DVD "jitters"

Discussion in 'DVD' started by ScottR, Aug 22, 2005.

  1. ScottR

    ScottR Cinematographer

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    What is the cause of this? For example, when there is a cut to a new shot, and part of the frame (a person's arm, etc.)starts to jitter, even in still frame mode. Only part of the frame shakes, the rest is still. Is this cause by frame over-lapping, and do newer players correct this problem? Thanks.
     
  2. ScottR

    ScottR Cinematographer

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    A perfect example of this is I Love Lucy (S.5) Lucy Meets the Queen..9:26 mark.
     
  3. Max Leung

    Max Leung Producer

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    Have you tried a different DVD player? What you are saying might be deinterlacing as handled by the player when in pause mode. I am assuming that the source material is already interlaced however...

    Also, what equipment are you using? Is your DVD player in progressive mode?
     
  4. ScottR

    ScottR Cinematographer

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    I don't think it is in progressive mode. But it is noticeable when you play it at normal speed too. I am using a Panasonic 310.
     
  5. Max Leung

    Max Leung Producer

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    Hmmm, I used to have a Panasonic A310 DVD player - and darned if I can remember seeing the same thing when I had it years ago. The A310 player doesn't support progressive mode.

    You are probably seeing the player output 2 fields of a single interlaced frame (even if the DVD was encoded progressive, it would have to interlace them anyways for a non-progressive TV), and it jitters a bit. It could be worse for improperly mastered DVDs. I would expect big name DVDs (like Lord of the Rings movies or other major releases) to not have this problem.
     
  6. ChristopherDAC

    ChristopherDAC Producer

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    Sounds like what we used to call "white-flag" error, in the LD days. You're watching a TV show, yes? shot on film, yes? And the result is that the 24 fps film does not map correctly to the 30 fps video -- not only has it been 3-2 pulled down and mastered as interlaced video, but the MPEG frames are assigned at 30 fps, so two or three out of every five freeze-frames [depending how it was done] will be jittery. That's my best guess -- if you observe a pattern to the jitter, yes-no-yes-no-yes or something like that, when doing a frame-by-frame stepthrough, I would bet money that the DVD producers did not bother doing a new film-to-video transfer and instead used an old telecine tape they had lying around; after all, "Lucy" was black-and-white, yes? so nobody would notive... [​IMG]
     
  7. ScottR

    ScottR Cinematographer

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    But it is noticeable during normal playback.
     
  8. ChristopherDAC

    ChristopherDAC Producer

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    Right, but is it noticable on something other than TV programmes? and does the jitter exhibit a pattern in still-frame mode? is what I'm asking. An MPEG decoder trying to interpret what I'm going to call an improperly flagged sequence could well mess up.
     
  9. ScottR

    ScottR Cinematographer

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    Carousel does it right before "You'll Never Walk Alone" as Shirley Jones is running to hug the older lady (can't remember her name).
     

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