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  1. Member RangerCat's Avatar
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    Hello everybody,

    I'm trying to restore capture from an old VHS tapes. I already done some steps and experiments with various AviSynth and VirtualDub filters in order to restore picture. Basically I have an idea how to process the whole thing with the major exception of those darker horizontal lines:

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    I'm newcomer to AviSynth scripts and will appreciate every help. What is done on the video so far is capture to YUV2 in Lagarith codec and QTMC deinterlacing. The goal is to make DVD and x264 video later. My wish is to use as less damaging tehnique as possible. I dont't like to use heavy manual intervention, but time for processing is not critical.

    I have played with Smart Skating Rink, Camcorder color denoise, Color Mill filters on VirtualDubto to achive better results, but those are not applied on samples. If we can come to entire AviSynth chain, it is even better.
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  2. Member 2Bdecided's Avatar
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    I don't have a fix (though remove dirt helps when it's just on one frame), but I'm sure someone is going to ask for raw samples (i.e. before you deinterlaced using QTGMC).

    Cheers,
    David.
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    Last edited by sanlyn; 19th Mar 2014 at 10:55.
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  4. Member RangerCat's Avatar
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    Originally Posted by sanlyn View Post
    Your samples have been encoded to lossy h264. h264 is not considered an editing format, but is a "final delivery format". If you have cleanup cleanup to be worked from analog source, you should be capturing and working with losssless media.
    I'm using Lagarith internally.

    There is no information how how the source was captured or the software you are using. The source is not tracking properly and/or is damaged. Colors and bright highlights are clipped to the point where some of the brightest colors are being changed or otherwise corrupted. There also appear to be something that looks like improper colorspace conversion.
    I used VirtualDub to capture from Asus TV 7134. The attached bellow sample is what I can get, because no access to pro equipment. Also it is not possible to recapture anymore. However I'm convinced that the main damage is from the tape/recorder itself.

    If your final output target is standard definition BD or AVCHD or DVD, those SD formats are usually interlaced. In any case you will get more precise advice if you submit a sample of the original captures, before processing.
    I agree. The main concern here is that I evaluate computer format the most. I don't like to process twice. Also I'm not sure that the most filters will work properly than. But You can convince me about that.

    Originally Posted by 2Bdecided View Post
    ...but I'm sure someone is going to ask for raw samples (i.e. before you deinterlaced using QTGMC).
    New raw input sample is attached bellow.

    Thanks!
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  5. Try capturing the same scene twice. If the dark lines aren't in the same place in both caps make a third cap and use a "median of 3" filter to remove the dark lines.

    http://forum.videohelp.com/threads/340963-Best-quality-and-speed-video-denoisers-2011?...=1#post2122313
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  6. Member 2Bdecided's Avatar
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    If it's tape damage, it'll always be in the same place though.

    EDIT: OK, many of the lines don't look like tape damage, but like a faulty VCR. Parts obviously are tape damage though.
    Last edited by 2Bdecided; 9th Dec 2013 at 09:35.
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  7. Member RangerCat's Avatar
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    Originally Posted by jagabo View Post
    Try capturing the same scene twice. If the dark lines aren't in the same place in both caps make a third cap and use a "median of 3" filter to remove the dark lines.
    Great advice! Unfortunately neither the tape, nor the video are available any longer. Shame on me.

    The question is can I squeeze a bit more. Otherwise I will process with the current quality.
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    Last edited by sanlyn; 19th Mar 2014 at 10:56.
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  9. I found:

    Code:
    SeparateFields()
    evn=SelectEven().RemoveSpotsMC()
    odd=SelectOdd().RemoveSpotsMC()
    Interleave(evn,odd)
    Weave()
    removed some of them (especially in the blue sky) without damaging the rest of the picture much.

    I tried using McTemporalDenoise() but you have to use strong settings to remove the dark bands -- and that damages the rest of the picture a lot.

    Since the dark bands usually only appear for one field I'm looking into using GeneralConvolution() to build a mask that highlights areas with alternating bright/dark scan lines. Then one might be able to use that with to overlay of a strongly filtered video with the original.
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    Last edited by sanlyn; 19th Mar 2014 at 10:56.
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  11. Member RangerCat's Avatar
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    Some of those rolling bars were cleaned up in the sample below, but many remain.
    Even a little is a lot better. Also most of the videos are moving slowly and have less damage. But those lines are common, the only difference is that sometimes they are thicker. In fact I was so upset with the colors and other things at the beginning, that I didn't recognize them as so irritating.

    Since the dark bands usually only appear for one field I'm looking into using GeneralConvolution() to build a mask that highlights areas with alternating bright/dark scan lines. Then one might be able to use that with to overlay of a strongly filtered video with the original.
    I will greatly appreciate that! I was thinking about the same, but don't know how to achieve that.
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  12. He can also use DeVcr (best if used multiple times like run 1 =0,run 2=20/30 or Descratch after the removespotsMC or even RemoveDirtMC

    SeparateFields()
    evn=SelectEven().RemoveSpotsMC().DeVCR(0)
    odd=SelectOdd().RemoveSpotsMC().DeVCR(0)
    Interleave(evn,odd) Weave()

    In cases like this when "colored lines" appear it is best to use camera color denoise vdub after. I think Neat video can also help.
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    Last edited by sanlyn; 19th Mar 2014 at 10:57.
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  14. Originally Posted by RangerCat View Post
    Since the dark bands usually only appear for one field I'm looking into using GeneralConvolution() to build a mask that highlights areas with alternating bright/dark scan lines. Then one might be able to use that with to overlay of a strongly filtered video with the original.
    I will greatly appreciate that! I was thinking about the same, but don't know how to achieve that.
    It didn't work out. It mask marked the interlace comb artifacts much more than the dark bands.
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  15. Member RangerCat's Avatar
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    It didn't work out. It mask marked the interlace comb artifacts much more than the dark bands.
    I see.
    I was trying to use DeScratch, but have kind of similar results - it is either too much sensitive or doesn't detect them. Further more, even it "sees" defects it can't repair them well.

    Code:
    inputClip = AVISource("video.avi")
    lowColorClip = ConvertToYV12(inputClip, interlaced = true)
    rotatedClip = TurnLeft(lowColorClip)
    descratchClip = DeScratch(rotatedClip, mindif=1, maxgap=12, minlen=510, maxlen=770, blurlen=0, keep=95, border=0, modeY=1, maxangle=2, mark=true)
    resultClip = TurnRight(descratchClip)
    StackHorizontal(lowColorClip,resultClip)
    Click image for larger version

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    Sad to say, NatVideo has only a minimal effect on this kind of disturbance.
    I didn't like NatVideo much. It once was able to do good job about these lines, but I never remake it.

    He can also use DeVcr (best if used multiple times like run 1 =0,run 2=20/30 or Descratch after the removespotsMC or even RemoveDirtMC
    My initial effort with DeVcr and RemoveDirtMC does not came to good results. Did't try removespotsMC so far.

    In cases like this when "colored lines" appear it is best to use camera color denoise vdub after.
    Yes, I think CCD is worthy. I plan to use it.
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