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HD Confusion

Discussion in 'TVs' started by AnnatarUK, Jul 11, 2005.

  1. AnnatarUK

    AnnatarUK
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    Hi,

    can someone please advise?

    I understand Sky are going HD for the World Cup next year etc, and i've been looking at TV's and stuff, but it seems all TV's i've been looking at ,which are HD ready are 720p and 1080i.

    HD-DVD and Blue-Ray are apparently 1080p, so surely these HD tv's are not going to be able to display an image?

    So surely they are going to be even higher HD Tv's coming out, once the new DVD format's are released?

    Is this correct? Or am i reading something wrong into all of this?

    Thanks in advance.
     
  2. Welwynnick

    Welwynnick
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    The two high definition standards are 720p and 1080i.
    The number refers to the number of lines in the visible image.
    The suffix refers to progressive or interlaced scanning.
    Progressive is superior, and draws every line in every scan of the frame.
    Interlaced means only every other line is draw in each scan of the frame (the even lines in one field, then the odd lines in the second field of the frame).
    Both formats are used with HD TV.

    Most current HD displays have 720 or 768 lines. Very few have 1080 lines.
    Whatever the input, the display will process the video and display it at it's own native resolution, irrespective of it's input capability.

    Digital displays also display only progressive video, so if interlaced is input, then it will be converted to progressive by de-interlacing, but this is likely to be poorer than feeding an original progressive input.

    Broadcast HD standards do not cover 1080p, which is the ultimate medium term goal, but this may come in time as media and displays develop.

    regards, Nick
     
  3. Stephen Neal

    Stephen Neal
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    Not strictly true. The ATSC standard used in the US DOES include 1080/24p and 1080/30p as broadcast standards. Lots of US drama and comedy is shot in 1080/24p - though this is not related to the transmission system directly.

    However no US broadcaster is actually using the 1080/24p or 1080/30p ATSC modes for transmission - as you say they are sticking with 1080/60i (and interlacing 1080/24p material via 3:2 pull down to 1080/60i) or 720/60p (and frame repeating again using 3:2 and scaling)

    The reason - it is not easy to change transmission standards on the fly - and any TV transmision system needs to run at 50 or 60 pictures a second to provide decent motion rendition for sports etc.

    If you ran a network fixed at 1080/24p or 1080/30p you'd not have the fluid motion that 1080/60i or 720/60p delivers.

    The case for pre-recorded material is a bit different - so 1080/24p HD-DVDs or BluRay DVDs could well be produced - with the player converting to 720/60p or 1080/60i on replay.

    (1080/60p or 1080/50p are not quite practical formats yet - though they may well be in quite a short space of time)
     
  4. hornydragon

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    Just like you will never get a picture from an SD plasma with a 720p or 1080i source????

    SCALING the way that all fixed pixel devices map an incoming image to the available display components (CD, DLP, PLasma etc) the pixels as long as the scaling engine can accept and process 1080p at the relevant refresh rate there is no issue diaplying a 1920x1080p image on an 852x480 SD display
     
  5. AnnatarUK

    AnnatarUK
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    Hi,

    Thanks for the information guys.

    Surely though you are not going to want to see a 1080P image at 720P as you will lose lots of details.

    This is what I am saying.

    Will there be more TV's out shortly that are 1080P and not just 720P?

    I don't want to upgrade to have to upgrade again when the new DVD's are out.

    thanks
     
  6. Rob20

    Rob20
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    The only tv I know of that has the full 1920 by 1080 resolution is Sharp's 45" lcd. However, it's dear at around £4,500-5000, and it can't actually display 1080p, only 1080i. Which is odd when you consider lcd panels are inherently progressive.

    There are a few 1080p sets on their way though I have no idea when. Sony has it's 'Qualia' range, (004/005/006), that consists of a 45" LED tv, (red/green/blue LED per pixel replaces the need for a backlight giving better colour range, contrast etc), a 50-70" SXRD rear pro, (SXRD being an LCOS variant), and an SXRD projector capable of displaying a 10 foot screen. Then JVC has a 45" 1080p lcd. This sets should be out later this year, early next at a guess!? I'm sure there must be other 1080p sets in development. Especially from Sharp.
     
  7. hornydragon

    hornydragon
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    Fujitsu have a 1080p LCD projector and JVC pro have 4000X3000 RES LCOS Projectors but if you go for an HDTV the difference between 720p and 1080p will still be seen (video is not like PC resolutions there are people using 852x480 42" PDP for PC use and while not ideal are very usable you woul need a large screen over 42" and to be close to seen a real difference...................
     
  8. Rob20

    Rob20
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  9. sharper

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    Sky dont show the world cup its BBC and ITV I believe.

    All this HD pre-planning is a little premature as it will all change by the time we get enough HD material to worry about.
     

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