# NNAPI Execution Provider

[Android Neural Networks API (NNAPI)](https://developer.android.com/ndk/guides/neuralnetworks) is a unified interface to CPU, GPU, and NN accelerators on Android. It is supported by onnxruntime via [DNNLibrary](https://github.com/JDAI-CV/DNNLibrary).

## Minimum requirements

The NNAPI EP requires Android devices with Android 8.1 or higher.

## Build NNAPI EP

For build instructions, please see the [BUILD page](../../BUILD.md#Android-NNAPI).

## Using NNAPI EP in C/C++

To use NNAPI EP for inferencing, please register it as below.
```
string log_id = "Foo";
auto logging_manager = std::make_unique<LoggingManager>
(std::unique_ptr<ISink>{new CLogSink{}},
                                  static_cast<Severity>(lm_info.default_warning_level),
                                  false,
                                  LoggingManager::InstanceType::Default,
                                  &log_id)
Environment::Create(std::move(logging_manager), env)
InferenceSession session_object{so,env};
session_object.RegisterExecutionProvider(std::make_unique<::onnxruntime::NnapiExecutionProvider>());
status = session_object.Load(model_file_name);
```
The C API details are [here](../C_API.md#c-api).

## Performance

![NNAPI EP on RK3399](./images/nnapi-ep-rk3399.png)

![NNAPI EP on OnePlus 6T](./images/nnapi-ep-oneplus6t.png)

![NNAPI EP on Huawei Honor V10](./images/nnapi-ep-huaweihonorv10.png)