Interference artifacts on VHS capture

[vivan]

I'm trying to capture VHS tapes and I'm getting this artifact (diagonal lines, not poor deinterlacing):

http://i.imgur.com/WWaYFuW.png

I want to know what is it, what causes it and how to avoid it (or, at least, how to clean it).

Tapes are regular VHS (I don't see any S-VHS mentions anywhere - neither on tapes, nor on VTR. But VTR says that it has "HQ Picture System"). I'm playing them on Panasonic NV-HD650EE. It has only 2 SCART ports, so I'm using small SCART->composite adapter.
I'm capturing using AVerMedia DVD EZMaker 7 via VirtualDub.

Video was originally recorded on Hi8 tapes using Sony CCD-TR920E, but then was transferred to VHS tapes using this VTR (I believe). Sadly I don't seem to have all the originals. But those that I have don't have such artifacts (hi8 (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/capt_hi8.png), vhs (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/capt_vhs.png)). However when capturing video from that camera (even when it's not playing) using S-Video (it has it) I'm getting something kinda similar (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/hi8.png) (but almost invisible and in this case defreq helps very well).

With each capture artifacts look different, but located in more or less same places: capture 1 (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/capt_1.png), capture 2 (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/capt_2.png). Some parts of the video are less affected, some are more.

I have another SCART->composite adapter, but it shows same result. I don't have SCART->S-Video adapter but I believe that it wouldn't work (I'm under impression that S-Video works only with S-VHS, otherwise it should show only luma).

When playing on TV (it has SCART input) there're no such artifacts: capture (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/capture.png), TV (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/photo.png). Which means there should be a way to fix this.

I've tried using defreq, but with no success (no horizontal peaks, only vertical).

Video sample (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/sample.avi) (I'm using MagicYUV (http://forum.doom9.org/showthread.php?t=170227) codec).

[TheSkiller]

The pattern's frequency is too high to be stored on VHS, so yes something in your playback/capture chain must be causing it.


I'm under impression that S-Video works only with S-VHS, otherwise it should show only luma
Indeed, your VCR not an S-VHS deck so Composite is all you can get out of it.


When playing on TV (it has SCART input) there're no such artifactsOK, but see what happens if you use the exact same Scart adapter and Composite cable that you use to connect the VCR to your AVerMedia (assuming the TV has RCA inputs). Is the pattern absent as well?

[vivan]

OK, but see what happens if you use the exact same Scart adapter and Composite cable that you use to connect the VCR to your AVerMedia (assuming the TV has RCA inputs). Is the pattern absent as well?My TV (Philips 32PFL9613D/10) d̶o̶e̶s̶n̶'̶t̶ ̶h̶a̶v̶e̶ ̶R̶C̶A̶ ̶i̶n̶p̶u̶t (only 2 SCARTs, YPbPr and HDMIs), so I've tried chaining 2 SCART adapters (SCART -> RCA -> SCART) - it works, and TV gives picture without artifacts.
Then I've tried YPbPr input. It obviously gives b/w image, but that image is really similar to those artifacts (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/photo2.jpg). Even if it's an expected result - I hope that it might explain something...

Hm, could it be dot crawl? Wikipedia says that Dot crawl can be greatly reduced by using a good comb filter in the receiver to separate the encoded chrominance signal from the luminance signal.Which would mean that I should get a better capture card.

[TheSkiller]

It obviously gives b/w image, but that image is really similar to those artifacts (https://dl.dropboxusercontent.com/u/16254258/d9/vhs/photo2.jpg).Yes, but that pattern is to be expected if you connect a color Composite signal (CVBS) to the Y input. The TV does not expect any color modulation on the Y input so you get to see the raw color modulation (which looks like fine checkerboards) over a black and white image.


I think the problem lies in your AVerMedia. It somehow seems to be unable to demodulate the color fully with imperfect signal timings like from a raw VHS playback. It could be a grounding or shielding issue inside the AVerMedia as well.


I see two options for you:

1) Get a Panasonic DVD-recorder (DMR-ES, DMR-EH or DMR-EX) for the purpose of pass-through and connect it between the VCR and your capture AVerMedia. It will aid jitter, possible flagging, color instabilities and other defects – and most importantly it will output a constant and stable signal for the AVerMedia to capture. This is not going to remove the pattern if it's caused by the AVerMedia itself however.

2) Ditch the AVerMedia and try another capture device. But even then you would benefit from a Panasonic DVD-recorder in the chain.



Hm, could it be dot crawl?Dot-crawl shows up at sharp luma/chroma transitions, not in flat and low detail areas. It's not dot-crawl.

[vivan]

1) Get a Panasonic DVD-recorder (DMR-ES, DMR-EH or DMR-EX) for the purpose of pass-through and connect it between the VCR and your capture AVerMedia. It will aid jitter, possible flagging, color instabilities and other defects – and most importantly it will output a constant and stable signal for the AVerMedia to capture. This is not going to remove the pattern if it's caused by the AVerMedia itself however.I guess I could use receiver that way? I have Sony STR-DA2400ES sitting under TV, but moving it to PC would be a real pain.

UPD: Tried it, didn't help. Oh, well, time to get a proper capture card. Thanks for your help.
UPD2: Hmm, I wonder if using it for digitizing is a good idea - when outputting signal from VTR to TV via HDMI it looks fine. Which means any cheap hdmi capture card should be good enough.

[TheSkiller]

UPD2: Hmm, I wonder if using it for digitizing is a good idea - when outputting signal from VTR to TV via HDMI it looks fine. Which means any cheap hdmi capture card should be good enough.That would work (maybe you need to find a way around HDCP). But if you are looking for a lossless capture (not H.264) then unfortunately there aren't that many capture cards to choose from and they aren't cheap (Blackmagic Intensity).

