Why 720p found only in high-end HDTVs?

Discussion in 'Archived Threads 2001-2004' started by Thik Nongyow, Aug 26, 2002.

  1. Thik Nongyow

    Thik Nongyow Stunt Coordinator

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    I noticed that while 720p does not appear on HDTV-ready sets, they even do not appear on most true HDTV sets. Only a few HDTVs (the Samsung HLM series as an example) are 720p-compatible. Is there a reason why 720p is found only in high-end HDTVs?
     
  2. brian_olmsted

    brian_olmsted Auditioning

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    most broadcasts are in 1080i (CBS, NBC, etc). 720p (ABC) is better for sporting events as there is less motion blur, etc. Fox is only broadcasting 480p
    often it is a choice of manufacturers but the defacto standard for RPTVs is 1080i and Plasma/DLP are 720p, with the new Toshiba LCOS set at 1080i/1080p.
    1080i has more pixel information but is interlaced, 720p has less resolution but no motion blur, etc. due to being progressive.
    Most set-top-boxes, etc only output 1080i, while some export at 480p, 720p, 1080i.
    http://www.alvyray.com/DigitalTV/Naming_Proposal.htm
     
  3. Bill Slack

    Bill Slack Supporting Actor

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    It's also more complex to make. 720p is a higher scan rate than 1080i.

    480p = 31.5khz
    1080i = 33.75khz
    720p = 45khz
     
  4. David E Smith

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    Greetings,
    I am renting a Motorola HDD200 from TWC. This box has a switch in the back to output 1080i, 720p, 480p native. I also own a JVC AV-56WP30 and it supports 1080i, 720p, 480p. Now, TWC in my area offers ABC, NBC, CBS, FOX, PBS, HBO, SHO. with all that said, is my best option to leave the HDD200 set to 1080i? Is 720p better for anything else besides football? [​IMG] I am assuming that I basically have a choice as to the settings I choose. Also, is there a difference between 480p and 480p Native?
    Dave
     
  5. Les Holt

    Les Holt Agent

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    One reason is that it's MORE EXPENSIVE to make. Manufacturers want to reduce costs.

    However, some think that it's just a matter of bad engineering habits left over from the analog design world.

    Joe Kane, for one, is pushing for 720P because he thinks it's a superior format to 1080i.

    Les
     
  6. Bill Lucas

    Bill Lucas Supporting Actor

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    David,

    Will your display accept a 720p signal? Is it a 7" CRT based RPTV or a digital projector with a native resolution of 720p? If it's the former then it probably won't accept a 720p signal and it would look significantly softer than a 1080i signal anyway. If it's the latter then yes, 720p is probably your best choice. It really depends on the display. It also depends on how good that cable box is at upconversion and I'm making an educated guess that it is somewhat lacking. Regards.
     
  7. Jorge M

    Jorge M Stunt Coordinator

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    David,

    Are you sure you mean 480p and 480p native? I think that the settings on the box are
    1. 1080i
    2. 720p
    3. 480p
    4. Native[/list=1]Meaning (respectively)
      1. Convert everything to 1080i
      2. Convert everything to 720p
      3. Convert everything to 480p
      4. No conversion, just pass everything in its native resolution to the TV[/list=1]If this is correct, you would set it to "Native", as your TV set can handle every HDTV format the box throws at it, and it'll look better than if up or downconverted to a different resolution.
     
  8. David E Smith

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    George, you are correct, I checked, and its a 4 setting switch. Thank you for figuring that out. I should have caught that. I will try the 'native' setting for a while and see how it works.

    Thanks,

    Dave
     
  9. Hugh Scrivener

    Hugh Scrivener Stunt Coordinator

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    Would I be correct in assuming TWC is Time Warner Cable, and that you are renting a box from them for cable use? Or am I compleatly off?
     
  10. Jorge M

    Jorge M Stunt Coordinator

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    You're welcome. And don't call me George[​IMG].
     
  11. David E Smith

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    Jorge,
    Sorry about that.. [​IMG] Wont happen again!
    Hugh,
    Yes, it is Time Warner. And I am renting the box.
    Bill,
    Please excuse me if I do not answer these correctly, as I am fairly new to HT, and the RPTV is new as well, but let me have a shot.
    1. The display will accept a 720P signal.
    2. It must be a 7" CRT, although it does have DVI inputs on the back.
    3. As I noted previously, the TV will display 1080i, 720P, 480P, and 480i. The manual says:
    "Notes About HDTV Operation" (pg 15)
    "The AV-56WP30 or AV-48WP30 can display 480p, 480i, 1080i, and 720p signal formats using the Component Video Inputs. It cannot display 1080p signal. For High Definition (HDTV)picture display a DTV decoder must be connected to the TV."
    I cannot find anything in the manual, but there has been rumor on the boards that this model does automatic upconverting to 1080i signal. I have not been able to verify this as fact though, and the last statement from the manual does not seem to support this theory. However, I do have a very clean picture all the time. If this is the case, I would have to ask which is better: Up converting the native signal at the DTV converter (using the 1080i setting on the converter) or by automatic TV upconverting. (sending the native signal to the TV)
     
  12. David E Smith

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    Actually, Its probably more complex than whats stated above:

    Currently, I have a S-Video connection (in addition to the High Speed Data Link) going from the STB to the HDD. This is "converted" to a component signal and sent to the TV. If the HDD setting is set to Native, the signal from S-Video (channels below 99) will be sent to the TV as an analog 480i signal? converted to component signal? Perhaps its converted to digital signal first?Should this be the same quality as if I routed the S-Video from the STB directly to the AVR, then to the TV on a separate input? or the same input? I think the signal quality has been reduced on the analog signals being routed through the HDD. Do most people hook up the s-video or composite video separately from the HDD.

    I would like to know more about these processes. The manuals have been less than helpful here.

    Dave
     
  13. David E Smith

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    I am bumping this into the tweaks section. Thanks for the feedback.

    Dave
     

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