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  1. I'm dealing with some hard telecined DVDs. It's 29.97 "interlaced" but it's 23.976 content telecined to 29.97. No pulldown flags. What I've read is an IVTC filter deinterlaces the video to 29.97p, then removes the duped frames to make it 23.976p. I thought I would make a script like this:

    Code:
    QTGMC(Preset = "Slower", InputType=0, SourceMatch=3, Sharpness=0.2, TR2=2, EdiThreads=8, FPSDivisor=2)
    TDecimate()
    QTGMC "Slower" is the best deinterlacer I've used, it's a bit slow but worth it. Would this work as a good IVTC script?
    Last edited by Vitality; 20th Nov 2018 at 20:33.
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  2. It will work but TFM is usually more accurate -- QTGMC often creates temporal ghosting, especially with animation. You can always follow up with QTGMC(InputType=1,...) if you want additional cleanup after TFM (it still may add ghosting).
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  3. Originally Posted by Vitality View Post
    What I've read is an IVTC filter deinterlaces the video to 29.97p...
    .
    .

    QTGMC "Slower" is the best deinterlacer I've used...
    You have the mistaken impression that an IVTC deinterlaces. Although progressive video is the result, it's not from deinterlacing. It's from field matching. There's a big difference. As jagabo mentioned, it's especially problematic with animations. I don't know what your aversion to a real IVTC is. If it's because it's not perfect with animations at default settings, then learn how to tweak the settings. Working with Japanese anime is often not easy and requires some serious skills. And work.
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  4. Originally Posted by jagabo View Post
    It will work but TFM is usually more accurate -- QTGMC often creates temporal ghosting, especially with animation. You can always follow up with QTGMC(InputType=1,...) if you want additional cleanup after TFM (it still may add ghosting).
    Just realized, I was using the default IVTC script with StaxRip:

    Code:
    Telecide(guide = 1)
    Decimate()
    Is TFM better than Telecide?
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  5. IVTC and deinterlacing are two different things. With material that has been telecined, there is NO temporal difference between fields, meaning that once you eliminate the duplicated fields, the remaining fields of each frame are from the same point in time. By contrast, the fields in interlaced material are from different moments in time and therefore the deinterlacing process always degrades the video compared to the original because you must invent a new filed that matches the other field temporaly.

    Therefore, you should only deinterlace when you absolutely must do it (for resizing, as one example). By contrast you should ALWAYS IVTC material that has been telecined, and the result will not be degraded at all. When I say degraded vs. not-degraded, I am neglecting in both cases the degradation from re-encoding the results of the operation.

    I have not used Telecide, but I have used TFM()/TDecimate() hundreds of times and am impressed with how well it works and how many parameters you can set when you have complicated telecine patterns. Fortunately, for most IVTC work all you need is this:

    Code:
    TFM()
    TDecimate()
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  6. Originally Posted by manono View Post
    Originally Posted by Vitality View Post
    What I've read is an IVTC filter deinterlaces the video to 29.97p...
    .
    .

    QTGMC "Slower" is the best deinterlacer I've used...
    You have the mistaken impression that an IVTC deinterlaces. Although progressive video is the result, it's not from deinterlacing. It's from field matching. There's a big difference. As jagabo mentioned, it's especially problematic with animations. I don't know what your aversion to a real IVTC is. If it's because it's not perfect with animations at default settings, then learn how to tweak the settings. Working with Japanese anime is often not easy and requires some serious skills. And work.
    I'm working with American cartoons.
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  7. Originally Posted by Vitality View Post
    I'm working with American cartoons.
    My mistake, sorry. But the points still stand.

    There's nothing wrong with using the StaxRip Decomb. But just as when using TIVTC, learn your way around it and how to tweak it.
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  8. As a side note, when combining QTGMC and TFM for IVTC, one would typically use something like:
    Code:
    A2 = last
    A2 = A2.QTGMC(Preset="Very Slow", ediThreads=2, FPSDivisor=2)
    TFM(mChroma=true,clip2 = A2)
    TDecimate(cycleR=1,cycle=5)
    Cu Selur
    users currently on my ignore list: deadrats, Stears555
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  9. Wouldn't it be much better to denoise the video after it has had the repeated fields removed? Denoising usually looks at adjacent field & frames, and if there are repeats (which is what telecine does), is won't see any difference and therefore won't be able to denoise. Therefore, I think you need to first remove those repeats (i.e., do IVTC) and then do the denoising.
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  10. Originally Posted by johnmeyer View Post
    Wouldn't it be much better to denoise the video after it has had the repeated fields removed? Denoising usually looks at adjacent field & frames, and if there are repeats (which is what telecine does), is won't see any difference and therefore won't be able to denoise. Therefore, I think you need to first remove those repeats (i.e., do IVTC) and then do the denoising.
    Of course. I usually do it that way. One exception would be dot crawl removal.
    Last edited by jagabo; 22nd Nov 2018 at 19:30.
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