perf: Remove FrameProcessorPlugin HybridClass (#467)

* Rename `JImageProxyHostObject` -> `FrameHostObject`

* `FrameProcessorPlugin` -> `JFrameProcessorPlugin` 1/2

* `FrameProcessorPlugin` -> `JFrameProcessorPlugin` 2/2

* Make `const`

* Make `getName()` instance based

* Update JFrameProcessorPlugin.h

* Update JImageProxy.h

* `T`

* T

* Remove default ctor

* Use `TSelf` again

* Return `local_ref<CameraView*>` instead of `CameraView*`

* Make `findCameraViewById` return a raw pointer again...

* Extract `setFrameProcessor` and `unsetFrameProcessor`

* Use `global_ref`

* Use `static_cast` for `FrameHostObject`

* Update FrameProcessorRuntimeManager.cpp

* Fix reference lint error

* linelength

* Fix `unsetFrameProcessor` call

android/CMakeLists.txt

@@ -15,12 +15,12 @@ add_library(
         SHARED
         src/main/cpp/VisionCamera.cpp
         src/main/cpp/JSIJNIConversion.cpp
+        src/main/cpp/FrameHostObject.cpp
         src/main/cpp/FrameProcessorRuntimeManager.cpp
-        src/main/cpp/FrameProcessorPlugin.cpp
         src/main/cpp/CameraView.cpp
         src/main/cpp/VisionCameraScheduler.cpp
+        src/main/cpp/java-bindings/JFrameProcessorPlugin.cpp
         src/main/cpp/java-bindings/JImageProxy.cpp
-        src/main/cpp/java-bindings/JImageProxyHostObject.cpp
         src/main/cpp/java-bindings/JHashMap.cpp
 )
 

android/src/main/cpp/CameraView.cpp

@@ -15,7 +15,7 @@ namespace vision {
 using namespace facebook;
 using namespace jni;
 
-using TSelf = local_ref<HybridClass<vision::CameraView>::jhybriddata>;
+using TSelf = local_ref<CameraView::jhybriddata>;
 
 TSelf CameraView::initHybrid(alias_ref<HybridClass::jhybridobject> jThis) {
     return makeCxxInstance(jThis);
@@ -42,7 +42,7 @@ void CameraView::frameProcessorCallback(const alias_ref<JImageProxy::javaobject>
   }
 }
 
-void CameraView::setFrameProcessor(const FrameProcessor&& frameProcessor) {
+void CameraView::setFrameProcessor(const TFrameProcessor&& frameProcessor) {
   frameProcessor_ = frameProcessor;
 }
 

android/src/main/cpp/CameraView.h

@@ -14,7 +14,7 @@
 namespace vision {
 
 using namespace facebook;
-using FrameProcessor = std::function<void(jni::alias_ref<JImageProxy::javaobject>)>;
+using TFrameProcessor = std::function<void(jni::alias_ref<JImageProxy::javaobject>)>;
 
 class CameraView : public jni::HybridClass<CameraView> {
  public:
@@ -24,13 +24,13 @@ class CameraView : public jni::HybridClass<CameraView> {
   static void registerNatives();
 
   // TODO: Use template<> to avoid heap allocation for std::function<>
-  void setFrameProcessor(const FrameProcessor&& frameProcessor);
+  void setFrameProcessor(const TFrameProcessor&& frameProcessor);
   void unsetFrameProcessor();
 
  private:
   friend HybridBase;
   jni::global_ref<CameraView::javaobject> javaPart_;
-  FrameProcessor frameProcessor_;
+  TFrameProcessor frameProcessor_;
 
   void frameProcessorCallback(const jni::alias_ref<JImageProxy::javaobject>& frame);
 

android/src/main/cpp/FrameHostObject.cpp

@@ -2,7 +2,7 @@
 // Created by Marc on 19/06/2021.
 //
 
-#include "JImageProxyHostObject.h"
+#include "FrameHostObject.h"
 #include <android/log.h>
 #include <fbjni/fbjni.h>
 #include <jni.h>
@@ -13,9 +13,9 @@ namespace vision {
 
 using namespace facebook;
 
