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  1. Member
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    I'm trying to apply a deinterlace filter to my video in Virtual Dub, but it doesn't work.

    Video - Full processing mode
    Video - Filters
    (Add -> deinterlace -> Blend fields together (best))
    Save AVI

    Avi output = interlaced.

    What's wrong?
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  2. What's your source? My guess is it's a video was originally interlaced but was resized improperly before you got it. It may look interlaced but the two fields are not intact (ie, one picture in one field and the other picture in the other field) and attempting to deinterlace is just blurring the frame without blending the two fields together.

    Try discard field 1 instead of blend (the output frame will be half high). Do you see any comb-like artifacts in the output window? If so, you have the above mentioned problem.
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    It's not what I see, but what MediaInfo tells me.

    Originally Posted by MediaInfo
    Scan type: Interlaced
    Scan order: Bottom Field First
    I tried another deinterlacing function, didn't give any different result (at least not in MediaInfo). As for the source, it's from a DVD recorded with Philips DVDR70.
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  4. MediaInfo just reads a flag in the video. It has no idea if the video is really interlaced or not.
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    Originally Posted by jagabo
    MediaInfo just reads a flag in the video. It has no idea if the video is really interlaced or not.
    So the only way to know is to use my eyes? Are there no programs that can detect it to be certain? It's not really that important to me, but when I'm first going to spend time encoding I might as well do it the "best I can".

    Can I add deinterlace filter for second pass, or do I have to enable it during the first pass?
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  6. Originally Posted by Xavier
    Originally Posted by jagabo
    MediaInfo just reads a flag in the video. It has no idea if the video is really interlaced or not.
    So the only way to know is to use my eyes?
    Yes.

    Originally Posted by Xavier
    Are there no programs that can detect it to be certain?
    Your eyes are better than any program at this.

    Originally Posted by Xavier
    Can I add deinterlace filter for second pass, or do I have to enable it during the first pass?
    The video should be the same for both passes.
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  7. Video Restorer lordsmurf's Avatar
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    Why are you deinterlacing, anyway?
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  8. Member
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    Originally Posted by lordsmurf
    Why are you deinterlacing, anyway?
    Because the video is interlaced? And I don't want it to be? What does that have to do with anything?


    Btw, I think it IS interlaced. A guy told me it was partially, so if anyone can still help me, please. Do you have to do anything else than put on filter? Doesn't blend work 100%?
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  9. If you are unsure, maybe you can post a sample clip of the source
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  10. Originally Posted by Xavier
    Originally Posted by lordsmurf
    Why are you deinterlacing, anyway?
    Because the video is interlaced? And I don't want it to be? What does that have to do with anything?
    lordsmurf is trying to save you some time and effort. If your final destination is DVD, then you will retain better quality by keeping it interlaced.

    Originally Posted by Xavier
    Btw, I think it IS interlaced. A guy told me it was partially, so if anyone can still help me, please. Do you have to do anything else than put on filter? Doesn't blend work 100%?
    Maybe you should ask "a guy" for help. I don't know what he means by "partially" and applying a filter without knowing what you are trying to correct will almost certainly give worse results.
    Maybe if you were to post a few seconds of the source video we could give you some more help. Currently we don't have enough information to offer anything but wild guesses.
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  11. Member
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    Final result is supposed to be watched on my computer screen. If I'm converting to xvid, I doubt the final destination is DVD...

    I updated VirtualDub, and now MediaInfo shows it as progressive. Not sure if anything but the flag is different though.

    And is it even possible for it to be "partially", or has he just read the flag?
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  12. Yes , as explained above, mediainfo just reads the header information. It can be wrong.

    The actual content can be progressive, interlaced, or hybrid, or some weird combination. If you are still seeing artifacts in the output, it was either wrong, or your process was not ideal.

    To be fair, you never mentioned "xvid", only "avi". It's not uncommon to use lossless avi intermediates (e.g. lagarith, huffyuv), even if the final goal is DVD.
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    Well, I thought I mentioned xvid :P Sorry about that

    Anyways, is there a chance my last output wasn't progressive? I did it exactly the same way, only now with a newer version of VirtualDub. For some reason it would display as "interlaced" in MediaInfo earlier, while it displays as "progressive" now. No differences at all in procedure, only newer VirtualDub.

    Is the last output fine? I know that my previous output was "less" interlaced than the input, but I'm not sure how you can see if it's a hybrid or something like that.

    I have another question once you bring it up, encoding between lossless formats, say 5 times, will it not lose ANY quality at all? Or will it only lose less than lossy formats?
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  14. The best way is to use your eyes. The output can still be progressive, but if you used a poor quality method you can have artifacts left over from the deinterlacing - in this case I wouldn't call the output "fine", but it can be a matter of personal opinion.

    Yes, lossless means lossless; i.e. there is no quality loss between generations if you maintain the lossless format.
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  15. Originally Posted by Xavier
    I think it IS interlaced.
    If the video is interlaced you will see comb artifacts whenever there is movement:



    Originally Posted by Xavier
    A guy told me it was partially (interlaced)
    Partially? Maybe he means it's telecined film where 2 out of every 5 frames are interlaced. The rest are progressive. In a PPPIIPPPIIPPPII... sequence.

    Originally Posted by Xavier
    so if anyone can still help me, please. Do you have to do anything else than put on filter?
    What filters you want to use will depend on the video, whether it's fully interlaced, paritally field blended PAL/NTSC conversion, telecined film, MPEG2 with pulldown flags, etc.

    Originally Posted by Xavier
    Doesn't blend work 100%?
    Blend usually only works on video where motions are very small and/or slow. When motions get large it looks like double exposures and it's always a bit fuzzy. Same frame as above, blend deinterlaced.

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