一、創(chuàng)建native項(xiàng)目

1.1、選擇Native C++

1.2、命名項(xiàng)目名稱

1.3、選擇C++標(biāo)準(zhǔn)

1.4、項(xiàng)目結(jié)構(gòu)

1.5、app的build.gradle

plugins {
    id 'com.android.application'
}

android {
    compileSdk 32

    defaultConfig {
        applicationId "com.anniljing.ffmpegnative"
        minSdk 25
        targetSdk 32
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags '-std=c++11'
            }
        }
    }

    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 'androidx.appcompat:appcompat:1.6.1'
    implementation 'com.google.android.material:material:1.9.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}

• android -> defaultConfig ->externalNativeBuild -> cmake
  配置c++使用標(biāo)準(zhǔn)
• android -> externalNativeBuild -> cmake
  1 、配置cmake文件路徑
  2、配置cmake的版本

1.6、CMakeLists.txt

cmake_minimum_required(VERSION 3.18.1)

project("ffmpegnative")


add_library( # Sets the name of the library.
        ffmpegnative

        # Sets the library as a shared library.
        SHARED

        # Provides a relative path to your source file(s).
        native-lib.cpp)

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)


target_link_libraries( # Specifies the target library.
        ffmpegnative

        # Links the target library to the log library
        # included in the NDK.
        ${log-lib})

• cmake_minimum_required
  cmake最低版本要求

• project
  設(shè)置項(xiàng)目名稱

• add_library
  添加庫并設(shè)置庫的源文件
  1、 Normal Libraries

add_library(<name> [STATIC | SHARED | MODULE]
            [EXCLUDE_FROM_ALL]
            [<source>...])

name:庫名稱
STATIC|SHARED|MODULE:庫類型（靜態(tài)、動(dòng)態(tài)、模塊）
source:源文件

2、Imported Libraries

add_library(<name> <type> IMPORTED [GLOBAL])

導(dǎo)入已經(jīng)生成的庫,通常情況搭配set_target_properties，指定庫的相關(guān)配置信息

set_target_properties(target1 target2 ...
                      PROPERTIES prop1 value1
                      prop2 value2 ...)

• find_library
  查找本地庫，一般位于NDK中

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)

• target_link_libraries
  用于指定目標(biāo)（target）與其所需的庫之間的鏈接關(guān)系。它被用于在構(gòu)建過程中將庫文件鏈接到可執(zhí)行文件或共享庫。

target_link_libraries(
        ffmpegnative
        ${log-lib})

將log-lib庫鏈接到ffmpegnative中

二、配置FFmpeg頭文件和庫

2.1、配置FFmpeg頭文件

#設(shè)置頭文件路徑
include_directories(${CMAKE_SOURCE_DIR}/include)

2.2、配置ffmpeg相關(guān)的so庫

2.2.1、添加so庫

#聲明ffmpeg_lib_dir變量，設(shè)置統(tǒng)一的庫文件路徑
set(ffmpeg_lib_dir ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI})
#添加ffmpeg相關(guān)的庫
#avcodec庫(音視頻編解碼核心庫)
add_library( avcodec
        SHARED
        IMPORTED )
set_target_properties( avcodec
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libavcodec.so )

#avfilter庫(音視頻濾鏡庫 如視頻加水印、音頻變聲)
add_library( avfilter
        SHARED
        IMPORTED)
set_target_properties( avfilter
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libavfilter.so )

#swscale庫(圖像格式轉(zhuǎn)換的模塊)
add_library( swscale
        SHARED
        IMPORTED)
set_target_properties( swscale
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libswscale.so )

#avformat庫(音視頻容器格式的封裝和解析)
add_library( avformat
        SHARED
        IMPORTED)
set_target_properties( avformat
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libavformat.so )

#avdevice庫(輸入輸出設(shè)備庫，提供設(shè)備數(shù)據(jù)的輸入與輸出)
add_library( avdevice
        SHARED
        IMPORTED)
set_target_properties( avdevice
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libavdevice.so )

#avutil庫(核心工具庫)
add_library( avutil
        SHARED
        IMPORTED )
set_target_properties( avutil
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libavutil.so )

#swresample庫(音頻重采樣)
add_library( swresample
        SHARED
        IMPORTED )
set_target_properties( swresample
        PROPERTIES IMPORTED_LOCATION
        ${ffmpeg_lib_dir}/libswresample.so )

2.2.2、鏈接ffmpeg庫

target_link_libraries(
        ffmpegnative
        #鏈接ffmpeg相關(guān)庫
        avutil
        swresample
        avcodec
        avfilter
        swscale
        avformat
        avdevice
        #鏈接本地日志庫
        ${log-lib})

