---
id: frame-processors-plugins-cpp
title: Creating Frame Processor Plugins (C++)
sidebar_label: Creating Frame Processor Plugins (C++)
---

import Tabs from '@theme/Tabs'
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import useBaseUrl from '@docusaurus/useBaseUrl'

## C++ Frame Processor Plugins

C++ based Frame Processor Plugins are built with JSI and can be directly called from a Frame Processor as native JSI functions can be shared across contexts.
The benefits of C++ based Frame Processor Plugins lie in the nature of C++ based code:

- **Better Performance** due to less marshalling required and lower level access
- **Shared platform code** - e.g. OpenCV Frame Processor Plugins only need to be implemented once

For example:

```cpp
// 1. Include headers
#include "frameprocessor/FrameHostObject.h"

// 2. Create C++ func
auto myPlugin = [=](jsi::Runtime& runtime,
                    const jsi::Value& thisArg,
                    const jsi::Value* args,
                    size_t count) -> jsi::Value {
  auto frame = args[0].asObject(runtime).asHostObject<FrameHostObject>(runtime);
  // Unwrap the Frame, then do your Frame Processing here, and return any JSI value as a result.
  // For example, you can run very efficient OpenCV tasks here.
  return jsi::Value(42);
};
// 3. Wrap C++ func in jsi::Function
auto jsiFunc = jsi::Function::createFromHostFunction(runtime,
                                                     jsi::PropNameID::forUtf8(runtime,
                                                                              "myCppPlugin"),
                                                     1,
                                                     myPlugin);
// 4. Add it to global so it can be called from JS
runtime.global().setProperty(runtime, "myCppPlugin", jsiFunc);
```

Then to call that function:

```js
const frameProcessor = useFrameProcessor((frame) => {
  'worklet'
  const result = global.myCppPlugin(frame)
  console.log(`C++ result: ${result}`) // <-- 42
}, [])
```

To include VisionCamera's C++ library in your plugin's C++ code, you need to link it and include the headers.


<Tabs
  groupId="platform"
  defaultValue="ios"
  values={[
    {label: 'iOS', value: 'ios'},
    {label: 'android', value: 'android'}
  ]}>
<TabItem value="ios">

VisionCamera is built using **CocoaPods**, which allow you to include local dependencies.
To add VisionCamera to your package's `.podspec`, just add the dependency:

```ruby
s.dependency "VisionCamera"
```

Then include it in your C++ code:

```cpp
#include "Frame Processor/FrameHostObject.h"
```

</TabItem>
<TabItem value="android">

VisionCamera is built using **prefabs**, which allow you to easily extend the library with your own native code.
To link VisionCamera in your package's `CMakeLists.txt`, just add the library:

```make
find_package(react-native-vision-camera REQUIRED CONFIG)
# ...
target_link_libraries(
  ${PACKAGE_NAME}
  # ... other libs
  react-native-vision-camera::VisionCamera
)
```

Then include it in your C++ code:

```cpp
#include "frame-processor/FrameHostObject.h"
```

</TabItem>
</Tabs>

<br />

#### 🚀 Next section: [Browse Community Plugins](frame-processor-plugins)
