The licenses are included in the header files tho which they applies:
/usr/include/ffnvcodec/dynlink_cuda.h
/usr/include/ffnvcodec/dynlink_cuviddec.h
/usr/include/ffnvcodec/dynlink_loader.h
/usr/include/ffnvcodec/dynlink_nvcuvid.h
/usr/include/nvEncodeAPI.h