filter for diagonal lines?

[eng3]

depending on what channel I capture from, I get diagonal lines across the screen. The lines are usually moving too.

Are there any filters that can help get rid of these?

[Wilbert]

Could you provide a screen shot?

[eng3]

Sure, here is a frame
http://www.rcsnetwork.com/test3.jpg

You can see the lines going from top left to bottom right.
Depending on channel (and other conditions) it may be going top right to bottom left, or both, making a crossing pattern.

As you can see the video is also interlaced, but I am able to fix this problem. The graininess seems to just be an affect of the divx compression from capture. I am guessing that the diagonal lines cause problems when compressing and make things more difficult.

I have tried getting rid of this in hardware, but I'm not sure how.

[Wilbert]

Sorry, no idea what the cause is.

I moved it to the capture forum, maybe they can help you there.

[eng3]

is there an AVISynth (or virtualdub) filter that might help fix this problem (after capture)?

[jggimi]

Since this problem depends upon the channel; my assumption is that you are getting RF interference.

This is a common problem with inside-the-PC tuners. Common sources of electromagnetic interference are other PCI cards, the PCI bus, and Motherboard chipsets.

You can circumvent the problem by using an external tuner, such as a VCR or cable box, and using composite video or another non-RF connections for capture.

Some members have reported that switching PCI slots may produce positive results.

[eng3]

hmm, I do have alot of cards in my computer, I think that all my slots are used up.

what if I tried to shield the card some how?
like wrapping it with Al Foil.

I do remember one day it was getting to warm in my room so I took a case panel off when I was capturing. That video turned out much worse.

I would think that tv tuner makers would have thought of this problem and tried to do something about it.

[kastro68]

what if I tried to shield the card some how?

You can't be serious. Aluminium conducts electricity...you can easily shortcircuit your mobo.

[eng3]

yes, but I thought Al FOIL did not.
but anyways, even if what I want to use does conduct, I can easily stick something around it that does not.
like if I wrapped it in plastic or put it in a plastic bag.

[jggimi]

I doubt you will be able to effectively shield the card; in addition, attempts to jury-rig foil will increase the risk of short circuiting and damaging components, or affect thermal cooling.

Your best alternative would be to use an external tuner, as I described.

If you are unwilling or unable to use an external tuner, your alternatives are to attempt swapping PCI card slot positions, and/or removing cards or other PC components not used during capture, including PCI cards, USB devices, and the like. If the source of the RF interference is the PCI bus or the Motherboard, or PCI card(s) or other components that cannot be removed, then you will not be able to eliminate the interference.

[eng3]

ah, its from the PCI Bus.
hmm, I guess and external tuner would be the only choice for me.
The main problem with this is that that would disrupt several other programs that I am running that use the tuner.

[pandv]

One year ago, testing a card, I captured a very similar video (from VHS), only with a little more separation between the lines.

I can't and i don't capture now. But if there exists a Avisynth or VirtualDub filter to clean the sources, maybe it's possible to use it in ffdswhow to see this capture clean.

So, the original question remains. Exists one filter to clean this artifact?.

If not, it's possible to program one? Do you have any clue about the algorithm (15 days to my hollidays, and maybe time to program).


Pandv.

[eng3]

Can anyone recc. any good external tuners? (I want my computer to be able to change channels so hooking it up to a VCR would not work)

Many that I have seen only support MPEG1 or MPEG2, I want to beable to use any codec.

My first "video" capture device was a USB Dazzle, after using that I made sure to always use PCI video capture devices, but maybe the technology has gotten better.

I have both USB and Firewire ports available.

[Didée]

Originally posted by pandv
So, the original question remains. Exists one filter to clean this artifact
The "Wavelet Noise Reduction Filter" (WNR) for VirtualDub is probably the best try for this kind of artefact. Sometimes it doesn't catch at all, but often it does a pretty good job on that.
IRRC, search for the topic title "wavy yellow lines".

- Didée