Gammy ratio/overscan/cropping on NTL analogue??

Calibos · 04-10-2003 10:36PM #1

Am I the only one who has noticed the gammy ratio/overscan/cropping on NTL analogue for the last week or two?? Digital is fine. Channel logo's and credits etc half off the screen etc???

SPDUB · 05-10-2003 03:32AM

I noticed that as well but I noticed it only occurs on the BBC,ITV and CH4

Though there seems to be some problem with SKY1 on Stargate SG1 and Dead like Me missing various letters out of their opening credits

Can't comment on the digital situation as it is still not available in my area

celticfc · 05-10-2003 11:25AM

Yeah, I've noticed it myself orite, it's annoying.

BBC One, UTV & Channel 4 are all stuck in 4:3 pan and scan mode instead of being in 14:9 (half widescreen) mode that is uasually in. I expect it to be fixed soon because this problem seems to happen quite often & rarely lasts too much longer than a week.

As for Sky One, it has always been in 4:3 pan & scan mode on analogue. I dont know if they plan on changing that.

John R · 06-10-2003 06:51AM

It is because ntl are sourcing BBC1, UTV and Channel 4 from SKY digital, where they were previously terestrial analogue feeds on which the broadcasters use 14:9 for all widescreen programmes. BBC2 is still analogue sourced as the SKY digital version has alot of different programming.

Go Figure! · 09-10-2003 05:05PM

I too find this extreamly irritating! I bought a widescreen TV a few years ago because most of the programmes I watched were widescreen. Now that they aren't anymore the picture looks all wrong. I don't really except John R's explanation either because the digital channel BBC 2 NI has been up and running for two years now and this problem has only become permanent in the last two weeks. Has anybody tried to get an explanation for it from NTL themselves.

SPDUB · 10-10-2003 01:30AM

Well when I go to Pg100 on utv and CH4 and press reveal the letters DIV for Divis appear on the right hand side of the "TELETEXT" banner indicating what tx the signal is from so it they don't appear to be from Sky

highdef · 23-10-2003 01:29PM

We are currently using digital sources for BBC1, UTV and Ch4 for the Dublin analogue network. This is to overcome an intermittent problem with the sound on the analogue feeds. (Because the problem is so intermittent it is proving difficult to identify. We are working with our equipment supplier on this).

The digital feeds originate in 16:9 widescreen. For the analogue network we convert them to 4:3. Effectively, we zoom-in on the widescreen picture so that it fills a 4:3 TV screen. This results in some of the picture, at each side, being lost. This can present a problem where there is text over the full width of the picture.

An option is to convert the widescreen digital picture to letterbox instead of 4:3. The viewer will see all the content but there will be black bars top and bottom.

We will implement this on BBC1 and continue to monitor the reaction.

ntl technical

DMC · 23-10-2003 02:18PM

Welcome along, ntl Technical, thanks for the info.

highdef · 23-10-2003 02:27PM

Thanks DMC
What do your initials stand for? It's not the Digital Media Centre in Langley, London, by any chance???

DMC · 23-10-2003 02:40PM

No, just my name!

highdef · 23-10-2003 03:05PM

Just thought you were with ntl.
FYI
BBC 1 is now being broadcast in 16:9 letterbox on the Dublin analogue cable network

highdef · 23-10-2003 03:13PM

FYI

We are currently switching BBC1 back to 4:3 pan & scan as the current program (Murder She Wrote) is being broadcast as a 4:3 letterboxed program with widescreen signalling. The widescreen signalling is being broadcast by the BBC so we are unable to change this. The picture at the moment has black bars both at the top and bottom of the screen, and on the left and right. Basically there is a small window of picture within a large black frame. This is unsuitable for broadcast so I'm afraid we have to change it back to the original pan and scan 4:3 ratio until we get a fix on our analogue sources.

celticfc · 23-10-2003 03:56PM

Hi ntl Technical, welcome to the forums.

Thanks very much for all the information, it has cleared up a lot. I noticed that BBC One was in 4:3 Letterbox mode earlier on alright (which I much prefer) when Doctors was on, but as you say it does look ridiculous to broadcast when a 4:3 picture is on.

Also, is Sky One ever going to be viewable in 14:9 or is it to stay in 4:3 pan & scan mode on analogue cable?

oneweb · 23-10-2003 04:12PM

Thanks for the info ntl Technical! Very much appreciated. I had noticed the zoom problem, especially on Winning Lines on BBC1 - numbers on both sides missing. Also I'd posted about the sound glitches - same program where the sound would sound like it slowed for a split second or click.

So if it's not one problem, it seems to be the other?

While I'm at it, can I ask if the pixelation which is most noticable during transitions and fast action scenes is present in the source signal or is it a result of NTL reprocessing the signal for output?

