Compilation of CPP files for YOLOX object detection based on MegEngine.

• Native building

  sudo apt install gcc/g++ (gcc/g++, which version >= 6) build-essential git git-lfs gfortran libgfortran-6-dev autoconf gnupg flex bison gperf curl zlib1g-dev gcc-multilib g++-multilib cmake

• Cross building with Android

  1. download NDK

  2. unzip NDK

  3. export NDK_ROOT="path of NDK"

     Replace path of NDK according to your situation.

1. Download MegEngine

   git clone https://github.com/MegEngine/MegEngine.git

2. Init third_party

   # Replace `path of MegEngine` according to your situation.
   export megengine_root="path of MegEngine"
   
   cd $megengine_root 
   
   ./third_party/prepare.sh
   
   ./third_party/install-mkl.sh

3. Build example:

   • Native building without CUDA

     ./scripts/cmake-build/host_build.sh

   • Native building with CUDA

     ./scripts/cmake-build/host_build.sh -c

   • Cross building for Android AArch64

     ./scripts/cmake-build/cross_build_android_arm_inference.sh

   • Cross building for Android AArch64 (V8.2+fp16)

     ./scripts/cmake-build/cross_build_android_arm_inference.sh -f

4. Export MGE_INSTALL_PATH

   • Native building without CUDA

     export MGE_INSTALL_PATH=${megengine_root}/build_dir/host/MGE_WITH_CUDA_OFF/MGE_INFERENCE_ONLY_ON/Release/install

   • Native building with CUDA

     export MGE_INSTALL_PATH=${megengine_root}/build_dir/host/MGE_WITH_CUDA_ON/MGE_INFERENCE_ONLY_ON/Release/install

   • Cross building for Android AArch64

     export MGE_INSTALL_PATH=${megengine_root}/build_dir/android/arm64-v8a/Release/install

5. Refer to Build Tutorial of MegEngine to build for other platforms (windows, macos, etc.).

1. Download OpenCV

   git clone https://github.com/opencv/opencv.git
   
   # Replace `path of opencv` according to your situation.
   export opencv_root="path of opencv"

2. Choose Version

   # Our test is based on version 3.4.15.
   # If test other versions, following building steps may not work and some changes need to be made.
   git checkout 3.4.15 

3. Build

   • Native building

     cd root_dir_of_opencv
     
     mkdir -p build/install
     
     cd build
     
     cmake -DBUILD_JAVA=OFF -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX=$PWD/install 
     
     make install -j32

   • Cross building for Android-AArch64

     • Apply Patch

     # Patch for Android
     diff --git a/CMakeLists.txt b/CMakeLists.txt
     index f6a2da5310..10354312c9 100644
     --- a/CMakeLists.txt
     +++ b/CMakeLists.txt
     @@ -643,7 +643,7 @@ if(UNIX)
         if(NOT APPLE)
           CHECK_INCLUDE_FILE(pthread.h HAVE_PTHREAD)
           if(ANDROID)
     -      set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} dl m log)
     +      set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} dl m log z)
           elseif(CMAKE_SYSTEM_NAME MATCHES "FreeBSD|NetBSD|DragonFly|OpenBSD|Haiku")
             set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} m pthread)
           elseif(EMSCRIPTEN)

     • Build

     cd root_dir_of_opencv
     
     mkdir -p build_android/install
     
     cd build_android
     
     cmake -DCMAKE_TOOLCHAIN_FILE="$NDK_ROOT/build/cmake/android.toolchain.cmake" -DANDROID_NDK="$NDK_ROOT"  -DANDROID_ABI=arm64-v8a -DANDROID_NATIVE_API_LEVEL=21 -DBUILD_JAVA=OFF -DBUILD_ANDROID_PROJECTS=OFF -DBUILD_ANDROID_EXAMPLES=OFF -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX=$PWD/install ..
     
     make install -j32

4. Export OPENCV_INSTALL_INCLUDE_PATH and OPENCV_INSTALL_LIB_PATH

   • Native building

     export OPENCV_INSTALL_INCLUDE_PATH=${opencv_root}/build/install/include
     
     export OPENCV_INSTALL_LIB_PATH=${opencv_root}/build/install/lib

   • Cross building for Android AArch64

     export OPENCV_INSTALL_INCLUDE_PATH=${opencv_root}/build_android/install/sdk/native/jni/include
     
     export OPENCV_INSTALL_LIB_PATH=${opencv_root}/build_android/install/sdk/native/libs/arm64-v8a

• Native building

  export CXX=g++
  
  ./build.sh

• Cross building for Android AArch64

  export PATH=${NDK_ROOT}/toolchains/llvm/prebuilt/linux-x86_64/bin/:$PATH
  
  export CXX=aarch64-linux-android21-clang++
  
  ./build.sh

Note: Two ways to get yolox_s.mge model file

1. Reference python demo's dump.py script.
2. wget https://github.com/Megvii-BaseDetection/storage/releases/download/0.0.1/yolox_s.mge

• Native building

  LD_LIBRARY_PATH=$MGE_INSTALL_PATH/lib/:$OPENCV_INSTALL_LIB_PATH ./yolox yolox_s.mge ../../../assets/dog.jpg cuda/cpu <warmup_count> <thread_number> <run_with_fp16>

• Cross building for Android

  adb push/scp $MGE_INSTALL_PATH/lib/libmegengine.so android_phone
  
  adb push/scp $OPENCV_INSTALL_LIB_PATH/*.so android_phone
  
  adb push/scp ./yolox yolox_s.mge ../../../assets/dog.jpg android_phone
  
  # Execute the following cmd after logging in android_phone by adb or ssh
  
  # <warmup_count> means warmup count, valid number >=0
  # <thread_number> means thread number, valid number >=1, only take effect on `cpu` device
  # <run_with_fp16> if >=1, will run with fp16 mode
  
  LD_LIBRARY_PATH=. ./yolox yolox_s.mge dog.jpg cpu <warmup_count> <thread_number>  <run_with_fp16>

• Model Info: yolox-s @ input(1,3,640,640)

• Testing Devices

  • x86_64 -- Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
  • AArch64 -- xiamo phone mi9
  • CUDA -- 1080TI @ cuda-10.1-cudnn-v7.6.3-TensorRT-6.0.1.5.sh @ Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz

• MegEngine
• OpenCV
• NDK
• CMAKE