attempt to fix segment corruption w/ tfhd base data offset & tfdt injection, moof size updaes -- very messy code, WIP

Implements HLS-compatible fragmented MP4 recording on Android using
AndroidX Media3 FragmentedMp4Muxer, matching the iOS implementation.

Changes:
- Add FragmentedRecordingManager for fMP4 segment output
- Add ChunkedRecorderInterface to abstract recorder implementations
- Add onInitSegmentReady callback for init segment (init.mp4)
- Update onVideoChunkReady to include segment duration
- RecordingSession now uses FragmentedRecordingManager by default

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package/android/build.gradle

@@ -178,6 +178,10 @@ dependencies {
   implementation "com.facebook.react:react-android:+"
   implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3"
 
+  // Media3 muxer for fragmented MP4 (HLS-compatible) recording
+  implementation "androidx.media3:media3-muxer:1.5.0"
+  implementation "androidx.media3:media3-common:1.5.0"
+
   if (enableCodeScanner) {
     // User enabled code-scanner, so we bundle the 2.4 MB model in the app.
     implementation 'com.google.mlkit:barcode-scanning:17.2.0'

package/android/src/main/cpp/OpenGLRenderer.cpp

@@ -26,6 +26,7 @@ OpenGLRenderer::OpenGLRenderer(std::shared_ptr<OpenGLContext> context, ANativeWi
   _outputSurface = surface;
   _width = ANativeWindow_getWidth(surface);
   _height = ANativeWindow_getHeight(surface);
+  __android_log_print(ANDROID_LOG_INFO, TAG, "ROTATION_DEBUG OpenGLRenderer created with output surface dimensions: %dx%d", _width, _height);
 }
 
 OpenGLRenderer::~OpenGLRenderer() {

package/android/src/main/cpp/VideoPipeline.cpp

@@ -56,6 +56,11 @@ void VideoPipeline::setRecordingSessionOutputSurface(jobject surface) {
   _recordingSessionOutput = OpenGLRenderer::CreateWithWindowSurface(_context, window);
 }
 
+void VideoPipeline::setRecordingOrientation(int orientation) {
+  _recordingOrientation = orientation;
+  __android_log_print(ANDROID_LOG_INFO, TAG, "Recording orientation set to: %d", orientation);
+}
+
 int VideoPipeline::getInputTextureId() {
   if (_inputTexture == std::nullopt) {
     _inputTexture = _context->createTexture(OpenGLTexture::Type::ExternalOES, _width, _height);
@@ -78,8 +83,29 @@ void VideoPipeline::onFrame(jni::alias_ref<jni::JArrayFloat> transformMatrixPara
   OpenGLTexture& texture = _inputTexture.value();
 
   if (_recordingSessionOutput) {
-    __android_log_print(ANDROID_LOG_INFO, TAG, "Rendering to RecordingSession..");
+    __android_log_print(ANDROID_LOG_INFO, TAG, "Rendering to RecordingSession.. orientation=%d", _recordingOrientation);
-    _recordingSessionOutput->renderTextureToSurface(texture, transformMatrix);
+
+    // For recording, use a simple transform matrix instead of the display transform.
+    // The display transform includes rotations for preview which we don't want in recordings.
+    float recordingMatrix[16];
+
+    if (_recordingOrientation == 1) {
+      // LANDSCAPE_RIGHT (CW): Y-flip + 180° rotation = flip both X and Y
+      // This negates both X and Y, then translates by (1,1)
+      recordingMatrix[0] = -1.0f; recordingMatrix[1] =  0.0f; recordingMatrix[2] = 0.0f; recordingMatrix[3] = 0.0f;
+      recordingMatrix[4] =  0.0f; recordingMatrix[5] =  1.0f; recordingMatrix[6] = 0.0f; recordingMatrix[7] = 0.0f;
+      recordingMatrix[8] =  0.0f; recordingMatrix[9] =  0.0f; recordingMatrix[10] = 1.0f; recordingMatrix[11] = 0.0f;
+      recordingMatrix[12] = 1.0f; recordingMatrix[13] = 0.0f; recordingMatrix[14] = 0.0f; recordingMatrix[15] = 1.0f;
+    } else {
+      // LANDSCAPE_LEFT (CCW): Simple Y-flip
+      // OpenGL origin is bottom-left, video expects top-left
+      recordingMatrix[0] = 1.0f; recordingMatrix[1] =  0.0f; recordingMatrix[2] = 0.0f; recordingMatrix[3] = 0.0f;
+      recordingMatrix[4] = 0.0f; recordingMatrix[5] = -1.0f; recordingMatrix[6] = 0.0f; recordingMatrix[7] = 0.0f;
+      recordingMatrix[8] = 0.0f; recordingMatrix[9] =  0.0f; recordingMatrix[10] = 1.0f; recordingMatrix[11] = 0.0f;
+      recordingMatrix[12] = 0.0f; recordingMatrix[13] = 1.0f; recordingMatrix[14] = 0.0f; recordingMatrix[15] = 1.0f;
+    }
+
+    _recordingSessionOutput->renderTextureToSurface(texture, recordingMatrix);
   }
 }
 
@@ -88,6 +114,7 @@ void VideoPipeline::registerNatives() {
       makeNativeMethod("initHybrid", VideoPipeline::initHybrid),
       makeNativeMethod("setRecordingSessionOutputSurface", VideoPipeline::setRecordingSessionOutputSurface),
       makeNativeMethod("removeRecordingSessionOutputSurface", VideoPipeline::removeRecordingSessionOutputSurface),
+      makeNativeMethod("setRecordingOrientation", VideoPipeline::setRecordingOrientation),
       makeNativeMethod("getInputTextureId", VideoPipeline::getInputTextureId),
       makeNativeMethod("onBeforeFrame", VideoPipeline::onBeforeFrame),
       makeNativeMethod("onFrame", VideoPipeline::onFrame),

package/android/src/main/cpp/VideoPipeline.h

@@ -33,6 +33,7 @@ public:
   // <- MediaRecorder output
   void setRecordingSessionOutputSurface(jobject surface);
   void removeRecordingSessionOutputSurface();
+  void setRecordingOrientation(int orientation);
 
   // Frame callbacks
   void onBeforeFrame();
@@ -47,6 +48,7 @@ private:
   std::optional<OpenGLTexture> _inputTexture = std::nullopt;
   int _width = 0;
   int _height = 0;
+  int _recordingOrientation = 0; // 0=LANDSCAPE_LEFT, 1=LANDSCAPE_RIGHT
 
   // Output Contexts
   std::shared_ptr<OpenGLContext> _context = nullptr;

package/android/src/main/java/com/mrousavy/camera/CameraView+Events.kt

@@ -40,15 +40,26 @@ fun CameraView.invokeOnStopped() {
   this.sendEvent(event)
 }
 
