I never used their app, but I have a Yi camera. There are several open source firmwares for them that provide many more features than stock. I feed my cameras into Frigate, which isn’t particularly simple to configure, but gives you a great open source DVR.

I don’t really like the Yi camera actually. I’ve had much better luck with Amcrest.

I haven’t used it, but agendav - https://github.com/agendav/agendav looks like it might be what you’re looking for. There are similar projects for iCal format, which many calendar apps can emit as well.

It’s disappointing that this is the highest voted comment on a thread in the selfhosted topic…