[Discuss-gnuradio] Using fft::fft_complex in an out-of-tree moudle

[Nguyễn Văn Lý]

Hi all,

I created an out-of-tree module for my personal project. 

In one block, I need to perform FFT and IFFF, so I put "#include <gnuradio/fft/fft.h>" in the header file, and then declare fft::fft_complex *d_ifft;

​In the .cc file, I wrote d_ifft = new fft::fft_complex(64, false, 1);​

​Then I can compile without any error messages, but when I run a flow graph to ​test the block, it turns out an error message like this:

Traceback (most recent call last):

  File "/home/van-ly/sandbox/gnuradio-builds/Test/top_block.py", line 15, in <module>

    import PNC4TWRN

  File "/opt/gnuradio-3.7.3/lib/python2.7/dist-packages/PNC4TWRN/__init__.py", line 45, in <module>

    from PNC4TWRN_swig import *

  File "/opt/gnuradio-3.7.3/lib/python2.7/dist-packages/PNC4TWRN/PNC4TWRN_swig.py", line 28, in <module>

    _PNC4TWRN_swig = swig_import_helper()

  File "/opt/gnuradio-3.7.3/lib/python2.7/dist-packages/PNC4TWRN/PNC4TWRN_swig.py", line 24, in swig_import_helper

    _mod = imp.load_module('_PNC4TWRN_swig', fp, pathname, description)

ImportError: /opt/gnuradio-3.7.3/lib/libgnuradio-PNC4TWRN.so: undefined symbol: _ZN2gr3fft11fft_complexC1Eibi

​Could any one please help me with this?

Does any one know how to use the perform FFT ​in an out-of-tree module?

Thank you in advance,

Van-Ly

Van-Ly Nguyen,

Research Assistant, 

Signals and Systems Laboratory - SSL  

Faculty of Electronics and Telecommunications - FET         

University of Engineering and Technology - UET      

Vietnam National University, Hanoi - VNU  

Phone: (+84) 97 881 9406