Seeing Pixels

G8GTDon

Hi everyone,I signed up to find out why on some HD channels I can see some pixels in action scenes on some channels? I have a brand new Samsung 50" plasma TV. Are some HD channels better than others? Speed Racer on CinimaxHD was very noticeable but on DVD was perfect. But watching football you can see the pixels on some scenes for a brief moment,I know plasma has a much higher refresh rate so this should not be a problem,I'm wondering about my Fios instead. I'm using HDMI directly into the TV and Toslink cable into my A/V reciever for sound.The Verizon HD reciever is model # QIP6200-2 I also have a HD DVR model # QIP6416-2 hooked up to a Toshiba 26" LCD TV with no problems. Any ideas? thanks.

KenAF

---

@G8GTDon wrote:

Hi everyone,I signed up to find out why on some HD channels I can see some pixels in action scenes on some channels? I have a brand new Samsung 50" plasma TV. Are some HD channels better than others? Speed Racer on CinimaxHD was very noticeable but on DVD was perfect. But watching football you can see the pixels on some scenes for a brief moment,I know plasma has a much higher refresh rate so this should not be a problem,I'm wondering about my Fios instead. I'm using HDMI directly into the TV and Toslink cable into my A/V reciever for sound.The Verizon HD reciever is model # QIP6200-2 I also have a HD DVR model # QIP6416-2 hooked up to a Toshiba 26" LCD TV with no problems. Any ideas? thanks.

---

You are describing compression artifacts. Motion requires more bandwidth than static imagery. The greater the amount of motion, the greater the amount of bandwidth needed to maintain a pristine image. During intense motion and/or image transitions where the needed bandwidth exceeds the available bandwidth, you'll see compression artifacts and blurred images. This is more obvious on some channels than others, because some channels devote more bandwidth to their HD feed than others.

Verizon passes many HD channels as they receive them (aside from commercial insertion), but they have no control over the compression applied by the content owner.

HBO and Cinemax are some of the most heavily compressed channels. Leased satellite space is expensive, so HBO sacrifices some quality to provide more channels in the same space. Essentially, HBO decided that it would rather provide 26 HD channels at quality X rather than than 13 HD channels at quality Y. Channels like ESPN, Hdnet, and MHD allocate 50+% more bandwidth to their channels.

Verizon passes local channels as is, but outside of FOX (where quality is about the same everywhere), quality varies by market. Each local affiliate has 19.4Mbps to split between their HD channel and any other feeds they want to offer (carried by Verizon in the 450-499 range). Some local affiliates devote 15-16Mbps to their HD feed and 3-4Mbps to a separate SD channel. Other local affiliates devote 10-11Mbps to their HD feed and the remaining 8-9Mbps to several SD channels for weather, traffic, local news, etc. The more bandwidth an affiliate devotes to their HD feed, the better the quality of the picture (i.e. fewer artifacts and less blurring during motion).

The larger the screen, the larger the artifacts, and the more obvious they seem to the viewer. You may be able to minimize the appearance of artifacts by adjusting the settings on your TV. In some cases, the default settings on a TV will make artifacts more obvious / prominent than they should be. As an example, Samsung's DNIE is an artificial detail enhancement feature that make artifacts look much worse than they would otherwise. You should find recommended settings for your TV in the AVS Plasma TV forum; search that forum to find the "owners thread" for your particular Samsung plasma.