Is there standard protocol or way for frameserving?
Have you looked at OBS Studio?  It sounds like it can do all four of your steps for you, and it's free and open-source too.  If not, then it could also just do step 1, depending on what your original video source is.  OBS can use these sources:


Webpages
Displays/monitors
Video games
Local files


Text files

Webcams &amp; video capture devices
Windows on your computer
A few others, like audio, plain colors, images, and slide shows