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14:29 by 雪夜&流星, ... 阅读,
如何在Android上使用FFmpeg解码图像参考文章&，如何在Android上使用SDL2.0来显示图像参考&。有了以上两篇文章的基础我们就可以在Android使用FFmpeg来解码图像并且使用SDL2.0来显示输出的图像了。
博主的开发环境：Ubuntu 14.04 64位，Eclipse+CDT+ADT+NDK。
在文章开始之前假定你已经知道如何使用NDK编译FFmpeg，以及知道如何移植SDL2.0到Android平台上来了，如有不明白的可以参考文章开头的两篇文章。
工程中的目录结构：ffmpeg文件夹下是ffmpeg相关的头文件以及编译的Android makefile文件，SDL文件夹下面是SDL2.0相关的头文件以及相关的源码和编译用的Android makefile 文件，player文件下是用来解码与显示相关的代码和Android makefile。
一、参考&创建一个工程，创建jni文件，在jni下创建SDL文件夹，将相应的头文件以及源码拷贝过来。在这里也可以参考&将编译好的动态库作为PREBUILT_SHARED_LIBRARY来加载。SDL文件下的Android.mk内容：
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)
二、参考， 在工程中新建一个ffmpeg文件夹，将与ffmpeg相关的头文件include进来。ffmpeg文件夹下的Android.mk内容：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := /path/to/build/ffmpeg/libffmpeg.so
include $(PREBUILT_SHARED_LIBRARY)
三、新建player文件夹，用来编写解码与显示文件。player.c文件内容：
* SDL_Lesson.c
Created on: Aug 12, 2014
Author: clarck
#include &jni.h&
#include &android/native_window_jni.h&
#include "SDL.h"
#include "SDL_thread.h"
#include "SDL_events.h"
#include "../include/logger.h"
#include "../ffmpeg/include/libavcodec/avcodec.h"
#include "../ffmpeg/include/libavformat/avformat.h"
#include "../ffmpeg/include/libavutil/pixfmt.h"
#include "../ffmpeg/include/libswscale/swscale.h"
int main(int argc, char *argv[]) {
char *file_path = argv[1];
LOGI("file_path:%s", file_path);
AVFormatContext *pFormatC
AVCodecContext *pCodecC
AVCodec *pC
AVFrame *pFrame, *pFrameYUV;
AVPacket *
uint8_t *out_
SDL_Texture *bmp = NULL;
SDL_Window *screen = NULL;
SDL_Event event;
static struct SwsContext *img_convert_
int videoStream, i, numB
int ret, got_
av_register_all();
pFormatCtx = avformat_alloc_context();
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
LOGE("Could not initialize SDL - %s. \n", SDL_GetError());
if (avformat_open_input(&pFormatCtx, file_path, NULL, NULL) != 0) {
LOGE("can't open the file. \n");
return -1;
if (avformat_find_stream_info(pFormatCtx, NULL) & 0) {
LOGE("Could't find stream infomation.\n");
return -1;
videoStream = 1;
for (i = 0; i & pFormatCtx-&nb_ i++) {
if (pFormatCtx-&streams[i]-&codec-&codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream =
LOGI("videoStream:%d", videoStream);
if (videoStream == -1) {
LOGE("Didn't find a video stream.\n");
return -1;
pCodecCtx = pFormatCtx-&streams[videoStream]-&
pCodec = avcodec_find_decoder(pCodecCtx-&codec_id);
if (pCodec == NULL) {
LOGE("Codec not found.\n");
return -1;
if (avcodec_open2(pCodecCtx, pCodec, NULL) & 0) {
LOGE("Could not open codec.\n");
return -1;
pFrame = av_frame_alloc();
pFrameYUV = av_frame_alloc();
//---------------------------init sdl---------------------------//
screen = SDL_CreateWindow("My Player Window", SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, pCodecCtx-&width, pCodecCtx-&height,
SDL_WINDOW_FULLSCREEN | SDL_WINDOW_OPENGL);
SDL_Renderer *renderer = SDL_CreateRenderer(screen, -1, 0);
