Preview Screen problem -- lockup or 'smear-out'

[coffeecup-sf]

Did a search on the forums, nothing of this topic found.

Strange. Doing some test capturing with Virtual Dub 1.5.4 tonight, and all of a sudden my preview screen is doing either one of two things: either freezeup during capturing (capture goes well, just can't see what's going on) or it's hard to explain but the preview screen does stay in motion but it's like one big massive blur -- looks like perhaps the video has been extremely expanded so badly that it's garbled and swirled.

The only thing I can remember that might have caused this is, I was messing with the Noise Reduction feature and decided to push it up really high -- at about 75% or 3/4 between min and max -- and all of a sudden the preview scrn did that. However, even if I turn off all filters and turn off noise reduc, preview scrn is still same.

Good thing is that with messed up preview scrn, the CPU% usage is way down even with noise reduc on and hovers around 50% (nice). Otherwise not only I can't see what I'm doing, but it is just downright bizarre and not 'healthy' capturing. Anyone know about this?

[coffeecup-sf]

--> Update.

Well today, I turned on the computer after a nights rest and fired up virtual dub, lo and behold the Preview Screen in virtdub is working very well again. That problem before of getting either prvw scrn freezes during cpture (or that blown up looking motion frame) seems to have disappeared. This again makes me wonder if perhaps the CPU and/or system was just a little too warm and affected the pvw scrn? However I don't think so, and also last night when I checked temp in BIOS it was the normal temp in the 50 degree range. I am just trying to figure out which setting I might have altered that messed up the prvw scrn.

The only thing I did that might have made the whacky prvw scrn to return back to normal is did some HD defragging, started it when I went to sleep last night, however I don't even think I defragged the whole thing as I set my GetRight program to automatically turn off the comp after 3.5 hours so it might not have finished.

But then I don't think defrag still has any direct effect on how the preview screen appears. The prvw scrn should be more directly related to the CPU, or else some in-program setting(?). Anyone with any real clues on the matter please let me know, so that I can avoid this in the future and am still wondering!!