How to build OpenCV 3.2.0 with MinGW on Windows [closed]

Answer 1

1. Download and unpack OpenCV to a folder of your choice.

2. opencv\sources now contains CMakeLists.txt and all the other files necessary. Configure the project in CMake. CLion users may just open CMakeLists.txt.

   • Fix 1: sprintf () family security error.
     Add add_definitions(-DSTRSAFE_NO_DEPRECATE) to the beginning of CMakeLists.txt. This will define STRSAFE_NO_DEPRECATE symbol for the project and suppress the error.

   • Fix 2: 'too many sections' as.exe error.
     Add the following lines to the beginning of CMakeLists.txt (source):

     set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-Wa,-mbig-obj")
     set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} "-Wa,-mbig-obj")
     

   • Fix 3: 'the last argument must be an 8-bit immediate'.
     Found nothing better than hardcoding 0x88 instead of mask_lo = _MM_SHUFFLE(2, 0, 2, 0) (binary 10 00 10 00) and 0xDD instead of mask_hi.
     As soon as my question gets a better answer, I will update this paragraph.
   • Fix 4: no c++11 threads in MinGW.
     Again, a dirty solution: added #include <mingw.*.h> to <mutex>, <thread>, <condition_variable> before #endif // C++11. (Source)
3. Build it! It will take about 30-40 minutes.
4. Find the output folder. It is still a mess but contains a Makefile.
   Launch cmd, cd to the output folder and call [path to compiler]\mingw32-make.exe install. (Source)
5. Voila, your library is in the install folder! Now you can move it to a desired destination and set up environment variables.