title: FFTW in Qt Creator
body: <p>I try to make a program that computes FFTW from IQ data. 
  Windows 10 64 bits. Qt Creator 4.8.2 Based on Qt 5.12.2 (MSVC 2015, 32 bit)
  The program crashed when I use </p>
  
  <pre><code>fftw_plan_dft_1d(N, in, out, FFT_FORWARD, FFTW_ESTIMATE);
  </code></pre>
  
  <p>I download fftw-3.3.5-dll64 and dll32, with both the same result.</p>
  
  <p>.pro</p>
  
  <pre><code>INCLUDEPATH += $$PWD/fftw-3.3.5-dll32
  QMAKE_LIBDIR += $$PWD/fftw-3.3.5-dll32
  LIBS += $$PWD/fftw-3.3.5-dll32/ -llibfftw3-3
  LIBS += $$PWD/fftw-3.3.5-dll32/ -llibfftw3f-3
  LIBS += $$PWD/fftw-3.3.5-dll32/ -llibfftw3l-3
  </code></pre>
  
  <p>.cpp</p>
  
  <pre><code>include "fftw3.h"
  
  int main()
  {
      int N;
      fftw_complex *in, *out;
      fftw_plan myPlan;
  
      in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex)* N);
      out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex)* N);
  
  
      fftw_plan_dft_1d(N, in, out, FFT_FORWARD, FFTW_ESTIMATE);  //this line crashed the program.
  
      fftw_execute(myPlan);
  
      fftw_destroy_plan(myPlan);
      fftw_free(in);
      fftw_free(out);
  }
  </code></pre>
  
  <p>I hope some one can help me. 
  Thanks. </p>