-JImageProxyHostObject::JImageProxyHostObject(jni::alias_ref<JImageProxy::javaobject> image): frame(make_local(image)) { }
+FrameHostObject::FrameHostObject(jni::alias_ref<JImageProxy::javaobject> image): frame(make_local(image)) { }
 
-JImageProxyHostObject::~JImageProxyHostObject() {
+FrameHostObject::~FrameHostObject() {
   // Hermes' Garbage Collector (Hades GC) calls destructors on a separate Thread
   // which might not be attached to JNI. Ensure that we use the JNI class loader when
   // deallocating the `frame` HybridClass, because otherwise JNI cannot call the Java
@@ -23,7 +23,7 @@ JImageProxyHostObject::~JImageProxyHostObject() {
   jni::ThreadScope::WithClassLoader([=] { frame.reset(); });
 }
 
-std::vector<jsi::PropNameID> JImageProxyHostObject::getPropertyNames(jsi::Runtime& rt) {
+std::vector<jsi::PropNameID> FrameHostObject::getPropertyNames(jsi::Runtime& rt) {
   std::vector<jsi::PropNameID> result;
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("toString")));
   result.push_back(jsi::PropNameID::forUtf8(rt, std::string("isValid")));
@@ -35,7 +35,7 @@ std::vector<jsi::PropNameID> JImageProxyHostObject::getPropertyNames(jsi::Runtim
   return result;
 }
 
-jsi::Value JImageProxyHostObject::get(jsi::Runtime& runtime, const jsi::PropNameID& propNameId) {
+jsi::Value FrameHostObject::get(jsi::Runtime& runtime, const jsi::PropNameID& propNameId) {
   auto name = propNameId.utf8(runtime);
 
   if (name == "toString") {
@@ -84,14 +84,14 @@ jsi::Value JImageProxyHostObject::get(jsi::Runtime& runtime, const jsi::PropName
   return jsi::Value::undefined();
 }
 
-void JImageProxyHostObject::assertIsFrameStrong(jsi::Runtime& runtime, const std::string& accessedPropName) const {
+void FrameHostObject::assertIsFrameStrong(jsi::Runtime& runtime, const std::string& accessedPropName) const {
   if (!this->frame) {
     auto message = "Cannot get `" + accessedPropName + "`, frame is already closed!";
     throw jsi::JSError(runtime, message.c_str());
   }
 }
 
-void JImageProxyHostObject::close() {
+void FrameHostObject::close() {
   if (this->frame) {
     this->frame->close();
   }

android/src/main/cpp/FrameHostObject.h

@@ -10,16 +10,16 @@
 #include <vector>
 #include <string>
 
-#include "JImageProxy.h"
+#include "java-bindings/JImageProxy.h"
 
 namespace vision {
 
 using namespace facebook;
 
-class JSI_EXPORT JImageProxyHostObject : public jsi::HostObject {
+class JSI_EXPORT FrameHostObject : public jsi::HostObject {
  public:
-  explicit JImageProxyHostObject(jni::alias_ref<JImageProxy::javaobject> image);
-  ~JImageProxyHostObject();
+  explicit FrameHostObject(jni::alias_ref<JImageProxy::javaobject> image);
+  ~FrameHostObject();
 
  public:
   jsi::Value get(jsi::Runtime &, const jsi::PropNameID &name) override;

