的倍距范围与当前值。
   Future<void> setZoomRatio(double ratio) async {
     final session = state.session;
+    if (session.isSwitchingLens) {
+      return;
+    }
     final clamped = ratio
         .clamp(session.minZoomRatio, session.maxZoomRatio)
         .toDouble();
 
+    _updateSession((s) => s.copyWith(isSwitchingLens: true));
     try {
       final zoom = await RecordingPlatform.setZoomRatio(clamped);
       _updateSession(
@@ -364,8 +368,13 @@ class RecordingViewModel extends Notifier<RecordingModel> {
         ),
       );
     } on PlatformException catch (error) {
+      final message = error.code == 'ZOOM_FAILED'
+          ? '切换镜头失败，请重试'
+          : (error.message ?? '相机倍距设置失败');
+      _updateSession((s) => s.copyWith(errorMessage: message));
+    } finally {
       _updateSession(
-        (s) => s.copyWith(errorMessage: error.message ?? '相机倍距设置失败'),
+        (s) => s.copyWith(isSwitchingLens: false, errorMessage: s.errorMessage),
       );
     }
   }
@@ -373,7 +382,9 @@ class RecordingViewModel extends Notifier<RecordingModel> {
   /// 开始录制，可选开启勿扰模式。
   Future<void> startRecording({bool enableDoNotDisturb = true}) async {
     final session = state.session;
-    if (session.isRecording || session.isStartingRecording) {
+    if (session.isRecording ||
+        session.isStartingRecording ||
+        session.isSwitchingLens) {
       return;
     }
     if (!session.isPreviewReady) {
@@ -400,6 +411,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
           isTouchLocked: true,
           errorMessage: null,
           fileSaveFailed: false,
+          segmentOutputPaths: const [],
           clearLastSaved: true,
         ),
       );
@@ -414,7 +426,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
 
   /// 停止录制、保存到文件夹，并恢复相机预览。
   Future<void> stopRecording() async {
-    if (!state.session.isRecording) return;
+    if (!state.session.isRecording || state.session.isSwitchingLens) return;
 
     try {
       final result = await RecordingPlatform.stopRecording();
@@ -431,6 +443,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
               ? (result.fileErrorMessage ?? '保存到文件夹失败，请检查文件保存权限')
               : null,
           fileSaveFailed: fileFailed,
+          segmentOutputPaths: result.segmentOutputPaths,
         ),
       );
     } on PlatformException catch (error) {
diff --git a/lib/features/recording/widgets/widget_recording_hud.dart b/lib/features/recording/widgets/widget_recording_hud.dart
index 10d25af..ab76bc3 100644
--- a/lib/features/recording/widgets/widget_recording_hud.dart
+++ b/lib/features/recording/widgets/widget_recording_hud.dart
@@ -18,6 +18,7 @@ class RecordingHudWidget extends StatelessWidget {
     required this.notificationsGranted,
     required this.isRecording,
     required this.isStartingRecording,
+    required this.isSwitchingLens,
     required this.isTouchLocked,
     this.showClipboardHint = false,
     this.clipboardAddress = '',
@@ -39,6 +40,7 @@ class RecordingHudWidget extends StatelessWidget {
   final bool notificationsGranted;
   final bool isRecording;
   final bool isStartingRecording;
+  final bool isSwitchingLens;
   final bool isTouchLocked;
   final bool showClipboardHint;
   final String clipboardAddress;
@@ -56,7 +58,6 @@ class RecordingHudWidget extends StatelessWidget {
   static double get _recordButtonBottom => 63.r;
   static double get _overlayInfoLeft => 13.r;
   static double get _overlayInfoBottom => 10.r;
-  static const List<double> _zoomPresets = [0.6, 1.0];
 
   @override
   Widget build(BuildContext context) {
@@ -144,13 +145,13 @@ class RecordingHudWidget extends StatelessWidget {
           ),
         Positioned(
           right: 16.r,
-          bottom: _recordButtonBottom + _recordButtonSize + 14.h,
+          bottom: 260.r,
           child: _ZoomPresetControl(
-            isRecording: isRecording,
+            enabled: !isSwitchingLens,
             zoomRatio: zoomRatio,
             minZoomRatio: minZoomRatio,
             maxZoomRatio: maxZoomRatio,
-            presets: _zoomPresets,
+            presets: _zoomPresetsForRange(minZoomRatio),
             onSelected: onZoomSelected,
           ),
         ),
@@ -162,7 +163,7 @@ class RecordingHudWidget extends StatelessWidget {
             child: RecordingControlButton(
               isRecording: isRecording,
               isStartingRecording: isStartingRecording,
-              enabled: !isStartingRecording,
+              enabled: !isStartingRecording && !isSwitchingLens,
               size: _recordButtonSize,
               onTap: () {
                 if (isRecording) {
@@ -191,11 +192,15 @@ class RecordingHudWidget extends StatelessWidget {
       ],
     );
   }
+
+  List<double> _zoomPresetsForRange(double minZoomRatio) {
+    return [if (minZoomRatio < 1.0) minZoomRatio, 1.0];
+  }
 }
 
