Calculation of TV L1 flow

I tried to use the DualTVL1OpticalFlow_create from opencv but it is not available at the latest version of cv2. Then, I tried to import cv2.optflow.DualTVL1OpticalFlow and, despite I can do it, I got an error when I calculated the flow.

cv2.error: OpenCV(4.5.4) D:\a\opencv-python\opencv-python\opencv_contrib\modules\optflow\src\tvl1flow.cpp:415: error: (-215:Assertion failed) I0.type() == CV_8UC1 || I0.type() == CV_32FC1 in function 'cv::optflow::OpticalFlowDual_TVL1::calc'

Can someone help me, please?

Start by reproducing the reported calls to cv2.optflow.DualTVL1OpticalFlow and the failing calc invocation, using the error details in the issue. Check the expected input types and the availability of DualTVL1OpticalFlow_create in the installed cv2 version. Done means identifying a confirmed cause and documenting or correcting the repository’s relevant usage, but no file or test is named.

Written by the indexing model from the issue text.