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View Full Version : Black and white bar on top of display, certain SD channels...?



jacquesy90
25-05-14, 16:56
I have noticed this very annoying black and white bar at the top of certain sd broadcasts.

I think its a bit like the marker you see on itv when just about to go to adverts, however this is constant and anoyying.

Any way to get rid?

34883

Very top of picture, cannot quite make it out as good on the pic but on screen its very noticable, ecspesially dark scenes!

Donnie
25-05-14, 17:48
Interesting if you get an answer as I get the same with my Duo2 and Samsung 46"

Alanp
25-05-14, 17:55
This is common when overscan is switched off on the tv different makes of tv may have a different name for it try turning it on in the tv menu settings

Rob van der Does
25-05-14, 18:17
Turning overscan is the worst you can do. See a.o.

http://www.engadget.com/2010/05/27/hd-101-overscan-and-why-all-tvs-do-it/
The bar mentioned here is only showing the lack of interest the contents provider has in his quality assurance process (if any) and has nothing to do with the TV.

Trial
25-05-14, 19:29
hi,
btw. when you activate high resolution for a screen shot the quality is much better.

As Rob said complain with the provider.

ciao

Alanp
28-05-14, 08:37
Turning overscan is the worst you can do. See a.o.

http://www.engadget.com/2010/05/27/hd-101-overscan-and-why-all-tvs-do-it/
The bar mentioned here is only showing the lack of interest the contents provider has in his quality assurance process (if any) and has nothing to do with the TV.

Rob I could'nt agree more i always have mine set to off but the qustion was how to get rid of the issue, its the only way i know

Trial
28-05-14, 09:26
Hi,
but when you turn on overscan you decrease PQ for 100 services only to get 1-2 without the bars.

ciao

Joe_90
28-05-14, 11:42
I feel I must agree with Alanp on this one - the only quick way for the OP to get rid of the bars (they are probably teletext info in the overscan area) is to turn on overscan in the TV or else go into the the advanced picture menu (if one exists) to shift or stretch the image up a couple of lines. The downside of this is that you may then have to adjust the VIX on-screen-display (OSD) to fit into the stretched image. It's a compromise, unfortunately - live with the bars on the picture on some channels or move the image which results in some loss at the edges. The broadcasters probably won't be interested in fixing the problem as it's in the safe area normally hidden by overscan, which is the default mode on most flat-screen TVs and unnoticeable on CRT TV.
I have overscan turned off myself and notice this issue only very rarely. As for overscan causing picture quality issues, that's debatable. Most SD images are 720x576 (or thereabouts) and have to be stretched to fit the screen size of 1920x1080 of most HD TVs, so a little overscan is not going to affect picture quality. Full HD images on overscan might suffer a bit of quality loss, but I doubt if you would notice unless you are sitting very close to the screen.

abu baniaz
28-05-14, 11:54
As far as I am aware ITV always broadcast cast those bars before an advert.

Joe_90
28-05-14, 12:00
ITV certainly used to display a single "dot" for a time before a advert break - I think to allow for regional opt-out or different advertising or whatever. But today, with full automation in the playout suites, this is unnecessary. I certainly don't see any dots or bars on ITV (London) on my main TV which is set for exact pixel. Usually the bars are from teletext or closed captioning on programmes from an analogue source. Most digital terrestrial or satellite TV would carry text or subtitles etc. in a separate digital stream and not in the actual picture information.

abu baniaz
28-05-14, 12:36
It wasn't a single dot, but a a box with black and white checks. I still see them.


http://www.youtube.com/watch?v=UkjVGt4YKsc&list=PLGD2tjST16V9W8pWMM4bJxQj lnOR11qt-&index=3

Joe_90
28-05-14, 12:52
Those are advertising break cues all right. I wonder if it's specific to certain regions? I don't recall seeing them in a long time. Is the video yours or just an example? It seems to be a 16:9 image squashed to 4:3
I had another check of my TV settings and verified that overscan was set to off. My HDMI connection is fed from my AV amp (Onkyo 875) which upscales to 1080p, so I turned off upscaling and let the TV handle it instead. Checking through all the usual BBC/ITV/C4/More4 etc. I could not see any of the checkerboard bars at the top of picture. The only odd thing I did notice was that on ITV1 (london), both SD and HD channels had a black line down the left of picture, like a portion of the image was cut off (maybe 10 pixels). This was on the "This Morning" programme. The ITV1+1 variant was ok. The following programme on ITV1 was perfect - no pixels cut off. So it would seem that there can be slight variances in picture output from different studios within the network, but which would not be noticed if overscan was turned on. The moral of the story is probably to live with the issue and remind broadcasters regularly that they need to improve their standards :)

jacquesy90
28-05-14, 15:44
Thanks for all the good information everyone. Its really annoying but tbh i think its only a few channels with this issue, sky 1, +1 and another one i cant remember. For one i dont fancy turning overscan on and messing around with the image so for the sake of 2 or 3 channels il just deal with it lol :thumbsup:

Rob van der Does
28-05-14, 18:01
Of course: for SD services overscan won't make any difference. But we're talking about HD-boxes and HD-TV's, right?

Anyway: I simply don't look at that half-a-bar that shows sometimes on some services.
And Teletext has nothing to do with that: the time that TT was 'hidden' in invisible lines is behind us. It's pure and simple lack of quality assurance of contents providers.

Joe_90
28-05-14, 20:23
Rob - still lots of SD services on satellite and terrestrial, upscaled to HD. Also lots of teletext services(incl. closed captioning) still in scan lines originated in analogue services - not everyone has gone digital (although most of Europe has!). You can't be absolute in your condemnation:p In an ideal world we could all switch to "exact pixel" or "zero overscan" or whatever and all see a perfect picture but unfortunately most broadcasters are chasing audience not videophiles so standards are not what we might expect:(

Rob van der Does
28-05-14, 21:40
True. And hence I accept the 'strange bar' that appears now and again.