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View Full Version : Color Droop in Vdub but not in DScaler


ZenFire
5th May 2007, 22:48
Hi,

I usually use DScaler for capturing video. Today I used VirtualDub for that purpose for the first time in a long time. Anyway, long story short: the results had color bleeding. It seemed like the chroma values of the second (last/future/dunno what else to call it) field were either bleeding or completely shifted into the old (first) field of in every frame. I will attach an example. On the left is the result of Avisynth's SeparateFields() and on the right is the original interlaced source. I tried switching around the color formats from rgb32 to yuy2 to something else, but not surprisingly the problem did not go away. After reading the capturing guide I learnt about the flaxen VHS filter for vdub, but I didn't bother simply because DScaler doesn't have this problem at all. And since I was already using that, I don't really NEED to fix this problem, but I'm still curious.

Now I'm wondering: "why the difference". Does DScaler's direct hardware access simply get better results than Pinnacle's latest and yet 3-year-old drivers, or does DScaler automatically detect and correct this? I've got a PCTV Stereo with the SAA7134 chip. A simple answer would be much appreciated. I'm still learning about video.

setarip_old
5th May 2007, 23:10
@ZenFire

Hi!

May I ask what Pinnacle drivers have to do with using VirtualDub or DScaler?

ZenFire
6th May 2007, 00:54
I was (and still am) under the impression that when I capture in Vdub I'm using microsoft's VFW wrappers to access the Pinnacle WDM drivers.

setarip_old
6th May 2007, 01:17
What version of VirtualDub are you using?

ZenFire
6th May 2007, 09:04
1.6.17

EDIT: Though I haven't changed anything, I just tried again and the captures in Vdub now no longer have color bleeding. I guess it might have been a one time thing, though I have no explination for it.