新建项目VoicePlayer，项目包括主app和一个库voicelib，所有关于操作音频、jni的编写都在voicelib库中

注意在新建module的时候使用的是第二个，不要搞错

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看一下我们的工程目录：

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CMakeList.txt

cmake_minimum_required(VERSION 3.4.1)

#导入include路径
include_directories(src/main/cpp/include)


add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             src/main/cpp/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 )


#添加动态库
add_library( avcodec-57 SHARED IMPORTED)
#设置动态库路径
set_target_properties( avcodec-57
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libavcodec-57.so)


add_library( avdevice-57 SHARED IMPORTED)
set_target_properties( avdevice-57
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libavdevice-57.so)


add_library( avfilter-6 SHARED IMPORTED)
set_target_properties( avfilter-6
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libavfilter-6.so)


add_library( avformat-57 SHARED IMPORTED)
set_target_properties( avformat-57
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libavformat-57.so)


add_library( avutil-55 SHARED IMPORTED)
set_target_properties( avutil-55
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libavutil-55.so)

add_library( postproc-54 SHARED IMPORTED)
set_target_properties( postproc-54
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libpostproc-54.so)

add_library( swresample-2 SHARED IMPORTED)
set_target_properties( swresample-2
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libswresample-2.so)


add_library( swscale-4 SHARED IMPORTED)
set_target_properties( swscale-4
                       PROPERTIES IMPORTED_LOCATION
                       ${CMAKE_SOURCE_DIR}/libs/${ANDROID_ABI}/libswscale-4.so)


target_link_libraries( # Specifies the target library.
                       native-lib

                       avcodec-57
                       avdevice-57
                       avfilter-6
                       avformat-57
                       avutil-55
                       postproc-54
                       swresample-2
                       swscale-4

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

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Player.java

package com.example.voicelib;

/**
 * 作者 huozhenpeng
 * 日期 2018/10/18
 * 邮箱 huohacker@sina.com
 */

public class Player {

    // Used to load the 'native-lib' library on application startup.
    static {
        System.loadLibrary("native-lib");
        System.loadLibrary("avutil-55");
        System.loadLibrary("swresample-2");
        System.loadLibrary("avcodec-57");
        System.loadLibrary("avformat-57");
        System.loadLibrary("swscale-4");
        System.loadLibrary("postproc-54");
        System.loadLibrary("avfilter-6");
        System.loadLibrary("avdevice-57");
    }


    /**
     * A native method that is implemented by the 'native-lib' native library,
     * which is packaged with this application.
     */
    public native String stringFromJNI();

    /**
     * 测试集成ffmpeg，打印ffmpeg支持的所有解码器
     */
    public native void printCodec();
}

native-lib.cpp

#include <jni.h>
#include <string>
#include <android/log.h>
extern "C"
{
#include <libavformat/avformat.h>
}

#define LOGI(FORMAT,...) __android_log_print(ANDROID_LOG_INFO,"VoicePlayer",FORMAT,##__VA_ARGS__);

extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_voicelib_Player_stringFromJNI(JNIEnv *env, jobject instance) {

    // TODO
    std::string hello = "Hello from C++";


    av_register_all();
    return env->NewStringUTF(hello.c_str());


}

extern "C"
JNIEXPORT void JNICALL
Java_com_example_voicelib_Player_printCodec(JNIEnv *env, jobject instance) {

    av_register_all();
    AVCodec *codec=av_codec_next(NULL);
    while (codec!=NULL)
    {
        switch (codec->type)
        {
            case AVMEDIA_TYPE_VIDEO:
                LOGI("[Video]:%s",codec->name);
                break;
            case AVMEDIA_TYPE_AUDIO:
                LOGI("[Audio]:%s", codec->name);
                break;
            default:
                LOGI("[Other]:%s", codec->name);
                break;
        }
        codec=codec->next;
    }

}

主项目MainActivity调用

package com.example.huozhenpeng.voiceplayer;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import com.example.voicelib.Player;

public class MainActivity extends AppCompatActivity {



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Example of a call to a native method
        TextView tv = (TextView) findViewById(R.id.sample_text);
        Player player=new Player();
        tv.setText(player.stringFromJNI());
        player.printCodec();
    }


}

输出：

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