WDDM - dump virtual extended desktop content to file

Hi,
I am working on desktop extension project where in I need to support multiple USB monitors.?As a preliminary step, ?I am working on dumping the content of the ?extended desktop to a file.
I have my virtual miniport driver up and its getting all the calls.?
In XPDDM, in EngCreateDeviceSurface and subsequently EngModifySurface we can specify the memory where the drawing takes place. (lpdelta parameter of EngModifySurface specifies the virtual address of the bitmap where drawing takes place). ?Now this can be pointer to a buffer or a file .
But how to do in WDDM ? I have returned +1 as child count in QueryChildRelationFunction. What else I need to do…??There is this function?DxgkDdiCreateAllocation which creates allocation of system or video memory. Do I need to target this function. But it creates allocation resource wise but not for all the drawing operation.?
Please suggest and share your thoughts on this.
ThanksAnshul Makkarwww.justkernel.com

Hi Anshul,

Even I am working on a similar project.

I think DxgDdiCreateAllocation will do the trick for you… You need to manipulate certain parameter so that drawing takes place on the allocated buffer/ file.

Thanks
Alan Hopes

Thanks Alan.

Please , if some can share some more details about which parameter can be useful or how can we dump the desktop bits to a file…

Thanks
Anshul Makkar
www.justkernel.com

— On Tue, 23/8/11, xxxxx@gmail.com wrote:

From: xxxxx@gmail.com
Subject: RE:[ntdev] WDDM - dump virtual extended desktop content to file
To: “Windows System Software Devs Interest List”
Date: Tuesday, 23 August, 2011, 7:21 AM

Hi Anshul,

Even I am working on a similar project.

I think DxgDdiCreateAllocation will do the trick for you… You need to manipulate certain parameter so that drawing takes place on the allocated buffer/ file.

Thanks
Alan Hopes


NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer