Digital Cable - Pixelization during motion


Hello Audioigoners,

I don't claim to be a videophile by any notion of the word... Though I'm sure I would be if I had $$$

I have a normal, non-HD CRT 27" TV and Comcast digital cable. As I was sitting down last night to watch the pinnacle of consumer entertainment AKA "American Idol" I was extremely disturbed. Not only from the content, but even more so from the phenominon my TV was producing.

A Static image looks OK, but whenever there is movement, there is pixelization. The images look "chunky." Fast movement makes the entire screen look like a hodge-podge of convoluted colors and shapes. It looks like playing back an MPEG vieo file on a 486 conputer whose CPU is not fast enough to keep up.

To me, this problem is completely unbearable. It starts as a minor distraction, then it become all I can focus on, then it gets even worse and makes me ill. It disturbs my inner balance, and frankly, seeing it makes me 'not OK' with the world.

I have noticed this at various friends houses as well who also have digital cable.

I CAN'T be the only one who's seeing this. I've never seen this phenominom in the many years that I've used analog cable.

Questions:
* What is causing this?
* Do all digital cable receives/services/whatevers have this problem? Or is there some band-aid that can fix it?
* Does satellite TV (DirecTV or DISH) have this problem at all?
* HOW DO YOU GUYS COPE?!?!?
goatwuss
it's your cable company compressing the hell out of the signal. they figure they can save bandwidth by taking the standard analogue channels, compressing and digitizing them, then broadcasting them, which is why you get the mpeg-like compression artifacts. the worst part is that they sit there and tell average joe consumer that they're going *digital* which they tout as being better in every way. in all honesty, it just means you get VOD (which i love), possibly HD (if they're not compressing that) and a crapload of analogue stations that look like crap if you have a tv bought past 1993.

sadly, there's nothing you can do about it.
Lazarus28 - If I switch to DISH or DirecTV will I still have this problem???

Thanks!
Switching to DirecTV won't help. If anything, the problem that you describe has gotten worse in the past year or so with them. I don't know about Dish Network.
This situation is really frustrating.

If you don't like MP3s, you can listen to CDs...

If you don't like CDs, you can listen to vinyl...

If you don't like your TV picture, you can take a hike.
Er, if you don't like your TV, you can wait a year and then pony up $60 for the "Season 912 of American Idol" box set. ;)
YOu could go back to ota (over the air) which is suppossed to be remarkable for HD. The SD stations on directv were just as bad if not worse than comcast. Hoever, I will report that some cable systems provide a better than average analog signal. My conventional cable at a second house that i own is outstanding. Not HD, but way better than the conventional cable on my non-HD tvs at home. Same cable provider, but each system was purchased by comcast from a different system builder, so there likely is different technology somewhere.
as i understand it, cable companies can only send so much information over their lines. they have phone, internet, cable tv, etc, running over outdated and extremely long feeding lines. satellite, which i can't get, supposably(suppossedly?), has a stronger tv signal for the following reasons: the signal is passed through the length of cable from the dish to your tv only reducing a TON of interfernce and transfer loss. also they have less signal passing through that line and can pass more signal than cable lines so more information can pass through to your system. the stations are apparently all digital, not analgue crap like cable, which imho, is still alot bettter even from m y cable provider. hope thjis helps even though i can't verify. it is just some "science" behind the madness. on another note i just aded a power conidtioner and it helped a TON with my tv picture. d.
All of this stuff sadly depends upon things outside of your control. If you really want to optimize video, check out http://www.avsforum.com--those guys are nuts for video the way the a'gon users are nuts for audio.

The problem with CATV is that a lot depends on the signal to noise (S/N) ratio of the signal delivered to your particular house, which depends upon the quality of the CATV plant in your area. Its not even CATV-provider specific--some people get great S/N with Comcast, others hate it because they are the tail of a looong run with lots of repeaters, others love Time Warner, others hate it, etc. The AVS guys can tell you how to access functions on your cable box to figure out what your "delivered" S/N is--if its really low, tightening all the connections may in fact improve it. If that doesn't work, a call to the CATV company may net you a tech--if the quality is bad enough, it may motivate them to upgrade some upstream plant to get you a better signal.