 class _ZoomPresetControl extends StatelessWidget {
   const _ZoomPresetControl({
-    required this.isRecording,
+    required this.enabled,
     required this.zoomRatio,
     required this.minZoomRatio,
     required this.maxZoomRatio,
@@ -203,7 +208,7 @@ class _ZoomPresetControl extends StatelessWidget {
     required this.onSelected,
   });
 
-  final bool isRecording;
+  final bool enabled;
   final double zoomRatio;
   final double minZoomRatio;
   final double maxZoomRatio;
@@ -215,7 +220,6 @@ class _ZoomPresetControl extends StatelessWidget {
     final availablePresets = presets
         .where(_isPresetAvailable)
         .toList(growable: false);
-
     if (availablePresets.isEmpty) {
       return const SizedBox.shrink();
     }
@@ -236,7 +240,7 @@ class _ZoomPresetControl extends StatelessWidget {
                 displayRatio: preset,
                 requestRatio: preset,
                 selected: _isPresetSelected(preset),
-                enabled: !_wouldSwitchPhysicalCamera(preset),
+                enabled: enabled,
                 onSelected: onSelected,
               ),
           ],
@@ -258,15 +262,6 @@ class _ZoomPresetControl extends StatelessWidget {
     }
     return (zoomRatio - preset).abs() < 0.05;
   }
-
-  bool _wouldSwitchPhysicalCamera(double preset) {
-    if (!isRecording) {
-      return false;
-    }
-    final currentIsUltraWide = zoomRatio < 1.0;
-    final targetIsUltraWide = preset < 1.0;
-    return currentIsUltraWide != targetIsUltraWide;
-  }
 }
 
 class _ZoomPresetButton extends StatelessWidget {
@@ -289,7 +284,17 @@ class _ZoomPresetButton extends StatelessWidget {
     return Padding(
       padding: EdgeInsets.symmetric(horizontal: 1.r),
       child: TextButton(
-        onPressed: selected || !enabled ? null : () => onSelected(requestRatio),
+        onPressed: selected || !enabled
+            ? null
+            : () => RateLimit.instance.debounce<void>(
+                key:
+                    'recording.session.zoom.${requestRatio.toStringAsFixed(1)}',
+                value: null,
+                duration: Duration(milliseconds: 300),
+                onCallback: (_) async {
+                  onSelected(requestRatio);
+                },
+              ),
         style: TextButton.styleFrom(
           minimumSize: Size(38.r, 32.r),
           padding: EdgeInsets.zero,
@@ -303,7 +308,7 @@ class _ZoomPresetButton extends StatelessWidget {
           ),
         ),
         child: Text(
-          '${_formatZoomRatio(displayRatio)}x',
+          _formatZoomRatio(displayRatio),
           style: TextStyle(
             fontSize: 13.sp,
             fontWeight: FontWeight.w700,
@@ -315,9 +320,12 @@ class _ZoomPresetButton extends StatelessWidget {
   }
 
   String _formatZoomRatio(double ratio) {
-    if (ratio == ratio.roundToDouble()) {
-      return ratio.toStringAsFixed(0);
+    if (ratio < 1.0) {
+      return '广角';
     }
-    return ratio.toStringAsFixed(1);
+    if (ratio == ratio.roundToDouble()) {
+      return '${ratio.toStringAsFixed(0)}x';
+    }
+    return '${ratio.toStringAsFixed(1)}x';
   }
 }
diff --git a/test/features/recording/recording_platform_test.dart b/test/features/recording/recording_platform_test.dart
index 54bd537..9774d92 100644
--- a/test/features/recording/recording_platform_test.dart
+++ b/test/features/recording/recording_platform_test.dart
@@ -1,7 +1,15 @@
 import 'package:flutter_test/flutter_test.dart';
+import 'package:recording_tool/features/recording/platform/recording_channel_names.dart';
 import 'package:recording_tool/features/recording/platform/recording_platform.dart';
 
