最简单的android studio调用ffmpeg动态库

准备工作：

1.编译好的ffmpeg动态库.so文件，以及ffmpeg的头文件；

2.android studio开发环境，包括NDK等可用环境；

步骤一：

新建一个android studio工程，命名netplayer，勾选“Include C++ support”；其他选择默认，直到完成；

步骤二：

将ffmpeg的动态库和include头文件，拷贝到netplayer工程的libs目录下：

android studio会自动更新工程列表，后续主要修改以下几个文件：

//C++接口的实现，内部封装ffmpeg功能

E:\MyAndroidWorkSpace\netplayer\app\src\main\cpp\native-lib.cpp

//java界面，调用C++接口
E:\MyAndroidWorkSpace\netplayer\app\src\main\java\player\cn\com\netplayer\MainActivity.java

//编译参数，指定库
E:\MyAndroidWorkSpace\netplayer\app\CMakeLists.txt

//jni相关
E:\MyAndroidWorkSpace\netplayer\app\build.gradle

步骤三（CMakeList.txt）

cmake_minimum_required(VERSION 3.4.1)

find_library( log-lib
              log )

set(distribution_DIR ../../../../libs)

add_library( native-lib
             SHARED
             src/main/cpp/native-lib.cpp )

add_library( avcodec-57
             SHARED
             IMPORTED)
set_target_properties( avcodec-57
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libavcodec-57.so)

add_library( avfilter-6
             SHARED
             IMPORTED)
set_target_properties( avfilter-6
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libavfilter-6.so)

add_library( avformat-57
             SHARED
             IMPORTED)
set_target_properties( avformat-57
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libavformat-57.so)

add_library( avutil-55
             SHARED
             IMPORTED)
set_target_properties( avutil-55
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libavutil-55.so)

add_library( swresample-2
             SHARED
             IMPORTED)
set_target_properties( swresample-2
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libswresample-2.so)

add_library( swscale-4
             SHARED
             IMPORTED)
set_target_properties( swscale-4
                       PROPERTIES IMPORTED_LOCATION
                       ${distribution_DIR}/armeabi/libswscale-4.so)

include_directories(libs/include)

target_link_libraries( native-lib
                       avcodec-57
                       avfilter-6
                       avformat-57
                       avutil-55
                       swresample-2
                       swscale-4
                       ${log-lib} )

步骤四(build.gradle)：

在系统生成的原来基础上，加入：

defaultConfig下加入：

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

externalNativeBuild下加入：

ndk{
    abiFilters "armeabi"
}

完整内容：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "26.0.0"
    defaultConfig {
        applicationId "player.cn.com.netplayer"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        sourceSets {
            main {
                jniLibs.srcDirs = ['libs']
            }
        }
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
            ndk{
                abiFilters "armeabi"
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path "CMakeLists.txt"
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
}

经过以上4个步骤，已经可以build成功了。

步骤5（native-lib.cpp）

#include 
#include 
#include 


extern "C" {
//编码
#include "libavcodec/avcodec.h"
//封装格式处理
#include "libavformat/avformat.h"
//像素处理
#include "libswscale/swscale.h"
}

#define FFLOGI(FORMAT,...) __android_log_print(ANDROID_LOG_INFO,"ffmpeg",FORMAT,##__VA_ARGS__);
#define FFLOGE(FORMAT,...) __android_log_print(ANDROID_LOG_ERROR,"ffmpeg",FORMAT,##__VA_ARGS__);

extern "C"
JNIEXPORT jstring JNICALL
Java_player_cn_com_netplayer_MainActivity_stringFromJNI(
        JNIEnv *env,
        jobject /* this */) {
    std::string hello = "Hello from C++";
    return env->NewStringUTF(hello.c_str());
}

extern "C"
JNIEXPORT jstring JNICALL
Java_player_cn_com_netplayer_MainActivity_InitFFMPEG(
        JNIEnv* env,
        jobject /* this */) {
    //1.注册所有组件
    av_register_all();

    std::string hello = "av_register_all OK";
    return env->NewStringUTF(hello.c_str());
}

步骤六(MainActivity.java)：

package player.cn.com.netplayer;

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

public class MainActivity extends AppCompatActivity {

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

    @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);
        tv.setText(stringFromJNI());
        tv.setText(InitFFMPEG());
    }

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

演示结果：

Demo程序下载地址：https://github.com/zhuxian2009/netplayer