Pixalation watching fast action sporting events

M_Avila · Post by **M_Avila** » Mon Sep 10, 2007 7:09 pm

Hello,

Bought a new Vizio 50" HD from Costco last week. I'm noticing a lot of pixalation when the camera man pan's the camera during a football game. That's when I watch thru a regular set of amplified rabbit ears. Is there a special antenna I need to enhance HD? Is the problem the camera not processing fast enough?

Right now i'm watching a game broadcast via ESPN thru the Dish Network and notice no pixalation.

Thanks

regman · Post by **regman** » Tue Sep 11, 2007 2:43 am

If your OTA signal strength is borderline >70 that you may need a standard rooftop antenna. That may be causing your pixelation (or it could just be a USPN programming glitch as well). I have a rooftop standard Channel Master antenna (with a rotor) and have no reception problems at all - even in heavy weather. It outperforms the satellite dish. Don't waste your money on an "HD" antenna - it's just a bunch of marketing hype. Radio Shack OTA rooftop antennas work equally well.

eliwhitney · Post by **eliwhitney** » Tue Sep 11, 2007 4:19 am

'Morning--

www.antennasdirect.com is just one of many web sites which offer reasonable selections... YES... any "hype" about special antenna for "HD" is simply that.

Most "HD" reception should involve an outside antenna, with very few exceptions... even the normal plywood decking / roof shingles construction usually takes away over 50 % of the gain provided by an antenna, compared to that same one outside.

eli whitney

akirby · Post by **akirby** » Tue Sep 11, 2007 6:10 am

Is it losing part of the picture? What about audio? If it's just pixellating when the picture moves quickly then that sounds like a transmission problem. Could be the network feed to the local station or it could be the local station shaving bits.

Which network was it and what's the resolution of your HDTV? Vizios are not known for good picture quality.

M_Avila · Post by **M_Avila** » Tue Sep 11, 2007 7:46 am

Akirby,

The set isn't losing any part of the picture and the audio is completely in tact. Looks almost as if the camera isn't able to process the video fast enough.

M_Avila · Post by **M_Avila** » Tue Sep 11, 2007 7:53 am

Thanks for the advice. The only problem I

regman · Post by **regman** » Tue Sep 11, 2007 10:29 am

Some have have had success placing a full size antenna in their attic. Audio problems don't always reflect pixelation.

akirby · Post by **akirby** » Tue Sep 11, 2007 11:44 am

That doesn't sound like a reception issue. Sounds like a compression problem. The number of bits being broadcast isn't enough to capture fast movement. Your local station receives the digital feed from the network, then rebroadcasts it - sometimes at a lower bitrate, especially if the local station is multi-casting (multiple logical channels on one physical channel). There isn't really anything you can do about it AFAIK.

Richard · Post by **Richard** » Tue Sep 11, 2007 4:25 pm

I have yet to see broadcast or distributed HDTV meet the 3 screen heights viewing distance it was designed for.

Highly likely you would not see this with a properly scaled DVD or better yet HD disc and if you do then it is the calibration of your display or the design of it. Still, bet you think it looks fine with those...

aaronstout · Post by **aaronstout** » Wed Sep 12, 2007 7:17 am

Manny,

As Akirby mentioned, it sounds like you are seeing an issue with compression, likely due to multicasting as he indicated.

Regarding your comment about your neighborhood not accepting antennas though, it is my understanding that no deed restriction or neighborhood restrictions are allowed to block the use of an outdoor antenna by federal law. I don't think however that you are having a problem with insufficient signal.

By pixelation most of us mean that a picture breaks up and pieces of the picture are "missing". I believe you are describing a blocky sort of picture that occurs frequently in fast motion and appears like a blurring of the picture. I have observed this since day one with my HD set and have never been 100% certain if it was an MPEG artifact, the result of 1080i vs 720p broadcast, or a deinterlacing artifact of my particular set/brand.

In reading about HDTV in general you will see a description of 1080i and 720p where 1080i is described as having higher resolution of static and slow moving scenes, such as outdoor productions of non moving objects. Then you will see descriptions that 720p offers better resolution of faster moving objects, such as sporting events. Some networks like NBC and CBS use 1080i as their transmission technology and others like ABC, FOX and ESPN use 720p.

But to make it all even more complex, your TV will display the pictures in whatever is it's own native resolution rescaling the picture to fill your screen. So, basically there are many sources to the problem you are seeing and it may in fact be a limitation of 1080i in itself. But, clearly a reduction in broadcast bandwidth as a result of multicasting is very common and will also result in some of the lack of clarity in fast motion also...

Welcome to the complex world of HDTV! Fortunately aside from this annoyance, it is quite a step beyond the SD world we lived in previously.

AaronS

HDTV Forum

Pixalation watching fast action sporting events

Pixalation watching fast action sporting events

"HD" VIA O.T.A. antenna....