ffmpeg系列之移植到安卓中调用

基础调用

1）编译安卓需要的so，请参考2）将so引入安卓中使用3）cpp中进行cmake配置4) 编写jni测试代码5) 配置gradle相关位置6）build运行即可

编译ffmpeg的安卓版本

在module的src/main/下创建cpp和jniLibs模块，jniLibs中存放so文件

将ffmpeg的头文件拷贝到src/main/cpp下

配置cmakelist

# 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 3.10.2)

# Declares and names the project.

project("ffmpeg")

#设置FFmpeg头文件的路径，共享库,include里面h文件调用其他h文件用到的
include_directories(
        include#因为和CMakeLists.txt在同一级，所以直接写include
)

add_library(ffmpeg
        SHARED
        ffmpeg_util.cpp)

find_library(
        log-lib
        log)

add_library(avcodec
        SHARED
        importED)
#给avcodec这个变量赋值
set_target_properties(avcodec
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libavcodec.so)


add_library(avdevice
        SHARED
        importED)
set_target_properties(avdevice
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libavdevice.so)

add_library(avformat
        SHARED
        importED)
set_target_properties(avformat
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libavformat.so)

add_library(avutil
        SHARED
        importED)
set_target_properties(avutil
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libavutil.so)


add_library(swresample
        SHARED
        importED)
set_target_properties(swresample
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libswresample.so)

add_library(swscale
        SHARED
        importED)
set_target_properties(swscale
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libswscale.so)

add_library(avfilter
        SHARED
        importED)
set_target_properties(avfilter
        PROPERTIES importED_LOCATION
        ${CMAKE_SOURCE_DIR}/../jniLibs/${ANDROID_ABI}/libavfilter.so)



target_link_libraries(ffmpeg
        ${log-lib}
        avcodec swresample avutil)

#include 

#include 
#include 


#ifdef __cplusplus
extern "C"
{
#endif

#include "libavcodec/avcodec.h"

#ifdef __cplusplus
}
#endif

extern "C" JNIEXPORT jstring JNICALL
Java_com_cd_lib_ffmpeg_FfmpegUtil_stringFromJNI(
        JNIEnv* env,
        jobject ) {
    return env->NewStringUTF(avcodec_configuration());
}

根据jni规则编码java

public class FfmpegUtil {

    // Used to load the 'ffmpeg' library on application startup.
    static {
        System.loadLibrary("ffmpeg");
    }

    
    public static native String stringFromJNI();
}

android {
    ...

    defaultConfig {
       ...
        ndk {
            abiFilters  'armeabi-v7a', 'arm64-v8a'
        }
    }
    sourceSets {
        main {
            jniLibs.srcDirs = ['libs']
        }
    }

    externalNativeBuild {
        cmake {
            path file('src/main/cpp/CMakeLists.txt')
            version '3.10.2'
        }
    }
    ...
}