Gotta love Comcast. looks like one of their encoders is screwed up. in the DC area, does anyone know what other channel is on the QAM channel that NGCHD (224 is on).... have called comcast.... alerted them to the problem. can anyone from other markets test the issue on your NGC HD channel? is it affecting satellite as well? never seen a macroblocking issue like this... obviously an issue with the encoder somewhere. I am recording it on my DVR for future reference if i can ever figure out how to dump recordings.... also gonna see how long it takes comcast to fix it! also made a small firewire recording on the PC (33 mb) but most of the data got completely dumped and eventually VLC crashed entirely. just noticed it while channel surfing. heh... gotta love these issues! well.... report back ur experience. do it soon... not sure how long it will take to fix. this is with comcast, rockville, md where i am so if you're in other areas i'm more curious. thanks! maybe this will get comcast to stop mapping 3 channels on a QAM band.

There's no issue with the NGCHD source feed, so it is something Comcast is doing. As far as 3 per QAM, that is not going to change. That's how Comcast is making room for new HD channels in 2008.

I know the NGC-HD 720p source feed is 13.3Mbps ABR (reduced from its launch ABR of >16Mbps) but I never was able to correctly determine its peaks. The NGC program stream crashed the tool I normally use to determine peaks, and an alternate tool reported peaks of close to 20Mbps, which sounds too high.

Once Comcast tweaks their settings to reduce peak bitrate (by removing fine detail), that should eliminate the macroblocking.

sorry maybe i wasn't clear. there's lines of bad pixels (macroblocks) streaking across the screen and its continuous.... not ur typical macroblocking issue

another quick note: just checked out channel assignments. we're not on HD Lite yet so thats not the issue (just 2 chans per QAM).... Food HD, the other chan on this QAM is experiencing no issues.

No problems on D* so it must be a Comcrap issue.

another quick note: just checked out channel assignments. we're not on HD Lite yet so thats not the issue (just 2 chans per QAM).... Food HD, the other chan on this QAM is experiencing no issues.That isn't definitive.

In a number of areas, Comcast has installed rate shaping equipment for QAMs with two channels, basically as preparation for adding a third channel.

They may be trying to see how much quality degradation customers are willing to accept, as a means to judge the available space for the third channel.