Desktop Duplication Sample - The desktop updates become infrequent when the mouse is moved.

Question

Hi,
I noticed the following problem when running the desktop duplication sample. I also saw the same issue when implementing the desktop 
duplication API in my own application.  I'd like to know if this is a known issue and how to resolve it.

Thanks,
Paul

Problem:
The desktop updates become infrequent when the mouse is moved.

Setup:
Win8 Consumer Preview, Desktop Duplication sample, Lenovo T410.
To reproduce:
1. Run DesktopDuplication.exe
2. Run a video or other activity which updates the desktop continuously.
3. Observe that the DesktopDuplication app window is correctly updated with the desktop contents.  The updates are frequent and the video looks 
smooth in the DesktopDuplication app window.
4. Move the mouse continuously. Observe that the desktop contents are updated infrequently (every 3-5 seconds) in the DesktopDuplication app
 window.  The video appears to stop, although the mouse pointer is correctly drawn in the DesktopDuplication app window.

Answer 1

Any feedback?  I've reproduce this issue on multiple machines.

Answer 2

Does the DesktopDuplication app window return to the normal refresh rate when you stop moving the mouse?  (does it "catch up?")

Thanks,

Dan

Answer 3

Thanks for responding.

Yes.  It returns to normal functionality.

Paul

Answer 4

I also reproduced this bug on Win8 Consumer Preview Update 2 (build 8350).

Answer 5

Thanks Paul for reporting this.  I can reproduce the behavior you mentioned to a lesser degree (latency ~1s with 3-5 fps).  I'll followup on this, and will let you know if I find a solution.

Thanks,
Dan

Answer 6

Great.  Thanks for the update, Dan.

I'm not sure if it helps, but I also filed a Win8 bug for this issue. The bug number is Win8-873863 (The desktop updates via Desktop Duplication API become infrequent when the mouse is moved.).

Paul

Answer 7

I'm glad that was you. :-)  (the wording sure was familiar...)

-Dan

Answer 8

Just to close the loop on this, Microsoft is working to find a resolution to the problem reported by PaulS_.

Thanks for posting!

Answer 9

I am experiencing similar problems. The Desktop Duplication API call AcquireNextFrame() can take anything from 30ms to 3s to complete. That makes the interface pretty much unusable.

My config is:

OS Name: Microsoft Windows 8 Release Preview
Version:    6.2.8400 Build 8400
Processor    Intel(R) Core(TM) i5 CPU         760  @ 2.80GHz, 2794 Mhz, 4 Core(s), 4 Logical Processor(s)

ATI Radeon HD 5450 (Engineering Sample - WDDM v1.20)