Go Figure! · 23-10-2003 04:50PM

Hi NTL Technical, Welcome to the Forums!
You are a breath of fresh air in your company and I think the first representative from NTL I have ever come across who actually gives straight answers to questions. Having said that I have two more questions to ask you now. Shouldn't E4 also be broadcast in 4:3 Letterbox format as it is on your digital service and as it was on the analogue service for a few months last year?. It looks ridiculous with half the station logo cut off on widescreen programming. Also as you are anonomous on this forum could you please give us the real reason why Eurosport was dropped from the service last year? Nobody I have spoken to since believes the reason you gave at the time.
Thanks very much!

celticfc · 23-10-2003 04:59PM

Originally posted by Go Figure!
Shouldn't E4 also be broadcast in 4:3 Letterbox format as it is on your digital service and as it was on the analogue service for a few months last year?. It looks ridiculous with half the station logo cut off on widescreen programming.

As far as I can remember it was changed because there were complaints from some people that the picture looked too small on a 4:3 TV. (Theres an old thread about it somewhere).

I agree though about it looking a bit odd with half a DOG in the corner of the screen, but thats really to do with E4's decicion not to use a "safe area" unlike most others.

highdef · 23-10-2003 05:02PM

Oneweb. With regards to the audio glitching you heard whilst watching "Winning Lines" - that is exactly the problem we are having with our anlogue UK terrestial sources and consequently why we are presently using the digital feeds. The source of this audio glitch is still unknown as all our equipment has checked out fine. There are still ongoing intensive investigations being carried out regarding this fault.
Some pixelation does occur on the UK channels during action/cut scenes, although it is fairly minor and infrequent. The signal we are using at the moment for the UK channels is digital. We receive it on a fibre optical from the Belfast headend. We then convert it to analogue signal for broadcast. Any pixelation seen is already present when we receive it as converting from digital to analogue cannot introduce any pixelation. Also, as we are broadcasting these channels in 4:3 (except BBC2), any pixelation is visually enhanced as what you see on your TV creen is zoomed in picture, thus you are zooming in on the pixels making any slight picture errors more obvious. Again, this will be resolved when we restore our analogue feeds.
CelticFC: RE: Sky One: Changing the aspect ratio on Sky One is a whole different ball game. To do this, we need to switch to our back-up whilst we change the aspect ratio on the main feed. Then we have to switch back. It can't be done this week, however I will put a request in with our analogue television manager to change the ratio to 4:3 early next week. If there are no widescreen signalling problems if or when we switch it, then we will guage the reaction from customers and hopefully keep it in letterbox mode.

celticfc · 23-10-2003 05:12PM

Originally posted by ntl Technical
CelticFC: RE: Sky One: Changing the aspect ratio on Sky One is a whole different ball game. To do this, we need to switch to our back-up whilst we change the aspect ratio on the main feed. Then we have to switch back. It can't be done this week, however I will put a request in with our analogue television manager to change the ratio to 4:3 early next week. If there are no widescreen signalling problems if or when we switch it, then we will guage the reaction from customers and hopefully keep it in letterbox mode.

Thanks very much, thats great.

highdef · 23-10-2003 05:17PM

Go Figure: E4 is in the same boat as Sky One.
Celtic FC: You are right about E4. We did originally broadcast E4 in letterbox on the analogue but complaints from customers prompted us to switch it to pan and scan. A lot of people do not like the black bars at the top and bottom of the screen. The majority of our analogue customers have standard 4:3 sets whilst a higher proportion of our digital customers have 16:9 sets. Also, with the digital service you can decide whether you want pan and scan, letterbox or anamorphic widecreen so everybody is happy.
Eurosport was dropped mainly because they were trying to charge us extortionate amounts of money to broadcast there service for what is actually a regular channel. I don't know what the exact figure was but rest assured, it was a lot. Hope this answers all your questions. I will be heading off shortly and won't be back till Monday so if I don't get back to your questions this evening, it will be Monday afteroon before I get back to you all.

Go Figure! · 23-10-2003 05:37PM

Thank you! Thank you! Thank you! NTL Technical

Gwynston · 24-10-2003 03:17PM

Hi ntl Tech - it's great to have someone in the know from NTL down here at ground level!

Hope you're not snowed under with queries.....
I'm on MMDS Digital in Galway and am I right in saying that selecting 16x9 instead of 4x3 on my decoder will not make any difference? I notice that E4 always comes through on widescreen with a signal, but I can't seem to get it on the regular channels. Is there only one feed per channel on MMDS?

While I'm happier with the picture quality of the Digital MMDS, I'm a bit fed up with 4x3 broadcasts on my widescreen TV

SPDUB · 24-10-2003 09:17PM

I may be in the minority here but I find the 4:3 pan and scan much more annoying than I ever found that sound problem

celticfc · 24-10-2003 09:30PM

Originally posted by SPDUB
I may be in the minority here but I find the 4:3 pan and scan much more annoying than I ever found that sound problem

Well now that you mention it, I never actually remember noticing that sound problem.

oneweb · 25-10-2003 12:26AM

ntl tech, your presence here is absolutely wonderful. It's great to know that there are still people out there who know exactly not only what they themselves are doing, but going beyond that to understand what their company is doing too!