-fun CameraView.invokeOnChunkReady(filepath: File, index: Int) {
+fun CameraView.invokeOnChunkReady(filepath: File, index: Int, durationUs: Long?) {
-  Log.e(CameraView.TAG, "invokeOnError(...):")
+  Log.i(CameraView.TAG, "invokeOnChunkReady(...): index=$index, filepath=$filepath, durationUs=$durationUs")
   val event = Arguments.createMap()
   event.putInt("index", index)
   event.putString("filepath", filepath.toString())
+  if (durationUs != null) {
+    event.putDouble("duration", durationUs / 1_000_000.0) // Convert microseconds to seconds
+  }
   val reactContext = context as ReactContext
   reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "onVideoChunkReady", event)
 }
 
+fun CameraView.invokeOnInitReady(filepath: File) {
+  Log.i(CameraView.TAG, "invokeOnInitReady(...): filepath=$filepath")
+  val event = Arguments.createMap()
+  event.putString("filepath", filepath.toString())
+  val reactContext = context as ReactContext
+  reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "onInitReady", event)
+}
+
 fun CameraView.invokeOnError(error: Throwable) {
   Log.e(CameraView.TAG, "invokeOnError(...):")
   error.printStackTrace()

package/android/src/main/java/com/mrousavy/camera/CameraView.kt

@@ -271,8 +271,12 @@ class CameraView(context: Context) :
     invokeOnStopped()
   }
 
-  override fun onVideoChunkReady(filepath: File, index: Int) {
+  override fun onVideoChunkReady(filepath: File, index: Int, durationUs: Long?) {
-    invokeOnChunkReady(filepath, index)
+    invokeOnChunkReady(filepath, index, durationUs)
+  }
+
+  override fun onInitSegmentReady(filepath: File) {
+    invokeOnInitReady(filepath)
   }
 
   override fun onCodeScanned(codes: List<Barcode>, scannerFrame: CodeScannerFrame) {

package/android/src/main/java/com/mrousavy/camera/CameraViewManager.kt

@@ -32,6 +32,7 @@ class CameraViewManager : ViewGroupManager<CameraView>() {
       .put("cameraError", MapBuilder.of("registrationName", "onError"))
       .put("cameraCodeScanned", MapBuilder.of("registrationName", "onCodeScanned"))
       .put("onVideoChunkReady", MapBuilder.of("registrationName", "onVideoChunkReady"))
+      .put("onInitReady", MapBuilder.of("registrationName", "onInitReady"))
       .build()?.toMutableMap()
 
   override fun getName(): String = TAG

package/android/src/main/java/com/mrousavy/camera/core/CameraSession.kt

@@ -409,7 +409,8 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
   private fun updateVideoOutputs() {
     val videoOutput = videoOutput ?: return
     Log.i(TAG, "Updating Video Outputs...")
-    videoOutput.videoPipeline.setRecordingSessionOutput(recording)
+    val orientation = recording?.cameraOrientation ?: Orientation.LANDSCAPE_LEFT
+    videoOutput.videoPipeline.setRecordingSessionOutput(recording, orientation)
   }
 
   suspend fun startRecording(
@@ -428,18 +429,16 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
 
       // Get actual device rotation from WindowManager since the React Native orientation hook
       // doesn't update when rotating between landscape-left and landscape-right on Android.
-      // Map device rotation to the correct orientationHint for video recording:
-      // - Counter-clockwise (ROTATION_90) → 270° hint
-      // - Clockwise (ROTATION_270) → 90° hint
       val windowManager = context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
       val deviceRotation = windowManager.defaultDisplay.rotation
       val recordingOrientation = when (deviceRotation) {
         Surface.ROTATION_0 -> Orientation.PORTRAIT
-        Surface.ROTATION_90 -> Orientation.LANDSCAPE_RIGHT
+        Surface.ROTATION_90 -> Orientation.LANDSCAPE_LEFT      // CCW rotation, top to left
         Surface.ROTATION_180 -> Orientation.PORTRAIT_UPSIDE_DOWN
-        Surface.ROTATION_270 -> Orientation.LANDSCAPE_LEFT
+        Surface.ROTATION_270 -> Orientation.LANDSCAPE_RIGHT    // CW rotation, top to right
         else -> Orientation.PORTRAIT
       }
+      Log.i(TAG, "ROTATION_DEBUG: deviceRotation=$deviceRotation, recordingOrientation=$recordingOrientation, options.orientation=${options.orientation}")
 
       val recording = RecordingSession(
         context,
@@ -448,7 +447,7 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
         enableAudio,
         fps,
         videoOutput.enableHdr,
-        orientation,
+        recordingOrientation,
         options,
         filePath,
         callback,
@@ -513,7 +512,8 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
     fun onInitialized()
     fun onStarted()
     fun onStopped()
-    fun onVideoChunkReady(filepath: File, index: Int)
+    fun onVideoChunkReady(filepath: File, index: Int, durationUs: Long?)
+    fun onInitSegmentReady(filepath: File)
     fun onCodeScanned(codes: List<Barcode>, scannerFrame: CodeScannerFrame)
   }
 }

package/android/src/main/java/com/mrousavy/camera/core/ChunkedRecorder.kt

@@ -14,7 +14,7 @@ import java.io.File
 import java.nio.ByteBuffer
 
 class ChunkedRecordingManager(private val encoder: MediaCodec, private val outputDirectory: File, private val orientationHint: Int, private val iFrameInterval: Int, private val callbacks: CameraSession.Callback) :
-  MediaCodec.Callback() {
+  MediaCodec.Callback(), ChunkedRecorderInterface {
   companion object {
     private const val TAG = "ChunkedRecorder"
 
@@ -73,7 +73,7 @@ class ChunkedRecordingManager(private val encoder: MediaCodec, private val outpu
 
   private val targetDurationUs = iFrameInterval * 1000000
 
-  val surface: Surface = encoder.createInputSurface()
+  override val surface: Surface = encoder.createInputSurface()
 
   init {
     if (!this.outputDirectory.exists()) {
@@ -95,7 +95,9 @@ class ChunkedRecordingManager(private val encoder: MediaCodec, private val outpu
     fun finish() {
       muxer.stop()
       muxer.release()
-      callbacks.onVideoChunkReady(filepath, chunkIndex)
+      // Calculate duration from start time - this is approximate
+      // The new FragmentedRecordingManager provides accurate duration
+      callbacks.onVideoChunkReady(filepath, chunkIndex, null)
     }
   }
 
@@ -133,12 +135,12 @@ class ChunkedRecordingManager(private val encoder: MediaCodec, private val outpu
     return bufferInfo.presentationTimeUs - context.startTimeUs
   }
 
-  fun start() {
+  override fun start() {
     encoder.start()
     recording = true
   }
 
-  fun finish() {
+  override fun finish() {
     synchronized(this) {
       muxerContext?.finish()
       recording = false

package/android/src/main/java/com/mrousavy/camera/core/ChunkedRecorderInterface.kt