 void main() {
+  group('RecordingChannelNames', () {
+    test('uses stable bridge names without package binding', () {
+      expect(RecordingChannelNames.method, 'app.record_tool/recording');
+      expect(RecordingChannelNames.events, 'app.record_tool/recording_events');
+    });
+  });
+
   group('RecordingPlatform support', () {
     test('supports Android and iOS hosts only', () {
       expect(
diff --git a/test/features/recording/view_model_recording_test.dart b/test/features/recording/view_model_recording_test.dart
index 8ac9ad2..25dde3f 100644
--- a/test/features/recording/view_model_recording_test.dart
+++ b/test/features/recording/view_model_recording_test.dart
@@ -1,9 +1,12 @@
+import 'dart:async';
+
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:recording_tool/features/recording/model/model_recording_session.dart';
 import 'package:recording_tool/features/recording/platform/recording_channel_names.dart';
+import 'package:recording_tool/features/recording/platform/recording_platform.dart';
 import 'package:recording_tool/features/recording/view-model/view_model_recording.dart';
 
 void main() {
@@ -76,45 +79,42 @@ void main() {
       expect(session.errorMessage, isNull);
     });
 
-    test(
-      'clamps legacy 0.5x request to 0.6x ultra-wide ratio',
-      () async {
-        final calls = <MethodCall>[];
-        TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-            .setMockMethodCallHandler(
-              const MethodChannel(RecordingChannelNames.method),
-              (call) async {
-                calls.add(call);
-                return <String, dynamic>{
-                  'zoomRatio': 0.6,
-                  'minZoomRatio': 0.6,
-                  'maxZoomRatio': 3.0,
-                };
-              },
-            );
-        final container = ProviderContainer();
-        addTearDown(container.dispose);
-        final notifier = container.read(recordingViewModelProvider.notifier);
-        // ignore: invalid_use_of_protected_member
-        notifier.state = container
-            .read(recordingViewModelProvider)
-            .copyWith(
-              session: const RecordingSessionState(
-                zoomRatio: 1.0,
-                minZoomRatio: 0.6,
-                maxZoomRatio: 3.0,
-              ),
-            );
+    test('passes 0.5x to native when camera capabilities allow it', () async {
+      final calls = <MethodCall>[];
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(
+            const MethodChannel(RecordingChannelNames.method),
+            (call) async {
+              calls.add(call);
+              return <String, dynamic>{
+                'zoomRatio': 0.5,
+                'minZoomRatio': 0.5,
+                'maxZoomRatio': 3.0,
+              };
+            },
+          );
+      final container = ProviderContainer();
+      addTearDown(container.dispose);
+      final notifier = container.read(recordingViewModelProvider.notifier);
+      // ignore: invalid_use_of_protected_member
+      notifier.state = container
+          .read(recordingViewModelProvider)
+          .copyWith(
+            session: const RecordingSessionState(
+              zoomRatio: 1.0,
+              minZoomRatio: 0.5,
+              maxZoomRatio: 3.0,
+            ),
+          );
 
-        await notifier.setZoomRatio(0.5);
+      await notifier.setZoomRatio(0.5);
 
-        expect(calls.single.arguments, <String, dynamic>{'zoomRatio': 0.6});
-        final session = container.read(recordingViewModelProvider).session;
-        expect(session.zoomRatio, 0.6);
-        expect(session.minZoomRatio, 0.6);
-        expect(session.maxZoomRatio, 3.0);
-      },
-    );
+      expect(calls.single.arguments, <String, dynamic>{'zoomRatio': 0.5});
+      final session = container.read(recordingViewModelProvider).session;
+      expect(session.zoomRatio, 0.5);
+      expect(session.minZoomRatio, 0.5);
+      expect(session.maxZoomRatio, 3.0);
+    });
 
     test('passes 0.6x to native when camera capabilities allow it', () async {
       final calls = <MethodCall>[];
@@ -229,7 +229,152 @@ void main() {
 
