webcam delay in VS2008

[RFarrell]

I apologise if I have posted this question in the wrong section, I was unsure
which was most suitable.

I am current working on a face tracking solution in VS2008. I am using the
image processing library EmguCV, an OpenCV C# wrapper, to capture and process
a USB webcam videostream. My problem is something is delaying the videostream
by 500ms, but only on my computer! I have tried my projects using the same
software configuration with the same webcam on both a higher and
significantly lower performance computer, neither of which suffered any time
delay at all.

The delay also occurs when the videostream is accessed through the
directShow library. However the delay does NOT occur when the webcam is run
through its own drivers, i.e. when I use it with Skype.

I have tried reinstalling the webcam drivers- I have tried using a different
webcam entirely- I have tried using a different USB2.0 port- I have trying
reinstalling the EmguCV library, all to no avail.

I don't have the time to back-up and completely reinstall everything on my
computer, I was kinda hoping someone might have a suggestion to this problem ?

[Chris P.]

Post by RFarrell
I don't have the time to back-up and completely reinstall everything on my
computer, I was kinda hoping someone might have a suggestion to this problem ?

You more than likely have a 3rd party filter injecting itself into the
graph. Remove 3rd party filters such as ffdshow, MainConcept etc and see
if that helps.

[RFarrell]

Post by Chris P.
You more than likely have a 3rd party filter injecting itself into the
graph. Remove 3rd party filters such as ffdshow, MainConcept etc and see
if that helps.

Thank you for the help.

I did indeed have ffdshow installed and it was activating when the webcam
turned on. I removed the filter but this did not improve the webcam
performance. I then re-installed the webcam AGAIN, and this time it improved
dramatically, but only for a few hours?! Come the evening and the webcam was
lagging again. The following morning the webcam refresh rate sped up again,
then come the evening it slowed down again. A pattern that has repeated the
last few days.

The only obvious reasons for this I can think of are my scheduled scandisk
which comes on in the evenings - deactivated this straight away, no
improvement - and possibly due to the diminishing evening light causing the
webcam to do some filtering of its own, so I experimented with different
lighting, curtains drawn, during the day / evening etc... but I have found no
correlation there either.

I think it will just be quicker if I spend a few days doing a full reinstall.