bmp = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_YV12,
SDL_TEXTUREACCESS_STREAMING, pCodecCtx-&width, pCodecCtx-&height);
//-------------------------------------------------------------//
img_convert_ctx = sws_getContext(pCodecCtx-&width, pCodecCtx-&height,
pCodecCtx-&pix_fmt, pCodecCtx-&width, pCodecCtx-&height,
AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx-&width,
pCodecCtx-&height);
out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
avpicture_fill((AVPicture *) pFrameYUV, out_buffer, AV_PIX_FMT_YUV420P,
pCodecCtx-&width, pCodecCtx-&height);
rect.x = 0;
rect.y = 0;
rect.w = pCodecCtx-&
rect.h = pCodecCtx-&
int y_size = pCodecCtx-&width * pCodecCtx-&
packet = (AVPacket *) malloc(sizeof(AVPacket));
av_new_packet(packet, y_size);
av_dump_format(pFormatCtx, 0, file_path, 0);
while (av_read_frame(pFormatCtx, packet) &= 0) {
if (packet-&stream_index == videoStream) {
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture,
if (ret & 0) {
LOGE("decode error.\n");
return -1;
LOGI("got_picture:%d", got_picture);
if (got_picture) {
sws_scale(img_convert_ctx,
(uint8_t const * const *) pFrame-&data,
pFrame-&linesize, 0, pCodecCtx-&height, pFrameYUV-&data,
pFrameYUV-&linesize);
////iPitch 计算yuv一行数据占的字节数
//SDL_UpdateTexture(bmp, &rect, pFrameYUV-&data[0], pFrameYUV-&linesize[0]);
SDL_UpdateYUVTexture(bmp, &rect,
pFrameYUV-&data[0], pFrameYUV-&linesize[0],
pFrameYUV-&data[1], pFrameYUV-&linesize[1],
pFrameYUV-&data[2], pFrameYUV-&linesize[2]);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, bmp, &rect, &rect);
SDL_RenderPresent(renderer);
SDL_Delay(50);
av_free_packet(packet);
SDL_PollEvent(&event);
switch (event.type) {
case SDL_QUIT:
SDL_Quit();
SDL_DestroyTexture(bmp);
av_free(out_buffer);
av_free(pFrameYUV);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);
四、编写player文件夹下面的Android makefile，内容如下：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := player
SDL_PATH := ../SDL
FFMPEG_PATH := ../ffmpeg
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(SDL_PATH)/include
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(FFMPEG_PATH)/include
# Add your application source files here...
LOCAL_SRC_FILES := $(SDL_PATH)/src/main/android/SDL_android_main.c
LOCAL_SRC_FILES += player.c
LOCAL_SHARED_LIBRARIES := SDL2
LOCAL_SHARED_LIBRARIES += ffmpeg
LOCAL_LDLIBS := -lGLESv1_CM -lGLESv2 -llog
include $(BUILD_SHARED_LIBRARY)
五、修改SDLActivity.java文件内容，用来加载libffmpeg.so以及libplayer.so，以及修改用来解码的文件路径。
// Load the .so
System.loadLibrary("ffmpeg");
System.loadLibrary("SDL2");
//System.loadLibrary("SDL2_image");
//System.loadLibrary("SDL2_mixer");
//System.loadLibrary("SDL2_net");
//System.loadLibrary("SDL2_ttf");
System.loadLibrary("player");
Simple nativeInit() runnable
class SDLMain implements Runnable {
public void run() {
// Runs SDL_main()
String sdcard = Environment.getExternalStorageDirectory().getAbsolutePath();
SDLActivity.nativeInit("/sdcard/a.mp4");
//Log.v("SDL", "SDL thread terminated");
工程项目截图：
运行效果截图：