[FFmpeg-user] error avformat_open_input

[geronimo eberle]

hellow!
im a new user whit FFmpeg and im trying to do a video editor whit c++.
my error its:
Severity Code Description Project File Line Suppression State
Error LNK2019 unresolved external symbol "int __cdecl avformat_open_input(struct AVFormatContext * *,char const *,struct AVInputFormat *,struct AVDictionary * *)" (?avformat_open_input@@YAHPAPAUAVFormatContext@@PBDPAUAVInputFormat@@PAPAUAVDictionary@@@Z) referenced in function "bool __cdecl load_video(char const *)" (?load_video@@YA_NPBD at Z) Video C:\Users\gerit\source\repos\Video\Main.obj 1

the code its:

const char *filename = "prueba.mp4";
bool load_video(const char* filename)
{
        AVFormatContext *av_format_context = NULL;
        if (!av_format_context)
        {
                cout << "no se pudo cargar context";
                return false;
        }
        if (avformat_open_input(&av_format_context, filename, NULL, NULL) != 0)
        {
                cout << "no se pudo cargar viedo";
                return false;
        }

        return true;
};

and the video its in the same path that the project.
sorry for my english, its very bad, and ty for your help!