         final session = container.read(recordingViewModelProvider).session;
         expect(session.zoomRatio, 1.0);
-        expect(session.errorMessage, 'Zoom is unavailable');
+        expect(session.errorMessage, '切换镜头失败，请重试');
+      },
+    );
+
+    test(
+      'maps native zoom failure to user friendly lens switch message',
+      () async {
+        TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+            .setMockMethodCallHandler(
+              const MethodChannel(RecordingChannelNames.method),
+              (call) async {
+                throw PlatformException(
+                  code: 'ZOOM_FAILED',
+                  message: 'Cannot switch physical camera while recording',
+                );
+              },
+            );
+        final container = ProviderContainer();
+        addTearDown(container.dispose);
+
+        await container
+            .read(recordingViewModelProvider.notifier)
+            .setZoomRatio(0.6);
+
+        final session = container.read(recordingViewModelProvider).session;
+        expect(session.zoomRatio, 1.0);
+        expect(session.errorMessage, '切换镜头失败，请重试');
+      },
+    );
+
+    test('sets switching lens while native zoom request is pending', () async {
+      final completer = Completer<Map<String, dynamic>>();
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(
+            const MethodChannel(RecordingChannelNames.method),
+            (call) => completer.future,
+          );
+      final container = ProviderContainer();
+      addTearDown(container.dispose);
+      final notifier = container.read(recordingViewModelProvider.notifier);
+
+      final future = notifier.setZoomRatio(2);
+      await Future<void>.delayed(Duration.zero);
+
+      expect(
+        container.read(recordingViewModelProvider).session.isSwitchingLens,
+        isTrue,
+      );
+
+      completer.complete(<String, dynamic>{
+        'zoomRatio': 2.0,
+        'minZoomRatio': 1.0,
+        'maxZoomRatio': 3.0,
+      });
+      await future;
+
+      expect(
+        container.read(recordingViewModelProvider).session.isSwitchingLens,
+        isFalse,
+      );
+    });
+  });
+
+  group('RecordingViewModel.stopRecording', () {
+    test('does not call native stop while switching lens', () async {
+      final calls = <MethodCall>[];
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(
+            const MethodChannel(RecordingChannelNames.method),
+            (call) async {
+              calls.add(call);
+              return <String, dynamic>{};
+            },
+          );
+      final container = ProviderContainer();
+      addTearDown(container.dispose);
+      final notifier = container.read(recordingViewModelProvider.notifier);
+      // ignore: invalid_use_of_protected_member
+      notifier.state = container
+          .read(recordingViewModelProvider)
+          .copyWith(
+            session: const RecordingSessionState(
+              status: RecordingStatus(state: RecordingState.recording),
+              isSwitchingLens: true,
+            ),
+          );
+
+      await notifier.stopRecording();
+
+      expect(calls, isEmpty);
+    });
+
+    test(
+      'stores segment output paths when native save falls back to parts',
+      () async {
+        TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+            .setMockMethodCallHandler(
+              const MethodChannel(RecordingChannelNames.method),
+              (call) async {
+                switch (call.method) {
+                  case 'stopRecording':
+                    return <String, dynamic>{
+                      'outputPath': 'content://recordings/part1',
+                      'status': <String, dynamic>{
+                        'state': 'error',
+                        'message': 'Merge failed',
+                      },
+                      'fileSaved': false,
+                      'fileErrorMessage': 'Merge failed',
+                      'segmentOutputPaths': <String>[
+                        'content://recordings/part1',
+                        'content://recordings/part2',
+                      ],
+                    };
+                  case 'initializePreview':
+                    return <String, dynamic>{'state': 'previewing'};
+                  case 'getZoomCapabilities':
+                    return <String, dynamic>{
+                      'zoomRatio': 1.0,
+                      'minZoomRatio': 1.0,
+                      'maxZoomRatio': 3.0,
+                    };
+                }
+                return <String, dynamic>{};
+              },
+            );
+        final container = ProviderContainer();
+        addTearDown(container.dispose);
+        final notifier = container.read(recordingViewModelProvider.notifier);
+        // ignore: invalid_use_of_protected_member
+        notifier.state = container
+            .read(recordingViewModelProvider)
+            .copyWith(
+              session: const RecordingSessionState(
+                status: RecordingStatus(state: RecordingState.recording),
+              ),
+            );
+
+        await notifier.stopRecording();
+
+        final session = container.read(recordingViewModelProvider).session;
+        expect(session.fileSaveFailed, isTrue);
+        expect(session.segmentOutputPaths, <String>[
+          'content://recordings/part1',
+          'content://recordings/part2',
+        ]);
       },
     );
   });
diff --git a/test/features/recording/widget_recording_hud_test.dart b/test/features/recording/widget_recording_hud_test.dart
index 382e9bb..867f036 100644
--- a/test/features/recording/widget_recording_hud_test.dart
+++ b/test/features/recording/widget_recording_hud_test.dart
@@ -10,6 +10,8 @@ void main() {
     double minZoomRatio = 1.0,
     double maxZoomRatio = 3.0,
     bool isRecording = false,
+    bool isSwitchingLens = false,
+    Future<void> Function()? onStop,
     ValueChanged<double>? onZoomSelected,
   }) async {
     await tester.pumpWidget(
@@ -25,12 +27,13 @@ void main() {
                 notificationsGranted: true,
                 isRecording: isRecording,
                 isStartingRecording: false,
+                isSwitchingLens: isSwitchingLens,
                 isTouchLocked: false,
                 zoomRatio: zoomRatio,
                 minZoomRatio: minZoomRatio,
                 maxZoomRatio: maxZoomRatio,
                 onStart: () async {},
-                onStop: () async {},
+                onStop: onStop ?? () async {},
                 onOpenDnd: () {},
                 onOpenBattery: () {},
                 onToggleTouchLock: () {},
@@ -47,50 +50,50 @@ void main() {
   testWidgets('shows preset zoom buttons', (tester) async {
     await pumpHud(tester);
 
