Need to capture the screen. How do I do it?

[rajasekharan]

Hi guys,

I am working on a screen capture program that to record the screen to a media file (avi/flv/mp4 etc) or transmit the screen across the network for live viewing.

How do i access the display contents programmatically?

Limitations:
The project has to be purely C++ and shouldn't use python as do some other projects.

So far I have:
Figured out how to make the GUI using Qt
How to transmit it via a network

I understand this question may be a little broad. I'd appreciate any pointers you can give me on this.

Thanks in advance,

Raja Sekharan

[GNU-Fan]

Assuming your display is driven by a X Window system, you should already have installed a tool called xwd.

[i92guboj]

Xwd is simple enough and looking at it's source you can see how to capture stuff. The "import" tool, shipped with imagemagick, and scrot are another couple that can do that (though imagemagick is not an easy piece of software to read). All these are in C if my memory serves correctly. Addpting the core functionalities to C++ should be trivial enough. You also have ksnapshot, which is one of the kdegraphics pieces, and it's done in qt using kdelibs, in case you want a more kde-ish approach.

To record live videos, I know of recordmydesktop. It's a small tool, and it's pure C as far as I know.