Axiom Home Page Forums General Discussion Home Theater "Clipping" on TV

Hi,

As Chris has pointed out, it's likely your cable operator who is at fault. Some networks, ABC if memory serves, use 720p to distribute their signals in HD because it's better for fast-moving sports, but most broadcasters go with 1080i for HD because it requires less bandwidth and is easier to transmit.

Of course, MPEG compression has become much more sophisticated than in the old days. I recall the first demo of satellite DirectTV at the Consumer Electronics Show in Las Vegas, and during a live broadcast of a basketball game, every time a player raced down the court and jumped to get a basket, the image would freeze and pixelate. It simply couldn't handle a combo of fast horizontal and vertical action. Those drawbacks were overcome fairly quickly as more refined versions of MPEG were developed.

Regards,
Alan

and the players got slower....weighed down with all those guns and such....

Ha, ha, ha!

Alan

Interestingly, I watched the games on our upstairs TV, which is a Panasonic plasma connected via HDMI to a Pioneer receiver. I didn't notice the problem upstairs, even though the cable box is the same. Makes me wonder a bit, but I'm not going to worry about it. I've never seen the problem in any other circumstance, so I'll just keep an eye out for it. If it pops up again maybe I'll try getting a new cable box for the basement.

"[The Ravens] should be able to address the cornerback situation in the upcoming draft. What other positions are needed?" I hope we can cover the cornerback problem somehow. That was the main weakness of the team. In fact, it was pretty brutal at times. As to other weaknesses, I am one of those who believes that the most important positions are on the offensive and devensive lines. So, I always worry about the lines . . . .

Hi Ray,

Oh, this changes things a bit. What is the make and model of the cable box on your upstairs TV, and on the downstairs TV? Is the downstairs HDTV the same as the Panasonic plasma? What type is it? If it's LCD rather than plasma, then you might be getting some motion artifacts from the LCD.

Also, cables boxes are cranked out by the millions with, in my experience, relatively poor quality control. I've had to exchange my Scientific Atlanta Explorer 8300HD twice because of various problems. My current one seems excellent and has been trouble-free.

Are you using different outputs from each box? Component or HDMI? Try substituting the upstairs "good box" for the one downstairs and see if the video artifacts go away. Make sure you use the same outputs, otherwise you're comparing apples and oranges.

Regards,
Alan

Thanks Alan. The setups are pretty much the same upstairs and downstairs, albeit with different brands. Upstairs I have the cable box connected to a Pioneer 72TXV AVR via HDMI, which is connected to a Panasonic 50 inch plasma, also via HDMI. I think the Panasonic model is a 50PX50U. Downstairs I have the cable box connected to a Denon 2310 AVR, which is then connected to a Pioneer Elite Kuro 101fd via HDMI. The cable box models are the same upstairs and downstairs. I will have to check on the cable box information. It is from Comcast, but beyond that I don't remember the specifics.

Your idea to switch cable boxes upstairs and downstairs is a really good idea. I think that will let me know if it is a cable box issue, at least. I'll do that this weekend, when the next set of games is on. (I didn't plan on watching anymore of the tournament, because I can't stand to watch Duke win, but I guess I have no choice, since the tourney games are the only time I've seen the issue!) If it still occurs downstairs but not upstairs, I may switch the HDMI cords as well, and see if that is the possible problem.

Again, thanks for your thoughts.

While all advice has been great. I 'd like to add from my experience managing a head end for a TV service (not cable) that although over compression of video is sadly all to common, it is not always just the fault of your local cable reseller.

As Alan pointed out, the networks themselves are free to manipulate their signal to whatever degree meets their quality verses costs needs. Add to that that the networks signal very often goes through a 'middleman' if you will, before it is sold again to the final provider. This reseller may also add compression in order to save on satellite uplink costs and other forms of bandwidth they might be using to resell the signal. And yes in the end, the local provider may add compression to the signal yet again to squeeze more channels into their available bandwidth.

Generally, they are all much more careful with HD programming but you can see where the domino effect can come into play.

Wow, good information Murph. That really explains why I used to flip through channels and for instance channel 7, 8 and 9 here used to all be CBS, but there was often a big difference in both the clarity of the picture, and the volume level between the three channels. Now I have a better understanding of why that might be.