Tuesday, April 27, 2010

HDTV Video Connections or why is everyone fat on My TV?

Part III
The Final Frontier
A few light years ago, we started to explain some of the small nuisances associated with HDTV, resolutions, scaling, connections, and a plethora of raw details that were fascinating and others plain boring. It is time to close this topic and move on to more interesting subjects, ie HDTV tuning and recording on your PC using Vista Media Center and Windows 7. You just can’t wait, neither can we, but let’s finish the business at hand.
Everyone is fat on your HDTV and disproportionately wide because you are not viewing a high definition program formatted properly. Your TV or set-top cable/satellite box is taking a standard definition 4:3 ratio signal and stretching it across your 16:9 ratio HDTV’s screen. This is distorting the picture content and one of the more heinous problems when viewing SDTV(Standard Definition) on a HDTV(High Definition) systems. Sounds like a bunch of perversion or STD’s(set-top diseases, got you!), it is. Some of you are paying for HDTV program and only viewing SDTV. How do your cure this without killing the HDTV? It is sometimes easy and some times impossible.
Let’s dive into our most recent example. Comcast Cable broadcast their HDTV channels in the 200-channel range. SDTV is below the 200 range and some are above 300. All my HDTV channels, when not broadcasting HDTV programs are proportional and correctly formatted to 4:3 with black side panels, as they should, since this is a digital HDTV signal. When tuned below the 200 channel all the pictures stretch to fit the screen. This is one of those aggravating big brother cable company problems, which you have to tolerate. The HDTV then actives the scaling that stretches a SDTV 4:3 picture to fit the 16:9 screen.

How do you fix this problem? On some set-top box, you can set the box to output 480i, 480p, 1080i or 720p. This sound like a good idea, but don’t. Setup the box to output the native channel resolution or pass-thru. The electronics in most new HDTV’s are far superior to the set-top box and does a better scaling job then any set-top box. If the picture has to stretch to fill, it will be a better stretch. ESPN, ABC and Fox HDTV broadcast fast action sports and use 720p, for better image performance. You will want these channels in the native 720p. How can you tell if your set-top is native? When you changing channels you will get a slight hesitation as the HDTV’s scaling adjust. You can also press display on your TV’s remote control to check the channels resolution. If any of your 720p channels are at a different resolution other than 720p, your set-top is scaling. Contact your HDTV provider and get them to set-up for pass-.thru.

One other thought on the situation, if you are not using a component video or HDMI connection from your set-top box or DVD player you can not get a high-definition picture. See our connection guide on all the types of video connection options available.


Finally, with all the programming available online many are connecting their PC’s to the HDTV. This is simple if you have VGA or HDMI outputs from your computer and matching VGA or HDMI connections on your HDTV. A cable connection will be sufficient. However, if the outputs and inputs are different types or resolutions, there are a number of converter options available for matching the two, but we will save that for another discussion.

1 comment:

  1. Great post Larry. Although I thought I understood the issues, I learned a a lot from your post.


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