1080p tv / 1080i cable box question?

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1080p tv / 1080i cable box question?

  • past weekend went shopping, "the boss" gave me the thumbs up.  got a great deal on a Sharp Aquos 1080p, and though i didn't know it at the time about the 1080p not being broadcasted, i did understand the 1080i scanning feature, and just assumed that the 1080p would be that much better.

    then i get the set home, hook it up with the digital cables, go in to the technical set up on the comcast dvr remote, and find out that there is no setting for 1080p, only goes as high as 1080i.

    so my first question is, does the tv then default to the 1080i setting, and does it do this on it's own, or does the comcast dvr force it to the 1080i setting?

     next question:  (new here, hope i'm allowed to ask two?..lol) also in the comcast box set up there is the "4:3 override" settings.

     am i to understand that these are user preferences, what ever looks best to you?  i know that one of the settings causes the screen to pause while it resyncs between 16:9 and 4:3, and that some of the tv's "video modes" options change depending on which 4:3 override setting i use, but it is really hard to tell if there is any quality difference in the picture?  or do any of these 4:3 override settings even effect the picture quality?


    thanxz much



  • Good question River.


    If your Sharp Aquos is a true 1080p, it displays all inputs signals at 1080p. Because this is the native resolution of the display, all videos sources are scaled to what the screen can produce. You may have 1080i from your cable box, 480p from your DVD player, and 480i from any other analog video sources. All these resolutions will be scaled to, and displayed at, 1080p by your Aquos.


    If your cable box offers multiple output resolutions, the 1080i option should be your best bet. While this resolution is not progressive, it does offer the same amount of information (lines of resolution). The interlaced version splits out two frames with 540 lines each and alternates between them at 60 frames per second. Your television can combine these interlaced frames and display the full 1080 lines in each frame at the same time. The resulting performance from your Aquos should be very comparable to a true 1080p video source.


    It will probably be several years before we begin seeing native 1080p resolutions from television programs. Most networks have already committed to their current resolution (1080i or 720p). The only way you can currently provide your Aquos with a true 1080p video source, is with an HD-DVD or Blu-ray disc player. Some up-converting DVD players can provide a 1080p output, but because they are starting with 480 lines of information (standard definition), and processing the image to a 1080p output, the results are not as good.


    I too have Comcast cable service and a compatible HD cable box (Scientific Atlanta Explorer 8300HD). While I have the output resolution set for 1080i, I am not familiar with the “4:3 override” setting. I assume this is an option for people with a 4:3 HD television and helps format the HD image by utilizing letterbox (black bars at top and bottom). Because you have a Sharp Aquos, your aspect ratio should be 16:9 which means any 4:3 video options from the cable box should be defeated.


    Anyone else have experience with an HD cable box and the “4:3 override” setting?


  • Ryan,

     since posting here, i sent an email off to sharp, and the response i got from them was that the tv would default to the 1080i setting for any tv broadcast, and that currently, like you said, the only 1080p mode is for blu-ray, or hd-dvd.  another person informed me that the 1080p mode is used by some of the gaming consoles (?)


    i also found a web page for the comcast dvr settings, for "user settings" which most users are not informed about, comcast tech change these settings when they come to your house for initial install, or if you call them and tell them you have a new tv, to come set it up for them.

    this is what i found about the "4:3 override" settings.....accessed by pushing "cable" "power" "menu" buttons on the remote.  when finished with settings, push "menu" then "cable" and last "power" on the remote.



    The options are:

    TV display LED Display Description
    OFF OFF SD is converted to the HDMI/YPbPR OUTPUT format with pillarboxes on the sides
    480I 480I SD is not converted
    480P 480P SD is converted to 480p
    STRETCH Strh SD is converted to the HDMI/YPbPR OUTPUT format and stretched horizontally for a 16:9 screen

    thanxz for your input, it is appreciated..


  • Great info River.

    I didn't have a Comcast tech install my box. I picked it up at the local office and installed it myself. My HD channels fill the screen great but the SD channels still format the picture with the black columns on the left and right. Both the cable box and my TV offer different "viewing modes" to stretch and zoom the picture to fit the entire screen. I used to bother with these settings, but now, I just deal with the black columns for the SD programming.

    Keep in mind, while the TV menu may state that the provided signal is 1080i, the LCD panel itself is displaying a 1080p image.

    As far as the gaming consoles are concerned, I can confirm that the PS3 does offer a 1080p output resolution via the HDMI. (I'm not sure if the Xbox 360 has a 1080p option). This is mainly because the PS3 is also a blu-ray disc player. The actual games themselves are produced at 720p and can be processed by the Playstation for a 1080p output. Currently, only the Blu-Ray movies are truly a 1080p output from the console.

    Thanks again for the infor about the cable box.

    [edited by: Ryan at 2:56 PM (GMT -5) on Fri, May 04 2007] After checking with some Xbox 360 owners, they confirmed that 1080p capability is possible with this console as well. HDMI is required for this resolution.


  • ryan, just like you, sharing the information.



  • I just baught a 42inch LG HDTV and ugraded to the HD Cable service.  I'm also using the hdmi cable. I turnd off my cable box and on the cable box you click "menu" and on your tv pops up the cable box menue.  In order to use the 1080i settings you need to turn off the 480p over ride.  Now once you do that then you need to strech the screen to the s16:9 for the non hd chanels to come on full screen.
  • the xbox360 has been doing 1080p since the end of last year.

    it was done via a firmware update. the people with the xbox360 that do not have 1080p support are those without a net connection to it.

    but like toshiba hd players, updates can probably be gotten via a disc as well.


