c++ - undefined reference to 'av_rdft_init(int, RDFTransformType)' -

i'm trying integrate ffmpeg library android ndk project. followed this documentation. when try call method avcodec library av_malloc, there no problem. when try call av_rdft_init or av_rdft_calc methods, ndk gives errors as;

 error: undefined reference 'av_rdft_init(int, rdftransformtype)'    error: undefined reference 'av_rdft_calc(rdftcontext*)' 

i can see methods in header file , see in libavcodec.so file's symbol table not build ndk.

any ideas fix problem? in advance.

problem fixed adding local_allow_undefined_symbols := true android makefile