1. Pre-environmental preparation
1.1 MNN environment compilation
See the article I wrote earlier for details: Article address
1.2 Installation of opencv for android
Enter the official website of opencv, download the installation package: download address
and unzip it after the download is complete
2. Android project environment configuration
2.1 Create an Android project
Open Android Studio and create a new Native C++ project
2.2 MNN environment configuration
- Copy the libMNN.so file under the build_64 folder generated by the previous MNN compilation of Android to the app/libs/arm64-v8a folder under the Android project (the arm64-v8a folder is created by itself)
libs folder not found Switch mode to Project
- Use CMakeLists.txt to compile
and edit CMakeLists.txt under the cpp folder
to add the following content
#----------------MNN环境---------------------
# MNN_DIR为自己安装的MNN的路径
set(MNN_DIR D:/APP/MNN)
# mnn的头文件
include_directories(${
MNN_DIR}/include)
include_directories(${
MNN_DIR}/include/MNN)
include_directories(${
MNN_DIR}/tools)
include_directories(${
MNN_DIR}/tools/cpp)
include_directories(${
MNN_DIR}/source)
include_directories(${
MNN_DIR}/source/backend)
include_directories(${
MNN_DIR}/source/core)
set(dis_DIR ../../../../libs)
add_library(
MNN
SHARED
IMPORTED
)
set_target_properties(
MNN
PROPERTIES IMPORTED_LOCATION
${
dis_DIR}/arm64-v8a/libMNN.so
)
#----------------------------------------------
- Modify the build.gradle file under app
plugins {
id 'com.android.application'
}
android {
compileSdk 32
defaultConfig {
applicationId "com.cjpnice.lcnet_mnn"
minSdk 21
targetSdk 32
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags '-std=c++14'
arguments "-DANDROID_STL=c++_shared"
abiFilters "arm64-v8a"
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
externalNativeBuild {
cmake {
path file('src/main/cpp/CMakeLists.txt')
version '3.18.1'
}
}
buildFeatures {
viewBinding true
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.3.0'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}
Opencv environment configuration
- Edit CMakeLists.txt under the cpp folder
#-----------opencv环境配置-----------------------
#设置OpenCV-android-sdk路径
set( OpenCV_DIR D:/APP/OpenCV-android-sdk/sdk/native/jni )
find_package(OpenCV REQUIRED )
if(OpenCV_FOUND)
include_directories(${OpenCV_INCLUDE_DIRS})
message(STATUS "OpenCV library status:")
message(STATUS " version: ${OpenCV_VERSION}")
message(STATUS " libraries: ${OpenCV_LIBS}")
message(STATUS " include path: ${OpenCV_INCLUDE_DIRS}")
else(OpenCV_FOUND)
message(FATAL_ERROR "OpenCV library not found")
endif(OpenCV_FOUND)
#-----------------------------------------------
Complete CMakeLists.txt
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.18.1)
# Declares and names the project.
project("lcnet_mnn")
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
#----------------MNN环境---------------------
# MNN_DIR为自己安装的MNN的路径
set(MNN_DIR D:/APP/MNN)
# mnn的头文件
include_directories(${
MNN_DIR}/include)
include_directories(${
MNN_DIR}/include/MNN)
include_directories(${
MNN_DIR}/tools)
include_directories(${
MNN_DIR}/tools/cpp)
include_directories(${
MNN_DIR}/source)
include_directories(${
MNN_DIR}/source/backend)
include_directories(${
MNN_DIR}/source/core)
set(dis_DIR ../../../../libs)
add_library(
MNN
SHARED
IMPORTED
)
set_target_properties(
MNN
PROPERTIES IMPORTED_LOCATION
${
dis_DIR}/arm64-v8a/libMNN.so
)
#----------------------------------------------
#-----------opencv环境配置-----------------------
#设置OpenCV-android-sdk路径
set( OpenCV_DIR D:/APP/OpenCV-android-sdk/sdk/native/jni )
find_package(OpenCV REQUIRED )
if(OpenCV_FOUND)
include_directories(${
OpenCV_INCLUDE_DIRS})
message(STATUS "OpenCV library status:")
message(STATUS " version: ${OpenCV_VERSION}")
message(STATUS " libraries: ${OpenCV_LIBS}")
message(STATUS " include path: ${OpenCV_INCLUDE_DIRS}")
else(OpenCV_FOUND)
message(FATAL_ERROR "OpenCV library not found")
endif(OpenCV_FOUND)
#-----------------------------------------------
aux_source_directory(. SRCS)
add_library( # Sets the name of the library.
lcnet_mnn
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
${
SRCS})
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
lcnet_mnn
# Links the target library to the log library
# included in the NDK.
MNN
jnigraphics
${
OpenCV_LIBS}
${
log-lib})
3. Write MNN for model reasoning
According to your own model, write jni to call MNN for model reasoning.
Details will be updated in the future