Vertical lines on PAL VHS transfer?

[thestarswitcher]

Hi,

So luckily, my capture problem is a thing of the past (yay)! Now I have an S-VHS PAL player imported from Germany in absolutely immaculate condition, and have been doing some captures in AmaRecTV. I'm using a JVC HR-S9600EU, and an AVT-8710 (the dumb black one). Basically, on PAL tapes (or possibly just the PAL signal itself, I can't test this sadly...), there's these very faint vertical lines. I was hoping there's some sort of Avisynth script to fix this, because these look really beautiful and want to have artifacts like that out. Raw capture pics: (in the darker scenes, you can see the distortion I'm talking about in the sky more clearly) Thanks!

[sanlyn]

Still photos are limited when trying to analyze noise patterns. Likely it's temporal noise of some kind, but temporal filters can't be tested on still shots.

[thestarswitcher]

Hi Sanlyn,
Thanks for your response! Below is a link to download a clip from the raw file (out of VLC). Hopefully you can provide a solution!

https://drive.google.com/file/d/14Ku...ew?usp=sharing

[lordsmurf]

That black Cypress/AVT-8710 has many temporal issues, and this could be yet another one. Those black boxes are all defective.

But have you confirmed these noise does not exist on the tape? Remove the TBC from the workflow. What do you see?

You didn't mention the capture card being used. That could also be it.

[sanlyn]

Looks like RF noise. If it's on all tapes, hardware is the problem (player, capture card, TBC). There's a VirtualDub filter for this. I'll look it up and respond later.

[thestarswitcher]

Hi,
I took both of your suggestions, and ran it without the TBC. It indeed fixed the problem, but how do I go about utilizing the performance of the TBC without the issues associated with it? Is there something other than the green Toolbox model that would fix the problem? Thanks!

[sanlyn]

You can get decent frame-level tbc activity using a recommended legacy DVD recorder as a tbc pass-thru (connect your VCR to the DVDR's input, connect the DVDR's output to your capture card). The recommended models are the Panasonic DMR-ES10 and DMR-ES15. They come in PAL and NTSC versions. They differ from the usual external tbc in that as commercial recorders they won't remove copy protection. You can try other DVDR's, but their tbc circuitry is either too weak or won't function as pass-thru. Another caveat is that you must turn off Panasonic's noise reduction to prevent posterizing effects.

I did manage to remove 90% of the noise using a VirtualDub filter (fsn.vdf, aka "Frequency Suppressor Of The Noise", using a rough Russian translation). I also used SmartSmoother-HighQuality (SmoothHiQ.vdf) and ColorCamcorderDenoise (aka ccd.vdf). Stronger settings are possible, but not without destroying every detail in sight. The VirtualDub filters must be in your VDub plugins folder for the Avisynth script to work.

I also used RemoveDirtMC to clean up some small dropouts (small white spots, and a white "string" just right of center in frame 372 of your original sample). I used QTGMC in progressive mode as a denoiser to clean up line shimmer and some chroma flickering. Your sample is progressive but the source was encoded as interlaced. It is apparently 24fps film-source PAL speeded up to 25fps -- unless someone has previously deinterlaced it and dropped alternate fields to maintain 25fps speed.

fsn.vdf is attached
SmoothHiQ.vdf and its html help file are attached.
You can get ccd plus HueSatInt, ColorMill, Exorcist, and Gradation Curves for VirtualDub here: Virtual Dub Plugins zip.
You can get the Avisynth plugin RemoveDirtMC.avs at http://www.digitalfaq.com/forum/atta...emovedirtmcavs

As you can see from the attached mp4, RF noise filters are similar to dot crawl cleaners in that they tend to soften a video. Given that this type of noise seldom changes shape or position during play, ordinary temporal filters, spatial filters and degrainers won't work.

Below is the Avisynth script I used to get the attached denoised mp4. You should change the path statements to reflect file locations in your system. The sequence of operations in the script is important -- you should remove the RF interference before using other filters. Also note that low-accutance scenes such as fog and mist require higher than usual bitrates to prevent macroblocks and hard gradation edges.

Import("D:\Avisynth 2.5\plugins\RemoveDirtMC.avs")
LoadVirtualDubPlugin("D:\virtualDub\plugins\ccd.vdf","CamcorderColorDenoise",1)
LoadVirtualDubPlugin("D:\virtualDub\plugins\fsn.vdf","FrequencyNoiseSuppressor",1)
LoadVirtualDubPlugin("D:\virtualDub\plugins\SmoothHiQ.vdf","SmartSmootherHiQ",1)

AviSource("E:\forum\faq\thestarwatcher\" 
 \ + "vlc-record-2018-07-28-12h00m37s-PURTILOT1(20180726-2301).avi-.avi")

ConvertToRGB32(interlaced=false,matrix="Rec601")
LoadVirtualDubPlugin("D:\virtualDub\plugins\ccd.vdf","CamcorderColorDenoise",1)
LoadVirtualDubPlugin("D:\virtualDub\plugins\fsn.vdf","FrequencyNoiseSuppressor",1)
LoadVirtualDubPlugin("D:\virtualDub\plugins\SmoothHiQ.vdf","SmartSmootherHiQ",1)
CamcorderColorDenoise(24,1)
FrequencyNoiseSuppressor(67,67,2,0,1)
SmartSmootherHiQ(5, 50, 0, 254, 1, 0, 1, 0)

ConvertToYV12(interlaced=false)
RemoveDirtMC(20,false)
QTGMC(InputType=2,preset="very fast",GrainRestore=0.3,border=true)
GradFun2DBmod(thr=1.8,mask=true)
LSFmod()
AddGrainC(1.5,1.5)
Crop(10,2,-16,-8).AddBorders(12,4,14,6)

Thanks again for the sample. I'm wondering why you used VLC to make it when it would be easier in VirtualDub using "direct stream copy" processing mode.