Is there a solid open-source Rpi-based home security camera solution yet? I'd like to set up something of comparable quality to say a Ring doorbell camera or a Nest/Blink security cam or a baby monitor but that I can fully control.
i (deeply) reject your inquiry as a harmfully narrow, reductive consumerist ask, when this could be a much more neutral, open ended friendly question. you have qualified this from the start as a "solution," which is against the best premises, the best strengths of open source: "small pieces, loosely coupled."
the best software is small, purposeful, targetted. interwoven with other systems. only then is open source able to continue to focus on innovation & advancement, without becoming mired down in endless maintenance & complexity.
you should re-evaluate your ask, to ask for something that, will, in the end, not becoming limiting & ossified. open source ought best avoid the pretense commercial software competes on, of being a complete and final thing, of being everything to everyone. open source ought be more humble, and for this, it is better. ask, instead of a solution, after what systems of software might help one accomplish the home security systems they might want to build.
the best piece of open source home security cameras that I've seen is Frigate, which has masking & less interesting to me but probably interesting to many, object detection. designed for home assistant but it has other uses. much assembly required. good. solve your problem how you want to solve it: not how everyone else also has to.
i'd point out that home assistant itself is regarded by many as somewhat of an abomination, too big, unwieldy. core has 1.4k issues open and almost 300 PRs open. it's a shit show. it does way too much, it's way too monolithic, the project is basically doomed to stay where it is. it's a solution, and one that will rot & be no better in 3, 30, or 300 years: there's no open future here. it's only upside is that it is a plugin architecture, that it is an interoperation layer, that projects like Frigate can contribute & add capabilities too. home assistant is hugely popular, but basically it's core redeeming feature is that it allows small pieces, loosely coupled, to do something. home assistant itself is an anti-solution. frigate is an anti-solution. they are both parts, pieces, and in that is the strength. and hopefully, someday, we can kind a better system of pieces such that we can get rid of bloody ugly home assistant.