The problem with satellite signals is that it depends upon the view you have to the satellite and whether you have a good antenna install. Again, there are ways of checking on the box the quality of your signal. That won't help, however, if you have a big 'ole oak tree with foliage 3/4s of the year that obscures your southern view--these sats are in equatorial orbit, so the view to geosync orbit is more "up" the further south you are. If you are in the extreme north, basically you are screwed b/c the likelihood there will be a tree or building in the way is increased substantially. Weather also affects the signal. I used to laugh at a device I once saw--a little umbrella to protect your dish from the rain. Draw a line from your satellite dish to 22,000 ft above the equator. Any rain in that path--which could be miles away from you (hell, you could have clear skies overhead) may render your signal unuseable.

The problem with over-the-air (OTA) is that it depends upon the quality of your antenna, terrestrial blockage, and where the transmitters are. You can go to http://www.antennaweb.org (or at least you used to be able too--I haven't checked in a while) and see the gain of antenna you need to get particular HD signals in your area. Some AVS freaks have arrays of directional antennae they use to pick up different signals. You will also need an OTA tuner device to take the digital signal and turn it into something you can get into your monitor via RGB or DVI. (Newer models should have OTA tuners built it if they are sold as TVs).

So, there are ways of tweaking yourself out of some of this stuff. In reality, the only thing you can blame on the CATV provider, broadcaster, or satellite provider is sucky content. But, that is a different thread. ;)

Hope this helps.
Not all cable plant is created equal. In some areas--actually--in some parts of some areas, the S/N can be quite good and in others, the S/N quite bad. Whether the operator has upgraded plant recently can also be a factor, as well as what got installed by the prior operator (there has been a lot of consolidation in the industry).

As far as capacity, sure, a satellite provider can send more video channels than an old analog CATV setup. Most CATV systems are not "old analog CATV setups" anymore. And, newer CATV systems with digital have capacity that is competitive with satellite--if you are lucky enough to be in an area where Verizon is deploying FiOS, you will have more capacity than you know what to do with--its fiber optic cable to your house... B'sides, the satellite guys are running out of capacity too--both Dish and DirecTV keep adding new satellites to offer more HD and local channels (since most satellites "see" the entire continental US, they chew up a lot of bandwidth when offering "local" channels because those tend to get broadcast to people who will *never* watch them--can't see wanting to watch NBC's local broadcast for Billings, MT in DC (OK, this is a bit of a simplification b/c they can use spot beams to narrow the problem a *little* bit)). The drawback is that you need more LNBs to receive those signals--your antenna suddenly has to be able to "see" three birds instead of just one. Makes optimizing reception harder and some birds are better placed than others for reception by users in different parts of the country. The signal from the three also may tend to go out of whack more because the precision needed to "point" and get three birds has to be higher, hence more wind effects.

Given all of that, the "losses" inside your house are probably fairly inconsequential. If you have old coax in your house, like RG58, you might consider replacing it with RG6. If you have it running through a lot of splitters, try to rework the topology to get rid of them and replace those that you need with high bandwidth, low noise splitters. Do any inside wiring runs in ways to limit the length of the runs, as much as possible. Make sure connectors are tight--that does make a difference. If you do that, inside wiring have the same impact as between CATV and satellite. Frankly, if you do those things, your signal quality is going to then depend upon the quality of the signal fed to your house--what comes off the antenna for satellite (which may be impacted by factors beyond your control) and what S/N you get in your location from your CATV provider (which may be totally beyond your control).

You can't simply make assertions that "CATV rocks and satellite sucks" or vice-versa. Unless you want on-demand, in which case satellite does suck.
would a signal booster or house amplifier to boost the magnitude of the cable signal coming into the house make a difference? If I'm not mistaken, these house amps cost about 50.00 and can increase signal strength...
Singal boosters/amplifiers also amplify noise. They may help and they may not. probably only a real issue if you have too many splitters. Edsilva is right on- there are LOTS of factors that affect the PQ you get. In my case, cable was better than sat, but as I said, the analog cable at my house at the beach is way better than my house here in West Hartford.