Question about color levels in capture

[BrainStorm69]

I am capturing VHS using my Avermedia EZMaker DVD capture card (Philips SAA7130) using Virtual VCR and huffyuv to YUY2. I have played around with the brightness and contrast of my capture card and checked my luma using Avisynth's histogram to help set my brightness and contrast correctly. According to Avisynth and as confirmed by the following screen caps of vdubmod using trevlac's color tools histograms, I seem to have got the luma level about right. However, my question is about the color histograms in the pic below. As you can see, I have red, green and blue all going from 0-255. THinking perhaps it was a color saturation issue, I tried a little experimentation with the color saturation control for my capture card, and couldn't seem to correct this. My question is whether this is a problem or not. If it is a problem, what exactly is the problem and what do I need to do to correct it?

Thanks in advance.

[jagabo]

I don't see any pictures but -- most programs perform the usual rec.601 contrast stretch when going from YUV to RGB. So you expect to see RGB values from 0 to 255, not 16, 235/240.

[BrainStorm69]

Yeah, I f'd up and forgot to post the pic, and then screwed up again and double posted it. Doing great! So are you saying that everything should be good, it's just vdubmod adjusting the color levels when it converrts the YUY2 to RBG to generate the histogram?

[jagabo]

it's just vdubmod adjusting the color levels when it converrts the YUY2 to RBG to generate the histogram?

Yes. If you want to see the video without the contrast stretch try ConvertToRGB(matrix="pc.601") in AviSynth. There might still be a little RGB outside the 16-235 range if there is too much saturation.

[BrainStorm69]

Thanks, jagabo. I'm just getting into Avisynth and am playing around with it a bit, but don't know much yet.

[jagabo]

Make a text file with Notepad with the following text:

AviSource("capture.avi")
ConvertToRGB(matrix="pc.601")

Name the file CAPTURE.AVS and put it in the same folder as CAPTURE.AVI. In VirtualDub use File -> Open AVI file and open the AVS instead of the AVI.