VirtualDub video preview blanks out when turning on features

stevevid · #1 08-02-2018, 10:53 AM

I have progressed to being able to see my video with preview on, histogram on, and levels control showing. I can adjust brightness and contrast for a much better image. However, the video preview disappears as soon as I turn on the audio volume meter. Turning off the volume meter does not bring back the preview. Turning off the histogram allows the video preview to reappear. Odd, since previously I was able to have the preview and the histogram on at the same time.

I closed all other programs--still didn't work. I restarted VirtualDub--still didn't work. I even tried switching from VirtualDub 1.9.11 to 1.10.4--did not help. Once in a while preview would flash on and off repeatedly. I had to reboot my computer to get the preview and histogram to show at the same time.

My computer runs Win 7pro on a quad-core Intel cpu with 16GB memory. The current capture device is a Hauppauge WinTV-HR-2250 pci-express-based card.

Help!

lordsmurf · #2 08-04-2018, 10:41 AM

Remember: don't adjust color to the monitor if the monitor is not calibrated!!!

I never capture with audio monitor, and really don't suggest it. It's best for testing/preview. But even then, I just pull captures into Sound Forge (Audacity also works), to verify the entire video worth of levels.

stevevid · #3 08-04-2018, 03:25 PM

I did see references to not messing with color during capture in other threads and guides. I found watching the histogram while adjusting brightness and contrast very interesting. I had read in several places how these controls affect the black and white levels. I did not grasp the full meaning until I saw the action on the histogram. It was very enlightening to see how the controls affect the width and left to right position of the data in the histogram.

Since I posted this thread, I did find references in other threads that VirtualDub's behavior can vary with different capture devices. The preview may be stable, flash in and out, or disappear. There's really nothing that can be done to stabilize preview for use with a given capture device.