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teac dv-b420 4:3


Guest gumpystb

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Guest gumpystb

Hi. This is my first post here.

I have an NEC 4:3 TV and the Teac DV-B420 set top box.

If I select 4:3 on the set top box what I appear to get is a zoom into the widescreen picture which goes too far ie it shows less than the analogue picture but what it shows is bigger. To put it another way it is even as if it is zooming into the analogue picture.

If I select widescreen everything looks skinny and letterboxed widescreen is ok but I want to watch 4:3 with the exact same picture dimensions and zoom as the analogue picture.

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Hmm, the only thing I can think of is that your TV's geometry settings may be different for its A/V input channel (too much overscan). This would be highly unlikely though since geometry settings are usually specific to each display mode of the TV, so it's more likely your STB is the problem. The 420 does have a screen adjust feature, but no adjustment of the horizontal and vertical size. Teac should put this in a future software upgrade so us 4:3 viewers can minimise the amount of overscan (I posted this in another thread somewhere).

My advice would be to swap it for another 420 and see if it's fixed, if not, find out how to access your TV's service mode to adjust the screen size, or get a NEC technician to do this.

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I don't think so.

I have found that a lot of the stuff on the analog channels is something like 14:9 or similar now instead of 4:3.

This means when you put the STB into 4:3 mode you do actually get less picture than on analogue, due to the fact that you get a 4:3 image instead of a 14:9 image.

The only way I could see around it, is if there was a 14:9 mode on the STB (which there isn't) - sort of like a half zoomed in letterbox.

I have a w/s tv, so it's not a problem for me, but I did notice it when I was fiddling around with the different modes on the STB.

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Yes but the problem with it looking too zoomed in would only happen when he is comparing it to stuff on analogue which is in 14:9, and this is only about 50% of the time, possibly less (rough estimate).

I watch almost everything in 4:3 full screen and it looks very acceptable. About 95% of TV programs have their titles within the 4:3 frame and it definitely doesn't look too zoomed in. Movies are the main exception which in my opinion deserve to be watched in widescreen (unless they are running a pan&scan version of course) and sometimes look plain stupid when zoomed into 4:3.

Really, it shouldn't look too zoomed in in 4:3 full screen.

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Guest gumpystb

The main time when I noticed this is when I was watching the news. I thought there is too much head on the screen. So I flicked over to analogue and it looked normal.

I don't think it is the tv as the stb is going through my video. I will try changing it so it goes direct into the tv and see if that changes it.

I have the option of moving this stb to our widescreen tv. We have 4 kids in the family and bugger me the widescreen tv is in the rumpus.

I decided I watch more foxtel than dvds so we got a 68cm 4:3 tv.

We may end up just swapping tvs.

I will experiment a little and post back here.

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And I have seen some shonky TVs for overscan.... sometimes 14:9 is fullscreen on these TVs (i.e. the black strips top and bottom for 14:9 dissapears completely into the TV overscan!) Thus doing a 4:3 Center Cut of a 16:9 image on a STB will definitely look like it is "zooming" too much due to all the overscan compared to the 14:9 that the viewer is claiming is fullscreen.

Time to see if you can knock down the overscan of the TV a bit, this is normally in a hidden service menu with most modern TVs.

A STB doesn't do any fancy zooming by the way, it simply chops off the black strips on the left and right (if you are centre cutting a 4:3 on digital TV program, obviously it will chop off useful stuff if it is a fullscreen 16:9 proggy), and sends the image with 4:3 flags. So it isn't doing any vertical zooming at all, merely stretching the image horizontally and changing the aspect.

Set the STB to 16:9 to see that the height of the image is identical between 16:9 and 4:3 Centre Cut, this proves the only thing the box does is stretches it horizontally.

Regards

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That's true, most TV's have way too much overscan, but he has already compared 4:3 cropped digital to 4:3 analogue and noticed a difference which there shouldn't be. Of course if he would give us a reply and tell us whether he was comparing it to analogue 14:9 or not it would help :blink: . Most chances are that he would have already noticed analogue 4:3 looking too zoomed in on the TV before getting a STB and noticing a difference.

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Guest gumpystb

I am at work now so can't try anything just yet.

I tried a couple of different shows but did not remember them specifically.

When I get a chance I will experiment and note which channels I am checking and post again.

