Q on new reverse pulldown feature on XBR450

Discussion in 'Archived Threads 2001-2004' started by Ken Stuart, May 24, 2001.

  1. Ken Stuart

    Ken Stuart Second Unit

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  2. Han

    Han Second Unit

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    I suppose it's also useful for the lot of people that can only afford to upgrade one thing at a time. Maybe they'll have a non-progressive DVD player that they're not ready to replace yet. Other TV manufacturers have 3-2 pulldown, so this isn't an uncommon thing to have the feature on a TV instead of a player.
     
  3. Mike I

    Mike I Supporting Actor

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    Progressive scan will always give you a superior picture to a hd ready sets internal line doubler evan if the internal line doubler does a 3.2 pull down..
    With progressive scan the 3.2 pulldown is accomplished in the digital domain using the frame flags encoded in the dvd's mpeg bitstream..
    Advantages of progressive conversion
    Line doublers are used in other high-end home entertainment systems to provide progressive scanning. These may be stand-alone devices or incorporated into a digital TV. Impressive as they may be, DVD in-player progressive conversion has three big advantages over line doublers:
    1) High precision and stability
    A DVD-Video disc mastered from a film holds all the data necessary to produce an accurate progressive image, whereas an external line doubler must take hints from the video source to determine the source material and frame allocation.
    2) All-digital conversion minimizes signal degradation
    Since the signal from the DVD-Video disc is digital, progressive conversion can be performed digitally inside the player. Signal quality is protected until it leaves the player's analog output. In contrast, a stand-alone or in-TV doubler first receives information from the analog output of the source device then converts this analog signal back to digital for processing. Finally, it must translate the signal back to analog before outputting it. All this back-and-forth translation is much more likely to degrade the signal.
    3) Processing is optimized to DVD-Video's high image quality
    Line doublers built into digital TV sets are designed to work with a variety of video sources, so their settings are not necessarily ideal for DVD-Video. Progressive conversion is optimized for the high resolution and low noise of the DVD-Video format. This enables the unit to preserve DVD-Video picture quality for display on all screen sizes, from direct-view CRT to projectors.
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  4. sasha

    sasha Extra

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    Where, where can I find an FAQ just like what you wrote (or copied from one?) on ALL the features like this one, easy to understand and comparative, yet not verbose to take up volumes if printed out... [​IMG]
    So is Sony KV32HS20 - practically the same TV as 32XBR400, while XBR450 that replaced 400 has added features like 3:2 pulldown? HS20 is cheaper than XBR400 was...
    Thanks,
    -Sasha.
     
  5. JasonRH

    JasonRH Second Unit

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    sasha,
    Look on the Panasonic website for explanations like the one above - I could have sworn I saw that there somewhere (I think in the progressive DVD player section).
     
  6. JoelW

    JoelW Stunt Coordinator

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    I'm new to the progressive scan DVD market and I don't quite understand all the 3:2 stuff. I do understand the concept of the fps, but I have a question.
    Take the Pioneer 434 DVD player, progressive scan but no 3:2 pulldown. If you were to output this player to a TV that has 3:2 pulldown, would you in effect be delivering the same thing as using a progressive scan DVD player with 3:2 pulldown?
    If not, can someone elaborate on the differences.
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    Joel White
    Editor CheapHomeTheater.com
     
  7. RyanDinan

    RyanDinan Stunt Coordinator

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    The thing you want to look for in a progressive DVD player is 3-2 pulldown detection. Every DVD player (progressive and interlaced) has 3-2 pulldown.
    The Pioneer 434, like you said, doesn't have a "film mode", or in other words, doesn't have any way of detecting the 3-2 pulldown applied to the source.
    3-2 pulldown is how 24 fps of film is adapted to the 60 fields of video. Each frame of film is sampled either 2 or 3 times (3-2-3-2-3-2-3-2...etc..). By detecting this pattern, the player can tell which two fields of video belong to the same frame of film. The Pioneer (as well as any other video de-interlacing scheme) can and will "mix" two different fields from two different frames of film, creating artifacts.
    Most of the time, if you output a 480p signal from a DVD player (lets use the Pioneer 434), any line doubling or de-interlacing built into the TV will be bypassed, since the signal is allready 480p. The only way to use the 3-2 pulldown detection included in some TV's, is by outputting an interlaced 480i signal to the TV, which all progressive scan DVD players can do as well. However, in order for the TV to perform it's de-interlacing, it needs to digitize the analog video signal sent from the DVD player. These extra A/D D/A conversions tend to soften the picture and fine detail.
    The benefit of having a progressive scan DVD player is to avoid those extra conversions by having the de-interlacing performed while the signal is still digital, so that no image detail is lost in the conversions.
    -Ryan Dinan
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    [​IMG]
     

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