Creating a video capture program in C\C++?

Question

C++ / C#

How to make your own video capture program for a monitor (or a specific window) on Windows (If possible, on Linux too)?

Answer 1

on Windows (If possible, then on Linux) ?

Don't confuse Windows with Linux.
You have to decide on one thing.
It is impossible to harness a Donkey and a quivering doe into one cart .

Answer 2

Something like this
stackoverflow.com/questions/3291167/how-to-make-sc...
stackoverflow.com/questions/5069104/fastest-method...

Answer 3

see OBS sources