OpenCV won't build with CUDA even though WITH_

Question

I have tried to build OpenCV 3.1 using CMake (the gui version) to enable Cuda. I have installed Cuda version 7.5 64-bit and CMake automatically found the correct path to the Cuda toolkit. I made sure that the WITH_CUDA value was set to ON, and pressed configure. This is what I got concerning Cuda:

CUDA detected: 7.5
CUDA NVCC target flags: -gencode;arch=compute_20,code=sm_20;-gencode;arch=compute_20,code=sm_21;-gencode;arch=compute_30,code=sm_30;-gencode;arch=compute_35,code=sm_35;-gencode;arch=compute_30,code=compute_30

...

Extra dependencies:          comctl32 gdi32 ole32 setupapi ws2_32 vfw32 cudart nppc nppi npps cufft -LC:/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v7.5/lib/x64

...

Other third-party libraries:
Use IPP:                     9.0.1 [9.0.1]
     at:                     C:/OpenCV-3.1.0/opencv/sources/3rdparty/ippicv/unpack/ippicv_win
Use IPP Async:               NO
Use Eigen:                   NO
Use Cuda:                    YES (ver 7.5)
Use OpenCL:                  YES
Use custom HAL:              NO

NVIDIA CUDA
Use CUFFT:                   YES
Use CUBLAS:                  NO
USE NVCUVID:                 NO
NVIDIA GPU arch:             20 21 30 35
NVIDIA PTX archs:            30
Use fast math:               YES

Then I generate using Visual Studio 12 2013 Win64.

Next I open the newly generated OpenCV.sln project in Visual Studio 2013 and build the project. It completes without any errors, but 103 warnings like this:

LINK : warning LNK4044: unrecognized option '/LC:/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v7.5/lib/x64'; ignored

OpenCV builds just fine and I can build programs with it. I can also include "opencv2/core/cuda.hpp" without any problem. However, when I try to use cuda::getDevice() i get this error:

OpenCV Error: No CUDA support (The library is compiled without CUDA support) in throw_no_cuda, file C:\builds\master_PackSlave-win64-vc12-shared\opencv\modules\core\include\opencv2/core/private.cuda.hpp, line 97

When I print the information from cv::getBuildInformation() i get:

Other third-party libraries:
Use IPP:                     9.0.1 [9.0.1]
     at:                     C:\builds\master_PackSlave-win64-vc12-shared\opencv\3rdparty/ippicv/unpack/ippicv_win
Use IPP Async:               NO
Use Eigen:                   NO
Use Cuda:                    NO
Use OpenCL:                  YES
Use custom HAL:              NO

It seems Cuda is disabled somewhere in the process, but I can't figure out why. I have tried to reconfigure and rebuild several times with the same results. Would love some help on this!

Answer 1

The problem is CMake: it generates wrong link options for Visual Studio.

LINK : warning LNK4044: unrecognized option '/LC:/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v7.5/lib/x64'; ignored

It should be "LIBPATH:C:" instead of "LC:".

To fix the problem:

• Generate the solution with CMake
• Go to the build directory
• Open an IDE/Text editor which is able to do a global search in this directory
• For each occurrence of "-LC:" in any file, replace it by "-LIBPATH:C:".

========= EDIT =========

I found the problem, it is in CMakeLists.txt :

foreach(p ${CUDA_LIBS_PATH})
  set(OPENCV_LINKER_LIBS ${OPENCV_LINKER_LIBS} -L${p})
endforeach()

Instead of using "${CMAKE_LIBRARY_PATH_FLAG}" which automatically put -LIBPATH, someone put "-L"...

So to fix it:

• Open CMakeLists.txt
• Replace "-L" by "${CMAKE_LIBRARY_PATH_FLAG}"

Configure & Generate the solution with CMake and compile with VS.

Hope it will help!

Answer 2

You can successfully compile OpenCV with Cuda after manually editing CMakeLists.txt as Dubrzr say.

Also You will have the same result if you download and compile OpenCV straight from github. It is already fixed.