But I mentioned those specific Panasonic DVD-recorders because they are known to be the best at stabilizing analog tape sources. Does the Sony STR-DA2400ES do it equally well? Most likely not. Is it still good? To find out you could just connect it to a TV and play a bad tape to test it's stabilizing capabilities. You could even cheat by misadjusting the tracking on purpose and see how the Sony handles really whacky signals.

[raffriff42]

Same problem was discussed here:
http://forum.doom9.org/showthread.php?t=171259

[Ghitulescu]

Your tiny capture card is most likely the issue.
Try finding a S-VHS deck and use it's S-Video output. This way the comb filter, which appears to be cheap/broken is bypassed and you'll get a better image.
You should also use a better card. Since HD, the prices for old, but good, pro, semi-pro and advanced SD cards dropped significantly.
From a certain number of cassettes up it may even be feasible to buy a TBC (also very cheap these days, for the same reasons).

[vivan]

Welp, guess finding better hw will cost more than paying ~150$ (for 50 hours of tapes) to a company specialized in this stuff. They claim to have Panasonic AG 8700, AG 7350, AG 4700 S-VHS and Canopus ADVC 300, ADVC 110 + pinnacle capture cards. This hw sounds great except lossy DV encoding for no reason. But maybe pinnacle card they have are good.
I wanted to speak about it with their tech person, but he's out on vacation till the end of next week...

[Ghitulescu]

You see, 3$ per tape cannot possibly mean more than
1. tape in
2. computer REC PAUSE
3. dubing in progress
4. eject tape
5. save AVI/MPEG2/VOB file
6. goto step 1.

I might be wrong, but time is precious and tapes that need special care means they really need special care.

[vivan]

What type of special care they need except being captured using good hardware? How would it be different from what I will be doing if I decide to get better hw myself? Because I have no idea, I've never worked with analog video before.
(sure I'll ask them do disable all crappy "professional" postprocessing they might use and ask them for uncompressed/lossless capture)

I don't want anyone other than me to do any further processing (trimming, cropping, dealing with artifacts, deinterlacing, encoding, etc.) anyway.

You see, 3$ per tapeper hour, and our currency is currently in agony - year ago that was 6 (http://www.xe.com/currencycharts/?from=USD&to=RUB&view=1Y)...

[vivan]

I went to those guys, tech guy was cool but he said that either they're doing it their way or they don't do it at all and made me a free sample. Unfortunately Canopus really sucks - even with postprocessing turned off it still sharps and saturates everything to hell. And then destroys everything with lossy DV compression (even after processing and encoding I still see blocking and extra deblocking blurs details too much).
Their capture (http://i.imgur.com/k40Lw3I.png) (1 field doubled with pointresize), my (http://i.imgur.com/coOVOBv.png), my.Sharpen(0.5).Tweak(sat=1.2, bright=4) (http://i.imgur.com/jZ0z3FA.png) (to match their capture).

I have found 3 other cards lying around:
First had the same chipset (Conexant CX23102) and captured video was exactly the same. So it has non-functional comb filter(?) and/or my VCR produces really bad signal.
Second is Pinnacle 710 that suddenly started working under Win10 (it hangs VDub on W7 on my 2 PCs and BSODs XP). Artifacts-wise it was much, much better but still have issues.
Third was HDMI one, and yeah, HDCP.

So which card would you suggest? What will it improve? The first one here (http://www.digitalfaq.com/forum/video-capture/3200-best-ati-wonder.html) is Hauppauge 610, which is based on Conexant CX23102 again. So that chipset is actually decent?
The one that others are praying on (ATI TV Wonder 600) is kinda hard to find (I feel bad paying $40+ just for shipping and waiting for a month without seeing comparasions).

So far I found Panasonic DMR ES10 for dirt cheap (will get it this week) and maybe will be able to get a decent VCR (Philips VR-1600 aka JVC HR-S9700/S8700).
That should cover those artifacts and TBC. Better VCR should also improve detail level (their sample still have more details so this is my goal). The only thing that bothers me is crushed white: their (http://i.imgur.com/OS6VZLX.png) my (http://i.imgur.com/nHUFRs1.png). A guess what I need is AGC - does VCR/DVD Recorder will have them for me, or I still need a capture card with it?

[Ghitulescu]

Although a video should not be judged by photos and definitely not on computers, I see more details in their photo.
BTW: why are the images stretched to 1440 px horizontally?

You may "import" better kois here (www.youtube.com/watch?v=M-QctGL3kUk) :)

[vivan]

BTW: why are the images stretched to 1440 px horizontally?I've doubled it in both directions with pointresize (one field is 720x288, doubled - 1440x576) so blocking will become obvious (and it easier to compare, unless you're have 2160 display and need extra doubling :)).

[Ghitulescu]

Let them do it - you cannot buy everything you need to get the image as good as they, you need a video-proc.

That Panny is not bad, it's not the best either: its fame comes from a single trump it has - it is able to correct a specific waving few consumer TBCs can correct. Of course, used as a TBC, not as ADC :). This flagging si so rare that I couldn't be able to replicate with my cassettes (it appears to me to be more of an NTSC thing).

I know people prefer to use JVC, yet comparing my TOTL JVC HR-DVS1 (with TBC and 4MB memory), JVC HR-5800 (European, not USA) and a few others I've sold meanwhile with a Panny AG-7600 (almost TOTL) and even with a BOTL AG-5700, the Pannies extracted more details (and a little bit more noise - but that's normal). I think it comes from the aggressive post-processing of JVC, to please the consumer.