My Topfield outputs 14:9 not 16:9 Options

[pneu]

And 14:9 isn't an offical aspect ratio as it is a comprimise between 12:9 (4:3 if my memory is working correctly (of course I could have said 4:3 in the first place)) and 16:9.
And George, the ABC does broadcast 14:9 on Rage (IMG:style_emoticons/default/smile.gif) Sorry I had to say it.

I'm going to have to agree with gclarke, whether or not he agrees with me.
This is what I recall from our ABC training sessions on WS.

There are two aspect ratios in use 4:3 (12:9) and 16:9.
Material produced in 4:3 is recorded in the conventional manner. Pixel aspect ratio is 1.07:1
Material produced in 16:9 is recorded in Full Height Anamorphic, (FHA) on broadcast tape machines/servers.
This consists of a 720 x 576 active pixel image, with a pixel aspect ratio of 1.422:1
Some material may be created in 1024 x 576 square pixel mode, but then scaled to 720 x 576 FHA.

Material shot in 16:9 for transmission in a 4:3 aspect ratio is shot with "protection".
This is not a technical standard, in that there is no electronic difference between recordings made with these various protection schemes. The difference is purely in the cameraman's framing of shots, or the placement of text on a graphic.


16:9 Protect
Is basically shot for display on a 16:9 display device. The title and action safe areas are closest to the edge of frame of the 3 modes described here. It assumes display only on 16:9 devices, or 16:9 deep letterbox on 4:3 service.


14:9 protect.
In this protection scheme, a compromise is made so that the action and title safe are is smaller, allowing for 14:9 aspect ratio conversion. (see below for TX info)

4:3 centre cut protect.
In this mode, the action and title safe areas occupy a middle part of the screen.
Intended where a 16:9 programme will be TX'd on a 4:3 service with no letterboxing, and therefore cropping of the left and right edges of frame.

Transmission of pictures.

On the digital service, images are transmitted as a 720 x 576 frame with pixel aspect ratio of 1.422. This is a full height anamorphic image and needs to be "unsqueezed" for display, by the STB or TV monitor.
If the image were transmitted at 1024 x 576 then it would still be known as 16:9 widescreen, but it is no longer "anamorphic", as the pixels are square.

On the analogue service, a widescreen programme can be transmitted in a number of different ways.

Listed are the 3 most common.

16:9 deep letterbox.
The full width of the 16:9 image is shown on the 4:3 display, with black bars top and bottom.

14:9
Basically the same as the deep letterbox except the image is effectively "zoomed" slightly to minimise the black bars top and bottom. This results in some slight "cropping" of image content at the sides of the frame. Therefore this is why "14:9" safe areas are a little more conservative than 16:9 versions.
* 14:9 is not an electronic production standard, it is simply a "framing guide" for a cameraman or graphic artist. It is also a setting for aspect ratio converters between the output of the presentation suite, and the analogue (4:3) transmitter.

In broadcasting and production, no material should be recorded in 14:9 because it doesn't really exist. Of course if you record an analogue off air broadcast of a 16:9 programme (arced to 14:9) then you have a 4:3 recording of a 16:9 transmission presented as 14:9.
In broadcasting and production, no material is (supposed to be) recorded with black bars, either top and bottom or left and right (pillar box).

Now as for the presentation of some clips on Rage, well these may have been recorded with "black bars" to simulate WS videos (this was popular before the advent of WS digital in Australia), or they may have been sourced from overseas where different standards applied before the creation of today's WS Production and transmission guidelines.

Hope this is not too confusing.

Cheers

JB

Great info, John_Barber! I assume you have some connections in the ABC - can you tell them to make more of their stuff 4:3 centre cut protect, in particular, Rage titles, so us non-widescreen TV owners don't have to keep missing song titles?

Cheers

[Donald]

I agree with Ross - you do get something that looks like 14:9 from a STB. I think it's to do with overscan. I find that you lose more pixels off the edges of the screen when you get the picture from a STB than you do with analog or with the picture from a DVD. That means that a 16:9 picture from a STB will appear to be a 14:9 because the other 2 units of width have been dropped off the sides of the screen.

