Sorry I didn't see you posted this already.
No problem. At least we agree
Then again, MOST people do
HD PQ Question
- Thread starter Frank Drebin
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No problem. At least we agree
Then again, MOST people do
That is the problem. To many channels versus available bandwidth, to much compression. It is not signal strength.
Dish does not care, if they went down to 4 channels per transponder they would care about PQ.
I have my 32" LCD HD set right next to my bed and with my 20/20 it's too easy to see how bad the compression is. I pause my DVR and just shake my head in disgust when I see how bad it is.
That's too bad, hopefully people will start to realize that more HD isn't necessarily better. PQ was one of the main reasons I switched to Dish from Uverse and will probably look to another provider if Dish doesn't correct the problem. Thing is, my only other option is Comcast and aside from them being an evil company, they compress their HD just as much.
Not to get too far off topic, but you say your only other option is comcast. What about Directv?That's too bad, hopefully people will start to realize that more HD isn't necessarily better. PQ was one of the main reasons I switched to Dish from Uverse and will probably look to another provider if Dish doesn't correct the problem. Thing is, my only other option is Comcast and aside from them being an evil company, they compress their HD just as much.
Yea why not Directv. I wouldn't choose D* just mainly because I've Been there done that. But If you never had D* you could give it a shot. You might like it better.
Having had D* at my apartment and Dish in my house, being able to watch the same type of program within a couple of weeks of each other, I feel fairly confident saying that D*'s HD PQ was slightly better - watching basketball in HD on FSN, for example, there is definitely some pixellation around the players that I didn't notice with D*. However, on many HD channels I started getting random moments of picture freezing without sound freezing after the switch to Mpeg4, and I haven't seen that yet on Dish (I would have loved to keep D* but the installer they sent out claimed he couldn't put a dish where the existing D* dish was in my yard, the Dish installer had no problem doing so, unless Dish gets with the program on sports channels I might try for D* again when my contract is up).
Didn't go with D* because they wanted me to sign a 24 month commitment, with E* I just paid the installation fee and don't have to worry about getting stuck with a cancellation fee.
It's not simply an issue of too much compression. It also has to do with:
- The quality of the encoders they use for compression (because many encoders are only designed to work well above certain bitrates, while others are designed to work very well at both high and low bitrates, and if an encoder is used out-of-spec it may work very poorly as can be seen most clearly on SD channels),
- How well their encoders are configured,
- How well their multiplex load balancing system allocates more bandwidth to video for a certain channel when the motion level suddenly rises,
- How much wasted (null) bandwidth isn't being allocated to any channels in a multiplex at any given time,
- What kind of video filtering is done after they receive a feed and before they re-encode it,
- How much bandwidth is being wasted encoding black areas as picture data with lots of motion at high bitrates due to poor detection of random noise in large, obvious, solid black areas (mostly on pillarboxed programming since not many HD channels air letterbox programming),
- How much bandwidth is being wasted encoding low-detail upscaled SD content (at any aspect ratio) at higher bitrates than channels simultaneously airing real HD content
- A number of other reasons I can't think of right now.
SD PQ has steadily declined over the years while very affordable, superior encoding technology has become available that could bring SD up to full-resolution, near-DVD quality at the current bitrates. Since the sat providers somehow think it is a good thing to degrade their product regularly and not bother to improve it when they easily can, I would expect the HD channels to eventually suffer the same fate as the SD channels have. Put simply, a steady decline in HD PQ is their one and only idea of a good business plan. Expect the video on the HD channels to become more heavily and noticeably filtered (more soft and with more "edge enhancement") and pixelated (further bitrate reductions to channels that need bits most) because it's the only way both sat providers have ever handled their video: as unprofessionally as possible.
I'm currently watching the Cavs vs. Celtics game on ESPN and the picture is spectacular. Even other channels such as CBS are looking much better. I don't know if Dish did something or if the culprit was the network's transmission all along. I hope this keeps up. If the NCAA tournament looks this nice I'll be in March Madness heaven.
I'm currently watching the Cavs vs. Celtics game on ESPN and the picture is spectacular. Even other channels such as CBS are looking much better. I don't know if Dish did something or if the culprit was the network's transmission all along. I hope this keeps up. If the NCAA tournament looks this nice I'll be in March Madness heaven.
I guess our definitions of spectacular are different.
And screen size and viewing distance have a lot to do with it.
IMHO I think we already hit the HD PQ low last year when they went from 3 mpeg2 channels per qspk transponder to 4 (~18 months or so ago). Since then all HD transponders have been upgraded to to mpeg4 8pspk turbo. I have not seen DISH HD look as good as it is now since DISH had 3 mpeg2 8psk channels per transponder a few years back.
FEC schemes all require a minimum amount of signal to work. And if your signal is too low, or if there is too much noise vs. signal, it can cause slow data (low bitrate) which limits the ability of forward error correction (FEC) to be able to even do what it is supposed to.
Here is some information that many of you will find shocking and some of you will still deny.
This is from: "On Shannon and “Shannon’s formula” written by Lars Lundheim of the Department of Telecommunication, Norwegian University of Science and Technology (NTNU)
“Shannon’s formula” (1) gives an expression for how many bits of information can be transmitted without error per second over a channel with a bandwidth of W Hz,
when the average signal power is limited to P watt,
and the signal is exposed to an additive, white (uncorrelated) noise of power N with Gaussian probability distribution."
AND,
"The essential elements of “Shannon’s formula” are:
1. Proportionality to bandwidth W
2. Signal power S
3. Noise power P
4. A logarithmic function (FEC)
The channel bandwidth sets a limit to how fast symbols can be transmitted over the channel.
The signal to noise ratio (P/N) determines how much information each symbol can represent.
The signal and noise power levels are, of course, expected to be measured at the receiver end of the channel. Thus, the power level is a function both of transmitted power and the attenuation of the signal over the
transmission medium (channel)."
AND,
"Why did it take twenty years to fill the gap between Hartley’s law and Shannon’s formula? The only necessary step was to substitute 1+C/N for m in (4). Why, all of a sudden, did three or more people independently “see the light” almost at the same time? Why did neither Nyquist, nor Hartley or Küpfmüller realize that noise, or more precisely the signal-to-noise ratio play as significant a role for the information transfer capacity of a system as does the bandwidth?"
"Shannon, furthermore, uses this concept in his general definition of channel
capacity:
C = max[ H(x) – Hy(x)].
This expression can be interpreted as the maximum of the difference of the uncertainty about the message before and after reception. The result is given in bit/second and gives an upper bound of how much information can be transmitted without error on a channel."
Yes, Virginia, low signal can affect picture quality.
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The important thing is that you believe it jeff.....
Does not make it any more true, but thats fine also:up
I guess our definitions of spectacular are different.
And screen size and viewing distance have a lot to do with it.
That could be, I might be so used to the horrible picture that any improvement blows me away. The picture quality is better though. I'm sure it could be even better, but this at least is good enough that I'll stick with the service. If it continues to look like it did Tuesday though, I'll consider switching providers.
I'm now watching the Texas-Kansas game on CBS and this is exactly the kind of crappy picture I was talking about. Tons of artifacts and soft edges in the picture. This is unacceptable as HD. I don't know if its my local CBS station or Dish, but considering the tournament looked great last year when I had cable, I'm thinking it's Dish.
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It's not great OTA either. Very shimmery and noisy unless it's a stationary shot like a free throw. Lots of compression artifacts. Still better than SD though, but nowhere near what a good HD broadcast looks like.
I'm afraid the NCAA tourney is not going to be pretty this year on CBS.
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