Include static library in VS C++ project

Question

Configuration I have

• Windows 10 64bit
• Visual Studio Community 2017 with Visual C++ 2017
• CMake 3.9.0
• opencv 3.3.0

Aim

Goal is to build opencv as a static library ( .lib ) and include into a Visual C++ project which is a DLL. Everything should be compiled for x86 architecture or simply 32bit.

Process

Latest opencv distributive does not contain dll's compiled for 32bit system and therefore, I need to compile own version. According to the opencv 2.4 documentation on "installation in Windows" . I have compiled the library with BUILD_SHARED_LIBS option disabled and configured target project as described in "how to build applications with OpenCV inside the Microsoft Visual Studio" .

Compilation of my project fails with following errors (totally error count is greater than 800)

Error type 1

LNK2038 mismatch detected for 'RuntimeLibrary': value 'MTd_StaticDebug' 
doesn't match value 'MDd_DynamicDebug' in main.obj  
\opencv_core320d.lib(alloc.obj)

Error type 2

LNK2005 "public: void __thiscall std::basic_ostream<char,struct 
std::char_traits<char> >::_Osfx(void)" (?_Osfx@?$basic_ostream@DU?
$char_traits@D@std@@@std@@QAEXXZ) already defined in 
opencv_core320d.lib(system.obj) \msvcprtd.lib(MSVCP140D.dll)

Error type 3

LNK2001 unresolved external symbol _ippicviHSVToRGB_16u_C3R@24  
\opencv_imgproc320d.lib(color.obj)

I believe it may be due to uncoordinated compilation options or erroneous configuration of my project, but because I am heavy Linux user I experience difficulties with setting up these things on Windows.

Update

After I have matched configuration shown in the screen below block of errors about code generation mismatch disappeared, but undefined references are still there.

Thank you for help!

Answer 1

To resolve "Error type 3" add *.lib files from "staticlib" dir to "Linker->Input->Additional Dependencies". For example "_ipp" symbols are defined in "ipp_iw.lib" and "ippicvmt.lib".

Just for info. I successfully built opencv from sources as a static and shared library (as opencv_world3**.lib) using MSVS 2012 and cmake 3.9.0. But also done that with MSVS 2017 community.

PS. Maybe a TYPO but you said that you use opencv 3.3.0 but in error messages there is opencv_core 320 d.lib

PPS. "Error type 1" is the result of using static debug runtime version in opencv_core (MTd) and dynamic debug runtime in your app (MDd)

Answer 2

I always have the same problems. This is why I have a property sheet ready for use.

The steps to follow for static compilation are:

1. Remember to Build the INSTALL project in the CMake generated Solution. Let's call $(OPENCV_DIR) the folder where the install happened (usually something like xxx\\install ). You can create an environment variable for this.
2. Add in front of [Configuration Properties]->[VC++ Directories]->[Include Directories] $(OPENCV_DIR)\\include; . The semicolon is to separate paths.
3. Add in front of [Configuration Properties]->[VC++ Directories]->[Library Directories] $(OPENCV_DIR)\\x86\\vc15\\staticlib; .
4. Match the runtime library linkage mode between OpenCV and your project. If you unselect BUILD_SHARED_LIBS by default the CRT is statically linked (/MT for Release or /MTd for Debug). If you want it dynamically linked deselect BUILD_WITH_STATIC_CRT . So, as you already realized, fix it in [Configuration Properties]->[C/C++]->[Code Generation]->[Runtime Library] .
5. Copy all filenames matching *.lib ( *d.lib for Debug) and add them in [Configuration Properties]->[Linker]->[Input]->[Additional Dependencies] separated by semicolons.

It's quite painful, so do it once in a Property Sheet and just include it when needed.