class cv::cuda::FastOpticalFlowBM
#include <cudalegacy.hpp>
class FastOpticalFlowBM
{
public:
    // methods
    void
    operator()(
        const GpuMat& I0,
        const GpuMat& I1,
        GpuMat& flowx,
        GpuMat& flowy,
        int search_window = 21,
        int block_window = 7,
        Stream& s = Stream::Null()
        );
};