Greensboro, NC - HDTV - Page 341

There is an unconfirmed report that This TV may reappear on WJZY 46.4 come September. But you may not be in their reception area, as I forget your location. But I am a bit worried about pic quality with 4 channels.

WJZY recently downgraded their signal to 720p, so that may be an indication of them adding This TV in the future.

Well maybe at 720p all 4 channels will look better, but we'll see . Just noticed the change since you pointed it out. Will have to see how the pic quality looks on CW programming now. Which I don't watch that much, but most shows have looked very good when 1080i.

WCWG has 4 channels:
20-1: CW, looks fine to me, no better or worse than WLFL.
20-2 BNT, not that spectacular, but watchable
20-3 Estrella, not that spectacular, but watchable
20-4 Shopping/Country videos, horrid but nothing worth watching anyway!

20-1 is 1080i. Perhaps a 720p -1 channel will make the -4 channel better. Good luck!

I'm fine with WJZY as far as reception. For me, 480i is fine for old TV and far better than any of it looked when first broadcast.with NTSC. I had all but stopped watching TV until I acquired a digital CRT 480i several years ago. That CRT is still producing a sharper picture (to my eyes) than a lot of widescreen recievers. I do watch live programs and some movies on a widescreen, because information can be lost on the edges, not because I think the picture better. I've seen some LED lit widescreens I think are good, though.

Some people who feel this way get upset about watching 480i on widescreen TVs because the image is stretched. Do you watch it stretched? Stretching a 4:3 image to a 16:9 screen, to me, is the biggest crime in TV and I simply can't watch it. The way that TV 8.2 is broadcast is the way all SD TV should be now (4:3 in a 16:9, with pillar boxes broadcast with the image so people can't screw it up!) in my opinion, but is far the exception than the norm.

I have my recievers set for each station and subchannel at what I believe to be the correct aspect for the format transmitted. The only times i ever encountered "streched" pictures was in the previous decade when numerous widescreen sets were sold without tuners. Using cable boxes, thees sets could produce some truly horrible displays.. Not only the streching, but brightness at some ridiculous factory setting that produced minimum contrast. I've got my prejudices. I like a real contrast between black and white on the picture, LCD's have been harder to set brightness on, generally. The luminance and chrominance contrst on my LCD is not as good as on my CRT, but acceptable.

Good point about contrast. I have noticed that if you get it set up nice for an HD channel, and then watch a SD channel, it's not perfect and vice-versa. Annoying, but I think I have finally (after 3 years) found a brightness/color/etc setting that works well for all. Black is most important to me, as well. A nice, real black is vital - almost as much as stretching. I have TBS, TNT, and Cartoon Network HD and SD in my guide because they are NOTORIOUS for screwing with aspect ratio on the HD versions. Who on earth would think stretching a picture is okay? I just don't understand it! Ever watch the Dash on My 48? Oh my is that a trainwreck!

I can tell you first hand that some Tv News anchors and reporters definitely don't like it...

Are all standard definition broadcasts designed to look best in 4:3?

Here in Raleigh, when I watch 50.2 (MeTV on WRAZ), I think it looks fine when the picture is stretched to 16:9.

On the other hand, when I compare WTVD's standard definition feed of LiveWell on 11.3 to the high def feed of the same network on 11.2, it is clear that when I let my set stretch the standard def image on 11.3 to 16:9, doing so makes the people look short and chubby. So, I do the sensible thing and just watch the high def 11.2.

 

I really dislike having the black bars on the sides or above and below the picture, so I usually force everything to display as 16:9, even if that produces some distortion.

 

Some stations must put info into their signals that specifies what dimension the image for each program should be, but sometimes that causes strange things like having bars around all four sides and just a small image in the center of the screen. That seems to happen mostly during commercials.

480i is 704 x 525 with 480 lines of usable video. You can broadcast it either in 4:3 or by anamorphicly distorting the image, you can broadcast a 16:9 image within that 704 x 525 lines which is 1.33 (4:3) aspect . Anamorphic is not a new technique. 35mm film is basically 4:3 and in the early 1950's, to compete with television, David Zanuck (then of 20th Century-Fox) funded the development of an anamorphic lense to provide widescreen, something that TV of the time could not compete with. This lead to all the other widescreen formats that we have today in the cinema industry.

Now, 480p is 864 x 480 (square pixels) is a true 16:9 format. I would rather transmit 480p over 480i so TV's don't have the issue of "is it 4:3 or is it 16:9" since 480i doesn't natively support AFD. Problem is, the cost of a 480i over 480p encoder is enough to use the 480i in anamorphic mode and force a formatting code of 16:9. That is what we do with TV8.2. It is 480i transmitted anamorphic with a 16:9 formatting bit set in the stream for TV's to format as 16:9. Problem is about half of the TV's don't recognize formatting in 480i. LG does, Samsung doesn't. If the HD AFD formatting code was recognized in 480i, it could be done much more easily.

