HD Semi-Stretch - AVS Forum
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post #1 of 16 Old 01-21-2004, 05:48 PM - Thread Starter
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Our local NBC station broadcasts their high definition 4:3 programs stretched mid-way between 16:9 and 4:3 with medium black bars on the side.
I personally dislike stretching, and when they broadcast like this, I really don't have any options to correct it.
Someone from the station asked me what are the views of other people I have ran into. So I figured I should get a broad view of this topic from here before I respond to him.

So please give me as many opinions as possible. Here are my thoughts and questions, please comment.
1) Do many people prefer the semi-stretch? Or do people that stretch, stretch all the way to 16:9.
2) As I see it, most devices can stretch (maybe not semi-stretch), so why not just broadcast 4:3 and let the end user stretch or not? At least that gives everyone an option. When they broadcast semi-stretch, we don't have any options.
3) Are there a lot of HD receivers/display devices that don't have a stretch option?
4) High definition is all about PQ. Stretch is bad PQ, correct? Isn't PQ the best representation of the image as it was captured/designed?
5) Any other threads out there that discuss this? I tried to find some.
6) Here it is straight and general: Should the station broadcast with no stretch, a semi-stretch, or full stretch?

Please give me any other ideas or comments.
Thank you very much for your input. Please pardone ignorance, and correct me where I have mispoke.
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post #2 of 16 Old 01-21-2004, 05:57 PM
 
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This kind of distortion of the picture is atrocious. It's absolutely the worst way a station could handle 4:3 material. As you said, it give the user no reasonable options to control the aspect ratio. KTLA and KABC in Los Angeles do this with their 4:3 material and I don't watch non HD on these channels.

I talked with these station's engineers about this some time ago. They insist it's a good compromise and that no picture is lost. That's a load of BS as they zoom the picture and do lose picture information while leaving thin side bars that really accomplish nothing over leaving wider side bars that are present with 4:3 material being left at 4:3 material.
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post #3 of 16 Old 01-21-2004, 06:07 PM
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Doesn't bother me. If on occasion it did I'd just switch to the main 4:3 analog channel.
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post #4 of 16 Old 01-21-2004, 08:27 PM
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From my experience, people can't usually stretch 1080i/720p material anyway. It has to be 480i for most tv stretch modes to work correctly, so here's a thought: Broadcast in 1080i/720p for HD material, then switch to 480i for 4:3 material. I don't know if this is a pain for the stations to do, but it would get rid of the need for the analog channel (which is the point of all this DTV stuff, too, right?)

Lee
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post #5 of 16 Old 01-21-2004, 08:32 PM
 
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Quote:
Originally posted by leewcraft
From my experience, people can't usually stretch 1080i/720p material anyway. It has to be 480i for most tv stretch modes to work correctly, so here's a thought: Broadcast in 1080i/720p for HD material, then switch to 480i for 4:3 material. I don't know if this is a pain for the stations to do, but it would get rid of the need for the analog channel (which is the point of all this DTV stuff, too, right?)

Lee
Dish HD STBs can stretch, zoom, etc a 1080/720 signal.

It would actually look terrible for a station to change it's signal when it switched from 4:3 to widescreen material. With each switch, you display would have to change it's sync to display the new signal. Very disruptive.

The simple solution is for the stations to simply broadcast the material in it's native format. Let the viewer decide to stretch, zoom, or do nothing. Those companies that are manufacturing STBs that don't allow aspect control for 720 or 1080 need to come to reality and realize that there is a need to do that as long as any 4:3 material is being broadcast.
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post #6 of 16 Old 01-22-2004, 04:21 AM
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We are having the same discussion on the local Columbus OH HD board, as our local CBS station has started some 14x9 SD stretching.

My opinion is if they can use technology like my Hitachi51s700 that seems to stretch only the edges the distortion is almost unnoticable. AND, there is no chance of screen burn in.

I now watch all my analog tv in this mode.
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post #7 of 16 Old 01-22-2004, 06:24 AM
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JD - Welcome to AVS. Do yourself a favor and add your location to your profile. A lot of issues are location specific. I know WNBC-DT is zooming their 4:3 SD (not HD) stuff like you described. I do not like anything I watch to be zoomed (WNBC-DT) or stretched (ESPNHD). Some may add HBO to that list for they crop most of their HD movies.
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post #8 of 16 Old 01-22-2004, 08:24 AM
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This comes up here once in awhile. A couple weeks ago I even made a web page about it. See this thread.

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post #9 of 16 Old 01-22-2004, 08:36 AM
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I rather like KTLA's stretch mode and wish my Mits had the same thing. That said, I can understand why others object, esp. those with sets that cannot burn in. At least it's better than EStretchPN that makes people look fat.

It's a tough one for the station. I understand it's not technically easy for them to switch format on the fly from SD<->HD; that's why they're doing the black bars / stretch / zoom thing.
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post #10 of 16 Old 01-22-2004, 08:44 AM
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Our local CBS station broadcasts upconverted SD material with gray side bars, I find them less distracting than the black side bars, that our local ABC station uses. I guess it is better for burn-in as well. The semi-stretch does nothing good, it both distorts the picture and still has the burn-in possibilities. I have a Toshiba 50H82 and it will stretch a HD source. Their TW1 stretch mode is arguably the best available for 4:3 material, but unfortuately it doesn't stretch the same way with the HD source, it appears more linear. I was under the impression that many current RPTVs will allow a stretch of HD material. My STB is a Samsung TS-160 and it does not stretch HD material, only SD material over the component outs.

