rotate frag recording output instead of relying on muxer metadata

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

@@ -17,15 +17,18 @@
 
 namespace vision {
 
-std::unique_ptr<OpenGLRenderer> OpenGLRenderer::CreateWithWindowSurface(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface) {
-  return std::unique_ptr<OpenGLRenderer>(new OpenGLRenderer(std::move(context), surface));
+std::unique_ptr<OpenGLRenderer> OpenGLRenderer::CreateWithWindowSurface(std::shared_ptr<OpenGLContext> context,
+                                                                        ANativeWindow* surface,
+                                                                        int rotationDegrees) {
+  return std::unique_ptr<OpenGLRenderer>(new OpenGLRenderer(std::move(context), surface, rotationDegrees));
 }
 
-OpenGLRenderer::OpenGLRenderer(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface) {
+OpenGLRenderer::OpenGLRenderer(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface, int rotationDegrees) {
   _context = std::move(context);
   _outputSurface = surface;
   _width = ANativeWindow_getWidth(surface);
   _height = ANativeWindow_getHeight(surface);
+  _rotationDegrees = rotationDegrees;
 }
 
 OpenGLRenderer::~OpenGLRenderer() {
@@ -66,7 +69,7 @@ void OpenGLRenderer::renderTextureToSurface(const OpenGLTexture& texture, float*
   glTexParameteri(texture.target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
   // 4. Draw it using the pass-through shader which also applies transforms
-  _passThroughShader.draw(texture, transformMatrix);
+  _passThroughShader.draw(texture, transformMatrix, _rotationDegrees);
 
   // 5. Swap buffers to pass it to the window surface
   eglSwapBuffers(_context->display, _surface);

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

@@ -24,7 +24,7 @@ public:
    * Note: The `surface` is considered moved, and the OpenGL context will release it when it is
    * being deleted.
    */
-  static std::unique_ptr<OpenGLRenderer> CreateWithWindowSurface(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface);
+  static std::unique_ptr<OpenGLRenderer> CreateWithWindowSurface(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface, int rotationDegrees);
   /**
    * Destroy the OpenGL Context. This needs to be called on the same thread that `use()` was called.
    */
@@ -43,10 +43,11 @@ public:
   void destroy();
 
 private:
-  explicit OpenGLRenderer(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface);
+  explicit OpenGLRenderer(std::shared_ptr<OpenGLContext> context, ANativeWindow* surface, int rotationDegrees);
 
 private:
   int _width = 0, _height = 0;
+  int _rotationDegrees = 0;
   std::shared_ptr<OpenGLContext> _context;
   ANativeWindow* _outputSurface;
   EGLSurface _surface = EGL_NO_SURFACE;

package/android/src/main/cpp/PassThroughShader.cpp

@@ -7,11 +7,76 @@
 #include <EGL/egl.h>
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
+#include <cmath>
 #include <memory>
 #include <string>
 
 namespace vision {
 
+namespace {
+
+void setIdentity(float* matrix) {
+  for (int i = 0; i < 16; i++) {
+    matrix[i] = 0.0f;
+  }
+  matrix[0] = 1.0f;
+  matrix[5] = 1.0f;
+  matrix[10] = 1.0f;
+  matrix[15] = 1.0f;
+}
+
+void multiply4x4(const float* left, const float* right, float* out) {
+  for (int column = 0; column < 4; column++) {
+    for (int row = 0; row < 4; row++) {
+      float sum = 0.0f;
+      for (int k = 0; k < 4; k++) {
+        sum += left[k * 4 + row] * right[column * 4 + k];
+      }
+      out[column * 4 + row] = sum;
+    }
+  }
+}
+
+void makeTranslation(float tx, float ty, float* matrix) {
+  setIdentity(matrix);
+  matrix[12] = tx;
+  matrix[13] = ty;
+}
+
+void makeRotation(float degrees, float* matrix) {
+  setIdentity(matrix);
+  const float radians = degrees * static_cast<float>(M_PI) / 180.0f;
+  const float cosine = std::cos(radians);
+  const float sine = std::sin(radians);
+
+  matrix[0] = cosine;
+  matrix[1] = sine;
+  matrix[4] = -sine;
+  matrix[5] = cosine;
+}
+
+void makeCenteredRotation(int rotationDegrees, float* matrix) {
+  const int normalized = ((rotationDegrees % 360) + 360) % 360;
+  if (normalized == 0) {
+    setIdentity(matrix);
+    return;
+  }
+
+  float translateToOrigin[16];
+  float rotation[16];
+  float translateBack[16];
+  float temp[16];
+
+  makeTranslation(-0.5f, -0.5f, translateToOrigin);
+  makeRotation(static_cast<float>(normalized), rotation);
+  makeTranslation(0.5f, 0.5f, translateBack);
+
+  multiply4x4(rotation, translateToOrigin, temp);
+  multiply4x4(translateBack, temp, matrix);
+}
+
+} // namespace
+
 PassThroughShader::~PassThroughShader() {
   if (_programId != NO_SHADER) {
     glDeleteProgram(_programId);
@@ -24,7 +89,7 @@ PassThroughShader::~PassThroughShader() {
   }
 }
 
-void PassThroughShader::draw(const OpenGLTexture& texture, float* transformMatrix) {
+void PassThroughShader::draw(const OpenGLTexture& texture, float* transformMatrix, int rotationDegrees) {
   // 1. Set up Shader Program
   if (_programId == NO_SHADER) {
     _programId = createProgram();
@@ -57,7 +122,12 @@ void PassThroughShader::draw(const OpenGLTexture& texture, float* transformMatri
   glVertexAttribPointer(_vertexParameters.aTexCoord, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
                         reinterpret_cast<void*>(offsetof(Vertex, texCoord)));
 
