Comment A bit late, but look into Thingino firmware (Score 1) 143
Thingino is an open source project that provides alternative firmware for lots of cheap commercially available IP cameras, specifically those based on Ingenic processors. This includes models from brands like Wyze, Wansview, and more. Development is completely public, we use Github and Discord, and it's a very active project with tons of features and users.
Thingino gives you rtsp and ONVIF, to integrate with any locally running NVR (like Frigate, HomeAssistant, etc) and provides basic motion detection and other features directly on the device as well. There's no subscription, no cloud, you only need internet connectivity for features that would specifically require it (ota firmware updates, ntp if your dhcp doesn't specify a local one, sending diagnostic logs, or using the button to read out your IP address). You can modify and build your own firmware images with different features using our Docker/Podman based builder.
Some devices can be installed with just a specially prepared SD card, others require different levels of effort. Check out https://youtube.com/@wltechblo... for video walk-throughs on a bunch of popular devices.