android/src/main/cpp/FrameProcessorPlugin.cpp

@@ -1,38 +0,0 @@
-//
-// Created by Marc Rousavy on 22.06.21.
-//
-
-#include "FrameProcessorPlugin.h"
-#include <string>
-
-namespace vision {
-
-using namespace facebook;
-using namespace jni;
-
-using TSelf = local_ref<HybridClass<FrameProcessorPlugin>::jhybriddata>;
-using TFrameProcessorPlugin = jobject(alias_ref<JImageProxy::javaobject>, alias_ref<JArrayClass<jobject>>);
-
-TSelf vision::FrameProcessorPlugin::initHybrid(alias_ref<HybridClass::jhybridobject> jThis, const std::string& name) {
-  return makeCxxInstance(jThis, name);
-}
-
-void FrameProcessorPlugin::registerNatives() {
-  registerHybrid({
-    makeNativeMethod("initHybrid",
-                     FrameProcessorPlugin::initHybrid),
-  });
-}
-
-local_ref<jobject> FrameProcessorPlugin::callback(alias_ref<JImageProxy::javaobject> image, alias_ref<JArrayClass<jobject>> params) {
-  auto func = javaPart_->getClass()->getMethod<TFrameProcessorPlugin>("callback");
-
-  auto result = func(javaPart_.get(), image, params);
-  return make_local(result);
-}
-
-std::string FrameProcessorPlugin::getName() {
-  return name;
-}
-
-} // namespace vision

android/src/main/cpp/FrameProcessorPlugin.h

@@ -1,39 +0,0 @@
-//
-// Created by Marc Rousavy on 22.06.21.
-//
-
-#pragma once
-
-#include <jni.h>
-#include <fbjni/fbjni.h>
-#include <string>
-
-#include "java-bindings/JImageProxy.h"
-
-namespace vision {
-
-using namespace facebook;
-using namespace jni;
-
-class FrameProcessorPlugin: public HybridClass<FrameProcessorPlugin> {
- public:
-  static auto constexpr kJavaDescriptor = "Lcom/mrousavy/camera/frameprocessor/FrameProcessorPlugin;";
-  static jni::local_ref<jhybriddata> initHybrid(jni::alias_ref<jhybridobject> jThis,
-                                                const std::string& name);
-  static void registerNatives();
-
-  local_ref<jobject> callback(alias_ref<JImageProxy::javaobject> image, alias_ref<JArrayClass<jobject>> params);
-  std::string getName();
-
- private:
-  friend HybridBase;
-  jni::global_ref<FrameProcessorPlugin::javaobject> javaPart_;
-  std::string name;
-
-  FrameProcessorPlugin(alias_ref<FrameProcessorPlugin::jhybridobject> jThis,
-                       std::string name): javaPart_(make_global(jThis)),
-                       name(name)
-  {}
-};
-
-} // namespace vision

android/src/main/cpp/FrameProcessorRuntimeManager.cpp

@@ -15,17 +15,18 @@
 
 #include "MakeJSIRuntime.h"
 #include "CameraView.h"
-#include "java-bindings/JImageProxy.h"
-#include "java-bindings/JImageProxyHostObject.h"
+#include "FrameHostObject.h"
 #include "JSIJNIConversion.h"
 #include "VisionCameraScheduler.h"
+#include "java-bindings/JImageProxy.h"
+#include "java-bindings/JFrameProcessorPlugin.h"
 
 namespace vision {
 
 // type aliases
 using TSelf = local_ref<HybridClass<vision::FrameProcessorRuntimeManager>::jhybriddata>;
-using JSCallInvokerHolder = jni::alias_ref<facebook::react::CallInvokerHolder::javaobject>;
-using AndroidScheduler = jni::alias_ref<VisionCameraScheduler::javaobject>;
+using TJSCallInvokerHolder = jni::alias_ref<facebook::react::CallInvokerHolder::javaobject>;
+using TAndroidScheduler = jni::alias_ref<VisionCameraScheduler::javaobject>;
 
 // JNI binding
 void vision::FrameProcessorRuntimeManager::registerNatives() {
@@ -44,18 +45,19 @@ void vision::FrameProcessorRuntimeManager::registerNatives() {
 // JNI init
 TSelf vision::FrameProcessorRuntimeManager::initHybrid(
     alias_ref<jhybridobject> jThis,
-    jlong jsContext,
-    JSCallInvokerHolder jsCallInvokerHolder,
-    AndroidScheduler androidScheduler) {
+    jlong jsRuntimePointer,
+    TJSCallInvokerHolder jsCallInvokerHolder,
+    TAndroidScheduler androidScheduler) {
   __android_log_write(ANDROID_LOG_INFO, TAG,
                       "Initializing FrameProcessorRuntimeManager...");
 
