Screen capture from AIR for desktop

I am working on an app concept that will capture the screen or ideally a (fixed) portion of the screen from a Windows hotkey. Is there a library or suggestion on how to achieve this? The capture will be taken from a full-screen or borderless-windowed application. (Eventually, I will need to deal with capturing from a specific one of multiple monitors, but realizing the capture is most important now.)

you will certainly have to build your own ANE to do such functionality

depending on where/what you want to do (Windows, macOS, etc)
I would suggest finding an open source C or C++ library

OK, thank you, I will look there. Maybe there is something pre-built with an API that I can hook into.