Originally Posted by NBC17ENG
Interesting that DirecTV picks our signal up off air at Departure Ave in Raleigh, and Dish picks it up off air off Capital Blvd with regular antennas near Wake Forest. Time-Warner gets their feed directly off my HD switcher via fiber with enough bandwidth to carry several HD channels. There's nothing but a beam of light between us and them.
As for bandwidth, you got 17.2 Mbs for the Super Bowl, and normally I send you 14-15 Mbs. 1080i is fine between 12 and 14 Mbs and my TWC DVR in my office looks great, even frame by frame.
It is a known fact that in some neighborhoods the TWC distribution system has had problems with our QAM frequency and passed other stations just fine. In every report I have gotten and passed on to TWC, they were able to resolve the issue 100% of the time. If you have pixellation and blocking, call them and they can usually ping your box from the Durham headend and know exactly what is happening. If you can't get results with their regular customer service reps, shoot me an email and I'll forward it to them and they will gladly look into it. It is not uncommon for a problem to come and go, so it may take them some time to determine what is going on.
We all read this forum. Not every engineer has the company's blessing to respond, but we all read and try to determine who has legitimate complaints. Engineers will not usually respond well to rants and opinions, but everyone of us will beat the bushes to resolve a real problem. You can certainly search the specs on our Harmonic MV 450 HD encoder. I have another software upgrade currently being shipped to enable the AFD passthrough that instructs the cable and satellite decoders how to down-convert the SD feed you get to letterbox or center cut. That's software version 4.10 if you want to keep track since I'm currently running version 3.85.
I've been a little busy lately, but I'll call TWC in the morning (or they will call me fist after reading this) and we'll see what we can see. Shoot, I'll punch up color bars for a few minutes tomorrow if we think it might show something is whacked.
As for News in HD, we really wanted to do it this month, but it just isn't cheap and easy to do, and money is tighter than I've ever seen it in over 30 years in broadcasting. We hope to do it as soon as the economy gets better and let's hope for later this year. I would stretch the picture for you, but you can do that yourself.
I am sorry if I offended you. I got the impression of low quality from many things: the presidential debates last year where WNCN's feed was less detailed and more full of artifacts like mosquito noise, football games, and the national news in HD.
As for how I guessed that there was an H.264 encoder on-site (even though it turned out to be wrong), here is how I thought:
- MPEG-2 and H.264 are lossy. Therefore, each time either one is applied, something is lost in the image quality. Tiered compression helps minimize this, but best quality is achieved by just one compression. That is why I do not expect broadcast TV to match HDNet.
- If something is decompressed and recompressed, expect picture quality to go down, not up.
- Someone reported that WNCN picture quality was better on DirecTV than on cable, which I believe is equivalent to OTA due to the reported lack of rate-shaping on broadcast TV stations by TWC.
- Therefore, I thought that to get better picture quality on DirecTV, someone must have installed an H.264 encoder onsite to WNCN to bypass its MPEG-2 encoder.
What puzzles me is if DirecTV is getting its signal OTA, how is the picture quality better on DirecTV than OTA or Time Warner Cable?
I wonder if DirecTV is substituting the national NBC feed whenever there is not enough difference between the national NBC feed and the local feed from WNCN? This would be one way to mitigate the multiple compression trap.
I don't know about the picture quality of the various primetime dramas because I am a news and sports junkie. It is possible that your encoder is able to handle the primetime dramas very well because such content originates as 24 frames per second, giving your encoder oodles of redundancy to dispose of, giving it more room to preserve detail. However, I am a news and sports watcher, not a drama watcher.
One excellent test I stumbled upon is whenever Obama is televised in HD, his small amount of hair seems to be giving many stations trouble. WRAL is able to show its detail, while WTVD and WNCN blurs out his hair. WTVD cannot be blamed because 720p has less pixels than 1080i, so such detail could possibly never have been captured in the first place. 720p is much better for sports at least when HDTV was in its infancy because sports in 1080i is much harder to compress, but is inappropriate for low-action stuff like most kinds of news. WTVD is given 720p and has to do the best it can with 720p. The blame lies with ABC in this case. Now, when it is obvious that Obama is being televised as upconverted 480i, this test is invalid.
P.S. Good job on not stretching the news.
P.P.S. I hope the software update will improve the compression algorithms used.