I notice a tremendous drop in quality (increase in compression, with resulting artifacts) when we visit my in-laws. They have Cablevision IO and it's positively awful.

We were watching Godfather Part II on AMC HD this past weekend at their house and the compression caused the subtitles to visibly flicker. It was insane.

 

I guess I am not crazy after all. At this time I have their basic HD receiver which is connected through HD Component cables, can that be one of the reasons for poor HD quality? I am planning to get new Tivo Premiere but if the quality is going to be the same I am not sure if is worth investing money, does anyone know?

 

PQ is mostly affected by your provider, its not usually affected nearly as much by what device you have between the cable and your tv....unless its not setup correctly for your service.

 

Cable quality can vary greatly from city to city, even block to block in some cases. Just depends on quality of the drops up and down the street, how compressed the feeds are at your particlular headend, etc.

DirecTv and Dish, by the very nature of their distribution, what you get at one place is exactly what you will get somewhere else.

To put things in perspective, I've been in homes where the cable drop is 40+ years old. Quality is god awful. Think, 4th generation copy VHS with snow. Yeah, that bad. Drive 1/2 mile away to a newer developement where the drop is under 5 years old, and the picture looks amazing.

Much like the rest of the countries infrastructur, cable is falling apart and no one wants to spend the money to update things.

 

DirecTV and Dish's systems provide a consistant quality picture to every subscriber, due to the fact that the same signals get broadcast nationally. So, a DirecTV customer with an HD-DVR watching ESPN is going to get the same video signal going to the HDMI output whether he's in New York, Florida, North Dakota, or California. We're all looking at the same sats.

Cable, though, is LOCAL. Cable companies may own your local cable franchise, but your local franchise determines the limits of what that company can offer in your area, and there is surprisingly little standardization. So, you might be served by one franchise, and your buddy in the next town may be served by a different franchise, and you could have very different offerings as a result. The differences could be features (fast internet, OnDemand, VOIP phone service, etc.), or they could be picture quality.

While many factors play into picture quality, the biggest one is "how much bandwidth does a channel get?" Cable companies use MPEG2 compression, which is less efficient, and needs more bandwidth than MPEG4 (which is used by the sat companies for HD) to maintain a given level of picture quality. While ESPN on DirecTV in MPEG4 may need 7-9 Mb/s of bandwidth to deliver a good picture, MPEG2 might need 12-15 Mb/s to give the same quality. But the cable companies can't switch to MPEG4 until they replace ALL of their cable boxes, and they can't use MPEG4 for the local channels that they are required to provide unencrypted (i.e., "clear" QAM) for people who don't need a cable box.

But cable companies don't have enough bandwidth on their cable to simultaneously provide all the channels they want to provide AND still offer Internet and VOIP phone service. So, for now at least, many cable systems have only a limited number of HD channels, and even for those, they've had to squeeze the bandwidth down on each channel to make them fit. This means lower PQ.

There is a solution on the way (and in use in some areas), called SDV (Switched Digital Video), where you are only sent the channels you are actively watching. This requires newer cable boxes and updated head-end equipment at the main office, so it isn't available everywhere, but it is how the cable companies will expand their channel lineups for the near future.

 

Did not know that difference can be that drastic in some cases.

 

The more time I spend watching Cox HD the more i see how huge difference is between it and the DTV. SOmetimes when i change channel i get pixelization for a second or two on the new channel, is this normal? I love their internet but the HD quality (for me) is just bad; could this be since they did not have receiver with HDMI so i had to connect it with HD component cables?

 

I have both DirecTV and Comcast (with HD Tivo). In many cases, they are the same PQ, in some cases not. Some locals tend to be better with Comcast, while some nationals are stunningly better on DirecTV. So, even with side by side systems, channels themselves can be better or worse.

As to your pixelization when you tune somtimes, that is sort of the nature of the beast as the tuner is settling down. Most tuners do not display until the picture has settled down but I have seen that occasionally on my HD Tivo on channel changes. I would not worry about that so much unless it continues while watching the channel. Sort of the nature of the beast.