3-2 Pulldown

Discussion in 'Archived Threads 2001-2004' started by AllanN, Apr 1, 2002.

  1. AllanN

    AllanN Supporting Actor

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    To achieve the effect that 3-2 pulldown gives you, do you have to have a DVD and a Monitor that support this feature. Im thinking about purchaseing the Sony KV-36XBR450 TV and the DVP-NS700P DVD Player. They both talk about 3-2 Pulldown but do not specify that you have to have the other compatible component.
    If you dont have to have 3-2 pulldown in both components woudl I be better off getting the HS series TV over the XBR to save money? Anyone out there who owns such a configuration?
    Allan
     
  2. Allan Jayne

    Allan Jayne Cinematographer

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    One or the other will suffice but...
    With a DVD player with progressive scan and 3-2 pulldown optimized output all you need is any TV with progressive scan input capability. Handling the 3-2 pulldown in the player generally gives slightly better results but then only DVD playback can utilize that benefit.
    With a TV with doubler and 3-2 pulldown sensing and optimizing, all you need is any interlaced DVD player. All your other interlaced program material including VHS tapes benefit from it as well. Progressive scan material skips the TV's 3-2 pulldown handling.
    Video hints:
    http://members.aol.com/ajaynejr/vidprog.htm
     
  3. jeff peterson

    jeff peterson Supporting Actor

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    I know the definition of 3:2 pulldown but what actual viewing "problem" does it correct? Smoother movement? Better scene transitions?
     
  4. Allan Jayne

    Allan Jayne Cinematographer

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    The purpose of recognizing the 3-2 pulldown during de-interlacing is to construct each progressive video frame from odd and even fields that were made from the same film frame. This produces crisper movement and consistently sharper picture quality.

    Without recognizing the 3-2 pulldown and blindly taking the next field to combine and make a full video frame, occasionally unmatched fields will be woven together, producing subtle blurring.
     
  5. Niranjan

    Niranjan Auditioning

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    3-2 pull down usually helps on films since film is 24 frames per second but tvs show 30 frames per second, with out 3-2 pull down some films look choppy during sections of the film with lots of movement
     
  6. RyanSR

    RyanSR Extra

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    So, to get this straight, the film material on a VHS tape is indeed in the native format at 24fps and a TV equipped with 3:2 pulldown would be able to enhance the playback. Presumably then this problem is moot if the film source is a network broadcast as the video field/frame is dictated directly by the broadcaster and has already been optimized, correct?
     
  7. Allan Jayne

    Allan Jayne Cinematographer

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    VHS tapes and NTSC broadcasts of 24 fps film are 60 fields per second and already have the 3-2 pulldown in them (occasionally some esoteric blending which is usually for the worse it used instead). When the TV has the "3-2 pulldown feature" we get the clearest picture. The purpose of the "3-2 pulldown feature" in the TV or DVD player is to preserve the pulldown because no consistently better and efficient alternative way of constructing the progressive scan frames has been found yet. If the film as seen in the theater shows choppy or jerky motion due to the 24 fps frame rate, this will not be smoothed over in a video presentation. (Actually in the theater the 24 fps film is shown as 48 short flashes of each frame twice instead of 24 long flashes per second.) Some esoteric processing methods attempt to smooth out the jerkiness inherent to 24 fps but on average videophiles judge the overall result to be worse than finding the matching even and odd fields from the 3-2 pulldown in the source and reconstructing the progressive video frames directly from matching fields.
     
  8. RyanDinan

    RyanDinan Stunt Coordinator

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  9. Allan Jayne

    Allan Jayne Cinematographer

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    Quote: Don't the new Toshiba's break this rule [progressive scan skips the TV's 3-2 pulldown detection], since they upconvert everything to 540P?

    No need to break this rule. Incoming 480p frames can be upconverted to 540 scan lines each without having to look for 3-2 pulldown. Furthermore detecting 3-2 pulldown is only relevant during de-interlacing. If the video is already progressive, nothing more can be gained by analyzing it again for 3-2 pulldown. Then the 540 line frames go right into the TV's 1080i scanning without any difficulty.

    Incoming 480i video should be de-interlaced first, with detection and handling of 3-2 pulldown if applicable. When this is done then the full frames may be upconverted to 540 scan lines each. If individual fields are upconverted directly to 540 scan lines the result is inferior.
     

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