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Discussion Starter · #1 ·
Hi Everyone,


Did anyone else have the same problem we had at KPNX in Phoenix tonight during Leno? About 15 minutes into the show, the video went to black and when it came back the red chroma was offset to the right about the distance of the NBC Peacock!


Thinking it was a problem with our video server, I went to the backup videotape and it was goofy too! This implies it was an NBC problem... Did anyone in another city experience the same problem?


Inquiring minds want to know.


Karl Voss

KPNX-TV/DT

[email protected]
 

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Discussion Starter · #2 ·
As soon as I hit send, the problem disappeared! I guess the SEND button must have some magical connection to our HD feed!
 

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Hi Karl,


yeah I noticed it, too. Looked scary for a moment. But disapeared later in the show.


I still notice high pixelation effects on fast zooms or fire (red) and

fast running water, etc. Is that a 1080i limitation or are you limiting the 1080i signal spectrum in some way ? I heard somewhere that you guys at KPNX are experimenting with datacasting.



PS: I need some NBA in HDTV ;)
 

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Karl,


I saw it and wondered what in the world could cause such a picture. I also noticed you guys were showing some "Travel Cafe" yesterday morning. Were you testing or what?



Al Keown
 

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I've always wondered why networks with cable news didn't multicast their news channels on their second or third channel. Why doesn' t NBC broadcast CNBC or MSNBC on channels two and three?


Could KPNX rebroadcast these channels?
 

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Discussion Starter · #6 ·
Hi Everyone,


I'm not sure why we were running Travel Cafe but assume we were doing some testing of the Automation system. Travel Cafe is about the only HD programming we can run anytime without restrictions.


Speaking of rights, I believe this is the main reason why we don't run MSNBC or CNBC on a secondary channel. The other reason has to do with compression. In order to make room for other channels, we would need to "squeeze" the 1080i HD programming to make room for other programming - which would cause more pixelation in fast moving scenes


This brings me to datacasting. KPNX is/was a test market for the iBlast data service and therefore we were experimenting with various bitrates in an attempt to turn our DT channel from a money "drain" to "generator". Even though it appears iBlast has stopped testing, we are still testing MPEG software to push the technology...


Hope this answers your questions...
 

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Quote:
Speaking of rights, I believe this is the main reason why we don't run MSNBC or CNBC on a secondary channel. The other reason has to do with compression. In order to make room for other channels, we would need to "squeeze" the 1080i HD programming to make room for other programming - which would cause more pixelation in fast moving scenes.
That's too bad. It seems like a monumental waste to simply rebroadcast two copies of the same signal using that much digital bandwidth. (Or does KPNX broadcast only one channel..)


I was not aware that NBC broadcast enough 1080i HD content to make the loss of bandwidth for 1080i any sort of issue. KAET was broadcasting 3 simultaneous standard definition channels simultaneously at reasonable quality levels. And they still broadcast all HD with full bandwidth whenever it occured.


I guess some sort of a licensing or rebroadcast deal would have to be offered by NBC, and as they don't seem to like the digital transition too much, they're probably not interested.


But how about showing "I love lucy" 24 hours a day, B movie westerns, high school football tapes, public intrest recordings, or broadcasting a live Channel 12 official digital fishcam or something.
 

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Keep up the good work Karl! You put out a great picture on channel 36 even though most of it is SDTV. Could this possibly be due to the 4:2:2 signal you receive from NBC? Also the job you do with borders is terrific.


I prefer that you continue to broadcast the regular NBC shows on channel 36. The picture is far superior to that available on cable.:)
 

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Discussion Starter · #9 ·
bencooley writes...

That's too bad. It seems like a monumental waste to simply rebroadcast two copies of the same signal using that much digital bandwidth. (Or does KPNX broadcast only one channel..)


Karl Voss replies:

KPNX only transmits 1 digital channel, always 1080i, either upconverted KPNX programming or true HD NBC programming. In all cases (except when we are testing) our digital channel mirrors our analog channel. This is an FCC requirement.


bencooley continues...