The show that I can definitely remember was Today Tonight. I have just looked in the tv guide and it says WS but does this mean it is only broadcast as WS so the STB has to crop rather than choose the 4:3 signal ?

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Today Tonight is 14:9 on analogue, so if you were comparing it to 4:3 on your STB it will definitly look slightly more zoomed in.

When you select 4:3 fullscreen on the 420 it crops the edges off. The digital broadcast is a 16:9 broadcast, there is no different 4:3 digital signal to tune in to.

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Guest gumpystb

Mini update.

I was watching the channel 7 news, digital, 4:3.

The cricket highlights came on and the text bar at the bottom that shows the score was half off the bottom of the screen.

I now see what is happening but am surprised that it zooms so far.

The way I am fixing it is by changing the aspect on the set top box to widescreen.

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I said this before, going to 4:3 centre cut does not zoom vertically. Compare 4:3 Centre Cut with 16:9,and notice that the height of the image is identical (unless of course you have a 4:3 TV that understands 16:9 flags and does vertical compression to correct the aspect ratio).

Setting the STB to 4:3 Letterbox (or 4:3 widescreen) does the same thing as a DVD player set to this aspect, it removes one line in every 4 to vertically compress the image to correct its aspect from 16:9 to 4:3letterbox, and adds black strips to the top and bottom of the screen.

This certainly will ensure you get the whole program, of course if the broadcast is pillarboxed (black strips on the sides that the broadcaster adds to turn 4:3 into 16:9), then this will look bad on a 4:3 TV as it has black strips all the way around the image. So your only choice is to toggle to 4:3 Centre Cut, and then you get to watch it in fullscreen.

But definitely your TV is cutting off a fair bit of the broadcast, the STB is NOT zooming it to cut this stuff off the top and bottom, it is the TV doing it.

Regards

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Guest gumpystb

On the one hand I am new to this so go easy.

Let me ask another question.

When watching channel 7 news on digital do I have to set the stb to widescreen and then when the kids watch cartoons in the morning set it back to 4:3. This is what I ended up doing but find it frustrating and in my mind it should be easy to design a product to avoid this but anyway - is this what I need to do to see everything on my screen ? Is this what you are saying tonymy01 ?

Lets ignore the fact I am comparing to analogue.

I am watching the channel 7 news when the cricket comes on with the text bar at the bottom. Why is it that I only see half of the text bar ? I would have expected to see 100% of the vertical image but only 85% of the horizontal image. Instead I appear to get maybe 90% of the vertical image and less than 80% of the hoizontal image. tonymy01 the centre cut process does not zoom vertically ie all it does is cuts the black bars top and bottom and about 8% on either side but somewhere I am losing part of the vertical image.

I have just had a thought - does the stb think it has a 16:9 image when it actually has a 14:9 image. That would explain the problem I am having. With 16:9 it needs to cut more off horizontally. This would cut too much off a 14:9 image. If either the tv or stb then tries to fill the screen it needs to zoom vertically.

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He's right, it is due to the way ch7 are getting and/or choosing to display the footage.

Watch a variety of shows on every channel and you should see that 4:3 will look more than acceptable for about 95% of the content.

The digital broadcast is a 16:9 area, period. Whether the broadcaster decides to fill all of this picture up (either horizontally or vertically) is up to them. Just because you've set it to 16:9 or 4:3 doesnt mean all of that area will always be filled with an image in the correct format. An example of this is TV commercials where they've recorded it in widescreen 16:9 but it's within a 4:3 frame (ie not anamorphic), so on 4:3 fullscreen it looks fine, but in the STB's 16:9 mode it will look like zoomed out crap. You're never gonna always get a full perfect frame of maximum quality video 100% of the time. Just choose the best one for your TV (personally I would leave it in 4:3 for a 4:3 TV) and stick with it.

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gumpystb, you haven't tried the experiment that I asked you to do, and that is to try your STB in 16:9 mode, then swap it to 4:3 Centre Cut mode, and see that the height of the image is identical, proving that 4:3 centre cut doesn't do a vertical zoom at all. The only vertical zooming the STB actually does is a SHRINK, not a zoom. In 4:3 Letterbox mode, it vertically shrinks the 16:9 image, and puts black strips top and bottom to correct the aspect of the 16:9 image. This 16:9 image would normally look too tall and skinny if you kept the setting of your STB at 16:9 on a 4:3 TV, so when you set the STB to letterbox mode, this fixes the tall skinny look by removing bits to shrink it down to the middle.