   // cast from JNI hybrid objects to C++ instances
+  auto runtime = reinterpret_cast<jsi::Runtime*>(jsRuntimePointer);
   auto jsCallInvoker = jsCallInvokerHolder->cthis()->getCallInvoker();
   auto scheduler = std::shared_ptr<VisionCameraScheduler>(androidScheduler->cthis());
   scheduler->setJSCallInvoker(jsCallInvoker);
 
-  return makeCxxInstance(jThis, reinterpret_cast<jsi::Runtime *>(jsContext), jsCallInvoker, scheduler);
+  return makeCxxInstance(jThis, runtime, jsCallInvoker, scheduler);
 }
 
 void vision::FrameProcessorRuntimeManager::initializeRuntime() {
@@ -78,10 +80,10 @@ void vision::FrameProcessorRuntimeManager::initializeRuntime() {
                       "Initialized Vision JS-Runtime!");
 }
 
-CameraView* FrameProcessorRuntimeManager::findCameraViewById(int viewId) {
-  static const auto func = javaPart_->getClass()->getMethod<CameraView*(jint)>("findCameraViewById");
-  auto result = func(javaPart_.get(), viewId);
-  return result->cthis();
+global_ref<CameraView::javaobject> FrameProcessorRuntimeManager::findCameraViewById(int viewId) {
+  static const auto findCameraViewByIdMethod = javaPart_->getClass()->getMethod<CameraView(jint)>("findCameraViewById");
+  auto weakCameraView = findCameraViewByIdMethod(javaPart_.get(), viewId);
+  return make_global(weakCameraView);
 }
 
 void FrameProcessorRuntimeManager::logErrorToJS(const std::string& message) {
@@ -103,6 +105,63 @@ void FrameProcessorRuntimeManager::logErrorToJS(const std::string& message) {
   });
 }
 
+void FrameProcessorRuntimeManager::setFrameProcessor(jsi::Runtime& runtime,
+                                                     int viewTag,
+                                                     const jsi::Value& frameProcessor) {
+  __android_log_write(ANDROID_LOG_INFO, TAG,
+                      "Setting new Frame Processor...");
+
+  if (!_runtimeManager || !_runtimeManager->runtime) {
+    throw jsi::JSError(runtime,
+                       "setFrameProcessor(..): VisionCamera's RuntimeManager is not yet initialized!");
+  }
+
+  // find camera view
+  auto cameraView = findCameraViewById(viewTag);
+  __android_log_write(ANDROID_LOG_INFO, TAG, "Found CameraView!");
+
+  // convert jsi::Function to a ShareableValue (can be shared across runtimes)
+  __android_log_write(ANDROID_LOG_INFO, TAG,
+                      "Adapting Shareable value from function (conversion to worklet)...");
+  auto worklet = reanimated::ShareableValue::adapt(runtime,
+                                                   frameProcessor,
+                                                   _runtimeManager.get());
+  __android_log_write(ANDROID_LOG_INFO, TAG, "Successfully created worklet!");
+
+  scheduler_->scheduleOnUI([=]() {
+      // cast worklet to a jsi::Function for the new runtime
+      auto& rt = *_runtimeManager->runtime;
+      auto function = std::make_shared<jsi::Function>(worklet->getValue(rt).asObject(rt).asFunction(rt));
+
+      // assign lambda to frame processor
+      cameraView->cthis()->setFrameProcessor([this, &rt, function](jni::alias_ref<JImageProxy::javaobject> frame) {
+          try {
+            // create HostObject which holds the Frame (JImageProxy)
+            auto hostObject = std::make_shared<FrameHostObject>(frame);
+            function->callWithThis(rt, *function, jsi::Object::createFromHostObject(rt, hostObject));
+          } catch (jsi::JSError& jsError) {
+            auto message = "Frame Processor threw an error: " + jsError.getMessage();
+            __android_log_write(ANDROID_LOG_ERROR, TAG, message.c_str());
+            this->logErrorToJS(message);
+          }
+      });
+
+      __android_log_write(ANDROID_LOG_INFO, TAG, "Frame Processor set!");
+  });
+}
+
+void FrameProcessorRuntimeManager::unsetFrameProcessor(int viewTag) {
+  __android_log_write(ANDROID_LOG_INFO, TAG, "Removing Frame Processor...");
+
+  // find camera view
+  auto cameraView = findCameraViewById(viewTag);
+
+  // call Java method to unset frame processor
+  cameraView->cthis()->unsetFrameProcessor();
+
+  __android_log_write(ANDROID_LOG_INFO, TAG, "Frame Processor removed!");
+}
+
 // actual JSI installer
 void FrameProcessorRuntimeManager::installJSIBindings() {
   __android_log_write(ANDROID_LOG_INFO, TAG, "Installing JSI bindings...");
@@ -113,7 +172,7 @@ void FrameProcessorRuntimeManager::installJSIBindings() {
     return;
   }
 