@@ -0,0 +1,15 @@
+package com.mrousavy.camera.core
+
+import android.view.Surface
+
+/**
+ * Common interface for chunked video recorders.
+ * Implemented by both ChunkedRecordingManager (regular MP4) and
+ * FragmentedRecordingManager (HLS-compatible fMP4).
+ */
+interface ChunkedRecorderInterface {
+    val surface: Surface
+
+    fun start()
+    fun finish()
+}

package/android/src/main/java/com/mrousavy/camera/core/FragmentedRecordingManager.kt

@@ -0,0 +1,762 @@
+package com.mrousavy.camera.core
+
+import android.media.MediaCodec
+import android.media.MediaCodec.BufferInfo
+import android.media.MediaCodecInfo
+import android.media.MediaFormat
+import android.util.Log
+import android.util.Size
+import android.view.Surface
+import androidx.media3.common.Format
+import androidx.media3.common.MimeTypes
+import androidx.media3.common.util.UnstableApi
+import androidx.media3.muxer.FragmentedMp4Muxer
+import androidx.media3.muxer.Muxer
+import com.mrousavy.camera.types.Orientation
+import com.mrousavy.camera.types.RecordVideoOptions
+import java.io.File
+import java.io.FileOutputStream
+import java.io.RandomAccessFile
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+
+/**
+ * A recording manager that produces HLS-compatible fragmented MP4 segments.
+ *
+ * This produces output similar to the iOS implementation:
+ * - An initialization segment (init.mp4) containing codec configuration
+ * - Numbered data segments (0.mp4, 1.mp4, ...) containing media data
+ *
+ * Uses AndroidX Media3's FragmentedMp4Muxer which produces proper fMP4 output.
+ */
+@UnstableApi
+class FragmentedRecordingManager(
+    private val encoder: MediaCodec,
+    private val outputDirectory: File,
+    private val orientationDegrees: Int,
+    private val targetSegmentDurationUs: Long,
+    private val callbacks: CameraSession.Callback
+) : MediaCodec.Callback(), ChunkedRecorderInterface {
+
+    companion object {
+        private const val TAG = "FragmentedRecorder"
+
+        fun fromParams(
+            callbacks: CameraSession.Callback,
+            size: Size,
+            enableAudio: Boolean,
+            fps: Int? = null,
+            cameraOrientation: Orientation,
+            bitRate: Int,
+            options: RecordVideoOptions,
+            outputDirectory: File,
+            segmentDurationSeconds: Int = 6
+        ): FragmentedRecordingManager {
+            val mimeType = options.videoCodec.toMimeType()
+            // For fragmented MP4: DON'T swap dimensions, use camera's native dimensions.
+            // The C++ VideoPipeline uses a custom transform matrix (not the display transform).
+            // This gives us raw sensor frames, and we rely on rotation metadata for playback.
+            val cameraOrientationDegrees = when (cameraOrientation) {
+                Orientation.LANDSCAPE_LEFT -> 0    // CCW landscape
+                Orientation.LANDSCAPE_RIGHT -> 0   // CW landscape
+                Orientation.PORTRAIT -> 90
+                Orientation.PORTRAIT_UPSIDE_DOWN -> 270
+            }
+            Log.i(TAG, "ROTATION_DEBUG FragmentedRecordingManager: cameraOrientation=$cameraOrientation, cameraOrientationDegrees=$cameraOrientationDegrees, inputSize=${size.width}x${size.height}")
+
+            // Keep original dimensions - don't swap. Let rotation metadata handle orientation.
+            val width = size.width
+            val height = size.height
+            Log.i(TAG, "ROTATION_DEBUG FragmentedRecordingManager: outputDimensions=${width}x${height} (no swap)")
+
+            val format = MediaFormat.createVideoFormat(mimeType, width, height)
+            val codec = MediaCodec.createEncoderByType(mimeType)
+
+            format.setInteger(
+                MediaFormat.KEY_COLOR_FORMAT,
+                MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface
+            )
+            fps?.apply {
+                format.setInteger(MediaFormat.KEY_FRAME_RATE, this)
+            }
+            // I-frame interval affects segment boundaries
+            format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, segmentDurationSeconds)
+            format.setInteger(MediaFormat.KEY_BIT_RATE, bitRate)
+
+            Log.d(TAG, "Video Format: $format, orientationDegrees: $cameraOrientationDegrees")
+
+            codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE)
+
+            return FragmentedRecordingManager(
+                codec,
+                outputDirectory,
+                cameraOrientationDegrees,
+                segmentDurationSeconds * 1_000_000L,
+                callbacks
+            )
+        }
+    }
+
+    // State management
+    private var chunkIndex = 0
+    private var encodedFormat: MediaFormat? = null
+    private var recording = false
+
+    // Segment tracking
+    private var segmentContext: SegmentContext? = null
+    private var initSegmentEmitted = false
+
+    // Cumulative base time for HLS-compatible timestamps (in timescale units)
+    // Each segment's baseMediaDecodeTime should be the sum of all previous segment durations
+    private var cumulativeBaseTimeUs: Long = 0L
+
+    // Timescale used in the fMP4 (typically 1000000 for microseconds)
+    private val timescale: Long = 1_000_000L
+
+    override val surface: Surface = encoder.createInputSurface()
+
+    init {
+        if (!outputDirectory.exists()) {
+            outputDirectory.mkdirs()
+        }
+        encoder.setCallback(this)
+    }
+
+    /**
+     * Result from finishing a segment, used for tfdt patching.
+     */
+    private data class SegmentResult(
+        val file: File,
+        val segmentIndex: Int,
+        val durationUs: Long
+    )
+
+    /**
+     * Context for a single data segment being written.
+     * Init segments are created separately via createInitSegment().
+     */
+    private inner class SegmentContext(
+        private val format: MediaFormat,
+        val segmentIndex: Int,
+        private val baseTimeUs: Long  // The baseMediaDecodeTime for this segment
+    ) {
+        private val filename = "$segmentIndex.mp4"
+        val file = File(outputDirectory, filename)
+        private val outputStream = FileOutputStream(file)
+        private val muxer = FragmentedMp4Muxer.Builder(outputStream).build()
+        private lateinit var videoTrack: Muxer.TrackToken
+        private var startTimeUs: Long = -1L
+        private var lastTimeUs: Long = 0L
+        private var sampleCount = 0
+
+        init {
+            val media3Format = convertToMedia3Format(format)
+            videoTrack = muxer.addTrack(media3Format)
+            Log.d(TAG, "Created segment context: $filename with baseTimeUs=$baseTimeUs")
+        }
+
+        fun writeSample(buffer: ByteBuffer, bufferInfo: BufferInfo) {
+            if (startTimeUs < 0) {
+                startTimeUs = bufferInfo.presentationTimeUs
+                Log.i(TAG, "PTS_DEBUG Segment $segmentIndex FIRST sample: absolutePTS=${bufferInfo.presentationTimeUs}us, baseTimeUs=$baseTimeUs")
+            }
+
+            // Log first 3 samples and every keyframe for debugging
+            val isKeyFrame = (bufferInfo.flags and MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0
+            if (sampleCount < 3 || isKeyFrame) {
+                Log.i(TAG, "PTS_DEBUG Segment $segmentIndex sample $sampleCount: PTS=${bufferInfo.presentationTimeUs}us, keyframe=$isKeyFrame")
+            }
+
+            lastTimeUs = bufferInfo.presentationTimeUs
+
+            muxer.writeSampleData(videoTrack, buffer, bufferInfo)
+            sampleCount++
+        }
+
+        /**
+         * Check if we've accumulated enough duration to start a new segment.
+         * Should only be called when we have a keyframe available.
+         */
+        fun shouldStartNewSegmentOnKeyframe(): Boolean {
+            if (sampleCount == 0) return false // Need at least one sample first
+            val currentDurationUs = lastTimeUs - startTimeUs
+            return currentDurationUs >= targetSegmentDurationUs
+        }
+
+        fun finish(): SegmentResult {
+            try {
+                muxer.close()
+                outputStream.close()
+            } catch (e: Exception) {
+                Log.e(TAG, "Error closing segment", e)
+            }
+
