If you’re up for using Jellyfin, you can check out something I’m working on to achieve this: github.com/MattMckenzy/Homehook

The main branch used to be compatible with chromecast devices, but I’ve stopped maintaining it in favor of the v2 branch, where HomeHook communicates directly with satellite devices through HomeCast. Working with Chromecasts were a huge pain.

Let me know if you have any questions about it, always glad to help!