ffmpeg下面几个函数与结构体找不到；//头文件加好了，版本太低?
avformat_open_input()
av_probe_input_buffer()
avformat_alloc_context()
avio_alloc_context()
AVIOContext* pb = NULL;
AVInputFormat* piFmt = NULL;
3.2版本的呀
extern "C"
{
#include "include/libavcodec/avcodec.h"
#include "include/libavformat/avformat.h"
#include "include/libswscale/swscale.h"
}
#pragma comment(lib,"lib/avcodec.lib")
#pragma comment(lib,"lib/avdevice.lib")
#pragma comment(lib,"lib/avfilter.lib")
#pragma comment(lib,"lib/avformat.lib")
#pragma comment(lib,"lib/avutil.lib")
#pragma comment(lib,"lib/swscale.lib")