  • To get into the setup on the Comcast box, turn the power off on the cable remote, and hit the Menu button, sometimes you have to hit menu twice.  Once in, you can change your box to 720P, 480P, 1080i (and hopefully, depending on what box they gave you, 1080P)  Note-i am fighting this same battle trying to find a box from Comast w/ 1080P. 

    and yes, you can override the 4:3, it's on the first menu.  oh yeah, if you have a pure hdmi cable and box, make sure you go into the section for hdmi...mine was set to dvi.


    good luck  -DJluch

  • hi,i have a 42 inch plasma(panasonic) i did what you did and it works, but i went to an hd channel and i had lines on the top and bottom of the t.v. i set the t.v up with hd wizard(i have time warner cable) i dont know how to tell if i am getting 1080i or p!!  can anyone help????
  • jobs:
    hi,i have a 42 inch plasma(panasonic) i did what you did and it works, but i went to an hd channel and i had lines on the top and bottom of the t.v. i set the t.v up with hd wizard(i have time warner cable) i dont know how to tell if i am getting 1080i or p!!  can anyone help????

    Are you getting these "Lines" on all of the HD channels or is it just one or two? Sometimes, the actual network has difficulty with their HD feed and switches back to standard definition. This happened the other night while watching the Westminster Kennel Club Dog show on USA Network HD, One minute they were providing a beautiful HD image and the next, they'd switched it to SD. I guess they fixed the problem because a few minutes later, they switched back to HD.

    The moral of this story is: It's not always your equipment. Sometimes, you're at the mercy of the actual network. Confused

    In reference to your statement about 1080i vs. 1080p, AFAIK, there are no cable services/cable boxes that provide a true 1080p video source. If it's broadcast, cable, or satellite service, 1080i should be the highest resolution of any channel you receive. As it stands right now, HD-DVD and Blu-Ray are the only formats that can provide a native 1080p resolution.

    I hope that helps.


  • thanks i kinda thiught that but didn't know if there was trick to it..i set the cable box to auto dvi that works there's a little hesitation at first but i guess nothing is perfect. thanks again     jobs
  • Ryan is correct about the 1080i comment.  The highest resolution you will see on an HD [TV broadcasted channel] is 1080i.  Cable, OTA or Satellite offer HD but the signal is only interlaced.


    To see a progressive video source you have to go High Definition DVD via one of the many current options available these days.

    Currently working on my MBA program.  I hope to return sometime in December 2010. 

  • I just bought the Panasonic TH-42PZ77U from Crutchfield.  This is a "true 1080p" display.  Currently my SA 8300HDC DVR (From TWC/NYC running Mystro) is connected to the television via HDMI.  When connected by HDMI, the cable box will not allow manual manipulation of the output resolution, as it always converts based on the source resolution.  This is fine... BUT, now I have two other compenents actually capable of 1080p output and so I want to switch the cable box to component video.  Once connected via component cables, the cable box will allow me to manually set the output resolution.  So should I use 720p or 1080i?

     Here is what I've heard so far:
    For 720p - progressive scan outweighs the extra pixels in the 1080i
                    SD programming will look better in 720p than 1880i

    For 1080i - Higher resolution

    So - who has any thoughts on this... apparently, the fact that this is a real 1080p display changes the answers a little bit...  any thoughts are welcome... especially from CRUTCHFIELD people!


  • First of all, congratulations on purchasing an excellent plasma display.

    The main thing to keep in mind when adjusting a video source output, is the native resolution of your display. The Panasonic TH-42PZ77U offers a display resolution of 1920x1080 and all incoming signals are converted to this native resolution. This means, you could connect a DVD player with a composite video cable (480i) and the Panasonic will scale the image to 1080p.

    It is for this reason that I recommend setting the output resolution of your cable box to 1080i. While this signal is interlaced, it offers about 30% more picture information for a sharper, cleaner image.

    Don’t get me wrong, a 720p video source displayed on a quality set like the Panasonic can look very good, but a 1080i source should look even better.

    The good news is; you don’t have to take anyone’s word for it. Beauty is in the eye of the beholder. You may want to try both output settings to see which looks best to you.

    I hope that helps.


  • Ryan,

    I read your response to the old 1080i source (Comcast Cable) to a High Def 1080p TV and found it quite fascinating.  

    I work for a very large TV Manufacturer as a sales rep and definitely need the correct info and am finding it hard to get good tech info from my company.  

    The reason its important....beyond the obvious is that I sell new HD TVs and I have a lot of potential buyers asking how to transmit audio and video wireless from either a HD cable box, OR HD satelite box,  to a new HD TV ~ and have found some third party devices that do this BUT am told that they can only transmit 1080i NOT p.

    If what you say is correct then that's fine because the 1080i signal will be upconverted (for the lack of knowing the correct terminology) to 1080p by the TV itself.  In otherwords, A). I didn't know that the signal from traditional cable was only 1080i and not p and B). the concern from the customers that the 1080i is not high enough resolution (and thus the bottleneck in bandwidth), especially if you THINK your paying for 1080p HD and you have a 1080p TV. I hate to ask but some of the guys I work with are going to test me on this if I bring it up. What data or documentation do you have that show the TV's upconvert i to p? Desperately need this if you can point me in the right direction would love to review it.  Lastly, is satelite only 1080p standard as well?

    I'd like to thank you in advance for your much needed assistance! Thanks again!