+            val durationUs = if (lastTimeUs > startTimeUs) lastTimeUs - startTimeUs else 0L
+
+            Log.i(TAG, "PTS_DEBUG Segment $segmentIndex FINISHED: startPTS=${startTimeUs}us, lastPTS=${lastTimeUs}us, duration=${durationUs/1000}ms, samples=$sampleCount, baseTimeUs=$baseTimeUs")
+            return SegmentResult(file, segmentIndex, durationUs)
+        }
+    }
+
+    private fun createNewSegment() {
+        val format = encodedFormat
+        if (format == null) {
+            Log.e(TAG, "Cannot create segment: encodedFormat is null")
+            return
+        }
+
+        // Close previous segment and process it for HLS
+        segmentContext?.let { ctx ->
+            val result = ctx.finish()
+            // Process the segment: extract init (if first), strip headers, inject tfdt
+            processSegmentForHLS(result.file, result.segmentIndex, cumulativeBaseTimeUs)
+            // Update cumulative time for next segment
+            cumulativeBaseTimeUs += result.durationUs
+            // Notify callback
+            callbacks.onVideoChunkReady(result.file, result.segmentIndex, result.durationUs)
+        }
+
+        // Create new data segment with current cumulative base time
+        segmentContext = SegmentContext(format, chunkIndex, cumulativeBaseTimeUs)
+        chunkIndex++
+    }
+
+    override fun start() {
+        encoder.start()
+        recording = true
+    }
+
+    override fun finish() {
+        synchronized(this) {
+            recording = false
+            // Close final segment and process it for HLS
+            segmentContext?.let { ctx ->
+                val result = ctx.finish()
+                processSegmentForHLS(result.file, result.segmentIndex, cumulativeBaseTimeUs)
+                callbacks.onVideoChunkReady(result.file, result.segmentIndex, result.durationUs)
+            }
+            segmentContext = null
+            try {
+                encoder.stop()
+                encoder.release()
+            } catch (e: Exception) {
+                Log.e(TAG, "Error stopping encoder", e)
+            }
+        }
+    }
+
+    // MediaCodec.Callback methods
+    override fun onInputBufferAvailable(codec: MediaCodec, index: Int) {
+        // Not used for Surface input
+    }
+
+    override fun onOutputBufferAvailable(codec: MediaCodec, index: Int, bufferInfo: BufferInfo) {
+        synchronized(this) {
+            if (!recording) {
+                encoder.releaseOutputBuffer(index, false)
+                return
+            }
+
+            // Skip codec config buffers - these contain SPS/PPS with annex-b start codes
+            // and should NOT be written as samples (they're already in the Format's initializationData)
+            if ((bufferInfo.flags and MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
+                Log.d(TAG, "Skipping codec config buffer (size=${bufferInfo.size})")
+                encoder.releaseOutputBuffer(index, false)
+                return
+            }
+
+            val encodedData = encoder.getOutputBuffer(index)
+            if (encodedData == null) {
+                Log.e(TAG, "getOutputBuffer returned null")
+                encoder.releaseOutputBuffer(index, false)
+                return
+            }
+
+            // Create first data segment if needed
+            if (segmentContext == null) {
+                createNewSegment()
+            }
+
+            val context = segmentContext
+            if (context == null) {
+                encoder.releaseOutputBuffer(index, false)
+                return
+            }
+
+            try {
+                // Check if this keyframe should start a new segment BEFORE writing
+                val isKeyFrame = (bufferInfo.flags and MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0
+                val shouldStartNewSegment = isKeyFrame && context.shouldStartNewSegmentOnKeyframe()
+
+                if (shouldStartNewSegment) {
+                    // Finish old segment WITHOUT writing this keyframe to it
+                    createNewSegment()
+                    // Write keyframe to the NEW segment only
+                    segmentContext?.writeSample(encodedData, bufferInfo)
+                } else {
+                    // Write to current segment
+                    context.writeSample(encodedData, bufferInfo)
+                }
+            } catch (e: Exception) {
+                Log.e(TAG, "Error writing sample", e)
+            }
+
+            encoder.releaseOutputBuffer(index, false)
+        }
+    }
+
+    override fun onError(codec: MediaCodec, e: MediaCodec.CodecException) {
+        Log.e(TAG, "Codec error: ${e.message}")
+    }
+
+    override fun onOutputFormatChanged(codec: MediaCodec, format: MediaFormat) {
+        Log.i(TAG, "Output format changed: $format")
+        encodedFormat = format
+        // Note: init segment is now extracted from the first segment's ftyp+moov
+        // rather than created separately (Media3's empty init was not working)
+    }
+
+    private fun convertToMedia3Format(mediaFormat: MediaFormat): Format {
+        val mimeType = mediaFormat.getString(MediaFormat.KEY_MIME) ?: MimeTypes.VIDEO_H264
+        val width = mediaFormat.getInteger(MediaFormat.KEY_WIDTH)
+        val height = mediaFormat.getInteger(MediaFormat.KEY_HEIGHT)
+        val bitRate = try { mediaFormat.getInteger(MediaFormat.KEY_BIT_RATE) } catch (e: Exception) { -1 }
+        val frameRate = try { mediaFormat.getInteger(MediaFormat.KEY_FRAME_RATE) } catch (e: Exception) { -1 }
+
+        // Get CSD (Codec Specific Data) if available - required for init segment
+        // csd-0 contains SPS (Sequence Parameter Set)
+        // csd-1 contains PPS (Picture Parameter Set)
+        val csd0 = mediaFormat.getByteBuffer("csd-0")
+        val csd1 = mediaFormat.getByteBuffer("csd-1")
+
+        val initData = mutableListOf<ByteArray>()
+        csd0?.let {
+            val bytes = ByteArray(it.remaining())
+            it.duplicate().get(bytes)
+            initData.add(bytes)
+            Log.i(TAG, "CSD_DEBUG: csd-0 (SPS) size=${bytes.size} bytes, hex=${bytes.take(32).joinToString("") { "%02x".format(it) }}...")
+        }
+        csd1?.let {
+            val bytes = ByteArray(it.remaining())
+            it.duplicate().get(bytes)
+            initData.add(bytes)
+            Log.i(TAG, "CSD_DEBUG: csd-1 (PPS) size=${bytes.size} bytes, hex=${bytes.joinToString("") { "%02x".format(it) }}")
+        }
+
+        val totalCsdSize = initData.sumOf { it.size }
+        Log.i(TAG, "CSD_DEBUG: Total CSD size=$totalCsdSize bytes (csd-0=${csd0?.remaining() ?: 0}, csd-1=${csd1?.remaining() ?: 0})")
+
+        Log.i(TAG, "ROTATION_DEBUG convertToMedia3Format: orientationDegrees=$orientationDegrees, width=$width, height=$height")
+        return Format.Builder()
+            .setSampleMimeType(mimeType)
+            .setWidth(width)
+            .setHeight(height)
+            .setRotationDegrees(orientationDegrees)
+            .apply {
+                if (bitRate > 0) setAverageBitrate(bitRate)
+                if (frameRate > 0) setFrameRate(frameRate.toFloat())
+                if (initData.isNotEmpty()) setInitializationData(initData)
+            }
+            .build()
+    }
+
+    /**
+     * Processes a segment file for HLS compatibility:
+     * 1. For segment 0: extracts ftyp+moov header as init.mp4
+     * 2. Strips ftyp+moov from segment, keeping only moof+mdat (the fragment)
+     * 3. Injects tfdt box into moof for proper HLS timing
+     *
+     * Media3's FragmentedMp4Muxer creates self-contained MP4s, but HLS needs:
+     * - init.mp4: ftyp + moov (codec configuration)
+     * - segments: moof + mdat only (fragments referencing init)
+     */
+    private fun processSegmentForHLS(file: File, segmentIndex: Int, baseMediaDecodeTimeUs: Long) {
+        try {
+            val originalBytes = file.readBytes()
+            val buffer = ByteBuffer.wrap(originalBytes).order(ByteOrder.BIG_ENDIAN)
+
+            // Find where moof starts (everything before is header: ftyp + moov)
+            val moofStartPos = findMoofPosition(buffer)
+            if (moofStartPos < 0) {
+                Log.e(TAG, "HLS_PROCESS: Could not find moof in ${file.name}")
+                return
+            }
+