KAET was broadcasting 3 simultaneous standard definition channels simultaneously at reasonable quality levels. And they still broadcast all HD with full bandwidth whenever it occurred.


Karl Voss replies:

However, I don't believe KAET ever had BOTH HD and SD programming on at the same time. They were switching between the single HD and multiple SD programs. Assuming we switched modes as KAET does, how do you explain the sudden loss of the multiple SD channels to a viewer that expects the "other" program (say MSNBC) to be there, when we have an HD program to air? As we find out every time we pre-empt a program, viewers expect THEIR program to be on no matter what else is happening and would get upset to have THEIR programming (again say MSNBC) pre-empted just to show some "silly HD program". (the non-HD viewers viewpoint)


KPNX made the decision that we were going to leave our DTV transmitter in HD all the time and constructed our plant around that assumption - Sort of a "If you build it for HD, the programming will follow". And even though the programming has not followed as fast as we would like, I applaud our Corporate owners for allowing us to build in that direction...


Does this make sense?
 

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Quote:
KPNX made the decision that we were going to leave our DTV transmitter in HD all the time and constructed our plant around that assumption - Sort of a "If you build it for HD, the programming will follow". And even though the programming has not followed as fast as we would like, I applaud our Corporate owners for allowing us to build in that direction...
Well, I am quite happy with KPNX's dedication to HD. The more the better!


I guess I don't understand the technical and financial aspects of the broadcast equipment needed to multicast. I actually enjoyed KAET's multicasting. Occasionally on channels 2 and 3 there were interesting programs which I would watch (well, perhaps not 2). I never noticed any problem with breaking away from channels 2 and 3 to show HD programming at full bandwidth. It seemed quite natural to me.


I applaud KPNX's digital support, even though I rarely tune to KPNX digital because of NBC's pitiful amount of HD. Perhaps soon we'll have more to watch.


Thanks Karl.
 

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Karl,


I watched it with my own eyes. KAET did transmit simultaneously 1080i programs on Ch. 8-1 and 480i SDTV programs (the "main" KAET PBS channel) on 8-2. The HDTV picture quality of 1080i was very good, but I do believe they experimented with the bitrate, too. I did notice a slight decrease in SDTV PQ on the 480i material. But it still was OK. I would compare it to a VHS tape in SP speed.


Regarding MSNBC and CNBC. I think KPNX should talk with the NBC parent. I do not understand why this can't be done.


Here is a good example how it could work:


From M-F from 5am - 7pm:


Ch. 12-1: Regular NBC/KPNX broadcasts in 480i or upcon to 720p (if technically possible)

Ch. 12-2: MSNBC in 480i

Ch. 12-3: CNBC in 480i


After 7 pm normal 1080i upcon or true HDTV programs on 12-1.


I really believe this is the fastest way for KPNX to create revenue. Datacasting will never catch on. It will suffer the same

fate as Wavetops attempt a couple of years ago.


You could gain a lot of viewers right away in offices that don't have Cable TV. And many don't have it. I am pretty sure a news and biz channel being offered OTA will be somewhat appealing to companies to buy some PC HDTV tuner cards for less than $350 a piece. Also they won't have any reoccurring costs once the purchase for the HDTV tuner cards has been made (Monthly Cable Bill). That Datacasting thingy will go nowhere and I would never put a single dime in purchasing stocks in those companies.
 

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Okay here's my two cents worth. Please don't try to simulcast. When KAET did it (one HD & one SD) their HD picture was noticibly worse. They worked with the encoder and allocation between the two programs but the result was not great. I'm sure you could get away with simulcasting during your upconverted programming, but the true HD quality would have to fall. It's not going to be long before NBC sees the light and KPNX will have plenty of HD programming. By the way, I'm referring to primetime, Leno and sports for periods not to simulcast. If you want to carry 16 different programs during soaps and afternoon talk stuff, I wouldn't complain a bit ;-)


Keep up the good work and thanks,


Al Keown
 
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