Widescreen TV

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Gavin Scott
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This is maybe a silly thing to ask all these years after widescreen has become commonplace, but as I now have a widescreen telly, my question is this:

What shape is the native picture being delivered to my screen?

When I change channel, my TV starts displaying a 16:9 picture in a 4:3 aspect ratio. Obviously the pictures look stretched tall, but they are pin-sharp. When the TV detects that it should be a widescreen image then it stretches out to fill the screen, but looks a fair bit softer in the process.

Is 16:9 TV actually an anamorphic 4:3 image "stretched"? In which case, isn't the horizontal resolution compromised as a result?
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Gavin Scott
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So if SD image capture and broadcast remains natively 4:3, why was there the great push to widescreen all those years ago, and was it driven by set manufacturers (because they could), or by broadcasters because of the aesthetic of that shape of picture?
Inspector Sands
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Electrically 16:9 anamorphic and 4:3 SD video is identical - they can be handled by the same equipment without adjustment. The only difference is how the image was originated.

When the video is displayed, it just gets stretched or squeezed to fit the shape of the screen. I'm not too hot on the horizontal resolution but IIRC it has something to do with the shape of the pixels.


I think there was/is an issue with the horizontal resolution on some 4:3 material. Not sure if it's still the case but in the old BBC TX areas all 4:3 video was converted to widescreen by adding pillars to both sides of the image. This meant that when it was transmitted on D-Sat or analogue these pillars were cut off again, thus you lost a lot of the original resolution. (DTT was different as that took the whole frame, pillars and all and the set-top box got rid of them if needed... but you still had a lower horizontal resolution)
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Gavin Scott
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Inspector Sands wrote:Electrically 16:9 anamorphic and 4:3 SD video is identical - they can be handled by the same equipment without adjustment. The only difference is how the image was originated.

When the video is displayed, it just gets stretched or squeezed to fit the shape of the screen. I'm not too hot on the horizontal resolution but IIRC it has something to do with the shape of the pixels.


I think there was/is an issue with the horizontal resolution on some 4:3 material. Not sure if it's still the case but in the old BBC TX areas all 4:3 video was converted to widescreen by adding pillars to both sides of the image. This meant that when it was transmitted on D-Sat or analogue these pillars were cut off again, thus you lost a lot of the original resolution. (DTT was different as that took the whole frame, pillars and all and the set-top box got rid of them if needed... but you still had a lower horizontal resolution)
I see. So from that would I be correct is saying that those channels who are not yet broadcasting in widescreen are offering higher resolution 4:3 programmes than the BBC?
Inspector Sands
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Gavin Scott wrote: I see. So from that would I be correct is saying that those channels who are not yet broadcasting in widescreen are offering higher resolution 4:3 programmes than the BBC?
That certainly was the case years ago. It's very possible that things have changed now though in the new Red Bee centre, I know that they now accept 4:3 material on digi whereas it used to be D3 for 4:3, Digi for 16:9

Unless everything swimming round the playout facility was the same shape it makes things a lot more complicated, especially in the early days of widescreen.
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nodnirG kraM wrote:In short, yes it is. Most widescreen broadcasts and storage media will have a non-square pixel 4:3 image resolution. Sky for example is 720x576 (except ITV), which will be stretched to 16:9 - by comparison, the true PAL 16:9 square pixel size should be 1024x576. I believe ITV broadcasts 544x576, or thereabouts, which means that a 16:9 programme on ITV1 will have its vertical pixels almost doubled to make up the picture.
Channel 4 is also guilty of the 544x576 mushiness on DSat, although their bitrate is higher than ITV, so it looks a bit sharper. In fact, it seems other than the BBC and Five, there's little on Sky at full SD resolution. Some of the UKTV channels in particular look bloody awful.

I guess in the early days of Sky Digital, the 544x576 compromise was less of an issue, but with more people watching on much bigger TVs now, it's very noticeable.

From what I understand, the 16:9 format originally came about as an agreed standard for HD, and the UK is one of only a handful of countries which broadcasts 16:9 SD. Many, like America, only broadcast widescreen in HD. So I suppose the anamorphic nature of widescreen SD pictures is a bit of a workaround in order to accommodate them using the existing infrastructure developed for 4:3. You have to go for HD if you want a full non-stretched picture with square pixels... although I understand BBC HD broadcasts at less than full HD res.
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Gavin Scott wrote:This is maybe a silly thing to ask all these years after widescreen has become commonplace, but as I now have a widescreen telly, my question is this:

What shape is the native picture being delivered to my screen?
It doesn't seem such a silly question after reading the responses from 'those in the know' on this thread, Gav.

Perhaps I can console myself in that the widescreen TV I bought in 2005 has freeview built in, which is always a nice supplement to Sky, and the fact that my previous main telly had 'died'. Otherwise, perhaps, I would feel a little cheated that on purpose I've now got a more naff resolution than before!
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marksi
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It amazes me that Discovery networks continue to broadcast their European channels in 4:3, given that the majority of their programming is available in 16:9 and then letterboxed to some extent on their output.

In addition, I'd guess from the look of it that Discovery is broadcasting in ITV-style sub-SD quality of 544x576, part of which is black because of the letterboxing.

This means you have a transmitted viewable picture which has a resolution not much in excess of the screen size of my mobile phone.
nwtv2003
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Euronews' letterboxing is rather annoying, considering all of the output they recieve is in 4:3 they go and put it in a rather dodgy looking 14:9, not too bad on a 4:3 set, but when you have a Widescreen set that will put the picture in 4:3 mode, it looks pants.

If they have 16:9, transmit 16:9, if not leave it at good old 4:3.
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marksi
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nwtv2003 wrote:Euronews' letterboxing is rather annoying, considering all of the output they recieve is in 4:3 they go and put it in a rather dodgy looking 14:9, not too bad on a 4:3 set, but when you have a Widescreen set that will put the picture in 4:3 mode, it looks pants.

If they have 16:9, transmit 16:9, if not leave it at good old 4:3.
With the overscan off you can see past the edges of the black rectangles they're covering 40% of the picture with.
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I hate Discovery Channel; before they were showing 4:3 programmes stretched on my TV to widescreen, now they're zooming 4:3 programmes to 16:9!
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