-  auto &jsiRuntime = *runtime_;
+  auto& jsiRuntime = *runtime_;
 
   auto setFrameProcessor = [this](jsi::Runtime &runtime,
                                   const jsi::Value &thisValue,
@@ -130,43 +189,10 @@ void FrameProcessorRuntimeManager::installJSIBindings() {
       throw jsi::JSError(runtime,
                          "Camera::setFrameProcessor: Second argument ('frameProcessor') must be a function!");
     }
-    if (!_runtimeManager || !_runtimeManager->runtime) {
-      throw jsi::JSError(runtime,
-                         "Camera::setFrameProcessor: The RuntimeManager is not yet initialized!");
-    }
 
-    // find camera view
-    auto viewTag = arguments[0].asNumber();
-    auto cameraView = findCameraViewById(static_cast<int>(viewTag));
-    __android_log_write(ANDROID_LOG_INFO, TAG, "Found CameraView!");
-
-    // convert jsi::Function to a ShareableValue (can be shared across runtimes)
-    __android_log_write(ANDROID_LOG_INFO, TAG, "Adapting Shareable value from function (conversion to worklet)...");
-    auto worklet = reanimated::ShareableValue::adapt(runtime, arguments[1],
-                                                     _runtimeManager.get());
-    __android_log_write(ANDROID_LOG_INFO, TAG, "Successfully created worklet!");
-
-
-    scheduler_->scheduleOnUI([=]() {
-      // cast worklet to a jsi::Function for the new runtime
-      auto &rt = *_runtimeManager->runtime;
-      auto function = std::make_shared<jsi::Function>(worklet->getValue(rt).asObject(rt).asFunction(rt));
-
-      // assign lambda to frame processor
-      cameraView->setFrameProcessor([this, &rt, function](jni::alias_ref<JImageProxy::javaobject> frame) {
-        try {
-          // create HostObject which holds the Frame (JImageProxy)
-          auto hostObject = std::make_shared<JImageProxyHostObject>(frame);
-          function->callWithThis(rt, *function, jsi::Object::createFromHostObject(rt, hostObject));
-        } catch (jsi::JSError& jsError) {
-          auto message = "Frame Processor threw an error: " + jsError.getMessage();
-          __android_log_write(ANDROID_LOG_ERROR, TAG, message.c_str());
-          this->logErrorToJS(message);
-        }
-      });
-
-      __android_log_write(ANDROID_LOG_INFO, TAG, "Frame Processor set!");
-    });
+    double viewTag = arguments[0].asNumber();
+    const jsi::Value& frameProcessor = arguments[1];
+    this->setFrameProcessor(runtime, static_cast<int>(viewTag), frameProcessor);
 
     return jsi::Value::undefined();
   };
@@ -190,14 +216,8 @@ void FrameProcessorRuntimeManager::installJSIBindings() {
                          "Camera::unsetFrameProcessor: First argument ('viewTag') must be a number!");
     }
 
-    // find camera view
     auto viewTag = arguments[0].asNumber();
-    auto cameraView = findCameraViewById(static_cast<int>(viewTag));
-
-    // call Java method to unset frame processor
-    cameraView->unsetFrameProcessor();
-
-    __android_log_write(ANDROID_LOG_INFO, TAG, "Frame Processor removed!");
+    this->unsetFrameProcessor(static_cast<int>(viewTag));
 
     return jsi::Value::undefined();
   };
@@ -213,7 +233,7 @@ void FrameProcessorRuntimeManager::installJSIBindings() {
   __android_log_write(ANDROID_LOG_INFO, TAG, "Finished installing JSI bindings!");
 }
 
