Question about 622 HD resolution settings

Discussion in 'ViP612/622/722/722K DVR Support Forum' started by Calvin386, Jul 5, 2007.

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  1. jsuboh

    jsuboh Cool Member

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    Jun 7, 2005
    Hi,

    I understand Rice's point. I believe he is trying to state if you pass native 720p resolution without scaling it to 768p (still 16x9) it will produce a black border around the entire picture (which it would). However, most LCD (or Fixed pixel) Tv's will scale it to its native resolution, including the Sony TV mentioned above. In my opinion, I would rather have a 1080i signal with more detail reduced to a 768p signal rather than a 720p signal upconverted to 768p. Again, it is subjective and both settings need to be viewed and determined to be the best. I have my Sony 60XBR800 which displays 1080i a lot better than 720p.

    Thanks,
     
  2. SaltiDawg

    SaltiDawg Active Member

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    Aug 30, 2004
    It will not produce a black border. By definition of a HDTV by the CEA, the set must take an ATSC Table 3 signal and be capable of displaying it at 16:9!

    I am looking at a 768p set with a built-in ATSC tuner, for example. I tune in a local over the air 1080i and it just fills the 768p screen. No stretch, no zoom, no nada. I change the channel to Fox at 720p. Same result. The internal TV scaler, are you ready, scales the incoming feed to match the TV's native resolution.

    Now, change the OTA tuner to your STB - say E* rcvr. You set the STB, say, to 720p. The E* receiver will put everything out at 720p, at a 16:9 Ratio! The TV will deal with it and scale that 720p to 768p, the Native Display of the TV. There will be no bars added!

    I tried. :nono2: :grin:
     
  3. TallGuyXP

    TallGuyXP Cool Member

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    Sep 18, 2006
    Salti,
    I'm thinking that we all agree with you... I believe Rice was hypothesizing that if the TV didn't scale the 720P to the native 768P, you'd end up with an image with small black bars all around because the image would be 1280x720 displayed on a screen size of 1366x768, while still maintaining a 16x9 image. But, as you say - the TV does scale to it's native 768P and so it won't display black borders.
     
  4. rice0209

    rice0209 Legend

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    Oct 11, 2005
    Yes Salti, I completely understand scaling and what you are saying. I understand that many tv's do automatically scale the image to the proper output resolution of the tv, no matter what the incoming resolution (unless they are incapable of handling that resolution for some reason.)

    My point was the IDEALLY, you would avoid scaling and try to obtain a 1:1 pixel map (which you would not be getting if you took a 720p signal and scaled it to 768p), thats all. Maybe I shouldn't have brought it up because very few sets are capable of this or you would have to purchase an external scaler that did the work for you in order to maintain the original resolution. without stretching 1 pixel into another pixel in order to be able to fill the screen.

    I know a lot of LCD manaufacturers are switching to these higher resolution chips that fall in between 1080p and 720p. I am not sure why exactly. Maybe they found a way to cut cost by adding some more resolution, but I personally have not seen (not saying it does not exist, probably just my ignorance) any 768p content, so right off the bat, you introduce scaling, which to me is just strange. I've seen the results and they are very good, but i just don't understand introducing this continuous scaling into the mix.

    I know some of the original lcd units were 1280 x 768 in order to match computer signal formats, which is a 15:9 ratio. Maybe the just added the extra horizontal pixels to utilize these chips and hardware and get them back to a 16:9 format.
     
  5. Slordak

    Slordak Hall Of Fame

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    Dec 17, 2003
    You're assuming:

    A) No overscan at all; every single pixel of the source image is displayed in the visible screen area of the television (including those areas which often do not contain video data in standard definition signals).

    B) Digital input with an all-digital path. Some older HDTVs do not have DVI or HDMI inputs, and some which do convert the signal to analog before the image is sent to the display.

    C) Source material resolution matching display resolution. If these two don't match, then someone has to do a conversation at some point in the path anyhow (either before or after sending the signal to the HDTV), rendering the concept of "1x1" moot.
     
  6. rice0209

    rice0209 Legend

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    Oct 11, 2005


    A) Yes, I set my overscan to "zero" on my projector so that when i have a true 720p signal, i can get a 1:1 ratio. For channels not in your native resolution, there is nothing you can do as scaling will be introduced.

    B) Yes, digital input. DVI or HDMI required.

    C) Yes, 1:1 only works when the signal matches your native output of your display. I never suggested it would work otherwise. My point all along is getting the best image when possible. Using your native resolution is more often than not going to give you that picture. In the end it does come down to personal taste as everyone sees things in their own way, but theoretically, matching pixels into a 1:1 situation whenever possibly is the best way to go, in my opinion.

    I just hope that 720p keeps becoming more and more the standard. I hate when new shows come out and are still broadcast in 480i. For my 110" screen, no 480 signal looks sharp when stretched over that amount of space, unless I move even further back then the standard, which defeats the purpose of a large screen.
     
  7. Stewart Vernon

    Stewart Vernon Roving Reporter Super Moderator DBSTalk Club

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    As far as HD is concerned... 1080i is becoming more and more the standard... as most HD is broadcast in that format. I believe only ABC, FOX, ESPN, and the fledgling MyNetwork (essentially ABC and FOX since the others are owned by the same folks as them, respectively) are the only 720p broadcast channels.
     
  8. paulcdavis

    paulcdavis Legend/Supporter DBSTalk Gold Club

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    Jan 22, 2004
    Just a note to carefully check the settings on your HDTV. On my Samsung 5063 DLP, the "expand" setting does no scaling, but the "wide" setting scales to increase over-scan. With the expand setting I get 2,2,2,2 over-scan on the HDNET test pattern, but I needed to go into service mode to center the picture to avoid seeing artifacts during the vertical retrace interval. (or it's digital equivalent)
     
  9. Calvin386

    Calvin386 Godfather

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    May 23, 2007
    Well I thought I was going to leave the resolution on 720p and forget about it, but I think I will do a little bit of comparing.

    To compare the two signals, can I use my HD recordings? I guess the question is...Is the scaling done when the DVR records or when the video is sent to the LCD?

    I currently have quite a bit of HD stuff on my receiver but the setting was on 720p when it was recorded.
     
  10. SaltiDawg

    SaltiDawg Active Member

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    Aug 30, 2004
    When it is recorded, it is in the format that was broadcast. Yes, you can use your existing recordings and select various DVR output formats to allow comparison.
     
  11. Stewart Vernon

    Stewart Vernon Roving Reporter Super Moderator DBSTalk Club

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    The Dish DVR/PVRs record the satellite stream as-received onto the hard drive. The resolution conversions according to your output (480p, 720p, 1080i) happen only to the video output signals from the receiver. Anything you record on your DVR is recorded the same regardless of your video output settings.
     
  12. Calvin386

    Calvin386 Godfather

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    May 23, 2007
    Good that will make things easier.

    Thanks.
     
  13. TBoneit

    TBoneit Hall Of Fame

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    Jul 27, 2006
    You could also look for the HDNet test pattern and record it for testing.
     
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