How does RealVNC work?

Question

I would like to know how the RealVNC Remote Viewer works.

Does he often send screenshots to the client in real time?

or uses a different approach?

Answer 1

As a very high level of overview, there are two types of VNC servers:

• Capture screen. These servers will display the current display in a buffer, compare it with the state of the client and send only those rectangles that differ from the client.
• Hook help. By acquiring the display update process, these servers will be informed when the screen changes to the display manager or OS. They can then use this information to send only the modified rectangles to the client.

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Answer 5

It essentially works by sending screenshots on the fly. (The "real time" here is something wrong, because there is no clear deadline.) It only tries to optimize by sending areas of the screen that have been changed, and some forks of the VNC code line use a mirror driver to receive a notification when the display areas are recorded, in while others use window message hooks to detect redraw requests.