Current version

v1.10.4 (stable)

Navigation

Main page
Archived news
Downloads
Documentation
   Capture
   Compiling
   Processing
   Crashes
Features
Filters
Plugin SDK
Knowledge base
Contact info
Forum
 
Other projects
   Altirra

Search

Archives

01 Dec - 31 Dec 2013
01 Oct - 31 Oct 2013
01 Aug - 31 Aug 2013
01 May - 31 May 2013
01 Mar - 31 Mar 2013
01 Feb - 29 Feb 2013
01 Dec - 31 Dec 2012
01 Nov - 30 Nov 2012
01 Oct - 31 Oct 2012
01 Sep - 30 Sep 2012
01 Aug - 31 Aug 2012
01 June - 30 June 2012
01 May - 31 May 2012
01 Apr - 30 Apr 2012
01 Dec - 31 Dec 2011
01 Nov - 30 Nov 2011
01 Oct - 31 Oct 2011
01 Sep - 30 Sep 2011
01 Aug - 31 Aug 2011
01 Jul - 31 Jul 2011
01 June - 30 June 2011
01 May - 31 May 2011
01 Apr - 30 Apr 2011
01 Mar - 31 Mar 2011
01 Feb - 29 Feb 2011
01 Jan - 31 Jan 2011
01 Dec - 31 Dec 2010
01 Nov - 30 Nov 2010
01 Oct - 31 Oct 2010
01 Sep - 30 Sep 2010
01 Aug - 31 Aug 2010
01 Jul - 31 Jul 2010
01 June - 30 June 2010
01 May - 31 May 2010
01 Apr - 30 Apr 2010
01 Mar - 31 Mar 2010
01 Feb - 29 Feb 2010
01 Jan - 31 Jan 2010
01 Dec - 31 Dec 2009
01 Nov - 30 Nov 2009
01 Oct - 31 Oct 2009
01 Sep - 30 Sep 2009
01 Aug - 31 Aug 2009
01 Jul - 31 Jul 2009
01 June - 30 June 2009
01 May - 31 May 2009
01 Apr - 30 Apr 2009
01 Mar - 31 Mar 2009
01 Feb - 29 Feb 2009
01 Jan - 31 Jan 2009
01 Dec - 31 Dec 2008
01 Nov - 30 Nov 2008
01 Oct - 31 Oct 2008
01 Sep - 30 Sep 2008
01 Aug - 31 Aug 2008
01 Jul - 31 Jul 2008
01 June - 30 June 2008
01 May - 31 May 2008
01 Apr - 30 Apr 2008
01 Mar - 31 Mar 2008
01 Feb - 29 Feb 2008
01 Jan - 31 Jan 2008
01 Dec - 31 Dec 2007
01 Nov - 30 Nov 2007
01 Oct - 31 Oct 2007
01 Sep - 30 Sep 2007
01 Aug - 31 Aug 2007
01 Jul - 31 Jul 2007
01 June - 30 June 2007
01 May - 31 May 2007
01 Apr - 30 Apr 2007
01 Mar - 31 Mar 2007
01 Feb - 29 Feb 2007
01 Jan - 31 Jan 2007
01 Dec - 31 Dec 2006
01 Nov - 30 Nov 2006
01 Oct - 31 Oct 2006
01 Sep - 30 Sep 2006
01 Aug - 31 Aug 2006
01 Jul - 31 Jul 2006
01 June - 30 June 2006
01 May - 31 May 2006
01 Apr - 30 Apr 2006
01 Mar - 31 Mar 2006
01 Feb - 29 Feb 2006
01 Jan - 31 Jan 2006
01 Dec - 31 Dec 2005
01 Nov - 30 Nov 2005
01 Oct - 31 Oct 2005
01 Sep - 30 Sep 2005
01 Aug - 31 Aug 2005
01 Jul - 31 Jul 2005
01 June - 30 June 2005
01 May - 31 May 2005
01 Apr - 30 Apr 2005
01 Mar - 31 Mar 2005
01 Feb - 29 Feb 2005
01 Jan - 31 Jan 2005
01 Dec - 31 Dec 2004
01 Nov - 30 Nov 2004
01 Oct - 31 Oct 2004
01 Sep - 30 Sep 2004
01 Aug - 31 Aug 2004

Stuff

Powered by Pivot  
XML: RSS feed 
XML: Atom feed 

§ File dialogs break in capture mode with UScreenCapture driver

If you are using VirtualDub with the UScreenCapture driver to capture video from the desktop screen, you may run into problems with the Set Capture File option in VirtualDub not bringing up a file dialog, at least on Windows 7. This appears to be due a problem within v2.0.14 of UScreenCapture.ax which also reproduces with Microsoft GraphEdit. I am trying to contact the vendor for a resolution, but have not gotten a reply as of yet.

Technical details:

VirtualDub's file dialogs fail to come up because of an internal error within the Windows common file dialog. The specific failure path is GetSaveFileName() -> DialogBoxIndirectParam() -> CreateWindowEx(ComboBoxEx) -> SetWindowSubclass() -> GlobalAddAtom(). That in turn is caused by UScreenCapture's worker thread calling SetProcessWindowStation() with a handle to WinSta0 that does not have the WINSTA_ACCESSGLOBALATOMS access right. This only happens while the capture driver is running, but as it pretty fundamentally borks UI process state, it's not something I can easily work around safely.

Comments

Comments posted:


Stupid vendor mutating process-global state. Cases like this make me doubt that being able to load plugins in-process is a good thing.

tobi - 19 05 13 - 09:51


Unfortunately more common than you think. I once tracked down a locale bug to D3DX calling setlocale() to force a particular CRT locale around its parser. Unfortunately, that's a process-wide state and D3DX is linked against the dynamic CRT, so you can imagine what that did to some of the other worker threads in the process.

Phaeron - 19 05 13 - 09:55


This has been already been fixed in UScreenCapture. Use version 2.0.15.

Steve Fox - 24 05 13 - 16:08


You mean "just fixed," since 2.0.14 was the latest available as of two weeks ago... but yes, I've confirmed 2.0.15 no longer calls SetProcessWindowStation() and the problem no longer occurs.

Phaeron - 24 05 13 - 17:09

Comment form


Please keep comments on-topic for this entry. If you have unrelated comments about VirtualDub, the forum is a better place to post them.
Name:  
Remember personal info?

Email (Optional):
Your email address is only revealed to the blog owner and is not shown to the public.
URL (Optional):
Comment: /

An authentication dialog may appear when you click Post Comment. Simply type in "post" as the user and "now" as the password. I have had to do this to stop automated comment spam.



Small print: All html tags except <b> and <i> will be removed from your comment. You can make links by just typing the url or mail-address.