最简单的基于FFmpeg的移动端样例附件：SDL Android HelloWorld

c)?编写Application.mk文件（可选）
Application.mk中的APP_ABI设定了编译后库文件支持的指令集。默认使用“armeabi”，这里使用默认值就能够了。

d)?执行ndk-build
编写完C语言代码和Android.mk之后就能够执行ndk-build命令进行编译了。

ndk-build命令执行成功后，会在根文件夹下的“libs/armeabi”文件夹中生成2个库文件：

libSDL2.so
libSDL2main.so

源码

项目的文件夹结构如图所看到的。Java源码位于src文件夹。而C代码位于jni文件夹。

Android程序Java端代码位于src\org\libsdl\app\SDLActivity.java。

该Activity取自于SDL2源码文件夹中的android-projectproject。在这里不再记录。

jni文件夹中的src和include文件夹各自是SDL2的源码文件夹中的src文件夹和include文件夹。

C语言端源码位于jni/simplest_showbmp.c。例如以下所看到的。该源码读取了存储卡中的一张test.bmp文件，并显示出来。

/**
 * 移植SDL到安卓平台的HelloWorld程序
 * Simplest SDL Android Helloworld
 *
 * 雷霄骅 Lei Xiaohua
 * leixiaohua1020@126.com
 * 中国传媒大学/数字电视技术
 * Communication University of China / Digital TV Technology
 * http://blog.csdn.net/leixiaohua1020
 *
 *
 * 本程序是移植SDL到安卓平台的最简单程序。它能够读取并显示一张BMP图片。

 *
 * This software is the simplest program transplant SDL2 to Android platform.
 * It shows a BMP file on the screen.
 */

#ifdef __ANDROID__

#include <jni.h>
#include <android/log.h>
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO , "(^_^)", __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR , "(^_^)", __VA_ARGS__)
#else
#define LOGE(format, ...)  printf("(>_<) " format "\n", ##__VA_ARGS__)
#define LOGI(format, ...)  printf("(^_^) " format "\n", ##__VA_ARGS__)
#endif

#include "SDL.h"
#include "SDL_log.h"
#include "SDL_main.h"

int main(int argc, char *argv[]) {
	struct SDL_Window *window = NULL;
	struct SDL_Renderer *render = NULL;
	struct SDL_Surface *bmp = NULL;
	struct SDL_Texture *texture = NULL;

    char *filepath = "/storage/emulated/0/test.bmp";

    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER) == -1) {
        LOGE("SDL_Init failed %s", SDL_GetError());
    }

    window = SDL_CreateWindow("SDL HelloWorld!", 100, 100, 640, 480,
            SDL_WINDOW_SHOWN);
    if (window == NULL) {
        LOGE("SDL_CreateWindow failed  %s", SDL_GetError());
    }

    render = SDL_CreateRenderer(window, -1,
            SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    if (render == NULL) {
        LOGE("SDL_CreateRenderer failed  %s", SDL_GetError());
    }

    bmp = SDL_LoadBMP(filepath);
    if (bmp == NULL) {
        LOGE("SDL_LoadBMP failed: %s", SDL_GetError());
    }

    texture = SDL_CreateTextureFromSurface(render, bmp);
    SDL_FreeSurface(bmp);

    SDL_RenderClear(render);
    SDL_RenderCopy(render, texture, NULL, NULL);
    SDL_RenderPresent(render);

    SDL_Delay(10000);

    SDL_DestroyTexture(texture);
    SDL_DestroyRenderer(render);
    SDL_DestroyWindow(window);

    //Quit SDL
    SDL_Quit();
    return 0;
}

LOCAL_PATH := $(call my-dir)

###########################
#
# SDL shared library
#
###########################

include $(CLEAR_VARS)

LOCAL_MODULE := SDL2

LOCAL_C_INCLUDES := $(LOCAL_PATH)/include

LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)

