Detecting screen capture

[suityou01]

Here you go:

http://www.codeproject.com/KB/system/hooksys.aspx

If you hooked calls to GetDC(NULL), you'd be able to create your own DC from a bitmap with anything you want on it and return that.

DirectX would be able to get around it though, and I'm not sure you could stop it.

I have read that article, thanks. I cannot see how you hook a specific api call though VM. Does the article contain this information?

[Ardesco]

Well with Linux you can have multiple workspaces and bind apps to specific workspaces.

Some guys have been trying to do something similar with windows:

http://www.otakusoftware.com/deskspace/

No idea if it lets you bind specific apps to specific desktops, but may be worth looking into.

Looks funky anyway

[suityou01]

Here you go:

http://www.codeproject.com/KB/system/hooksys.aspx

If you hooked calls to GetDC(NULL), you'd be able to create your own DC from a bitmap with anything you want on it and return that.

DirectX would be able to get around it though, and I'm not sure you could stop it.

noice

PM me if you like, might earn some coin this one.

[VectraMan]

Here you go:

http://www.codeproject.com/KB/system/hooksys.aspx

If you hooked calls to GetDC(NULL), you'd be able to create your own DC from a bitmap with anything you want on it and return that.

DirectX would be able to get around it though, and I'm not sure you could stop it.

[suityou01]

I geddit.

Can't help tho, sorry.

Might be useful to those in the US, companies like protecting their IP a lot there.

Good Luck!

[MPwannadecentincome]

I geddit.

Can't help tho, sorry.

Might be useful to those in the US, companies like protecting their IP a lot there.

Good Luck!

[suityou01]

Surely it's a lot of effort for something that will be of marginal use?

OK I'll level here.

I was on a web ex the other day, sharing my desktop. During the meeting my Skype window pops up with someone asking questions I did not want my audience to see. It set me thinking. What if you could cloak certain apps from screen grabbing apps?

Would also be useful for technical authors not wanting to edit out bits of the screen grab - assuming the screen grab was across multiple windows not just the ALT-PRTSC solution.

Also for companyies to prevent screen grabs being taken at all, or specifying that certain apps cannot participate in screen grabs.

It's just a fledgling idea for a plan B, and if anyone has a bright idea, or wants to pitch in then PM me.

There will obviously be a flurry of scathing posts from those that don't geddit, but if there is one who does it was worth the effort.

[suityou01]

Capture screen print button and alt-screen print button?

Put a hook into the keyboard handler.

Hi DP,

Not just the prtsc button. That's easy enough to do. What I'm thinking is something that listens and can detect ANY screen capture, be it prtsc, some kind of screen cam app, web ex, pc anywhere.

Clearly there are many different ways to capture the screen, GDI, directx, opengl etc but I thought I would just stick to the basics.

[Ardesco]

Surely it's a lot of effort for something that will be of marginal use?

[DimPrawn]

Capture screen print button and alt-screen print button?

Put a hook into the keyboard handler.

[suityou01]

Is is possible on a windows box to 'tap in' to the messaging sub system and listen for screen captures?

Typically an app would get a handle to the screen / window device context and BitBlt into a different device context for the purpose of creating a file.

Is is possible to listen for this? And possibly intercept it? And modify the bitmap en route so that the screen capture program gets a modified version of what's on the screen?