Pixalation watching fast action sporting events

Started by M_Avila Sep 11, 2007 13 posts
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#1
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
#2
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.
#3
'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
#4
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.
#5
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.
#6
Thanks for the advice. The only problem I
#7
Some have have had success placing a full size antenna in their attic. Audio problems don't always reflect pixelation.
#8
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.
#9
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...
#10
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
#11
...The only problem I
#12
Don't forget that your cable box or sat receiver could also up or down convert the resolution if you have one of those (won't apply to a built-in tuner).

I think the FCC rule is you're allowed 10 feet above the roofline, but if you're getting decent reception with rabbit ears then an attic mounted antenna should work just fine. Even though in this case we're pretty sure that won't solve your problem.
#13
This may be more information than you needed, but it should be comprehensive enough to lay to rest the so called right of homeowner associations to restrict our ability to obtain an adequate signal via an antenna.

The following is an excerpt from a FAQ regarding roof antennas:

My Homeowner's association does not allow outdoor or roof top antennas. What are my options?
It is against federal regulations to prohibit outdoor antennas for the purpose of receiving broadcast signals. The law is on your side if you decide to put one up. If you do not want to challenge your homeowner's association, place your antennas on the back side of your house to block their view from the street. Some people have installed antennas in their attic. Use the following link for more information:
http://www.fcc.gov/mb/facts/otard.html

Is the attic a good place for an antenna?
It works for some people in some locations. The structure of the house will reduce the signal strength. Physical space in the attic may prevent proper alignment of the antenna. If you live in an area where the broadcast signals are strong, the attic antenna is a viable option. If you have a metal roof or solar board don't even consider an attic antenna because the metal covering shields the signals.


This is a very interesting link. It reflects the homeowners association response to the Federal Regulations that protect our rights. The homeowners association acknowledges their inability to override Fed Regs, but puts forth some guidelines in mounting the antenna (which seem to be reasonable/common sense).
http://www.eaglewoodassn.com/antennae.pdf

And more:
FEDERAL COMMUNICATIONS COMMISSION

FACT SHEET

August 1996

Placement of Direct Broadcast Satellite, Multichannel Multipoint Distribution Service, and Television Broadcast Antennas

Q: Are all restrictions prohibited?

A: No, many restrictions are still valid. Safety restrictions are permitted even if they impair reception, because local governments bear primary responsibility for protecting public safety. Examples of valid safety restrictions include fire codes preventing people from installing antennas on fire escapes, restrictions requiring that a person not place an antenna within a certain distance from a power line, electrical code requirements to properly ground the antenna, and installation requirements that describe the proper method to secure an antenna. The safety reason for the restriction must be written in the text, preamble or legislative history of the restriction, or in a document that is readily available to antenna users, so that a person wanting to install an antenna knows what restrictions apply. The restriction cannot impose a more burdensome requirement than is needed to ensure safety.

Restrictions in historic areas may also be valid. Because certain areas are considered uniquely historical and strive to maintain the historical nature of their community, these areas are excepted from the rule. To qualify as an exempt area the area must be listed or eligible for listing in the National Register of Historic Places. In addition, the area cannot restrict antennas if such a restriction would not be applied to the extent practicable in a non-discriminatory manner to other modern structures that are comparable in size, weight and appearance and to which local regulation would normally apply. Valid historical areas cannot impose a more burdensome requirement than is needed to ensure the historic preservation goal.

Q: Whose restrictions are prohibited?

A: Restrictions are prohibited in state or local laws or regulations, including zoning, land-use or building regulations, private covenants, homeowners