Note that my experience is with an 80cm 4:3 TV with S-Video input.

Donald

(Apologies for not using technical language or assassinating any characters)

[kenneth]

Great info, John_Barber!  I assume you have some connections in the ABC - can you tell them to make more of their stuff 4:3 centre cut protect, in particular, Rage titles, so us non-widescreen TV owners don't have to keep missing song titles?

Cheers

He doesn't. It was an

ABC training sessions on WS.

. And it's people like you who do not understand how the ABC does things I won't bring this thread off-topic anymore than it somewhat was.


And to do with the original topic, any chance that the DVD's are shown in a movie aspect ratio (I think it's something like 18:9). That could be why DVD's look like they are 16:9 while the STB is 14:9

[lesftv]

And if you look at the rear cover of your DVDs, you will see there are a variety of aspect ratio standards. Some are 1.85:1 some are 2:1 others are 2.3:1. etc. I guess all these various standard have to be accommodated in the 16:9 broadcast. The differences are certainly noticable when playing various DVDs direct into the TV.

[pneu]

I agree with Ross - you do get something that looks like 14:9 from a STB.  I think it's to do with overscan.  I find that you lose more pixels off the edges of the screen when you get the picture from a STB than you do with analog or with the picture from a DVD.  That means that a 16:9 picture from a STB will appear to be a 14:9 because the other 2 units of width have been dropped off the sides of the screen.

Note that my experience is with an 80cm 4:3 TV with S-Video input.

Donald

(Apologies for not using technical language or assassinating any characters)

With my Topfield, 16:9 letterbox on my 4:3 TV is without a doubt 16:9, not 14:9. Analogue TV (when movies are in 16:9) and DVD (16:9 movies) are also a perfect 16:9 letterbox on my set.

These sources should not look any different to what is coming out of your STB, unless the STB is so poorly designed that it doesn't have the system's screen dimensions set properly, and on the Topfield this is definitely not the case since I've compared analogue screen dimensions to digital screen dimensions, and they are 100% in the same position.

[Ross in the West]

That's really bizarre.  If your TV's correctly producing 16:9 in a letterbox from your DVD then I'd have to say it's probably looking like the STB's fault.

A couple of questions:

What connection is your STB using?  and
What connection is your DVD using?

If youre running the STB through another device it might cause problems.

Also I noticed the Topfield's 16:9 letterbox mode is slightly shifted upwards (perhaps to raise the eye-level of the user).  This, when coupled with poor s-correction could result in the lower part of the tube being stretched.  It's a long shot but I only mention it because I recently adjusted the s-correction on my set and noticed it was out by quite a bit.

Hi Ikari,
sorry for the late reply.
STB and DVD both using RCA (or composite (the yellow video wire)) because that is all my tv will take. I go from STB via the VCR to my TV, but I tried going direct to tv and it made no diff.
The latest news is, I took the STB to my friends house and it displayed a.... 15:9 picture, lol. That was using composite, Svideo and then component.
Anyway, sorry to cause such a brouhaha.
Like I said, I've accepted 14:9 so everything's ok.
Thanks for all the feedback.

[John_Barber]

Great info, John_Barber!  I assume you have some connections in the ABC - can you tell them to make more of their stuff 4:3 centre cut protect, in particular, Rage titles, so us non-widescreen TV owners don't have to keep missing song titles?
Cheers

I don't work for the ABC, they had a training course that myself and some colleagues attended.

I do know some people at the ABC, but not in the applicable area, and I wouldn't be telling them how to suck eggs, (I have enough trouble trying to tell my colleagues how to do so!)

You'd actually be better off contacting them directly.

Cheers

JB

[Santa]

Whoa! (IMG:style_emoticons/default/ohmy.gif)

Missed this thread and its fireworks - the bloody "My Topfield" part of the subject line drove me off! (IMG:style_emoticons/default/wink.gif)

Oh, well ... anyone want to renew their Flat Earth Society membership? (IMG:style_emoticons/default/tongue.gif)

[gclark8]

This topic is the reason the B/C engineer wrote the poem.

