Webcams

[rdhw]

It is being reported on the Cygwin mailing list at http://cygwin.com/ml/cygwin/ that there appears to be a conflict between Windows applications that use the Cygwin environment (see http://www.cygwin.com/ ) and Logitech webcam software (in my case, Quickcam 9.5).  In particular, the conflict goes away if the Windows Service "LVPrcSrv" from Logitech is stopped, and the conflict re-appears if "LVPrcSrv" is restarted.  The "LVPrcSrv" service is named "Logitech Process Monitor", and has description "Webcam effects helper.".  This service runs an executable "c:\program files\common files\logitech\lvmvfm\LVPrcSrv.exe".

This conflict was also identified at http://aslongas.pe.kr/tt/ for those of you who read Korean.

One symptom of the conflict is that the Cygwin API "fork()" fails randomly with a Windows event log entry "Resource temporarily unavailable" message.  This conflict can be random, sometimes happening, and sometimes not, with no clear reason.  Sometimes fork() fails with different reasons being given, such as "fork of unprivileged child failed."

Is anyone with a deeper understanding of how LVPrcSrv.exe works able to add any light to this?  In particular:

1. How is it that LVPrcSrv.exe, running as a Windows Service, is able to cause conflicts with applications running in quite different Windows processes?

2. What functionality is lost if LVPrcSrv.exe is permanently disabled?  Is it crucial for normal webcam usage?

3. Is there a fix for LVPrcSrv to prevent it damaging other processes in ways such as those described above?

[KachiWachi Distinguished Logi Legend]

Welcome to the New Logitech Community Webcam Forum rdhw!

I'm not familiar with Cygwin, but it appears to be Linux oriented (allows you to have a Linux-like environment in Windows...from a brief read).

Since LVPrcSrv.exe is a new file (associated with the new Video Effects feature), not much is known about it.

I'm sure you can uninstall/disable the Video Effects...though you will have to look at the associated INF's and figure that out for yourself (Logitech AFAIK does not have an uninstall for this feature ).

As far as asking Logitech about this, they will claim it as "proprietary information"...so no help there.

[wadeb]

I can verify this problem, and also add that LVPrcSrv will occasionally consume 99% of CPU time, particularly when other intensive processes are running.

The workaround for both issues is to go to the Services control panel and Stop the service named "Logitech Process Monitor". Then, open up the Properties for this service and change Startup type to Manual.

The camera continues to work normally, aside from the Video Effects feature. When trying to enable a video effect, such as the Shark head, an error dialog will be raised but the program will not crash.

Regards,

Wade Brainerd

[KachiWachi Distinguished Logi Legend]

Welcome to the Logitech Community Webcam Forum wadeb!

Thanks for the confirmation...and the tip!

[Simpo]

I can also confirm similar symptoms compile a VB6 app. It's more likely to occur on a large project and doesn't happen every time however I was getting it consistently enough to research and haven't had an issue since disabling LVPRCSRV. C2.exe and VB6.exe just sit with 0% CPU utilisation but the compile never completes.

[KachiWachi Distinguished Logi Legend]

Welcome to the Logitech Community Webcam Forum Simpo!

Thanks for your information as well!

[Mirko]

I've run into the same issue while trying to compile code in cygwin.

Is there going to be any resolution to this issue?

[KachiWachi Distinguished Logi Legend]

As I mentioned in your other post, only Logitech can answer this for sure.

Please contact them directly for more information.

Thanks.

[sunsandfun]

Hi - your info about the cpu usage has been very helpful. I end the process each time I start up the computer.  Could you please explain to me how to get to the 'services control panel' to disable the feature?  I looked around and can't seem to find the place to make it start up manually.  Thanks, i'm a little computer illiterate! 

[KachiWachi Distinguished Logi Legend]

Welcome to the Logitech Community Webcam Forum sunsandfun!

It is one of the Windows Administrative Tools (Services).