-void FrameProcessorRuntimeManager::registerPlugin(alias_ref<FrameProcessorPlugin::javaobject> plugin) {
+void FrameProcessorRuntimeManager::registerPlugin(alias_ref<JFrameProcessorPlugin::javaobject> plugin) {
   // _runtimeManager might never be null, but we can never be too sure.
   if (!_runtimeManager || !_runtimeManager->runtime) {
     throw std::runtime_error("Tried to register plugin before initializing JS runtime! Call `initializeRuntime()` first.");
@@ -224,7 +244,7 @@ void FrameProcessorRuntimeManager::registerPlugin(alias_ref<FrameProcessorPlugin
   // we need a strong reference on the plugin, make_global does that.
   auto pluginGlobal = make_global(plugin);
   // name is always prefixed with two underscores (__)
-  auto name = "__" + pluginGlobal->cthis()->getName();
+  auto name = "__" + pluginGlobal->getName();
 
   __android_log_print(ANDROID_LOG_INFO, TAG, "Installing Frame Processor Plugin \"%s\"...", name.c_str());
 
@@ -234,7 +254,7 @@ void FrameProcessorRuntimeManager::registerPlugin(alias_ref<FrameProcessorPlugin
                                  size_t count) -> jsi::Value {
     // Unbox object and get typed HostObject
     auto boxedHostObject = arguments[0].asObject(runtime).asHostObject(runtime);
-    auto frameHostObject = dynamic_cast<JImageProxyHostObject*>(boxedHostObject.get());
+    auto frameHostObject = static_cast<FrameHostObject*>(boxedHostObject.get());
 
     // parse params - we are offset by `1` because the frame is the first parameter.
     auto params = JArrayClass<jobject>::newArray(count - 1);
@@ -243,7 +263,7 @@ void FrameProcessorRuntimeManager::registerPlugin(alias_ref<FrameProcessorPlugin
     }
 
     // call implemented virtual method
-    auto result = pluginGlobal->cthis()->callback(frameHostObject->frame, params);
+    auto result = pluginGlobal->callback(frameHostObject->frame, params);
 
     // convert result from JNI to JSI value
     return JSIJNIConversion::convertJNIObjectToJSIValue(runtime, result);

android/src/main/cpp/FrameProcessorRuntimeManager.h

@@ -14,8 +14,8 @@
 #include "reanimated-headers/AndroidScheduler.h"
 
 #include "CameraView.h"
-#include "FrameProcessorPlugin.h"
 #include "VisionCameraScheduler.h"
+#include "java-bindings/JFrameProcessorPlugin.h"
 
 namespace vision {
 
@@ -31,7 +31,6 @@ class FrameProcessorRuntimeManager : public jni::HybridClass<FrameProcessorRunti
                                                 jni::alias_ref<vision::VisionCameraScheduler::javaobject> androidScheduler);
   static void registerNatives();
 
-  FrameProcessorRuntimeManager() {}
   explicit FrameProcessorRuntimeManager(jni::alias_ref<FrameProcessorRuntimeManager::jhybridobject> jThis,
                                         jsi::Runtime* runtime,
                                         std::shared_ptr<facebook::react::CallInvoker> jsCallInvoker,
@@ -50,11 +49,16 @@ class FrameProcessorRuntimeManager : public jni::HybridClass<FrameProcessorRunti
   std::shared_ptr<reanimated::RuntimeManager> _runtimeManager;
   std::shared_ptr<vision::VisionCameraScheduler> scheduler_;
 
