Since vtest.avi is part of the official OpenCV sample data, the safest and most reliable place to download it is directly from the source:
Separating moving objects (pedestrians) from the static environment. vtest.avi download
If the video won't open, your system might lack the necessary AVI codecs . Installing opencv-contrib-python via pip often resolves background processing issues. Since vtest
Many computer vision datasets on Kaggle also include this file for tutorial purposes. vtest.avi download