I have a video which I need to analyse. The analysis software recognizes objects outside the area of interest and I would like to limit it to the specific arena. In order to do so I tried cropping but unfortunately my arena isn't rectangular. I thought about blackening parts of the video. But how will I be able to do so? I'm a technical person but I don't have any experience in video editing and I'm also working on a low budget.
Does anyone have any idea how to solve this problem?