-    expect(find.text('0.5x'), findsNothing);
-    expect(find.text('0.6x'), findsNothing);
+    expect(find.text('广角'), findsNothing);
     expect(find.text('1x'), findsOneWidget);
     expect(find.text('2x'), findsNothing);
     expect(find.text('3x'), findsNothing);
   });
 
-  testWidgets('shows 0.6x when ultra-wide camera capability is below 0.6', (
+  testWidgets('shows wide angle when ultra-wide camera capability is 0.5', (
     tester,
   ) async {
     await pumpHud(tester, minZoomRatio: 0.5);
 
-    expect(find.text('0.5x'), findsNothing);
-    expect(find.text('0.6x'), findsOneWidget);
+    expect(find.text('广角'), findsOneWidget);
     expect(find.text('1x'), findsOneWidget);
     expect(find.text('2x'), findsNothing);
     expect(find.text('3x'), findsNothing);
   });
 
-  testWidgets('shows 0.6x when 0.6x camera capability supports it', (
+  testWidgets('shows wide angle when 0.6x camera capability supports it', (
     tester,
   ) async {
     await pumpHud(tester, minZoomRatio: 0.6);
 
-    expect(find.text('0.6x'), findsOneWidget);
+    expect(find.text('广角'), findsOneWidget);
     expect(find.text('1x'), findsOneWidget);
   });
 
-  testWidgets('marks current ultra-wide zoom ratio as selected on 0.6x UI', (
+  testWidgets('marks current 0.5x wide angle ratio as selected', (
     tester,
   ) async {
     await pumpHud(tester, zoomRatio: 0.5, minZoomRatio: 0.5);
 
     final selectedButton = tester.widget<TextButton>(
-      find.ancestor(of: find.text('0.6x'), matching: find.byType(TextButton)),
+      find.ancestor(of: find.text('广角'), matching: find.byType(TextButton)),
     );
     expect(selectedButton.enabled, isFalse);
   });
 
-  testWidgets('marks current 0.6x zoom ratio as selected', (tester) async {
+  testWidgets('marks current 0.6x wide angle ratio as selected', (
+    tester,
+  ) async {
     await pumpHud(tester, zoomRatio: 0.6, minZoomRatio: 0.6);
 
     final selectedButton = tester.widget<TextButton>(
-      find.ancestor(of: find.text('0.6x'), matching: find.byType(TextButton)),
+      find.ancestor(of: find.text('广角'), matching: find.byType(TextButton)),
     );
     expect(selectedButton.enabled, isFalse);
   });
@@ -98,11 +101,11 @@ void main() {
   testWidgets('does not expose presets beyond max zoom ratio', (tester) async {
     await pumpHud(tester, minZoomRatio: 0.5, maxZoomRatio: 0.55);
 
-    expect(find.text('0.6x'), findsNothing);
+    expect(find.text('广角'), findsOneWidget);
     expect(find.text('1x'), findsNothing);
   });
 
-  testWidgets('tapping 0.6x reports 0.6 when camera capability is below 0.6', (
+  testWidgets('tapping 0.5x reports 0.5 when camera capability is 0.5', (
     tester,
   ) async {
     double? selected;
@@ -112,10 +115,10 @@ void main() {
       onZoomSelected: (ratio) => selected = ratio,
     );
 