Andy
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post #11 of 16 Old 01-22-2004, 09:05 AM
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I hate hate hate hate the stretch and refuse to watch the programs on my local ABC station that way.

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post #12 of 16 Old 01-22-2004, 07:42 PM
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Quote:
Originally posted by leewcraft
Here's a thought: Broadcast in 1080i/720p for HD material, then switch to 480i for 4:3 material.
The station in question has a 16.2 channel for 4:3 presentation. IMHO there is no reason to switch 16.1, just leave it all "HD" all the time. They are losing bandwidth somewhere .. both HD and HD don't perform well under stress (such as sports).

I'm glad (for sports fans) that the Superbowl is in 22.1 ... they seem to get the signal right, even with the 22.2 UPN.

And the stretchy thing on 16.1? On my screen it isn't centered. (One bar is bigger than the other.) I think they are just trying to fill out the screen.

I too have contacted the station, and they promised that repairs were on the way (for the compression problems) and they would raise the question on stretching. I HOPE they go to 4:3 simple upconversion - no stretch.

JL
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post #13 of 16 Old 01-22-2004, 08:34 PM
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Wow, deja vu. I had just e-mailed one of the engineers at WNDU-DT about this very subject, suggesting they let their ATSC viewers vote on how the programming should be presented. And, now, here's this thread!

WNDU-DT uses a 14:9 stretch on 16.01 to minimize "burn-in" issues on 4:3 material on 16:9 displays. Evidentually, 16:9 stretch was concidered too much distortion, with 14:9 filling the majority of 16:9 sets with the factory-default overscan. For those Michiana viewers with 4:3 digital TV sets and ATSC tuners (like, what, three people?), WNDU-DT has 16.02, basicaly the 4:3 480i NTSC feed.

Anyway, I feel that sub-channels are parasites that should be squashed when real HD programming is available. However, WNDU-DT was one of the first Digital TV stations on the air, and their older hardware isn't as adaptable at switching the sub-channel allocation on the fly. But, so far, WNDU-DT seems to have dialed in an acceptable balence between compression artifacts on HD shows and signal quality on the SD sub-channel.

WSBT-DT's solution is much better, IMHO, show 4:3 programming in 4:3 mode and 16:9 programming in 16:9. Hopefully, they crank down 22.02's bitrate to zero for the SuperBowl...:D

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post #14 of 16 Old 01-22-2004, 10:31 PM
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Quote:
Originally posted by Foxbat
But, so far, WNDU-DT seems to have dialed in an acceptable balence between compression artifacts on HD shows and signal quality on the SD sub-channel.
I respectfully disagree. WNDU is the only station where my wife questions how much I paid to see that quality of signal. Seeing the other channels makes her look forward to the day all TV is "digital". Seeing WNDU makes her rue the day.

Quote:
WSBT-DT's solution is much better, IMHO, show 4:3 programming in 4:3 mode and 16:9 programming in 16:9. Hopefully, they crank down 22.02's bitrate to zero for the SuperBowl...:D
UPN Michiana wouldn't like that. :) Seriously, I believe that the Superbowl will be an excellent showcase of how stations CAN do two feeds, one HD and one SD. It will be interesting to see how well it works.

(Even WNIT can get HD+SD right, when the audio isn't off tracking. Now if we can just get them to 34.1/34.2 instead of 35.1/35.2)

JL
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post #15 of 16 Old 01-25-2004, 03:47 PM - Thread Starter
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For those Michiana viewers with 4:3 digital TV sets and ATSC tuners (like, what, three people?), WNDU-DT has 16.02, basicaly the 4:3 480i NTSC feed.
I was told 16.2 is also for us who can't stand the stretch of 16.1.

I'm glad I bought thousands of dollars worth of HD hardware so I could enjoy an undistorted SD channel.

If I just would have bought equipment that burns in and equipment that can't stretch itself, I guess I would be all set right now.
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post #16 of 16 Old 01-26-2004, 12:13 AM
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WNDU apparently has made the commitment to be the worst HD and SD digital television in the market. They apparently DON'T count their DT viewers as important at all. Despite their bragging about being the first licensed (in the market), they are obviously not the best - and they won't be with the attitude and priority they have apparently placed on DT.

I could understand that attitude from a low budget station that can barely keep the lights on. But from WNDU? By falling behind they will have much further to go when DT does become an important market force. The FCC only says how much of the digital feed needs to be mirrored by April 1st each year. They don't say that it has to be a watchable quality. Apparently WNDU has taken that to heart. Not every station can be as good as WSBT and WNIT (both stations feeding HD+SD on their DTs in excellent quality).

The stretch would be an easy fix - and if they are tight on funds to get a better mux kill 16.2 and let 16.1 unstretched have the bandwidth. Be like WSJV and put up one GOOD signal instead of two bad ones.

JL
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