LOCAL_SRC_FILES := 	$(subst $(LOCAL_PATH)/,, 	$(wildcard $(LOCAL_PATH)/src/*.c) 	$(wildcard $(LOCAL_PATH)/src/audio/*.c) 	$(wildcard $(LOCAL_PATH)/src/audio/android/*.c) 	$(wildcard $(LOCAL_PATH)/src/audio/dummy/*.c) 	$(LOCAL_PATH)/src/atomic/SDL_atomic.c 	$(LOCAL_PATH)/src/atomic/SDL_spinlock.c.arm 	$(wildcard $(LOCAL_PATH)/src/core/android/*.c) 	$(wildcard $(LOCAL_PATH)/src/cpuinfo/*.c) 	$(wildcard $(LOCAL_PATH)/src/dynapi/*.c) 	$(wildcard $(LOCAL_PATH)/src/events/*.c) 	$(wildcard $(LOCAL_PATH)/src/file/*.c) 	$(wildcard $(LOCAL_PATH)/src/haptic/*.c) 	$(wildcard $(LOCAL_PATH)/src/haptic/dummy/*.c) 	$(wildcard $(LOCAL_PATH)/src/joystick/*.c) 	$(wildcard $(LOCAL_PATH)/src/joystick/android/*.c) 	$(wildcard $(LOCAL_PATH)/src/loadso/dlopen/*.c) 	$(wildcard $(LOCAL_PATH)/src/power/*.c) 	$(wildcard $(LOCAL_PATH)/src/power/android/*.c) 	$(wildcard $(LOCAL_PATH)/src/filesystem/dummy/*.c) 	$(wildcard $(LOCAL_PATH)/src/render/*.c) 	$(wildcard $(LOCAL_PATH)/src/render/*/*.c) 	$(wildcard $(LOCAL_PATH)/src/stdlib/*.c) 	$(wildcard $(LOCAL_PATH)/src/thread/*.c) 	$(wildcard $(LOCAL_PATH)/src/thread/pthread/*.c) 	$(wildcard $(LOCAL_PATH)/src/timer/*.c) 	$(wildcard $(LOCAL_PATH)/src/timer/unix/*.c) 	$(wildcard $(LOCAL_PATH)/src/video/*.c) 	$(wildcard $(LOCAL_PATH)/src/video/android/*.c)     $(wildcard $(LOCAL_PATH)/src/test/*.c))

LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES
LOCAL_LDLIBS := -ldl -lGLESv1_CM -lGLESv2 -llog -landroid

include $(BUILD_SHARED_LIBRARY)

###########################
#
# SDL static library
#
###########################

LOCAL_MODULE := SDL2_static

LOCAL_MODULE_FILENAME := libSDL2

LOCAL_SRC_FILES += $(LOCAL_PATH)/src/main/android/SDL_android_main.c

LOCAL_LDLIBS := 
LOCAL_EXPORT_LDLIBS := -Wl,--undefined=Java_org_libsdl_app_SDLActivity_nativeInit -ldl -lGLESv1_CM -lGLESv2 -llog -landroid

include $(BUILD_STATIC_LIBRARY)


#libSDL2main=======================================
# Lei Xiaohua
include $(CLEAR_VARS)
LOCAL_MODULE := SDL2main
SDL_PATH := ./
LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(SDL_PATH)/include
# Add your application source files here...
LOCAL_SRC_FILES := $(SDL_PATH)/src/main/android/SDL_android_main.c 	$(SDL_PATH)/simplest_showbmp.c
LOCAL_SHARED_LIBRARIES := SDL2
LOCAL_LDLIBS := -lGLESv1_CM -lGLESv2 -llog
include $(BUILD_SHARED_LIBRARY)

执行结果

App在手机上执行后的结果例如以下图所看到的。能够看出App读取了test.bmp文件而且显示出来。

注意须要把BMP文件拷贝至存储卡相应的文件夹中。程序默认情况下会读取根文件夹下的“test.bmp”文件。

下载

Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile

SourceForge：https://sourceforge.net/projects/simplestffmpegmobile/

[Android]
simplest_android_player: 基于安卓接口的视频播放器
simplest_ffmpeg_android_helloworld: 安卓平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_android_decoder: 安卓平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_android_decoder_onelib: 安卓平台下最简单的基于FFmpeg的视频解码器-单库版
simplest_ffmpeg_android_streamer: 安卓平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_android_transcoder: 安卓平台下移植的FFmpeg命令行工具
simplest_sdl_android_helloworld: 移植SDL到安卓平台的最简单程序
[IOS]
simplest_ios_player: 基于IOS接口的视频播放器
simplest_ffmpeg_ios_helloworld: IOS平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_ios_decoder: IOS平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_ios_streamer: IOS平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_ios_transcoder: IOS平台下移植的ffmpeg.c命令行工具
simplest_sdl_ios_helloworld: 移植SDL到IOS平台的最简单程序