What we have observed, if the signal is an anamorphic NTSC analog video signal, it looks pretty bad. That is due to the limited bandwidth filtering that is a part of the NTSC standard and when you introduce anamorphic, the stretching of the video horizontally really shows the NTSC artifacts in a pretty nasty way. Digital SD uses EIA 601 as the standard. A digital SD anamorphic signal doesn't suffer from that limited NTSC bandwidth and looks much better. That is how we get away with it.

Foxeng, thanks for giving some technical details that confirmed what my eyes were suggesting to me, that not all standard def signals are created equal when it comes to how good the picture looks when displayed in 16:9.

AntennaTV does not send a 16:9 image. it is 4:3 480i. We take that image, run it through an aspect ratio converter to convert it to anamorphic by adding black bars on the side and then insert it into the system as a 16:9 image since we only work in a 16:9 environment. So what you have is a 4:3 image with black bars distorted anamorphicly. When we add our local commercials or news, it is native 16:9, downconverted to anamorphic and fed to the encoder as such. The encoder has its formatting bit set for 16:9 even though it is transmitting 480i. Your TV (hopefully) sees the 16:9 formatting bit and "stretches" the video to fit your widescreen display. But as a cost cutting measure, some TV manufacturers will leave out the formatting bit and make the assumption that anything transmitted 480i is 4:3, period and leave any additional formatting up to the owner.

Here is the segment of PSIP that we transmit about TV8.2:

Thanks for the information, Foxeng. This tactic does cut down on the geometric resolution of the program?. I'm not sure it matters, given most of the programming, which was not visually stunning at its birth. Whatever, my enjoyment of the product is not diminished.

I agree with you about the way TV 8.2 is broadcast. No one really likes black bars or pillar boxes on the side of a widescreen TV. But this is a better alternative versus artificially stretching out a native 4:3 video to widescreen. Even though I can also watch Antenna TV on Charlotte's WJZY 46-2, I usually stick with WGHP 8-2 for this very reason.

 

People have different tastes, I guess. You prefer to watch all 480i programming in 4:3 regardless of what steps engineers might take to make the image capable of being displayed in 16:9 without too much distortion.

 

Fair enough. But how do you override the 16:9 formatting bit (encoded in the broadcast signal) that foxeng mentioned? Does your set simply not recognize the formatting bit, or did you choose a setting on your TV to tell it to always display anything marked as 480i in 4:3? Do you have to adjust the aspect settings each time you change the channel, or do you just pick a mode that works well for most channels and leave it at that?

 

Personally, I'm happy to hear that engineers are doing what they can to make images look better in 16:9.

As more and more programming becomes available in high def, the public may start appreciating even more any efforts to make images that were natively 4:3 look better in 16:9 so that even the old standard definition programming will look decent. It seems a shame to have a widescreen TV but have the image not fill the entire width. (In the analog days, I never liked the letterboxed movies that did not use the full screen height, though I do understand that the reason for letterboxing was to allow more of the wide image that was shown in movie theaters to appear on TV rather than having to use pan and scan to transform the movie to 4:3.)

 

What I absolutely agree with people about is that analog signals do not look good when displayed in 16:9.

But analog will completely disappear from cable systems within a couple of years.

veedon, where in Raleigh are you?

The best I can figure, older NTSC tapes cannot be improved beyond transmitting them as 480i DTV. Film material might be improved by a digital scan formatting at 750p for transmission. Unless done in a ham-handed manner, older programs are always going to look better transmitted in ATSC..

Any programming that was originally recorded to video tape such as All In The Family is as good as it will ever be. 35mm film on the other hand has more resolution than HD so it can be transferred very successfully. Up until the 70's, shows were shot on film. The live audience shows switched to video tape to save money while many of the longer dramas stayed in film. In the 80's they switched back to film but transferred it to video tape for editing up until they started shooting in HD 16:9 in the 90's. Shows like Star Trek:The Next Generation, Seinfeld, Cheers and such were shot on film and edited on video tape. To make them HD, they have had to go back to the original film negatives and re-edit them in HD.

I'll show my age. There are a few programs extant on 2" Video tape from the 60's, a very small number from the 50's. There would be more, except for the cost of archiving videotape then. NBC did not keep any of Johnny Carson's New York years because of the cost involved. A good number of variety, game, and other studio .productions are gone, as far as anyone knows, as far as tape goes. There are some kinescopes left. It is said that 16mm film, such as used in kinescopes, has more resolution than NTSC video. That's hard to see by viewing at times The Dumont kinescopes of the "Honeymooners" aren't bad. But, that program was produced on kinescope, by the best the was at the time. Unless there is something else I don't know about, the worst commercial video recording was color kinescope. Whether we like today's programs or not, technically, we are in great shape.

