gulinux@ubuntu:~/mmWorkspace$ gcc -o simplest_ffmpeg_player simplest_ffmpeg_player.c -I/usr/local/ffmpeg/include -L/usr/local/ffmpeg/lib -lavformat -lavcodec -lavutil
simplest_ffmpeg_player.c: In function ‘main’:
simplest_ffmpeg_player.c:64:2: warning: ‘avcodec_alloc_frame’ is deprecated (declared at /usr/local/ffmpeg/include/libavcodec/avcodec.h:3927) [-Wdeprecated-declarations]
pFrame=avcodec_alloc_frame();
^
simplest_ffmpeg_player.c:65:2: warning: ‘avcodec_alloc_frame’ is deprecated (declared at /usr/local/ffmpeg/include/libavcodec/avcodec.h:3927) [-Wdeprecated-declarations]
pFrameYUV=avcodec_alloc_frame();
^
/tmp/ccJLfKXD.o: In function `main':
simplest_ffmpeg_player.c:(.text+0x6e): undefined reference to `av_find_stream_info'
simplest_ffmpeg_player.c:(.text+0x1ee): undefined reference to `SDL_Init'
simplest_ffmpeg_player.c:(.text+0x1f7): undefined reference to `SDL_GetError'
simplest_ffmpeg_player.c:(.text+0x23b): undefined reference to `SDL_SetVideoMode'
simplest_ffmpeg_player.c:(.text+0x286): undefined reference to `SDL_CreateYUVOverlay'
simplest_ffmpeg_player.c:(.text+0x365): undefined reference to `sws_getContext'
simplest_ffmpeg_player.c:(.text+0x415): undefined reference to `sws_scale'
simplest_ffmpeg_player.c:(.text+0x421): undefined reference to `SDL_LockYUVOverlay'
simplest_ffmpeg_player.c:(.text+0x49b): undefined reference to `SDL_UnlockYUVOverlay'
simplest_ffmpeg_player.c:(.text+0x4d5): undefined reference to `SDL_DisplayYUVOverlay'
simplest_ffmpeg_player.c:(.text+0x4e1): undefined reference to `SDL_Delay'
simplest_ffmpeg_player.c:(.text+0x515): undefined reference to `sws_freeContext'
collect2: error: ld returned 1 exit status
个人认为是没有找到SDL.h文件造成的，但在代码里面已经加了这个头文件，请大神帮忙指点一二，再次感谢！！！