[Santa]

This topic is the reason the B/C engineer wrote the poem.

Yeah - I guessed that!

[pneu]

That's really bizarre.  If your TV's correctly producing 16:9 in a letterbox from your DVD then I'd have to say it's probably looking like the STB's fault.

A couple of questions:

What connection is your STB using?  and
What connection is your DVD using?

If youre running the STB through another device it might cause problems.

Also I noticed the Topfield's 16:9 letterbox mode is slightly shifted upwards (perhaps to raise the eye-level of the user).  This, when coupled with poor s-correction could result in the lower part of the tube being stretched.  It's a long shot but I only mention it because I recently adjusted the s-correction on my set and noticed it was out by quite a bit.

Hi Ikari,
sorry for the late reply.
STB and DVD both using RCA (or composite (the yellow video wire)) because that is all my tv will take. I go from STB via the VCR to my TV, but I tried going direct to tv and it made no diff.
The latest news is, I took the STB to my friends house and it displayed a.... 15:9 picture, lol. That was using composite, Svideo and then component.
Anyway, sorry to cause such a brouhaha.
Like I said, I've accepted 14:9 so everything's ok.
Thanks for all the feedback.

Ok, different amounts of overscan on different TV's, makes sense that the aspect ratio is going to vary a little from set to set.

The only thing I can say is, are you sure you're not comparing the STB's 16:9 letterbox to your DVD player with a movie that is in 1.85:1 letterbox?

[tonymy01]

So the original poster, does everything look a bit tall and skinny? If not, then why do you care what ratio you are viewing. You claim 14:9 which means, if the 16:9 TV program is a fullscreen 16:9 program, when the Toppy letterbox converts this to 4:3, things would look a bit tall and skinny if your measurements are correct.
Do you understand how letterbox conversion works? Let me explain it.
It throws away one horizontal line in every 4, which will make the image less high vertically, so it can add the black strips top and bottom.
So, 576/4=144 lines get thown away.
So 576-144=432 lines of image get displayed. Now typically there are 720 horizontal pixels.
720/432=1.6667.
1.6667*9=15.
So assuming square pixels, letterbox conversion of a fullscreen 16:9 image will give you a 15:9 picture in the middle of your 4:3 screen. Unfortunately I don't think the pixels are quite square, unless your TV overscan is more in one direction than another.
Certainly 720/576=1.25*9=11.25:9 picture, i.e not quite 4:3. So the scaling factor (or out of square pixel scale) looks to be around 1.0666. So 1.0666*15=16 aha, so throwing away one line in every 4 makes a 16:9 image into a 4:3 image with exactly the correct dimensions, assuming your display has the correct height and width adjustments.
The Toppy also slices off quite a few lines at the top and bottom of the image part of the letterbox, to try and eliminate all that VBI junk that creaps into the top few & bottom few lines of a broadcast, which is going to throw your millimeter perfect measurements out by 0.5% ;-)

edit:
My Loewe 4:3 TV supports a widescreen vertical compression mode (which is great to maintain maximum resolution of a widescreen image, and all happens automatically when connected by SCART or signalled with WSS in the VBI, both of which the Toppy sends). When I toggle the STB from 4:3 Letterbox to 16:9, the image on my Loewe is exactly the same height & width (apart from that blasted grey/white line that Loewes et al put just above the top of the image when doing this compression).

I'd say, like others, either something is very broken with one of your pieces of equipment, or you need to do some geometry adjustments on your TV. If you don't get the ruler out, but instead just enjoy the picture (esp if things DON'T look too tall and skinny), then I personally wouldn't fret over the whole thing.
Regards

[pneu]

Does tonymy01 always do this? (IMG:style_emoticons/default/blink.gif)

[John_Barber]

So assuming square pixels, letterbox conversion of a fullscreen 16:9 image will give you a 15:9 picture in the middle of your 4:3 screen.  Unfortunately I don't think the pixels are quite square, unless your TV overscan is more in one direction than another.
Certainly 720/576=1.25*9=11.25:9 picture, i.e not quite 4:3.  So the scaling factor (or out of square pixel scale) looks to be around 1.0666.   

