I'm new to OpenCV and I'm trying to figure this out. I have a .mp4 file saved on disk that I streamed from a webcam. Now I need to produce a lower res version of the video for upload to a web server (this idea is that a low-res preview uploads more or less in real-time, and then the full-res follows at some later point). I'm trying to use OpenCV/Python to do this but I can't find anything pointing me in the right direction. Resize() seems to be relevant but it looks like it's only applicable to images and not video. Is this really not possible using OpenCV and, if so, can anyone recommend an alternative?