+            Log.i(TAG, "HLS_PROCESS: Segment $segmentIndex - moof starts at $moofStartPos, total size=${originalBytes.size}")
+
+            // For segment 0, extract header as init.mp4
+            if (segmentIndex == 0 && !initSegmentEmitted) {
+                val headerBytes = originalBytes.copyOfRange(0, moofStartPos)
+                val initFile = File(outputDirectory, "init.mp4")
+                initFile.writeBytes(headerBytes)
+                Log.i(TAG, "HLS_PROCESS: Created init.mp4 with ${headerBytes.size} bytes (ftyp+moov)")
+                // Debug: dump the init.mp4 structure
+                dumpMp4BoxStructure(headerBytes, "INIT_STRUCTURE")
+                callbacks.onInitSegmentReady(initFile)
+                initSegmentEmitted = true
+            }
+
+            // Extract fragment (moof + mdat only)
+            val fragmentBytes = originalBytes.copyOfRange(moofStartPos, originalBytes.size)
+            Log.d(TAG, "HLS_PROCESS: Extracted fragment of ${fragmentBytes.size} bytes")
+
+            // Inject tfdt into the fragment
+            // Note: in the fragment, moof is at position 0
+            val processedFragment = injectTfdtIntoFragment(fragmentBytes, baseMediaDecodeTimeUs)
+
+            // Write back the processed fragment (stripped of header)
+            file.writeBytes(processedFragment)
+
+            Log.i(TAG, "HLS_PROCESS: Segment $segmentIndex processed - header stripped, tfdt injected, final size=${processedFragment.size}")
+        } catch (e: Exception) {
+            Log.e(TAG, "Error processing segment ${file.name} for HLS", e)
+        }
+    }
+
+    /**
+     * Finds the position of the moof box in the file.
+     * Returns -1 if not found.
+     */
+    private fun findMoofPosition(buffer: ByteBuffer): Int {
+        var pos = 0
+        while (pos < buffer.limit() - 8) {
+            buffer.position(pos)
+            val size = buffer.int.toLong() and 0xFFFFFFFFL
+            val type = buffer.int
+
+            if (size < 8) break
+
+            // 'moof' = 0x6D6F6F66
+            if (type == 0x6D6F6F66) {
+                return pos
+            }
+
+            pos += size.toInt()
+        }
+        return -1
+    }
+
+    /**
+     * Injects a tfdt box into a fragment (moof+mdat).
+     * The fragment has moof at position 0 (header already stripped).
+     * Also fixes tfhd.base_data_offset since we stripped the original file header.
+     */
+    private fun injectTfdtIntoFragment(fragmentBytes: ByteArray, baseMediaDecodeTimeUs: Long): ByteArray {
+        val buffer = ByteBuffer.wrap(fragmentBytes).order(ByteOrder.BIG_ENDIAN)
+
+        // Find box positions within the fragment (moof is at position 0)
+        val positions = findBoxPositionsInFragment(buffer)
+        if (positions == null) {
+            Log.e(TAG, "TFDT_INJECT: Could not find required boxes in fragment")
+            return fragmentBytes
+        }
+
+        val (moofPos, moofSize, trafPos, trafSize, tfhdPos, tfhdEnd, trunPos) = positions
+        Log.d(TAG, "TFDT_INJECT: Fragment boxes - moof@$moofPos(size=$moofSize), traf@$trafPos, tfhd@$tfhdPos, trun@$trunPos")
+
+        // First, fix tfhd.base_data_offset - it was pointing to the original file position
+        // but now moof is at position 0, so base_data_offset should be 0
+        fixTfhdBaseDataOffset(buffer, tfhdPos.toInt())
+
+        // Create tfdt box (version 1, 64-bit baseMediaDecodeTime)
+        val tfdtSize = 20
+        val tfdtBytes = ByteBuffer.allocate(tfdtSize).order(ByteOrder.BIG_ENDIAN)
+        tfdtBytes.putInt(tfdtSize)                  // size
+        tfdtBytes.putInt(0x74666474)                // 'tfdt'
+        tfdtBytes.put(1.toByte())                   // version = 1
+        tfdtBytes.put(0.toByte())                   // flags[0]
+        tfdtBytes.put(0.toByte())                   // flags[1]
+        tfdtBytes.put(0.toByte())                   // flags[2]
+        tfdtBytes.putLong(baseMediaDecodeTimeUs)    // baseMediaDecodeTime
+
+        // Create new fragment with tfdt injected after tfhd
+        val newBytes = ByteArray(fragmentBytes.size + tfdtSize)
+        val insertPos = tfhdEnd.toInt()
+
+        // Copy bytes before insertion point
+        System.arraycopy(fragmentBytes, 0, newBytes, 0, insertPos)
+
+        // Insert tfdt
+        System.arraycopy(tfdtBytes.array(), 0, newBytes, insertPos, tfdtSize)
+
+        // Copy bytes after insertion point
+        System.arraycopy(fragmentBytes, insertPos, newBytes, insertPos + tfdtSize, fragmentBytes.size - insertPos)
+
+        // Update box sizes in the new buffer
+        val newBuffer = ByteBuffer.wrap(newBytes).order(ByteOrder.BIG_ENDIAN)
+
+        // Update moof size
+        val newMoofSize = moofSize + tfdtSize
+        newBuffer.putInt(moofPos.toInt(), newMoofSize.toInt())
+
+        // Update traf size
+        val newTrafSize = trafSize + tfdtSize
+        newBuffer.putInt(trafPos.toInt(), newTrafSize.toInt())
+
+        // Update trun data_offset if present
+        val newTrunPos = trunPos.toInt() + tfdtSize
+        updateTrunDataOffset(newBuffer, newTrunPos, tfdtSize)
+
+        Log.i(TAG, "TFDT_INJECT: Injected tfdt with baseMediaDecodeTime=$baseMediaDecodeTimeUs us")
+        return newBytes
+    }
+
+    /**
+     * Data class to hold box positions for tfdt injection.
+     */
+    private data class BoxPositions(
+        val moofPos: Long,
+        val moofSize: Long,
+        val trafPos: Long,
+        val trafSize: Long,
+        val tfhdPos: Long,  // Position of tfhd (need to fix base_data_offset)
+        val tfhdEnd: Long,  // Position right after tfhd where we'll insert tfdt
+        val trunPos: Long   // Position of trun (need to update its data_offset)
+    )
+
+    /**
+     * Finds the positions of moof, traf, tfhd, and trun boxes in a fragment.
+     * In a fragment, moof is expected to be at position 0.
+     */
+    private fun findBoxPositionsInFragment(buffer: ByteBuffer): BoxPositions? {
+        val fileSize = buffer.limit()
+        var pos = 0
+
+        while (pos < fileSize - 8) {
+            buffer.position(pos)
+            val size = buffer.int.toLong() and 0xFFFFFFFFL
+            val type = buffer.int
+
+            if (size < 8) break
+
+            // 'moof' = 0x6D6F6F66
+            if (type == 0x6D6F6F66) {
+                val moofPos = pos.toLong()
+                val moofSize = size
+                val moofEnd = pos + size.toInt()
+                var childPos = pos + 8
+
+                while (childPos < moofEnd - 8) {
+                    buffer.position(childPos)
+                    val childSize = buffer.int.toLong() and 0xFFFFFFFFL
+                    val childType = buffer.int
+
+                    if (childSize < 8) break
+
+                    // 'traf' = 0x74726166
+                    if (childType == 0x74726166) {
+                        val trafPos = childPos.toLong()
+                        val trafSize = childSize
+                        val trafEnd = childPos + childSize.toInt()
+                        var trafChildPos = childPos + 8
+
+                        var tfhdPos: Long = -1
+                        var tfhdEnd: Long = -1
+                        var trunPos: Long = -1
+
+                        while (trafChildPos < trafEnd - 8) {
+                            buffer.position(trafChildPos)
+                            val trafChildSize = buffer.int.toLong() and 0xFFFFFFFFL
+                            val trafChildType = buffer.int
+
+                            if (trafChildSize < 8) break
+
+                            // 'tfhd' = 0x74666864
+                            if (trafChildType == 0x74666864) {
+                                tfhdPos = trafChildPos.toLong()
+                                tfhdEnd = trafChildPos + trafChildSize
+                            }
+                            // 'trun' = 0x7472756E
+                            else if (trafChildType == 0x7472756E) {
+                                trunPos = trafChildPos.toLong()
+                            }
+
+                            trafChildPos += trafChildSize.toInt()
+                        }
+
+                        if (tfhdPos > 0 && tfhdEnd > 0 && trunPos > 0) {
