"Now start the CMake (cmake-gui). You may again enter it in the start menu search or get it from the All Programs ‣ CMake 2.8 ‣ CMake (cmake-gui). First, select the directory for the source files of the OpenCV library (1). Then, specify a directory where you will build the binary files for OpenCV (2)." ------ I want to know where is the source files of the OpenCV library (1)? After I download the file from https://github.com/Itseez/opencv.git, there is no file named "source".