Thank you so much for sorting out a lot of queries

Buy that person a pint!

Go Figure! · 25-10-2003 02:45PM

I have to agree with SPDUB. I too find the 4:3 pan and scan format far more annoying then I ever found the sound problem. I hope NTL Technical is telling the truth when he says that intensive investigations are going on to resolve the fault. The sooner it is corrected the better. People who do not have
Widescreen TV's need to move with the times sometime! Why should those of us who have updated our televisions some time ago have to always wait for others to catch up?

oneweb · 25-10-2003 02:54PM

Originally posted by Go Figure!
Why should those of us who have updated our televisions some time ago have to always wait for others to catch up?

You have your aspect ratio button so you can choose the format you watch. I'd imagine most of those who have snazzy new televisions can also afford digital. The rest (I'd imagine the majority) of us find no need nor want to spend a small fortune on something that they neither need nor want.

Go Figure! · 25-10-2003 03:01PM

oneweb I have to tell if you aren't already you will increasingly become the monority over the next couple of years and I am getting digital television for Christmas!

oneweb · 25-10-2003 07:03PM

Good for you

I can wait a few years to upgrade. There's no compelling reason for me to do so yet given the advantage/cost ratio.

highdef · 28-10-2003 02:21PM

Even if we were to play out all channels in letterbox mode on the analogue platform (where available of course), this is still not true widescreen. When you view this letterboxed picture, your widescreen TV will either automatically zoom in so the picture fills the screen and everything appears in it's correct proportions or else your TV will do this itself.
However, when you zoom in on this picture, you are loosing a lot of resolution on your TV picture as you are effectively zooming in on the individual pixels. This is in much the same way as the way we are currently zooming in on the widescreen picture to create a 4:3 pan and scan image. However, as the equipment we use is professional, it is designed to display 4:3 pan and scan from a widescreen source with minimal degradation in quality. I have watched TV programmes on E4 on digital back in the days when it was transmitted in letterbox mode (this was the only option as we had problems with widescreen switching on one of our models of set top box, from Channel 4 when we first introduced E4 and also with Film Four) and I noticed that the picture was really not great at all. I was viewing on a Sony 28" WEGA which is an OK TV.
The widesceen option on digital is completely different to what some people want transmitted on the analogue platform. On digital, if you select widescenn and the program is being transmitted in widescreen, you will get a true anamorphic widescreen picture. Basically, the picture comes in stretched vertically together with a widesceen switching signal for your widescreen TV. When your TV sees this signal, it switches from whatever mode it is in to widescreen mode. This then squashes the picture down to correct proportion and size for a widescreen TV and, Hey Presto, you have a perfect widescreen picture in full 625 line (or thereabouts) resolution.

watty · 28-10-2003 02:33PM

No it isn't

The picture only *LOOKS* stretched vertically on a 4:3 display. It is actually squashed horisontally. For correct display the pixels are strecthed horizontally. Only 4:3 tubed sets with Animorphic support, then reduce the scan height as if a 16:9 tube was fitted. They then have an identical image to a same width WS TV.

It is just that Digital set-top boxes allow either "letterboxing" (throws away vertical resolution) or Crop (it is NOT true Pan & Scan), which throws away the edges of the picture. Resolution is really the same.

Animorphic WS works perfectly well on Analog and their is even a standard for what goes in Line23 to tell a WS TV what to do.

Some 4:3 TVs can reduce height to give a perfectly proportioned Animorphic WS image *WITHOUT* any of the loss of vertical resolution that "set top" box "letterboxing" does. For these TVs the Cable, MMDS, DTT, Satellite or DVD player should be set to 16:9 TV. In this mode 4:3 material is unaffected.

With an animorphic source you are really in a problem if the viewer can't handle it.
Simple Crop loses too much picture
Simple Letterbox loses too much resolution. Some people find the height of the black bars too much.

So the BBC and most others use truely professional gear to create a intermediate letterbox (14:9 often ort even less) with slightly chopped sides and smaller black bars for analog transmission.

Gwynston · 28-10-2003 02:37PM

Hello again NTL Technical,
Is what you say about digital true for MMDS Digital in Galway though? I notice that on E4 my TV catches the widescreen switching signal OK, but I don't seem to get this on other channels. What others should I be able to get anamorphic widescreen on? The decoder's "16x9" setting doesn't seem to affect any other channels which all come through 4x3, so I have to zoom in on the TV (losing resolution)

Gammy ratio/overscan/cropping on NTL analogue??

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