I don't change any of the aspect setting defaults. WGHP 8.2 is broadcast in 4:3 480i with the black bars on the side. As Foxeng states, they take the image and run it through an aspect ratio converter to convert it to anamorphic by adding black bars on the side and then inserting it into the system as a 16:9 image. So when I watch vintage TV, I don't see stretched out images of these old videos. If commericals are aired in widescreen on 8.2, my TV would see them in 16:9 standard definition. If I change the channel, my tuner defaults to it's intended resolution. So for example, if I tune into WGHP 8.1, my tuner automatically displays it in 720p HD by default.

I don't know all the technicalities, but I like the way WGHP broadcasts Antenna TV on 8.2. I've seen Antenna TV on WJZY 46.2 and the video looks distorted the way they've got the old video stretched out to fill in the entire screen with no bars on the side. I guess it's a matter of personal preference, but it just looks better on 8.2 in my opinion.

If you change your aspect ratio/picture size button on your TV from 16x9 to 4x3, it will display 46.2 Antenna TV in a correct 4x3 image with black bars on the side. But 8.2 appears to do it by default, even if your TV is set to 16x9. As explained previously by foxeng. Same situation with MeTV on WCCB 18.3 and WSPA 7.2. WSPA stretches it into a 16x9 fullscreen, whereas WCCB does not, but displays it as 4x3. But again, you can correct 7.2 on your own TV aspect ratio if you choose to.

 

Oh, I see. So WGHP isn't converting a 4:3 image to 16:9 in quite the way that I thought. What the station is doing is building in the black bars so that the whole deal, the program image plus the added black bars is in a 16:9 aspect ratio.

 

I thought that perhaps engineers had developed some clever way to stretch an image (filling the whole screen, with no bars at all) without producing as much visual distortion.

 

I'm in Raleigh, but I'm almost into Durham county.

I receive Greensboro stations only occasionally, when atmospheric conditions are just right.

Every now and then a station from the eastern part of the state will come in, too, but that is rarer.

 

WCWG seems to be the strongest signal from Greensboro,but I think that's because its transmitter is located further east than many of the other Greensboro stations.

Yes, good point. WGHP 8.2 defaults to 4x3 regardless of the aspect ratio setting (which is the way I like that particular channel). But as you say, you can adjust channels like WJZY 46.2 from 16x9 to 4x3 by changing the aspect ratio settings.

It would be nice if engineers could develop some way of stretching an image to fill the whole screen without producing visual distortion. If that could be done, I would be all for watching native 4x3 shows in 16x9. I just don't like the distortion that is created when 4x3 videos are stretched to fill in a full widescreen.

Yes, TV8.2 is a broadcast in 4:3 because 704 x 525 IS 4:3. But we "pre-distort" the video by taking the 4:3 image, adding bars on the side and creating a 16:9 image that is then put within the 4:3 704 x 525 the predistorted image and we put a 16:9 formatting bit in to tell you TV to "stretch" the "4:3" image out to 16:9 so it looks correct on your TV. Some will do that some won't and you have to change the format manually.

Here is the image we receive from AntennaTV (The new AVSForum doesn't format correctly in the thumbnail in the message so you will need click on each image to see the differences):



We add the black bars:



This is what is actually transmitted:



Along with this image, we send the 16:9 format bit to tell TVs to "stretch" this out so it looks correct. Some TVs don't recognize the bit because they see it is 4:3 and format it as 4:3 no matter what and you have to go back and format it yourself.

And that is what we do.

I believe the middle and bottom photos must be reversed.in order. The bottom photo is distorted.. It has the "Antenna TV" Logo almost square.

They are correct. The middle picture is what we do to it after we get it. It is all nice 16:9. The bottom picture is what we actually transmit (distorted). Your TV "straightens it back out" to correct.

Thanks for explaining that. I had not understood you were transmitting the distorted image.

 

I, too, did not understand at first. Basically what they are doing is adding the black bars on the sides and then deliberately distorting (does anamorphic mean "reshaping"?) the program image (making it look stretched too much vertically) before transmitting that distorted image, but they are also including in the signal an encoded formatting bit that is supposed to tell the receiving TV set how to "undistort" the image by stretching the whole deal (program image plus black bars) horizontally to compensate for the vertical stretching that was applied prior to transmission.

 

I guess the final image will look the way it should provided that the viewer's set either recognizes the formatting bit or is already set to the 16:9 setting that is the default on many TV sets. I guess the only people who might end up with a distorted image are people whose TV sets are set to an aspect ratio of 4:3. For them, people on the screen would look tall and slightly skinny because nothing would be done by the receiver to undistort the distortion that was deliberately introduced prior to transmission.

Manufacturers' sets have several different aspect ratio options, so I suppose TV stations have to try to figure out what processes will result in the best picture for most of their viewers. If most people just leave their sets on the default aspect ratio of 16:9 all the time, then the approach that foxeng described would at least work well for them and prevent them from seeing a lot of unnaturally short and chubby people on the screen.