Find if a face is in a saved video on iPhone

I need to have an app that does the following: 1. Select any video in photolibrary (or a local directory on the phone) 2. Takes all frames (with the option of also reduces the frames to speed up the process) from the video 3. Passes each frame through the vision framework from Apple to find whether a face (or using CoreML framework, if a human) is in the frame. 4. Returns for each video a boolean of Yes for face present and No for face not present