-  glUniformMatrix4fv(_vertexParameters.uTransformMatrix, 1, GL_FALSE, transformMatrix);
+  float outputRotationMatrix[16];
+  float combinedTransformMatrix[16];
+  makeCenteredRotation(rotationDegrees, outputRotationMatrix);
+  multiply4x4(transformMatrix, outputRotationMatrix, combinedTransformMatrix);
+
+  glUniformMatrix4fv(_vertexParameters.uTransformMatrix, 1, GL_FALSE, combinedTransformMatrix);
 
   // 4. Pass texture to fragment shader
   glActiveTexture(GL_TEXTURE0);

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

@@ -29,7 +29,7 @@ public:
    * Draw the texture using this shader.
    * Note: At the moment, only EXTERNAL textures are supported by the Shader.
    */
-  void draw(const OpenGLTexture& texture, float* transformMatrix);
+  void draw(const OpenGLTexture& texture, float* transformMatrix, int rotationDegrees);
 
 private:
   // Loading

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

@@ -47,13 +47,13 @@ void VideoPipeline::removeRecordingSessionOutputSurface() {
   _recordingSessionOutput = nullptr;
 }
 
-void VideoPipeline::setRecordingSessionOutputSurface(jobject surface) {
+void VideoPipeline::setRecordingSessionOutputSurface(jobject surface, int rotationDegrees) {
   // 1. Delete existing output surface
   removeRecordingSessionOutputSurface();
 
   // 2. Set new output surface if it is not null
   ANativeWindow* window = ANativeWindow_fromSurface(jni::Environment::current(), surface);
-  _recordingSessionOutput = OpenGLRenderer::CreateWithWindowSurface(_context, window);
+  _recordingSessionOutput = OpenGLRenderer::CreateWithWindowSurface(_context, window, rotationDegrees);
 }
 
 int VideoPipeline::getInputTextureId() {
@@ -78,7 +78,6 @@ 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..");
     _recordingSessionOutput->renderTextureToSurface(texture, transformMatrix);
   }
 }

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

@@ -31,7 +31,7 @@ public:
   int getInputTextureId();
 
   // <- MediaRecorder output
-  void setRecordingSessionOutputSurface(jobject surface);
+  void setRecordingSessionOutputSurface(jobject surface, int rotationDegrees);
   void removeRecordingSessionOutputSurface();
 
   // Frame callbacks

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

@@ -39,18 +39,11 @@ class FragmentedRecordingManager(
             segmentDurationSeconds: Int = DEFAULT_SEGMENT_DURATION_SECONDS
         ): FragmentedRecordingManager {
             val mimeType = options.videoCodec.toMimeType()
-            // Use cameraOrientation (from WindowManager) for rotation metadata
-            // The options.orientation from JavaScript is unreliable on Android when rotating between landscape modes
-            val orientationDegrees = cameraOrientation.toDegrees()
+            val cameraOrientationDegrees = cameraOrientation.toDegrees()
+            val orientationDegrees = 0
+            val (width, height) = size.width to size.height
 
-            // Swap dimensions based on camera orientation, same as ChunkedRecordingManager
-            val (width, height) = if (cameraOrientation.isLandscape()) {
-                size.height to size.width
-            } else {
-                size.width to size.height
-            }
-
-            Log.d(TAG, "Recording: ${width}x${height}, orientation=$orientationDegrees°")
+            Log.d(TAG, "Recording: ${width}x${height}, orientation=$orientationDegrees° (cameraOrientation=$cameraOrientationDegrees°)")
 
             val format = MediaFormat.createVideoFormat(mimeType, width, height)
             val codec = MediaCodec.createEncoderByType(mimeType)

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

@@ -43,6 +43,17 @@ class RecordingSession(
 
   data class Video(val path: String, val durationMs: Long, val size: Size)
 
+  val outputRotationDegrees: Int =
+    if (options.streamSegmentType == StreamSegmentType.FRAGMENTED_MP4) {
+      when (cameraOrientation.toDegrees()) {
+        90 -> 270
+        270 -> 90
+        else -> cameraOrientation.toDegrees()
+      }
+    } else {
+      0
+    }
+
   // Normalize path - expo-file-system passes file:// URIs but File expects raw paths
   // Handle both file:// and file:/ variants
   private val outputPath: File = File(filePath.replace(Regex("^file:/+"), "/"))

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

@@ -186,7 +186,7 @@ class VideoPipeline(
       if (recordingSession != null) {
         // Configure OpenGL pipeline to stream Frames into the Recording Session's surface
         Log.i(TAG, "Setting ${recordingSession.size} RecordingSession Output...")
-        setRecordingSessionOutputSurface(recordingSession.surface)
+        setRecordingSessionOutputSurface(recordingSession.surface, recordingSession.outputRotationDegrees)
         this.recordingSession = recordingSession
       } else {
         // Configure OpenGL pipeline to stop streaming Frames into the Recording Session's surface
@@ -250,7 +250,7 @@ class VideoPipeline(
   private external fun getInputTextureId(): Int
   private external fun onBeforeFrame()
   private external fun onFrame(transformMatrix: FloatArray)
-  private external fun setRecordingSessionOutputSurface(surface: Any)
+  private external fun setRecordingSessionOutputSurface(surface: Any, rotationDegrees: Int)
   private external fun removeRecordingSessionOutputSurface()
   private external fun initHybrid(width: Int, height: Int): HybridData
 }