Diagonal line noise on VHS video? Luma noise?
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I've got my set-up, er, set up (after having had my equipment repaired).
So: AG-1980 ---> DV TBC-3000 ---> BVP4+ ---> Radeon AIW 9800 Pro --> VirtualDub. However I'm having some trouble - there appear to be some diagonal lines in the picture. Usually these are difficult to see in screenshots but I managed to snag a good one just now - take a look. This persists across tapes of all kinds, and even when the TBC and proc amp are removed from the signal chain. The AG-1980 was just repaired by TGrant so I'd be surprised if that was the culprit here. Thoughts? Is this video cable corruption? Power interference? I've recently replaced the fan on the AIW 9800 with a quieter one with a copper HS - could that possibly have anything to do with it? Or is this just 'how it is' with video and I should try to filter it out later? |
Looks like herringbone noise. I would try swapping cables first.
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You can remove that with fanfilter plugin for avisynth
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So I've since tried four different S-Video cables and my Hi8 deck. It's persisted throughout. Does this mean there's something faulty with my breakout cable? Or with my AIW 9800? That would be annoying...
Thanks jmac - I'd rather not resort to filters until I have to, but appreciate the tip nonetheless :) |
It's a bit unrealistic to expect quality VHS transfers without post-process filtering of some kind (those mild gray hum bars aren't the only wrong with the image you posted).
The fanfilter plugin isn't likely to clear the noise, but anyone can try it if they like. I gave up on fanfilter years ago. Anyone who can change my mind would be enthusiastically supported. :) If this disturbance appears on all your tapes, you can suspect the capture card, environmental electrical interference, or the VCR. What most of us would do is try a different VCR, even if it isn't a good one, as a start at eliminating one of the most obvious suspects. It's difficult to advise about FM hash, hum bars, herringbone noise, etc., without seeing some actual video. I've seen similar noise on many captures over the years. If it can't be avoided during capture or if it's part of the broadcast noise often seen on VHS recordings, or on tapes improperly stored under hot/humid conditions or near large magneto assemblies like subwoofers, it can sometimes be cleaned up after capture. Did this problem start after you replaced the card's fan? Does the quieter fan have the same cooling capacity? |
Herringbone is my guess, too. But it's hard to tell with just an image. This is a case where a small video sampl helps.
Are you sure that this noise isn't just on the original tape? It probably is, especially if this a recording from analog cable. The late 90s were especially bad, as analog cable lines tended to be overloaded. (The digital MPEG/H264 broadcast era has corrected this.) With old VHS signals, processing is often a must. Even retail tapes had tons of errors. FM and power noise can sometimes be a problem where you live. For example, the TVA power grid used in middle Tennessee is often not nice to DataVideo TBCs. |
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Thanks for chiming in guys. So this persists across several retail VHS tapes - no TV recordings yet - a couple of Video8 recordings, plus a few different cables, with or without the proc amp or TBC in the chain. It's actually easiest to see with a blank screen, I realized. Sanlyn - I did make one short test recording while the stock (incessantly loud) fan was still on there, but there is so much wrong with the picture that it's difficult to see the effect I'm describing (that was with my pre-TGrant-recapping AG-1980). There is some chroma noise there, though, that kinda-sorta matches the shape of the pattern I'm describing, so I'll try to excerpt a part of it for here later, once I get home, along with one or two of my more recent attempts. In the meantime, it seems to me that it's the card, the fan, or this electrical interference that's causing this - unless all five cables I'm using are defective. If it is EMI - would something like this help? I use it to eliminate hum on one of my T-amps. |
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I wouldn't think the device you refer to would help, and it appears to work only with 3-prong a.c. connections. A more comprehensive power source cleaner would be more effective, like those that come with the better backup-UPS power supplies such as those from APC. If you decide to try those or true a.c. power cleaners, don't go anywhere near hyped brands like Monster Cable unless the only thing you want is a rip-off. Some users attach RF filters on their connecting cables -- that can be a little iffy, but some say it works and it's not that expensive. |
I have had this issue for a few years now...Just click my username, and then click posts regarding "RFI". (my latest turned into 5 pages of replies, got side-tracked into Huffyuv but by the end I posted video of RFI examples), Very faint Wiggly/Giggly lines, sometimes going northwest to southwest then changing north east to southeast..very frustrating!
