Spliting a conference call vido by topic

Once a week I host a video chat that has a series of presenters, one after the other. After the call, I manually split the video and upload each presenter’s presentation individually.
Having got into RPA in a big way, I’m wondering if anyone is aware of a tool or method where I could put something identifyable on screen before each presenter (eg a full colour wash, or a QR code or something) that could be used by software to determine where to split the video file?
I’ve been googling, but can’t seem to find anything that quite does the job, so I thought I’d ask the UIPath community Hive Mind!