I've searched around, but can't seem to find a post (or article elsewhere) that covers the sort of problem I am trying to solve. I have not bought a pi for this project yet (and maybe pi isn't even the right answer for the project), so I am not limited there.
Essentially for a Christmas display project I am brainstorming, I want to have a mix of a pair of projectors as well as some regular Christmas lights. The lights will be controlled via SSR, and need to be in sync (doesn't have to be too tight, milliseconds is MORE than enough) to the videos. The two videos themselves will need to be in sync with each other (again, sub-second is probably fine). The plan is to show about a 45 second clip on each projector that look like they are interacting with each other via the SSRs.
Since this is going outside, I have been looking at used projectors because I don't know how well this is going to work overall. Because of that, the projectors usually don't have Ethernet, USB, or HDMI. This means that I will need to display video to it over VGA or RCA.
I was trying not to break the bank on this (again I am not sure how well it will work yet), so I was trying to figure out if there was a way to use a single pi that had a script that kicked off both videos, and then controlled the SSRs via timing in the script (think simple sleep functions).
If it helps, the videos are actually pretty small. I am making them 320 pxl wide x 480 pxl tall, so I am by now means using the whole projector's image canvas.
Any thoughts? TIA