pub unsafe extern "C" fn ncnn_mat_from_pixels_roi( pixels: *const c_uchar, type_: c_int, w: c_int, h: c_int, stride: c_int, roix: c_int, roiy: c_int, roiw: c_int, roih: c_int, allocator: ncnn_allocator_t) -> ncnn_mat_t
