Pink & green signal intereferences

[prism]

Hello ,
I recently began capturing from VHS and reached to a dead end.

Getting pink & green transperant bars on the top of the screen flickering every few seconds.
It does not matter which codec , resolution , tape , edit/capture program I use.
I also tried other VCR and Video cable.

My card is ATI 9200 VIVO with the latest drivers.

Can anyone help please ?

Aidan.

[Savant]

Hmm, this sounds like a sync issue, but I can't be sure. Are the bars 'rainbow' coloured and dissappear to the bottom of the screen? I think the first thing to try would be to adjust the tracking (if yo uhaven't already) Next, if you can, perhaps post a screen cap of the lines in question. Its easier to figure it out that way.

Regards,

Savant

[prism]

Savant ,

please review the screen cap.
Those signals always appear on top for 1-3 seconds and disapear
for 1-20 seconds and vice versa.

Many Thanks,
Aidan.

[/img]

[Savant]

OK, do these line appear when you first start a recording? Yuno, the video comes on and then there are these lines for a few seconds and then they go away? Then the next time you start recording again the lines show up again? If that's what's happening I can give you an explanation for it. If not, it may just be a general sync issue. Depending on what it is will depend on what you can do. Also, are you in NTSC or PAL format?

Regards,

Savant

[prism]

Those lines appear randomly and not just at the begining even if I start the VCR again.

I noticed that when I capture for 1 hour the tendency is higher ,
and when I capture 4X15 min , the tendency is much lower at each part.
Thats the only way I can capture long tapes but those lines still exists.
If it is a sync. problem , how can it be resolved ?

By the way , I am in PAL.

Thanks,
Aidan.

[Savant]

I think it might be likely that it is a sync problem. The best way to deal with this is a Time Base Corrector. (TBC) They aren't cheap though. The cheapest TBC I have seen is US$180, but it does cover PAL format signals. The next cheapest is US$300+.

Regards,

Savant

[lordsmurf]

You cannot do anything about it but crop them out with a re-encode in an encoder like TMPGEnc. These are likely compound errors, and no amount of TBC and high-range VCR equipment will remove them.

Simply stated, you are screwed as far as "true removal" goes. Cropping is the only fix.

Keep you aspect ratio and crop off the top of the video, and a little off the sides in full screen mode... at least enough to move the error into the overscan where it won't be seen. Use TMPGEnc for this at MPEG encode, and capture AVI for the TMPGEnc source.

I deal with lots of video restorations, and this is a common problem on home-copied tapes, often from poor VCRs or those horrible dual-deck garbage machines by Go.Video.

Feel free to spend countless hours and unlimited amount of money for this, but in the end, cropping it out is what you're probably going to have to do. Only in a few rare cases have I been able to get my JVC with TBC/DNR to actually remove that error.

[Savant]

Actually you just gave me an idea. What he could do instead of investing in a TBC would be to take a tape to a big store (which should carry a VCR model with a TBC) and ask them to play his tape on it to see how it plays it. That way he can see what benefit a TBC might provide.

The problems with many of these issues is that you never really know what the problem is unless you have a video analyser. (and who has 10K for one of those?)

Regards,

Savant

[prism]

Thanks for the helpfull answers but
there is one thing i can not understand ,
Why do these interferences apear only when the VCR is connected
to my PC (even in the non-overscan area) , and not on the T.V. ?

[Savant]

In my personal experience, I have had problems like that which are related to ground loop problems. Ground loop can occur when you have audio/video signals that go between two sources and each source has its own power cord. Here's a good primer on the subject I found that may help you understand it. If you want to get into more detail, this guide will explore it in more detail. (just so you know, it's a LONG read - over 80 pages)

If it is a ground loop problem then you may be able to correct it by simply making sure the VCR and the computer are plugged into the same wall outlet. If that doesn't fix it, then you may need a filter to correct the problem. I would try checking your plugs first, and if that doesn't do the trick read over the guide and see if there are other suggestions that apply to your setup.

Regards,

Savant