Example of progressive image vs. interlaced

Discussion in 'Archived Threads 2001-2004' started by Stefan A, Aug 25, 2001.

  1. Stefan A

    Stefan A Second Unit

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    With my Toshiba 50h81, I am using my Yamaha 796 dvd player. This is not a progressive scan player. So far I have not seen anything wrong with the picture. The thing is, I don't know exactly what is inferior about the picture on an interlaced player. Can someone provide an example or 2 of what to look for on certain dvd's? Something that would obviously look better on a progressive scan player. Below is the link to my dvd's. It would be helpful to go with something I already have, but if there is a good example that is really clear, I could rent it.
    Stefan Antwarg
    My DVD Collection
    The Regal Brass Quintet Not HT related
     
  2. tommy_esq

    tommy_esq Stunt Coordinator

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  3. Brian_J

    Brian_J Second Unit

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    Your tv converts to 540 progressive, and thats what you are seeing, so going to a progressive player is going to provide only slight improvements assuming the doubler in the player is superior to the one in the tv (which is not by any means a certainty). If you are expecting a drastic change you will be dissapointed. But I like the scaling that a Pani RP91 offers and that alone makes it better to be doing the deinterlacing as you will get a clearer picture than having the toshiba do a zoom mode.
    Brian
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    Zed's Dead Baby...
     
  4. Tom Herman

    Tom Herman Auditioning

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    depends what is meant by "slight improvement" - I might cahracterize the diff between the TV's internal deinterlacer & a progressive DVD player as significant. I'm using a Tosh SD6200 player and 65H80 set (with the inverse 3:2 pulldown detection "enabled").
    When deinterlacing is done in the player (progressive), the construction of the full progressive frame is done strictly in the digital domain (a good thing).
    When you're doing the deinterlacing in the TV,
    - the interlaced digital frames from the DVD disc are converted to the DVD player's analog output,
    - analog signal from the player has to be converted back to to digital inside the TV,
    - deinterlaced digitally inside the TV,
    - finally converted again to analog inside the TV to form the actual picture on the CRTs.
    On my set up, I measure 500 horiz lines of resolution when the SD6200 player is in the Interlaced mode. This increases to 540 lines (the inherent design limit of the DVD format) when the player is in progressive mode. The picture IS sharper with more detail.
     
  5. Mike I

    Mike I Supporting Actor

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    I agree with Tom..The difference is significant...
    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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  6. Rick Radford

    Rick Radford Supporting Actor

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    This subject touches close to a question I have.
    I have a 32" SD TV. If I go to a 32" digital (like Panasonic 32hx41) will I see THAT much difference in PQ viewing from ~8 ft with a progressive vs interlaced input from a Panny RP91?
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    --RR
     
  7. Doug_L

    Doug_L Stunt Coordinator

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    Slightly off subject here...
    Tom Herman, I have 2 questions about your post.
    1) I thought that although DVD's have the capacity for 540 line of resolution, that only 480 are actually used for picture information. If I'm wrong, can you please explain why?
    2) In your post you refer to measuring either 500 or 540 lines of horizontal reslolution. What are you using to measure the resolution? Is there a specific tool, or are you just eyeballing the pattern?
    Please understand that I'm not challenging your post, but as it goes against what I've heard before, I'm wondering how you're doing it.
    Look forward to your answer.
     

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