Progressive Scan

Discussion in 'Blu-ray & DVD Players & Recorders' started by mobily, May 31, 2005.

  1. mobily

    mobily
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    Hey all,

    I picked up a guide to dvd recorders leafley in Currys the other day and was wondering if someone could clarify something for me. The leaflet talks about pal progressive scan and how it provides a 'rock steady image'. I presume that they mean PS can only be used if using a dvd recorder for playback of commercial dvds. They don't mean if you record a programme onto dvd that when you play it back it is progressively scanned do they?


    Cheers,

    James :)
     
  2. redsox_mark

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    If the DVD recorder is playing in PS mode, then anything it plays will be output progressive - even a homemade DVD.

    You'll need a display which can handle a progressive input of course... and note even then using PS on the DVD player won't neccessarily be better. It depends on how good the display is at "descaling" vs. the DVD player.

    Mark
     
  3. Nick_UK

    Nick_UK
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    Some DVD recorders will also "up-convert", so you can feed in RGB or s-video and get progressive output live.
     
  4. mobily

    mobily
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    Is PS only available through a component connection? Also how can you tell if your display device accepts a PS signal?

    Thanks for all your help
     
  5. redsox_mark

    redsox_mark
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    Yes, it is generally through a component connection. My display will accept a progressive signal from component or RGB, but my DVD recorder (Toshiba XS32) only outputs progressive via component. The Sonys are the same. The manual for your display should tell you, e.g. 525p/625p. The "p" is for progressive.

    Mark
     
  6. Nick_UK

    Nick_UK
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    Some manufacturers call progressive "non-interlaced".
     
  7. Bloomsburybill

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    I have tried viewing via component leads with and without progressive from three DVD recorders (JVC DR-M10, Sony GX210 and Sony GX700). On my humble 26" widescreen LCD TV (by JVC) I honestly can't tell the difference (except for the GX700 where, for some reason, black comes out rather light so everything looks a bit washed out). From a commercial DVD the horizontal resolution of the picture seems to be limited by the number of pixels on the TV even when progressive is turned off. Perhaps the LCDs don't have a quick enough response to see whether the picture is interlaced or progressive. Anyway, I suspect that this feature should only be a factor in your decision if you are going to invest in a much bigger TV screen (and obviously it needs to be compatible with progressive!). When I was looking around I made progressive one of my criteria, given that my TV can accept this signal. In retrospect I think that I could have ignored this feature; we are not intending to upgrade our TV in the near future.
     
  8. redsox_mark

    redsox_mark
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    Progressive doesn't change the resolution - it just sends a progressive image rather than interlaced to the display. The display will have a descaler itself, and the source video is interlaced anyway.... so it becomes a question of which is doing a better job at converting the interlaced to progressive; the DVD player/recorder or the display. Often the display is as good or better, in this case you won't see any improvement using progressive scan.

    Mark
     
  9. mobily

    mobily
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    Thanks for all your help guys,

    I own a Toshiba 28ZD26B television and that has progressive scan capability. However I do get confused as to ntsc and pal PS. Is anyone familiar with this model and its limitations?

    I currently hook up my dvd player through the component connection but the dvd player only has ntsc PS. Is it true to say that my tv could de-interlace the image just as good or better than the dvd player?

    Thanks for all your help on a most confusing area of AV. :hiya:
     
  10. Nick_UK

    Nick_UK
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    I think the biggest limitation of that particular TV is that it is a 100Hz model with a frame-store, and in many Toshiba 100Hz models that I've seen, the frame store has poor grey scales.

    To put this into English, a 100Hz TV takes the picture and stores it in a digital store, and then scans each 50Hz picture twice, to give the illusion of 100Hz. Unfortunately, to store a TV picture requires a lot of memory, and in years gone by, memory was not cheap, so a few corners were cut to reduce the amount of memory required. One of the things that was done was to reduce the number of grey-scale steps between black and peak white, and this can cause some srtange effects on grey and colour brightness gradients.

    I hope this makes sense, because it's not easy to explain in simple terms.
     
  11. mobily

    mobily
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    There are many picture settings which are natural, 100hz, progressive and some others. Progressive is the best by far. I think that 100hz is more suitable for large screens and plasmas.
     
  12. Nick_UK

    Nick_UK
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    Plasmas don't really have a "refresh rate", as such.
     

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