Knowing it is not inherent to original tape!...It actually made me walk away from the whole thing for a few years! It all boiled down to my S-Video cables picking up RFI/EMI noise on the original ATI 9600 INPUT Cable.(From VCR)..I had to attach clip-on "RFI Chokes" http://www.radioshack.com/radioshack...e/2730105.html around my S-Video cables. Wound up purchasing expensive, but TRULY SHIELDED, Bluejeans S-video cables just to be sure. (recommended by sanlyn) http://www.bluejeanscable.com/store/svideo/index.htm But even then ,my RFI problem required me to clip on 4 of these chokes around the Bluejeans cables! And nowdays there are so many possible devices emmitting RFI ,There is no telling where this is coming from. A simple trial-by -error test for your problem is to connect your VCR to a TV or Monitor (even with Yellow composite connectors) if possible, and see how that looks. I suspected everything,from my VCR to PC ATI Card for a while, But found out the problem RFI was not the Hardware, but was with the S-Video Cables picking up outside interference, (in my particular environment)..Please note that Radio-shack chokes is an example only of the type that will fit over S-video cable...do some googling for cheaper price of same type of choke! And yes, try to upload a 5 second .AVI video file of your problem, this site now supports up to (99Mb?) of direct video upload, as long as your DSL is fast enough to upload within 10 mins, otherwise it will time out!..If it times out,then you have to become a premium member,and then read requirements for uploading video,thru FTP server. BTW, I found out that possible "RFI" shows up better against a White (Winter/Snow) background/source tape, as opposed to a darker background tape! |
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Attached is an x264 encoded at crf13 showing the issue happening without anything being played at all, when my source VCR is on but play has not yet been pressed. Very easy to see, especially once you go fullscreen. |
Before anyone could advise in detail, judging from the sample posted above, we'd need the answers to a few questions:
Do you always capture VHS to YV12 color? Do you always capture VHS to low-bitrate lossy h264? Do you encode interlaced video as progressive during capture, or after, and why? Noise isn't visible until zero-black is raised to about RGB64. How much of the noise in your sample would you estimate to be low-bitrate h264 compression noise? Do you always work with video on monitors or TV with high gamma settings? Did you try this test with no VCR connected? If the only component that was actually powerd up is the captue card, then the noise is in the card. |
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I use pretty much what is S.O.P. in the forum guidelines: VCR's: AG-1980, PV-S4670, PV-4664 cables: s-video (BlueJeans YC-2), composite when required (AR Performance Series RCA or BlueJeans/Belden 1695A) AVT8710 (when required) or Panasonic DMR-ES10 or DMR-ES15 pass-thru SignVideo PA-100 proc amp (sometimes) or VirtualDub hook-in to Levels controls in ATI capture drivers AIW 7500 Radeon AGP or AIW 9600XT Radeon AGP VirtualDub capture -> lossless huffyuv YUY2 interlaced AVI post processing: lossless Lagarith YUY2, YV12, or RGB as required with Avisynth and/or VirtuaLDub Interlaced video is output to final delivery as DVD or BluRay, interlaced. Telecined or blended-frame video is unblended/inverse telecined in post processing. The final encode is with 3:2 pulldown. From what I can see in the processed sample, the fluttery moire pattern is moving pretty fast, and is not consistent. The last time I saw that kind of noise it was an ungrounded cooling fan power line in a DVD recorder. [EDIT] With the lossless original it's easier to see and judge the RF noise more clearly. Same comment on the noise as before. Regardless of the colorspace or compressor used for capture, it's usually best to submit cuts from original, unaltered samples. |
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Actually, since it's trivial to convert to HuffYUV... (see attached)
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Whether you have something wrong with the card itself or whether the RFI is afflicting your entire PC power supply is anyone's guess. What I would suggest is feeding cleaner power to the PC itself. Some cheap RF filter chokes attached to the a.c. power line might do the trick, if that RF is coming from your home a.c. sockets. That would be the least expensive trial I can think of for a start. Sometimes a home air conditioner on the same circuit can create a lot of power line noise. Yup, I will do that moving forward. Only compressed it because I thought I had to :smack:[/quote] |
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(a) a part of the one capture I did before sending my VCR to get fixed and replacing the fan on the video card (b) same part of the same source after the VCR was fixed and the fan replaced. A few notes on the caps:
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For ferrite chokes - do these look good? |
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http://www.amazon.com/Ferrite-CB-Rad.../dp/B009U14CVI. |
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