Originally Posted by c.kingsley
This whole conversation is off topic, and has been debated ad nauseum in the HDTV Programming and Hardware forums. There are a lot of non-techical opinions on this issue, but I have to disagree with you. The only quality degradation on DirecTV is from a lack of bandwidth. You would be hard pressed to prove that transmission of 1920x1080 (square pixels) in a 1280x1080 format (non-square pixels) results in any loss of information. All of the Voom channels on Dish network are in 1280x1080. Voom has been touted as "reference quality." Do an Internet search for square and non-square pixels. It is in the MPEG and WMV specs.
Also, pointing people to OTA as a reference is not correct, either. Many OTA channels have subchannels, and as such they are no longer allocating full bandwidth to their signals.
To sum it up: The quality issues on DirecTV are as a result of insufficient bandwidth. The 1280x1080 (while potentially a contributing factor) is certainly not the root of the problem. If they transmit 1280x1080 non-square pixels at 19Mb/sec and 1920x1080 square pixels at 19Mb/sec you would never be able to tell the difference, because the EXACT same amount of picture information is there, it is just being transmitted in a different format. The reason this whole HD-Lite term was coined is because of insufficient bandwidth, which causes pixelation anytime large portions of the screen require updates.
The pixels are not square. Even though it is 1280x1080 it still has to be widescreen. If it were not, you would see the stretch, because 1280x1080 with square pixels is basically 4:3. DirecTV can't just magically create information that isn't there, it would have to be stretched to fill the screen. And this is where the confusion comes from. 1920x1080 = 1280x1080, but the 1280 lines are 50% wider due to non-square pixels. Why does DirecTV do this? Who knows, maybe they are able to compress it better that way, I don't know. But I do know that DirecTV is not the only player in the business doing the same thing.
That is the most bizarre logic I've heard in a while. This is not a Chicken/Egg scenario.
#1 - DirecTV was broadcasting source material in 1920x1080 for quite a while. It looked great at the time.
#2 - Once bandwidth became an issue for DirecTV, they downrezzed the HD to 1280x1080. The bandwidth constraint is what forced them to downrez, to save bandwidth.
#3 - A 1080p television has discrete pixels to display every pixel of a 1920x1080 signal.
#4 - Downrezzing a 1080i signal to 1280x1080 means, at a minimum, on a 1080p TV, that you will have noticable reduced resolution.
#5 - Downrezzing a 1080i signal to 1280x1080 means you are removing pixels. And you can't just pluck them out, you have to smooth the picture, re-sharpen edges, etc. That is you have to mess with the source picture. This often results in a picture that looks worse on a 720p set since the source material had been messed with, not just scaled.
#6 - Keeping the same resolution and reducing bandwidth means you increase compression, and likely show compression artifacts, but you still maintain the resolution. Reducing the resolution means you are reducing picture quality, period.
To argue that this is solely a bandwidth issue is not rational. It all starts from the resolution of the source image. If you keep the resolution the same, then yes, bandwidth is the next issue. But if you reduce the resolution, that's guaranteeing a worse picture.
And very few OTA networks are recompressing their source feeds. There are some, but most just pass on the network feed. Subchannels by themselves don't mean they need to recompress, as they have a lot of wiggle room.
1 - DirecTV is both reducing bandwidth and reducing resolution of their HD source material, resulting in an inferior HD picture (hardly reference).
2 - OTA HD feeds are rarely recompressed, and far superior to all DirecTV HD channels.
And I'd love to see any sources you have that say a 1280x1080 signal is "reference" since it's not even a valid HD resolution. Perhaps it's reference for Dish, but it's not even close to reference HD.