Write some Software

I have a video-sharing website that looks like YouTube. I want to add the feature to be able to apply 'preroll, midroll and postroll' ads on the videos in the website. I want to be uploading MY OWN ADS to my server or uploading them to a specific YouTube channel, and then applying them to relevant videos based on a targeted criteria that matches the ads to a certain group of videos (target marketing). The website is already operational and can show ads from VAST/VPAID and Google, but I want to display MY OWN ADS from my own source so that I can be getting short adverts from local businesses and having them played within my website's videos.