-  CameraView* findCameraViewById(int viewId);
+  jni::global_ref<CameraView::javaobject> findCameraViewById(int viewId);
   void initializeRuntime();
   void installJSIBindings();
-  void registerPlugin(alias_ref<FrameProcessorPlugin::javaobject> plugin);
+  void registerPlugin(alias_ref<JFrameProcessorPlugin::javaobject> plugin);
   void logErrorToJS(const std::string& message);
+
+  void setFrameProcessor(jsi::Runtime& runtime,                 // NOLINT(runtime/references)
+                         int viewTag,
+                         const jsi::Value& frameProcessor);
+  void unsetFrameProcessor(int viewTag);
 };
 
 } // namespace vision

android/src/main/cpp/JSIJNIConversion.cpp

@@ -19,7 +19,7 @@
 #include <jsi/JSIDynamic.h>
 #include <folly/dynamic.h>
 
-#include "java-bindings/JImageProxyHostObject.h"
+#include "FrameHostObject.h"
 #include "java-bindings/JImageProxy.h"
 #include "java-bindings/JArrayList.h"
 #include "java-bindings/JHashMap.h"
@@ -68,7 +68,7 @@ jobject JSIJNIConversion::convertJSIValueToJNIObject(jsi::Runtime &runtime, cons
       // jsi::HostObject
 
       auto boxedHostObject = object.getHostObject(runtime);
-      auto hostObject = dynamic_cast<JImageProxyHostObject*>(boxedHostObject.get());
+      auto hostObject = dynamic_cast<FrameHostObject*>(boxedHostObject.get());
       if (hostObject != nullptr) {
         // return jni local_ref to the JImageProxy
         return hostObject->frame.get();

android/src/main/cpp/VisionCamera.cpp

@@ -1,14 +1,12 @@
 #include <jni.h>
 #include <fbjni/fbjni.h>
 #include "FrameProcessorRuntimeManager.h"
-#include "FrameProcessorPlugin.h"
 #include "CameraView.h"
 #include "VisionCameraScheduler.h"
 
 JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *) {
   return facebook::jni::initialize(vm, [] {
     vision::FrameProcessorRuntimeManager::registerNatives();
-    vision::FrameProcessorPlugin::registerNatives();
     vision::CameraView::registerNatives();
     vision::VisionCameraScheduler::registerNatives();
   });

android/src/main/cpp/java-bindings/JFrameProcessorPlugin.cpp

@@ -0,0 +1,30 @@
+//
+// Created by Marc Rousavy on 29.09.21.
+//
+
+#include "JFrameProcessorPlugin.h"
+
+#include <jni.h>
+#include <fbjni/fbjni.h>
+
+namespace vision {
+
+using namespace facebook;
+using namespace jni;
+
+using TCallback = jobject(alias_ref<JImageProxy::javaobject>, alias_ref<JArrayClass<jobject>>);
+
+local_ref<jobject> JFrameProcessorPlugin::callback(alias_ref<JImageProxy::javaobject> image,
+                                                   alias_ref<JArrayClass<jobject>> params) const {
+  auto callbackMethod = getClass()->getMethod<TCallback>("callback");
+
+  auto result = callbackMethod(self(), image, params);
+  return make_local(result);
+}
+
+std::string JFrameProcessorPlugin::getName() const {
+  auto getNameMethod = getClass()->getMethod<jstring()>("getName");
+  return getNameMethod(self())->toStdString();
+}
+
+} // namespace vision

android/src/main/cpp/java-bindings/JFrameProcessorPlugin.h

@@ -0,0 +1,33 @@
+//
+// Created by Marc Rousavy on 29.09.21
+//
+
+#pragma once
+
+#include <jni.h>
+#include <fbjni/fbjni.h>
+#include <string>
+
+#include "JImageProxy.h"
+
+namespace vision {
+
+using namespace facebook;
+using namespace jni;
+
+struct JFrameProcessorPlugin : public JavaClass<JFrameProcessorPlugin> {
+  static constexpr auto kJavaDescriptor = "Lcom/mrousavy/camera/frameprocessor/FrameProcessorPlugin;";
+
+ public:
+  /**
+   * Call the plugin.
+   */
+  local_ref<jobject> callback(alias_ref<JImageProxy::javaobject> image,
+                              alias_ref<JArrayClass<jobject>> params) const;
+  /**
+   * Get the user-defined name of the Frame Processor Plugin
+   */
+  std::string getName() const;
+};
+
+} // namespace vision

android/src/main/cpp/java-bindings/JImageProxy.cpp

@@ -12,12 +12,12 @@ namespace vision {
 using namespace facebook;
 using namespace jni;
 
