mmdeploy/docs/en/01-how-to-build/android.md

Build for Android

• Build for Android
  • Build From Source
    • Install Toolchains
    • Install Dependencies
      • Install Dependencies for SDK
    • Build MMDeploy
      • Build SDK and Demos

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MMDeploy provides cross compile for android platform.

Model converter is executed on linux platform, and SDK is executed on android platform.

Here are two steps for android build.

1. Build model converter on linux, please refer to How to build linux

2. Build SDK using android toolchain on linux.

This doc is only for how to build SDK using android toolchain on linux.

Build From Source

Install Toolchains

• cmake

  Make sure cmake version >= 3.14.0. If not, you can follow instructions below to install cmake 3.20.0. For more versions of cmake, please refer to cmake website.

  wget https://github.com/Kitware/CMake/releases/download/v3.20.0/cmake-3.20.0-linux-x86_64.tar.gz
  tar -xzvf cmake-3.20.0-linux-x86_64.tar.gz
  sudo ln -sf $(pwd)/cmake-3.20.0-linux-x86_64/bin/* /usr/bin/
  

• ANDROID NDK 19+

  Make sure android ndk version >= 19.0. If not, you can follow instructions below to install android ndk r23c. For more versions of android ndk, please refer to android ndk website.

  wget https://dl.google.com/android/repository/android-ndk-r23c-linux.zip
  unzip android-ndk-r23c-linux.zip
  cd android-ndk-r23c
  export NDK_PATH=${PWD}
  

Install Dependencies

Install Dependencies for SDK

You can skip this chapter if only interested in model converter.

NAME	INSTALLATION
OpenCV (>=3.0)	export OPENCV_VERSION=4.6.0 wget https://github.com/opencv/opencv/releases/download/${OPENCV_VERSION}/opencv-${OPENCV_VERSION}-android-sdk.zip unzip opencv-${OPENCV_VERSION}-android-sdk.zip export OPENCV_ANDROID_SDK_DIR=${PWD}/OpenCV-android-sdk
ncnn	A high-performance neural network inference computing framework supporting for android. Now, MMDeploy supports 20220721 and has to use git clone to download it. For supported android ABI, see here . git clone -b 20220721 https://github.com/Tencent/ncnn.git cd ncnn git submodule update --init export NCNN_DIR=${PWD} export ANDROID_ABI=arm64-v8a mkdir -p build_${ANDROID_ABI} cd build_${ANDROID_ABI} cmake -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake -DANDROID_ABI="${ANDROID_ABI}" -DANDROID_PLATFORM=android-30 -DNCNN_VULKAN=ON -DNCNN_DISABLE_EXCEPTION=OFF -DNCNN_DISABLE_RTTI=OFF .. make -j$(nproc) install
OpenJDK	It is necessary for building Java API. See Java API build for building tutorials.

Build MMDeploy

Build SDK and Demos

MMDeploy provides a recipe as shown below for building SDK with ncnn as inference engine for android.

• cpu + ncnn

  export ANDROID_ABI=arm64-v8a
  cd ${MMDEPLOY_DIR}
  mkdir -p build_${ANDROID_ABI} && cd build_${ANDROID_ABI}
  cmake .. \
      -DMMDEPLOY_BUILD_SDK=ON \
      -DMMDEPLOY_BUILD_SDK_JAVA_API=ON \
      -DMMDEPLOY_BUILD_EXAMPLES=ON \
      -DOpenCV_DIR=${OPENCV_ANDROID_SDK_DIR}/sdk/native/jni/abi-${ANDROID_ABI} \
      -Dncnn_DIR=${NCNN_DIR}/build_${ANDROID_ABI}/install/lib/cmake/ncnn \
      -DMMDEPLOY_TARGET_BACKENDS=ncnn \
      -DMMDEPLOY_SHARED_LIBS=OFF \
      -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake \
      -DANDROID_ABI=${ANDROID_ABI} \
      -DANDROID_PLATFORM=android-30 \
      -DANDROID_CPP_FEATURES="rtti exceptions"
  
  make -j$(nproc) && make install
  

Please check cmake build option spec