Corrupted HD signal

DLPDude · Post by **DLPDude** » Fri Feb 22, 2008 12:52 pm

I'm interested in this posting because of the remarks regarding pixellation.

But first, my input regarding HD signal quality and "not getting true HD" via cable. I am currently using Time Warner's HD service in the Charlotte, NC area. My Cable box is a Scientific Atlanta Model 8300HD w/DVR and my TV is a Samsung 56" DLP Model HLS5679 w/ LED Light engine. For the network HD broadcasts, the picture quality is truly outstanding. No blur, no "fuzzy" picture!! Some programs are more "tuned" to HD than others...such as ABC's Dancing With The Stars". The set lighting and scene color pallet that they use provide an almost "real life" experience. Both FOX and NBC's NFL broadcasts are equally stunning. I do not see any indication of a "fuzzy" picture and a 56" display would definitely intensify that, if it existed. So, based on my personal cable HD experience (18 months worth), I see nothing remotely like what is described by A330cow.

Now regarding pixellation; I do see occasional, random pixellation, most often in a small area of the overall picture. Not consistent, not repetitive and with varying degrees of pixel size. My "impression" is that this occurs more in the late afternoon and evening hours. After a lot of reading and research, I have come to the conclusion that the problem is most likely due to Time Warner's cable bandwidth limitations. More sets requesting more HD signal content... occasional dropped packets.

I am seriously considering Direct TV for a number of reasons, pixellation being one of them. I would like to hear more about the HD signal quality from the newest Direct TV satellites and the new encoding methodology, specifically can anyone offer information that shows that the compression artifacts have been reduced with this new technology?

Many Thanks and keep up the good communications!
DLPDude

akirby · Post by **akirby** » Fri Feb 22, 2008 1:38 pm

I've had OTA HD locals for over 4 years and I've had mpeg4 HD locals over satellite for about 18 months (Atlanta). I've done A/B tests on my 55" Mits CRT RPTV at 1080i on network shows and football games and I never noticed any significant difference in PQ between OTA and Satellite. I don't have any A/B comparison available for cable HD channels like HDNet but I've never seen a flaw in Discovery HD.

I have noticed what appears to be signal dropouts in the original feed from the HD locals to DirecTV. Given your description of your cable situation I can't imagine DirecTV would be any worse and might be better.

DLPDude · Post by **DLPDude** » Fri Feb 22, 2008 2:00 pm

Thanks for your input. I have not pursued OTA and it doesn't offer as much as I would like.

It looks like it's time to give satellite TV a chance. They certainly offer a wider range of HD programming.

Many Thanks!
DLPDude

Richard · Post by **Richard** » Fri Feb 22, 2008 2:59 pm

All broadcast systems have artifacts, some more than others. OTA is regarded as the best. That leaves you with satellite or cable. Cable can have an advantage over satellite - your mileage will vary.

Rick, I see those artifacts ALL THE TIME but I am also very sensitive to such things and most simply do not see it, at all.

What scan rate do you have the receiver set for?

a300cowyahoo · Post by **a300cowyahoo** » Fri Feb 22, 2008 11:09 pm

The question of scan rate you will have to explain as to what that is on my sat box. If you mean 1080i then yes. I do like DirerectTv for other reasons that I will not get into here. DirectTv will come out tomorrow and I will discuss my issue with the picture. Then I have c/c coming on Tuesday to look at my set. I told them they should bring a HD signal generator with them as I needed to rule out my set as the problem. But I am going full circle here as I can see the problem on HD sets at other locations in the Boston area, only not not as detailed as I see it on my set.
As to calibration...I can turn down the sharpness to a point where I can almost get rid of the pixelation but I am left with a worse out of focus picture. But then again I have had some very sharp techs already try this and several other approaches with no luck.
Most people would not even see what I am seeing, but I can't let it go. Not until it's right or I have an honest answer as to why it is not.
Rick

a300cowyahoo · Post by **a300cowyahoo** » Sat Feb 23, 2008 11:49 am

The DirectTv tech just left my house after a lengthy conversation. Much of what we discussed was off the record to keep him out of trouble. He said that I was one of only a few costumers that have noticed this problem. He also said it started about a year ago when more compression was needed to make room for the additional HD channels. He agreed with the Comcast techs as the picture being good but not even close to HD and that I needed to talk with someone at the engineering level as there was nothing a tech could do to fix it. Shame on the bozo's who allowed this kind of compression.

Richard · Post by **Richard** » Sat Feb 23, 2008 2:34 pm

Are our HD bits being shaved?
viewtopic.php?t=4175

I doubt he told you anything we don't already know...

a300cowyahoo · Post by **a300cowyahoo** » Sat Feb 23, 2008 5:47 pm

Thank you Richard for this info. So if I understand this correctly both cable, satellite and the networks are doing more with less at the consumers expense. I guess it is time to buy a BlueRay player.
Rick

Richard · Post by **Richard** » Sat Feb 23, 2008 6:26 pm

Yep, that is what I was just gonna suggest!

Broadcast HDTV was designed for 3 screen heights but I have yet to witness that level of quality. Don't forget the mess of other stuff up the chain before it ever makes it out of the studio. That's the beauty of DVD and even more so with Blu-ray providing a direct feed from disc to display at 1080p24. You simply can't get any closer the source!

If you are seeing this stuff then OTA is THE ONLY way to go to reduce it. Increasing your viewing distance helps but that same move will detract from HD because you are too far away to resolve the full resolution so you need to move back up for a quality delivery such as Blu-ray. Talked with a colleague today and that is exactly what he does. For me, we watch broadcast on a 50" at about 5-6 screen heights - helps a lot! HD disc is reserved for the 106" 1.78 or 124" 2.35. Even quality SD DVD upconversion works on the big rig and surpasses cable HD for noise.

What I find odd is that you say you are just now seeing this yet I have been seeing it since 2002 via OTA, my cable only makes it worse, satellite even more. This sounds like a case of finally seeing something you had not before and now that you know, well, the blissful ignorance has faded.

This is a great time to say that external scaling can help. Current scaling goes beyond quality conversion; the new marketing strength is in complex noise reduction to help folks like you and I but bear in mind they detract from the overall response in cleaning things up; it's not Hi Fi but it's cleaner looking to the eye. At over $2000 I'll stick with my methods instead - increase viewing distance by moving back or staying where I am and decrease screen size.

One thing is for sure, even bit starved HD looks far better than what we were getting before via NTSC. Let's not knock it around too much but let's also be real about it's short comings and that others may come to realize that.

a300cowyahoo · Post by **a300cowyahoo** » Sun Feb 24, 2008 8:13 pm

I went through my notes today of all the conversations I had with different techs and put together the puzzle as to why I did not notice this problem until early 2007. A Comcast tech told me that when Adelphia wired their towns that it was done with low quality...cheap cable. But they were not over taxing the system because they did not offer much with limited HD channels and sub par broadband. Along comes Comcast and they take over all of Adelphia systems in our area around the end of 2006. When then cut the Adelphia feed and put on their own around Feb 07 thats when I noticed the problem. Great broadband and a lousy picture. But my o/b failed on my TV so I was distracted from this as being a equipment problem. I still do not see a great picture in Comcast wired towns but it is better than my own.
So the big question I have is can Verizon Fios bring my picture back to what it was in 06?
Thanks, Rick

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