-    await tester.tap(find.text('0.6x'));
-    await tester.pump();
+    await tester.tap(find.text('广角'));
+    await tester.pump(const Duration(milliseconds: 350));
 
-    expect(selected, 0.6);
+    expect(selected, 0.5);
   });
 
   testWidgets('tapping 0.6x reports 0.6 when camera only supports 0.6x', (
@@ -128,39 +131,101 @@ void main() {
       onZoomSelected: (ratio) => selected = ratio,
     );
 
-    await tester.tap(find.text('0.6x'));
-    await tester.pump();
+    await tester.tap(find.text('广角'));
+    await tester.pump(const Duration(milliseconds: 350));
 
     expect(selected, 0.6);
   });
 
-  testWidgets('disables 0.6x while recording on main camera', (tester) async {
-    await pumpHud(tester, minZoomRatio: 0.5, isRecording: true);
-
-    final ultraWideButton = tester.widget<TextButton>(
-      find.ancestor(of: find.text('0.6x'), matching: find.byType(TextButton)),
-    );
-    final mainButton = tester.widget<TextButton>(
-      find.ancestor(of: find.text('1x'), matching: find.byType(TextButton)),
-    );
-
-    expect(ultraWideButton.enabled, isFalse);
-    expect(mainButton.enabled, isFalse);
-  });
-
-  testWidgets('disables main zoom presets while recording on ultra-wide', (
+  testWidgets('allows 0.6x while recording on main camera after unlock', (
     tester,
   ) async {
-    await pumpHud(tester, zoomRatio: 0.5, minZoomRatio: 0.5, isRecording: true);
+    double? selected;
+    await pumpHud(
+      tester,
+      minZoomRatio: 0.6,
+      isRecording: true,
+      onZoomSelected: (ratio) => selected = ratio,
+    );
 
     final ultraWideButton = tester.widget<TextButton>(
-      find.ancestor(of: find.text('0.6x'), matching: find.byType(TextButton)),
+      find.ancestor(of: find.text('广角'), matching: find.byType(TextButton)),
+    );
+    final mainButton = tester.widget<TextButton>(
+      find.ancestor(of: find.text('1x'), matching: find.byType(TextButton)),
+    );
+
+    expect(ultraWideButton.enabled, isTrue);
+    expect(mainButton.enabled, isFalse);
+
+    await tester.tap(find.text('广角'));
+    await tester.pump(const Duration(milliseconds: 350));
+
+    expect(selected, 0.6);
+  });
+
+  testWidgets('allows 1x while recording on ultra-wide after unlock', (
+    tester,
+  ) async {
+    double? selected;
+    await pumpHud(
+      tester,
+      zoomRatio: 0.5,
+      minZoomRatio: 0.5,
+      isRecording: true,
+      onZoomSelected: (ratio) => selected = ratio,
+    );
+
+    final ultraWideButton = tester.widget<TextButton>(
+      find.ancestor(of: find.text('广角'), matching: find.byType(TextButton)),
     );
     final mainButton = tester.widget<TextButton>(
       find.ancestor(of: find.text('1x'), matching: find.byType(TextButton)),
     );
 
     expect(ultraWideButton.enabled, isFalse);
-    expect(mainButton.enabled, isFalse);
+    expect(mainButton.enabled, isTrue);
+
+    await tester.tap(find.text('1x'));
+    await tester.pump(const Duration(milliseconds: 350));
+
+    expect(selected, 1.0);
+  });
+
+  testWidgets('disables stop button while switching lens', (tester) async {
+    var stopped = false;
+    await pumpHud(
+      tester,
+      minZoomRatio: 0.6,
+      isRecording: true,
+      isSwitchingLens: true,
+      onStop: () async => stopped = true,
+    );
+
+    await tester.tap(find.byType(GestureDetector).last);
+    await tester.pump();
+
+    expect(stopped, isFalse);
+  });
+
+  testWidgets('disables zoom buttons while switching lens', (tester) async {
+    double? selected;
+    await pumpHud(
+      tester,
+      minZoomRatio: 0.6,
+      isRecording: true,
+      isSwitchingLens: true,
+      onZoomSelected: (ratio) => selected = ratio,
+    );
+
+    final ultraWideButton = tester.widget<TextButton>(
+      find.ancestor(of: find.text('广角'), matching: find.byType(TextButton)),
+    );
+
+    expect(ultraWideButton.enabled, isFalse);
+    await tester.tap(find.text('广角'));
+    await tester.pump(const Duration(milliseconds: 350));
+
+    expect(selected, isNull);
   });
 }