-int JImageProxy::getWidth() {
+int JImageProxy::getWidth() const {
   static const auto getWidthMethod = getClass()->getMethod<jint()>("getWidth");
   return getWidthMethod(self());
 }
 
-int JImageProxy::getHeight() {
+int JImageProxy::getHeight() const {
   static const auto getWidthMethod = getClass()->getMethod<jint()>("getHeight");
   return getWidthMethod(self());
 }
@@ -27,19 +27,19 @@ alias_ref<JClass> getUtilsClass() {
   return ImageProxyUtilsClass;
 }
 
-bool JImageProxy::getIsValid() {
+bool JImageProxy::getIsValid() const {
   auto utilsClass = getUtilsClass();
   static const auto isImageProxyValidMethod = utilsClass->getStaticMethod<jboolean(JImageProxy::javaobject)>("isImageProxyValid");
   return isImageProxyValidMethod(utilsClass, self());
 }
 
-int JImageProxy::getPlanesCount() {
+int JImageProxy::getPlanesCount() const {
   auto utilsClass = getUtilsClass();
   static const auto getPlanesCountMethod = utilsClass->getStaticMethod<jint(JImageProxy::javaobject)>("getPlanesCount");
   return getPlanesCountMethod(utilsClass, self());
 }
 
-int JImageProxy::getBytesPerRow() {
+int JImageProxy::getBytesPerRow() const {
   auto utilsClass = getUtilsClass();
   static const auto getBytesPerRowMethod = utilsClass->getStaticMethod<jint(JImageProxy::javaobject)>("getBytesPerRow");
   return getBytesPerRowMethod(utilsClass, self());

android/src/main/cpp/java-bindings/JImageProxy.h

@@ -9,15 +9,18 @@
 
 namespace vision {
 
-struct JImageProxy : public facebook::jni::JavaClass<JImageProxy> {
+using namespace facebook;
+using namespace jni;
+
+struct JImageProxy : public JavaClass<JImageProxy> {
   static constexpr auto kJavaDescriptor = "Landroidx/camera/core/ImageProxy;";
 
  public:
-  int getWidth();
-  int getHeight();
-  bool getIsValid();
-  int getPlanesCount();
-  int getBytesPerRow();
+  int getWidth() const;
+  int getHeight() const;
+  bool getIsValid() const;
+  int getPlanesCount() const;
+  int getBytesPerRow() const;
   void close();
 };
 

android/src/main/java/com/mrousavy/camera/frameprocessor/FrameProcessorPlugin.java

@@ -4,21 +4,13 @@ import androidx.annotation.Keep;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.camera.core.ImageProxy;
-import com.facebook.jni.HybridData;
 import com.facebook.proguard.annotations.DoNotStrip;
 
 /**
  * Declares a Frame Processor Plugin.
  */
-@SuppressWarnings("JavaJniMissingFunction")
 public abstract class FrameProcessorPlugin {
-    static {
-        System.loadLibrary("VisionCamera");
-    }
-
-    @DoNotStrip
-    @SuppressWarnings({"FieldCanBeLocal", "unused"})
-    private final HybridData mHybridData;
+    private final @NonNull String mName;
 
     /**
      * The actual Frame Processor plugin callback. Called for every frame the ImageAnalyzer receives.
@@ -37,10 +29,15 @@ public abstract class FrameProcessorPlugin {
      *             The actual name in the JS Runtime will be prefixed with two underscores (`__`)
      */
     protected FrameProcessorPlugin(@NonNull String name) {
-        mHybridData = initHybrid(name);
+        mName = name;
     }
 
-    private native @NonNull HybridData initHybrid(@NonNull String name);
+    /**
+     * Get the user-defined name of the Frame Processor Plugin.
+     */
+    public @NonNull String getName() {
+        return mName;
+    }
 
     /**
      * Registers the given plugin in the Frame Processor Runtime.