[REQUEST] Streaming "checker"

Hello, this is my first post on the forum
I marked this thread as a request, but help will be appreciated as well.
Basically I'm looking for an add-on capable of starting at the boot of the host (raspberry pi in my case) and monitoring if a video stream is being sent to the unit, and if it is immediately start decoding and displaying the video and audio signal (no matter what the user is doing). Is it possibile?
Thanks