+                            return BoxPositions(moofPos, moofSize, trafPos, trafSize, tfhdPos, tfhdEnd, trunPos)
+                        }
+                    }
+
+                    childPos += childSize.toInt()
+                }
+            }
+
+            pos += size.toInt()
+        }
+
+        return null
+    }
+
+    /**
+     * Updates the trun box's data_offset field if present.
+     * The data_offset points to sample data in mdat, and needs to be
+     * increased by the size of the injected tfdt box.
+     *
+     * trun structure:
+     * - 4 bytes: size
+     * - 4 bytes: type ('trun')
+     * - 1 byte: version
+     * - 3 bytes: flags
+     * - 4 bytes: sample_count
+     * - [optional] 4 bytes: data_offset (if flags & 0x000001)
+     */
+    private fun updateTrunDataOffset(buffer: ByteBuffer, trunPos: Int, offsetDelta: Int) {
+        buffer.position(trunPos + 8) // Skip size and type
+        val version = buffer.get().toInt() and 0xFF
+        val flags = ((buffer.get().toInt() and 0xFF) shl 16) or
+                    ((buffer.get().toInt() and 0xFF) shl 8) or
+                    (buffer.get().toInt() and 0xFF)
+
+        // Check if data_offset_present flag (0x000001) is set
+        if ((flags and 0x000001) != 0) {
+            val sampleCount = buffer.int
+            val dataOffsetPos = trunPos + 16 // size(4) + type(4) + version(1) + flags(3) + sample_count(4)
+            buffer.position(dataOffsetPos)
+            val originalOffset = buffer.int
+            val newOffset = originalOffset + offsetDelta
+            buffer.putInt(dataOffsetPos, newOffset)
+            Log.d(TAG, "TFDT_INJECT: Updated trun data_offset: $originalOffset -> $newOffset")
+        } else {
+            Log.d(TAG, "TFDT_INJECT: trun has no data_offset field (flags=0x${flags.toString(16)})")
+        }
+    }
+
+    /**
+     * Fixes the tfhd box's base_data_offset field after stripping the file header.
+     * When we strip ftyp+moov from the original segment, the base_data_offset
+     * (which pointed to a position in the original file) becomes incorrect.
+     * We set it to 0 since moof is now at the start of the fragment.
+     *
+     * tfhd structure:
+     * - 4 bytes: size
+     * - 4 bytes: type ('tfhd')
+     * - 1 byte: version
+     * - 3 bytes: flags
+     * - 4 bytes: track_id
+     * - [optional] 8 bytes: base_data_offset (if flags & 0x000001)
+     */
+    private fun fixTfhdBaseDataOffset(buffer: ByteBuffer, tfhdPos: Int) {
+        buffer.position(tfhdPos + 8) // Skip size and type
+        val version = buffer.get().toInt() and 0xFF
+        val flags = ((buffer.get().toInt() and 0xFF) shl 16) or
+                    ((buffer.get().toInt() and 0xFF) shl 8) or
+                    (buffer.get().toInt() and 0xFF)
+
+        // Check if base_data_offset_present flag (0x000001) is set
+        if ((flags and 0x000001) != 0) {
+            val trackId = buffer.int
+            val baseDataOffsetPos = tfhdPos + 16 // size(4) + type(4) + version(1) + flags(3) + track_id(4)
+            buffer.position(baseDataOffsetPos)
+            val originalOffset = buffer.long
+            // Set to 0 since moof is now at start of fragment
+            buffer.putLong(baseDataOffsetPos, 0L)
+            Log.i(TAG, "TFHD_FIX: Fixed base_data_offset: $originalOffset -> 0")
+        } else {
+            Log.d(TAG, "TFHD_FIX: tfhd has no base_data_offset field (flags=0x${flags.toString(16)})")
+        }
+    }
+
+    /**
+     * Debug function to dump MP4 box structure and find avcC/stsd info.
+     */
+    private fun dumpMp4BoxStructure(data: ByteArray, logPrefix: String) {
+        val buffer = ByteBuffer.wrap(data).order(ByteOrder.BIG_ENDIAN)
+        dumpBoxesRecursive(buffer, 0, data.size, 0, logPrefix)
+    }
+
+    private fun dumpBoxesRecursive(buffer: ByteBuffer, start: Int, end: Int, depth: Int, logPrefix: String) {
+        var pos = start
+        val indent = "  ".repeat(depth)
+
+        while (pos < end - 8) {
+            buffer.position(pos)
+            val size = buffer.int.toLong() and 0xFFFFFFFFL
+            val typeInt = buffer.int
+            val typeBytes = ByteArray(4)
+            typeBytes[0] = ((typeInt shr 24) and 0xFF).toByte()
+            typeBytes[1] = ((typeInt shr 16) and 0xFF).toByte()
+            typeBytes[2] = ((typeInt shr 8) and 0xFF).toByte()
+            typeBytes[3] = (typeInt and 0xFF).toByte()
+            val typeStr = String(typeBytes, Charsets.US_ASCII)
+
+            if (size < 8 || pos + size > end) break
+
+            Log.i(TAG, "$logPrefix: $indent[$typeStr] size=$size @ $pos")
+
+            // For ftyp, dump the brands
+            if (typeStr == "ftyp" && size >= 16) {
+                buffer.position(pos + 8)
+                val majorBrand = ByteArray(4)
+                buffer.get(majorBrand)
+                val minorVersion = buffer.int
+                Log.i(TAG, "$logPrefix: $indent  major_brand=${String(majorBrand)}, minor_version=$minorVersion")
+
+                val compatBrandsStart = pos + 16
+                val compatBrandsEnd = pos + size.toInt()
+                val brands = mutableListOf<String>()
+                var brandPos = compatBrandsStart
+                while (brandPos + 4 <= compatBrandsEnd) {
+                    buffer.position(brandPos)
+                    val brand = ByteArray(4)
+                    buffer.get(brand)
+                    brands.add(String(brand))
+                    brandPos += 4
+                }
+                Log.i(TAG, "$logPrefix: $indent  compatible_brands=${brands.joinToString(",")}")
+            }
+
+            // For avcC, dump the SPS/PPS info
+            if (typeStr == "avcC" && size >= 13) {
+                buffer.position(pos + 8)
+                val configVersion = buffer.get().toInt() and 0xFF
+                val profileIdc = buffer.get().toInt() and 0xFF
+                val profileCompat = buffer.get().toInt() and 0xFF
+                val levelIdc = buffer.get().toInt() and 0xFF
+                val lengthSizeMinusOne = buffer.get().toInt() and 0x03
+                val numSps = buffer.get().toInt() and 0x1F
+
+                Log.i(TAG, "$logPrefix: $indent  avcC: version=$configVersion, profile=$profileIdc, level=$levelIdc, numSPS=$numSps")
+
+                // Read SPS lengths
+                var spsTotal = 0
+                for (i in 0 until numSps) {
+                    val spsLen = buffer.short.toInt() and 0xFFFF
+                    spsTotal += spsLen
+                    Log.i(TAG, "$logPrefix: $indent  SPS[$i] length=$spsLen")
+                    buffer.position(buffer.position() + spsLen)  // Skip SPS data
+                }
+
+                // Read PPS count and lengths
+                if (buffer.position() < pos + size) {
+                    val numPps = buffer.get().toInt() and 0xFF
+                    var ppsTotal = 0
+                    for (i in 0 until numPps) {
+                        if (buffer.position() + 2 <= pos + size) {
+                            val ppsLen = buffer.short.toInt() and 0xFFFF
+                            ppsTotal += ppsLen
+                            Log.i(TAG, "$logPrefix: $indent  PPS[$i] length=$ppsLen")
+                            buffer.position(buffer.position() + ppsLen)  // Skip PPS data
+                        }
+                    }
+                    Log.i(TAG, "$logPrefix: $indent  avcC total: ${size} bytes, SPS=$spsTotal bytes, PPS=$ppsTotal bytes")
+                }
+            }
+
+            // Recurse into container boxes
+            val containerBoxes = setOf("moov", "trak", "mdia", "minf", "stbl", "stsd", "mvex", "edts")
+            if (typeStr in containerBoxes) {
+                // stsd has 8 extra bytes (version/flags + entry_count) before children
+                val childStart = if (typeStr == "stsd") pos + 16 else pos + 8
+                dumpBoxesRecursive(buffer, childStart, pos + size.toInt(), depth + 1, logPrefix)
+            }
+            // avc1 is a sample entry, structure: 8 byte header + 78 byte fixed fields + child boxes
+            if (typeStr == "avc1") {
+                dumpBoxesRecursive(buffer, pos + 86, pos + size.toInt(), depth + 1, logPrefix)
+            }
+
+            pos += size.toInt()
+        }
+    }
+}

