title: Can't link to fftw library using visual C++ express on windows 64 bit
body: <p>I'm trying to link to the fftw library using visual c++ express, but am getting linker errors when I try to compile. I generated the lib files as the site (http://fftw.org/install/windows.html) explains by creating  .lib "import libraries" using the lib.exe program.</p>
  
  <p>I added the .lib files to "Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib", and fftw3.h to "Program Files (x86)\Microsoft Visual Studio 9.0\VC\include". I then put the dll files in "Windows/system32" folder. I linked the libraries by adding them (libfftw3f-3.lib, libfftw3-3.lib, libfftw3l-3.lib) to additional dependencies on the linker/input preferences. When I try to compile I get the following errors:</p>
  
  <pre><code>    process_wav.obj : error LNK2019: unresolved external symbol __imp__fftwf_destroy_plan referenced in function _main
      process_wav.obj : error LNK2019: unresolved external symbol __imp__fftwf_plan_dft_r2c_1d referenced in function _main
  </code></pre>
  
  <p>I searched on stack overflow but most of the answers explain that the libraries need to be added to additional dependencies to be found. When I put /verbose:lib on command line options I get the following:</p>
  
  <pre><code>    f
      fdf
  
  1&gt;Linking...
  1&gt;Searching libraries
  1&gt;    Searching libfftw3f-3.lib:
  1&gt;    Searching libfftw3-3.lib:
  1&gt;    Searching libfftw3l-3.lib:
  1&gt;    Searching F:\Program Files\Mega-Nerd\libsndfile-win32-bin-1.1.7\libsndfile-1.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbc32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbccp32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\kernel32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\user32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\gdi32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\winspool.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\comdlg32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\advapi32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\shell32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\ole32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\oleaut32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\uuid.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\MSVCRTD.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\OLDNAMES.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\msvcprtd.lib:
  1&gt;    Searching libfftw3f-3.lib:
  1&gt;    Searching libfftw3-3.lib:
  1&gt;    Searching libfftw3l-3.lib:
  1&gt;    Searching F:\Program Files\Mega-Nerd\libsndfile-win32-bin-1.1.7\libsndfile-1.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbc32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbccp32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\kernel32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\user32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\gdi32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\winspool.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\comdlg32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\advapi32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\shell32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\ole32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\oleaut32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\uuid.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\MSVCRTD.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\OLDNAMES.lib:
  1&gt;    Searching F:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\lib\msvcprtd.lib:
  1&gt;    Searching libfftw3f-3.lib:
  1&gt;    Searching libfftw3-3.lib:
  1&gt;    Searching libfftw3l-3.lib:
  1&gt;    Searching F:\Program Files\Mega-Nerd\libsndfile-win32-bin-1.1.7\libsndfile-1.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbc32.lib:
  1&gt;    Searching F:\Program Files\Microsoft SDKs\Windows\v6.0A\\lib\odbccp32.lib:
  1&gt;Finished searching libraries
  </code></pre>
  
  <p>It seems to find the libraries but does not know who to find the function names in them. I got the code from a website which also uses this library, interestingly the function names do not appear in "fftw3.h" but I don't think this is the cause of the problem.</p>
  
  <p>Any help would be greatly appreciated as I'm not sure where to turn now.</p>
  
  <p>Thanks.</p>