Yep, TV pixels are well known to be "1.07":1 aspect. Most computer based editing systems have settings for this ratio, as does software such as Photoshop.

768 x 576 is the square pixel setting for 4:3 and 1024 x 576 for 16:9 WS.

Cheers
JB

[pargy]

[quote=Ikari,Dec 14 2004, 04:03 PM]
[quote=Ross in the West,Dec 13 2004, 11:01 PM]Thanks everyone for your input. And thanks Tony for giving such an in-depth answer.
Unfortunately I am still unable to fix the problem.
I leave the stb in 4:3 and toggle between letterbox (14:9 on my tv), and centre cut.
16:9 DVDs produce a 16:9 picture so that should mean my tv's geometry is ok, right?
PAL, NTSC, AUTO is set to auto (and I tried setting it to PAL, did not fix things).
My Sony does not have the vertical compression function, although it sounds like that would solve my problem (or at least be an adequate band aid).
I've accepted the 14:9 picture, but if anyone can think of anything else I might be overlooking I'd be happy to hear from you.

[/quote]

You've tried everything else, so perhaps this is worth trying. My Toppy box uses the 0 digit key as a 4:3, 16:9 and letter box toggle switch. Hitting it in succession makes it easy to perceive any display changes, even if they are relaviley small. If you pause on an image so you have a frozen frmae and then toggle though the three settings it might show you some differnces.

Just a thought.

By the way, I accidentally locked a recording on my Toppy and now it's asking for an unlock code which I haven't set anywhere - does anyone know the factory default PIN code to save me searcing the manual?

Thanks.

Philip

[scurvy]

On the 14:9 subject:

All the bigscreen (30" and 40") LCD flat panel displays I have used are native 14:9 displays as are the new 46" LCD panels. 16:9 doesnt exist in their menus so clearly there is some misinformation here.

As I understant it Its driven by the computer industry and the film industry.as they didnt really want 16:9 as a standard anyway. Traditional cinemas are not 16:9 . So it appears a 14:9 standard exists because it does.

Scurvy

[tonymy01]

So it appears a 14:9 standard exists because it does.

What a load of codswallop.
14:9 exists because great big black bars on 50cm 4:3 TV sets (any size 4:3 really) can upset their owners some what... So instead of letterboxing 16:9 into a 4:3 aspect with great big black bars, they compromise by halving the height of the black bars, and slicing a little bit off the sides (but not a huge amount off the sides like 4:3 pan and scan) and thus 14:9 was born as a compromise to show 16:9 formatted material on 4:3 TV sets without losing a large percentage of the screen real estate to black bars.
Regards

[TheTigers]

I have a 68cm 4:3 Sony TV and decided to get a set top box because I enjoy the 16:9 picture I get when watching dvds.
After hooking up the box I thought the picture looked not very widescreen so I measured it.
It is 54cm wide by 35cm high which is 14:9.
I was under the impression 16:9 should be being displayed.
I'm sure I've read that most people are able to get 16:9 on their 4:3 tv. Can someone please shed some light?
Thanks.

My Topfield TF5000PVRt is like that into the same 68cm Sony TV as letterboxed on a 4:3 TV screen.

If you watch WS program this way, you'll never get true 16:9 viewing as it is letterboxed for that TV.

Having black bars on the top and bottom means you're not getting real 16:9.

The only way to enjoy true WS is on a WS TV, plasma, LCD monitor having a true 16:9 measured screen and for the Toppy to send a 16:9 video aspect ratio into it.

I have another STB which is a HD Receiver and this one I can't get real HDTV either.

I'll have to get one, a 16:9 WS HDTV someday this year. (IMG:style_emoticons/default/smile.gif)

ChrisX