package/android/src/main/java/com/mrousavy/camera/core/RecordingSession.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.util.Log
 import android.util.Size
 import android.view.Surface
+import androidx.media3.common.util.UnstableApi
 import com.facebook.common.statfs.StatFsHelper
 import com.mrousavy.camera.extensions.getRecommendedBitRate
 import com.mrousavy.camera.types.Orientation
@@ -14,6 +15,8 @@ import android.os.Environment
 import java.text.SimpleDateFormat
 import java.util.Locale
 import java.util.Date
+
+@UnstableApi
 class RecordingSession(
   context: Context,
   val cameraId: String,
@@ -21,12 +24,14 @@ class RecordingSession(
   private val enableAudio: Boolean,
   private val fps: Int? = null,
   private val hdr: Boolean = false,
-  private val cameraOrientation: Orientation,
+  val cameraOrientation: Orientation,
   private val options: RecordVideoOptions,
   private val filePath: String,
   private val callback: (video: Video) -> Unit,
   private val onError: (error: CameraError) -> Unit,
   private val allCallbacks: CameraSession.Callback,
+  // Use the new FragmentedMp4Muxer-based recorder for HLS-compatible output
+  private val useFragmentedMp4: Boolean = true
 ) {
   companion object {
     private const val TAG = "RecordingSession"
@@ -34,6 +39,9 @@ class RecordingSession(
     private const val AUDIO_SAMPLING_RATE = 44_100
     private const val AUDIO_BIT_RATE = 16 * AUDIO_SAMPLING_RATE
     private const val AUDIO_CHANNELS = 1
+
+    // Segment duration in seconds (matching iOS default of 6 seconds)
+    private const val SEGMENT_DURATION_SECONDS = 6
   }
 
