Blur line at bottom of Capture

[TheNob]

I am using an ATI ALL-IN-WONDER Radeon capture card to capture home movies. I have noticed that there is a blurry line at the bottom of the videos though. I don't get this problem if I capture from the TV Tuner. Only from video tapes. I have tried using two different VCRs and my video camera as the source. The size of the blur line did vary from source-to-source but it was always there.

Here is a link to a sample :
http://booneac.brinkster.net/mark/sample.jpg

Thanks,
TheNob

[Macros746]

I have heard that this is an issue that some people experience when capturing with the composite cable. I don't know a way around it but it is certainly easy enough to clip away using either virtualdub or TMPGenc...


Macros

[RFontenot]

It is video head switching noise. You don't usually see the absolute edges of what your VCR records because your TV overscans the image, but a capture windo shows you everything.

If you are only going to play your captures on your TV, then the overscanning will hide the switching noise. If you want to play back on both your TV and computer, then clip or mask the bottom 4-5 lines of your capture as suggested.

RF

[dphirschler]

Crop it. All VHS captures do this. Just crop it and re-center the image. You can do this in Vdub.


Darryl

[TheNob]

Thanks guys. I thought maybe it was just my specific card. If I crop the image everything seems to work well.

Thanks again,
TheNob

[afiorillo]

TheNob,

it isn't an AIW-specific issue, my Pinnacle PC-TV Pro does it too.
As already said, cropping will help.

Bye,
afiorillo

[homerpez]

Also... cropping might not be necessary...

This effect you see, if it's in like 10-20 pixels from the bottom, is merely overscan. This is the area where there's image data there, but TV's ignore it and it's not visible.

Instead of cropping, I would black it out instead. If you're encoding with TMPGEnc, you can use the "Clip Frame" and choose "mask" instead of "crop". This way, you'll black out the offending area when played back on a PC, but not throw off the picture zoom when played back on a TV.

...now that I said that...

I also experienced once on my Radeon card, what captures made from Composite would have a line in them, well ABOVE the overscan area, like 1/4 the way up the capture. This, I discovered was a driver issue. I haven't seen it in late releases.

It also, for me, only happened when I tried to apply a "DeMacrovision" driver patch to the ATI drivers. When I removed it, it was fixed. So, ever since, I just use a Sima Copymaster box for picture cleanup purposes...

[dphirschler]

VDub does the same thing. Crop, recenter image.

[TheNob]

Will croping the image at the bottom distort the image by then streching it to fit 352x240? Or do I have to crop from the side also to even it out?