1.新建XCode工程后，发现即使安装了SDL和FFMPEG也编译不成功，需要修改各种环境。经过我的不懈努力加百谷啥的...贴个能编译通过的过程出来。谨记！
2.首先需要编译好ffmpeg源代码，然后还需要安装SDL（ffmpeg直接编译，SDL我是通过brew安装的）
3.修改工程的搜索路径，Header search Path添加ffmpeg的include目录以及/usr/local/include目录，告知Xcode需要使用的FFMPEG以及SDL头文件的路径，Library search path则是对应的FFMPEG以及SDL的库目录
4.添加其他引用库以及框架，如下图所示：
5.基本不用改的代码如下：
/**6.我反正编译通过了，可以播放视频，不过木有声音
* 最简单的基于FFmpeg的视频播放器
* Simplest FFmpeg Player
*
* 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
*
* 本程序实现了视频文件的解码和显示（支持HEVC，H.264，MPEG2等）。
* 是最简单的FFmpeg视频解码方面的教程。
* 通过学习本例子可以了解FFmpeg的解码流程。
* This software is a simplest video player based on FFmpeg.
* Suitable for beginner of FFmpeg.
*
* Version:1.0
*/
extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "sdl/SDL.h"
#include "sdl/SDL_thread.h"
};
//Full Screen
#define SHOW_FULLSCREEN 0
//Output YUV420P
#define OUTPUT_YUV420P 0
int main(int argc, char* argv[])
{
AVFormatContext*pFormatCtx;
inti, videoindex;
AVCodecContext*pCodecCtx;
AVCodec*pCodec;
char filepath[]="/Users/wangwei/src/1.mkv";
av_register_all();
avformat_network_init();
pFormatCtx = avformat_alloc_context();
if(avformat_open_input(&pFormatCtx,filepath,NULL,NULL)!=0){
printf("Couldn't open input stream.（无法打开输入流）\n");
return -1;
}
if(avformat_find_stream_info(pFormatCtx, NULL) < 0)
{
printf("Couldn't find stream information.（无法获取流信息）\n");
return -1;
}
videoindex=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
{
videoindex=i;
break;
}
if(videoindex==-1)
{
printf("Didn't find a video stream.（没有找到视频流）\n");
return -1;
}
pCodecCtx=pFormatCtx->streams[videoindex]->codec;
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL)
{
printf("Codec not found.（没有找到解码器）\n");
return -1;
}
if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
{
printf("Could not open codec.（无法打开解码器）\n");
return -1;
}
AVFrame*pFrame,*pFrameYUV;
pFrame=avcodec_alloc_frame();
pFrameYUV=avcodec_alloc_frame();
uint8_t *out_buffer=(uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
//------------SDL----------------
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
printf( "Could not initialize SDL - %s\n", SDL_GetError());
return -1;
}
int screen_w=0,screen_h=0;
SDL_Surface *screen;
#if SHOW_FULLSCREEN
const SDL_VideoInfo *vi = SDL_GetVideoInfo();
screen_w = vi->current_w;
screen_h = vi->current_h;
screen = SDL_SetVideoMode(screen_w, screen_h, 0,SDL_FULLSCREEN);
#else
screen_w = pCodecCtx->width;
screen_h = pCodecCtx->height;
screen = SDL_SetVideoMode(screen_w, screen_h, 0,0);
#endif
if(!screen) {
printf("SDL: could not set video mode - exiting:%s\n",SDL_GetError());
return -1;
}
SDL_Overlay *bmp;
bmp = SDL_CreateYUVOverlay(pCodecCtx->width, pCodecCtx->height,SDL_YV12_OVERLAY, screen);
SDL_Rect rect;
int ret, got_picture;
AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket));
//输出一下信息-----------------------------
printf("File Information（文件信息）---------------------\n");
av_dump_format(pFormatCtx,0,filepath,0);
printf("-------------------------------------------------\n");
#if OUTPUT_YUV420P
FILE *fp_yuv=fopen("output.yuv","wb+");
#endif
struct SwsContext *img_convert_ctx;
img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
//------------------------------
while(av_read_frame(pFormatCtx, packet)>=0)
{
if(packet->stream_index==videoindex)
{
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
if(ret < 0)
{
printf("Decode Error.（解码错误）\n");
return -1;
}
if(got_picture)
{
sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize);
#if OUTPUT_YUV420P
int y_size=pCodecCtx->width*pCodecCtx->height;
fwrite(pFrameYUV->data[0],1,y_size,fp_yuv); //Y
fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv); //U
fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv); //V
#endif
SDL_LockYUVOverlay(bmp);
bmp->pixels[0]=pFrameYUV->data[0];
bmp->pixels[2]=pFrameYUV->data[1];
bmp->pixels[1]=pFrameYUV->data[2];
bmp->pitches[0]=pFrameYUV->linesize[0];
bmp->pitches[2]=pFrameYUV->linesize[1];
bmp->pitches[1]=pFrameYUV->linesize[2];
SDL_UnlockYUVOverlay(bmp);
rect.x = 0;
rect.y = 0;
rect.w = screen_w;
rect.h = screen_h;
//测试自己填充数据----------------
SDL_DisplayYUVOverlay(bmp, &rect);
//延时40ms
//SDL_Delay(40);
}
}
av_free_packet(packet);
}
sws_freeContext(img_convert_ctx);
#if OUTPUT_YUV420P
fclose(fp_yuv);
#endif
SDL_Quit();
av_free(out_buffer);
av_free(pFrameYUV);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);
return 0;
}