2.3、ffmpeg靜態(tài)庫配置

2.3.1、拷貝靜態(tài)庫到j(luò)niLibs文件夾

2.3.2、把靜態(tài)庫路徑設(shè)置到默認(rèn)的編譯變量或者庫的搜索變量中

2.3.2.1、設(shè)置CMAKE_CXX_FLAGS

CMAKE_CXX_FLAGS 是 CMake 構(gòu)建系統(tǒng)中用于設(shè)置 C++ 編譯器選項(xiàng)的變量。通過設(shè)置 CMAKE_CXX_FLAGS 變量，您可以向編譯器傳遞各種編譯選項(xiàng)和標(biāo)志。

#聲明ffmpeg路徑變量，設(shè)置統(tǒng)一的庫文件路徑
set(FFMPEG_DIR ${CMAKE_SOURCE_DIR}/../jniLibs/ffmpeg)
#聲明ffmpeg包含所有庫變量
set(FFMPEG_LIB avformat avcodec avdevice avfilter avutil swresample swscale)
set(ANDROID_LIB z -landroid log)

#設(shè)置ffmpeg庫文件路徑
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -L${FFMPEG_DIR}/lib/${ANDROID_ABI}")
#設(shè)置ffmpeg的頭文件
include_directories(${FFMPEG_DIR}/include)

CmakeLists.txt

cmake_minimum_required(VERSION 3.18.1)

project("ffmpegnative")

#聲明ffmpeg路徑變量，設(shè)置統(tǒng)一的庫文件路徑
set(FFMPEG_DIR ${CMAKE_SOURCE_DIR}/../jniLibs/ffmpeg)
#聲明ffmpeg包含所有庫變量
set(FFMPEG_LIB avformat avcodec avdevice avfilter avutil swresample swscale)
set(ANDROID_LIB z -landroid log)


#設(shè)置ffmpeg庫文件路徑
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -L${FFMPEG_DIR}/lib/${ANDROID_ABI}")
#設(shè)置ffmpeg的頭文件
include_directories(${FFMPEG_DIR}/include)


add_library(
        ffmpegnative
        SHARED
        native-lib.cpp

)


target_link_libraries(
        ffmpegnative
        #鏈接ffmpeg相關(guān)庫
        ${FFMPEG_LIB}
        #鏈接本地日志庫
        ${ANDROID_LIB})

2.3.2.2、使用LINK_DIRECTORIES，設(shè)置靜態(tài)庫

LINK_DIRECTORIES是CMake構(gòu)建系統(tǒng)中的一個(gè)命令，用于指定編譯器在鏈接階段查找?guī)煳募乃阉髀窂?/strong>。

#聲明ffmpeg路徑變量，設(shè)置統(tǒng)一的庫文件路徑
set(FFMPEG_DIR ${CMAKE_SOURCE_DIR}/../jniLibs/ffmpeg)
#聲明ffmpeg包含所有庫變量
set(FFMPEG_LIB avformat avcodec avdevice avfilter avutil swresample swscale)
set(ANDROID_LIB z -landroid log)


#設(shè)置ffmpeg庫文件搜索路徑
LINK_DIRECTORIES(${FFMPEG_DIR}/lib/${ANDROID_ABI})
#設(shè)置ffmpeg的頭文件
include_directories(${FFMPEG_DIR}/include)

cmake_minimum_required(VERSION 3.18.1)

project("ffmpegnative")

#聲明ffmpeg路徑變量，設(shè)置統(tǒng)一的庫文件路徑
set(FFMPEG_DIR ${CMAKE_SOURCE_DIR}/../jniLibs/ffmpeg)
#聲明ffmpeg包含所有庫變量
set(FFMPEG_LIB avformat avcodec avdevice avfilter avutil swresample swscale)
set(ANDROID_LIB z -landroid log)


#設(shè)置ffmpeg庫文件搜索路徑
LINK_DIRECTORIES(${FFMPEG_DIR}/lib/${ANDROID_ABI})
#設(shè)置ffmpeg的頭文件
include_directories(${FFMPEG_DIR}/include)


add_library(
        ffmpegnative
        SHARED
        native-lib.cpp

)


target_link_libraries(
        ffmpegnative
        #鏈接ffmpeg相關(guān)庫
        ${FFMPEG_LIB}
        #鏈接本地日志庫
        ${ANDROID_LIB})

 sourceSets {
        main {
            jniLibs.srcDirs = ['libs']
        }
    }

 sourceSets {
        main {
            jniLibs.srcDirs = ['src/main/jniLibs/lib']
        }
    }

public native String getFFmpegVersion();

#include <libavformat/avformat.h>

extern "C"
JNIEXPORT jstring JNICALL
Java_com_anniljing_ffmpegnative_MainActivity_getFFmpegVersion(JNIEnv *env, jobject thiz) {
    const char* version = av_version_info();

    return env->NewStringUTF(version);
}