   data class Video(val path: String, val durationMs: Long, val size: Size)
@@ -41,16 +49,33 @@ class RecordingSession(
   private val outputPath: File = File(filePath)
 
   private val bitRate = getBitRate()
-  private val recorder = ChunkedRecordingManager.fromParams(
+
-    allCallbacks,
+  // Use FragmentedRecordingManager for HLS-compatible fMP4 output,
-    size,
+  // or fall back to ChunkedRecordingManager for regular MP4 chunks
-    enableAudio,
+  private val recorder: ChunkedRecorderInterface = if (useFragmentedMp4) {
-    fps,
+    FragmentedRecordingManager.fromParams(
-    cameraOrientation,
+      allCallbacks,
-    bitRate,
+      size,
-    options,
+      enableAudio,
-    outputPath
+      fps,
-  )
+      cameraOrientation,
+      bitRate,
+      options,
+      outputPath,
+      SEGMENT_DURATION_SECONDS
+    )
+  } else {
+    ChunkedRecordingManager.fromParams(
+      allCallbacks,
+      size,
+      enableAudio,
+      fps,
+      cameraOrientation,
+      bitRate,
+      options,
+      outputPath
+    )
+  }
   private var startTime: Long? = null
   val surface: Surface
     get() {

package/android/src/main/java/com/mrousavy/camera/core/VideoPipeline.kt

@@ -162,6 +162,14 @@ class VideoPipeline(
       // 4. Get the transform matrix from the SurfaceTexture (rotations/scales applied by Camera)
       surfaceTexture.getTransformMatrix(transformMatrix)
 
+      // Log transform matrix for debugging rotation issues (only when recording)
+      if (recordingSession != null) {
+        Log.i(TAG, "ROTATION_DEBUG TransformMatrix: [${transformMatrix[0]}, ${transformMatrix[1]}, ${transformMatrix[2]}, ${transformMatrix[3]}], " +
+                   "[${transformMatrix[4]}, ${transformMatrix[5]}, ${transformMatrix[6]}, ${transformMatrix[7]}], " +
+                   "[${transformMatrix[8]}, ${transformMatrix[9]}, ${transformMatrix[10]}, ${transformMatrix[11]}], " +
+                   "[${transformMatrix[12]}, ${transformMatrix[13]}, ${transformMatrix[14]}, ${transformMatrix[15]}]")
+      }
+
       // 5. Draw it with applied rotation/mirroring
       onFrame(transformMatrix)
 
@@ -181,11 +189,15 @@ class VideoPipeline(
   /**
    * Configures the Pipeline to also write Frames to a Surface from a `MediaRecorder` (or null)
    */
-  fun setRecordingSessionOutput(recordingSession: RecordingSession?) {
+  fun setRecordingSessionOutput(recordingSession: RecordingSession?, orientation: Orientation = Orientation.LANDSCAPE_LEFT) {
     synchronized(this) {
       if (recordingSession != null) {
         // Configure OpenGL pipeline to stream Frames into the Recording Session's surface
-        Log.i(TAG, "Setting ${recordingSession.size} RecordingSession Output...")
+        Log.i(TAG, "Setting ${recordingSession.size} RecordingSession Output with orientation=$orientation...")
+        // Set the recording orientation for the native layer
+        // 0 = LANDSCAPE_LEFT (CCW), 1 = LANDSCAPE_RIGHT (CW)
+        val orientationValue = if (orientation == Orientation.LANDSCAPE_RIGHT) 1 else 0
+        setRecordingOrientation(orientationValue)
         setRecordingSessionOutputSurface(recordingSession.surface)
         this.recordingSession = recordingSession
       } else {
@@ -252,5 +264,6 @@ class VideoPipeline(
   private external fun onFrame(transformMatrix: FloatArray)
   private external fun setRecordingSessionOutputSurface(surface: Any)
   private external fun removeRecordingSessionOutputSurface()
+  private external fun setRecordingOrientation(orientation: Int)
   private external fun initHybrid(width: Int, height: Int): HybridData
 }

package/ios/Core/ChunkedRecorder.swift

@@ -56,32 +56,28 @@ extension ChunkedRecorder: AVAssetWriterDelegate {
 
   private func saveInitSegment(_ data: Data) {
     let url = outputURL.appendingPathComponent("init.mp4")
-    if save(data: data, url: url) {
+    save(data: data, url: url)
-      onChunkReady(url: url, type: .initialization)
+    onChunkReady(url: url, type: .initialization)
-    }
   }
 
   private func saveSegment(_ data: Data, report: AVAssetSegmentReport?) {
     let name = "\(chunkIndex).mp4"
     let url = outputURL.appendingPathComponent(name)
-    if save(data: data, url: url) {
+    save(data: data, url: url)
-      let duration = report?
+    let duration = report?
-        .trackReports
+      .trackReports
-        .filter { $0.mediaType == .video }
+      .filter { $0.mediaType == .video }
-        .first?
+      .first?
-        .duration
+      .duration
-      onChunkReady(url: url, type: .data(index: chunkIndex, duration: duration))
+    onChunkReady(url: url, type: .data(index: chunkIndex, duration: duration))
-      chunkIndex += 1
+    chunkIndex += 1
-    }
   }
 
-  private func save(data: Data, url: URL) -> Bool {
+  private func save(data: Data, url: URL) {
     do {
       try data.write(to: url)
-      return true
     } catch {
       ReactLogger.log(level: .error, message: "Unable to write \(url): \(error.localizedDescription)")
-      return false
     }
   }