I maintain that your problem is too much TV overscan. Just go into any store that sells a lot of TVs with the same image showing on each TV, and look at the position of, say, the watermark with each of the TVs. Notice how some chop off more than others? This setting is normally achieved in a hidden service menu, a bit like the menu on your PC monitor, and as you can see by the many varied TVs overscanning WAY too much image, looks to be due to hurried manufacturing and quick "yep, it is showing an image, overscan is less than 20%, she'll be right" attitude that all the manufacturers seem to take!

The reason you see the text perfectly in 4:3 letterbox mode, but not in 4:3 centre cut mode, is that in 4:3 letterbox mode, the only part of the image dissapearing off the edge of the visible area of your picture tube is the black strips. So the text that would normally be at the bottom of the frame in 16:9/4:3 centre cut mode is moved up to the screen as your STB converts the 16:9 to letterbox (by removing one horizontal line in every 4 to get enough of the image removed so it doesn't look tall and skinny).

Getting to your "does the stb think it has a 16:9 image when it actually has a 14:9 image"... ALL digital TV broadcast in Australia is 16:9 (with the exception of D44-EXPO). There is NO 14:9 mode for digital TV. Digital TV is 16:9, period. It is up to the end user to manually swap the aspect to suit the broadcasted material (a bit unfortunately really, they could have sent 4:3/16:9 flags instead, and then it would automatically switch, but this would involve too much intelligence and switching back at the broadcaster, and also requires that all STBs are DVB compliant with respect to aspect flags, and apparently not all are!)

Most STBs have aspect ratio buttons, to save you going into the menu system all the time, you are going to have to get used to pressing this button. The reason you would use the button is when the broadcasters send pillarboxed (black strips on the sides) material, so you can slice off the black bits and fill the screen with true 4:3. You would toggle to letterbox mode when watching fullscreen (widescreen without the pillarboxing) TV.

My aspect button gets a very good workout still while there is still so much pillarboxed material sent in this country (4:3 material that is aspect corrected to 16:9 by the broadcasters by horizontally shrinking the image and putting black bits on the sides).

Regards

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Guest gumpystb

I don't believe overscan is the issue. I have now seen shows with 4:3 as the natural mode and it comes out perfect. Digital and analogue pictures are the same.

If overscan was an issue wouldn't I be missing the bottom part of every image ? When I watch the cricket on foxtel I see all of the text bar, when I watch analogue I get all of the text bar but when I watch digital I miss part of it.

tonymy01 - On my stb the modes I have are 4:3 Letter box with black strips top and bottom on my tv for widescreen programs and side as well for 4:3 programs, 16:9 full screen with everything squashed horizontally and 4:3 full screen.

When I switch from 16:9 to 4:3 full screen the vertical image does not change. When I switch from there to 4:3 letterbox the image shrinks vertically but has slightly more to it at the top and bottom ie you see stuff that you did not see on the other images (I just did this and I would assume that it is a widescreen show as when I did it with cartoons this did not happen ie all modes provided the same amount of vertical image just changing the size)

If the aspect button is the answer then so be it but I am still surprised that for 16:9 images that it does not cut strips off the sides of the image and then fit the rest in the fullscreen.

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You have proved my point, 16:9 and 4:3 "full screen" are the same height, there is NO loss or vertical zooming with 4:3 full screen.

All material is broadcast 16:9 (did you see I stressed that point in my last post).

This means that the flags etc are also 16:9. The only difference between a pillarboxed image and a widescreen image is that the pillarboxed image has black bits "burnt" into it on the sides. There is no different flags, the flags are always 16:9. So the human interface has to deal with it, i.e. you pressing the aspect key on your remote.

The reason there is "slightly more to it top and bottom" for a letterboxed image IS due to your TV overscan. Your TV overscan is fixed, it doesn't change in the various STB modes. You just don't notice the overscan when in letterbox mode because your TV is only overscanning black bits (talking about top and bottom here, let's ignore left and right for this discussion, as it stemmed from you complaining about losing a text/info line on the bottom of the screen).

All TVs have overscan, it all depends on how much. If you are missing bits of writing, then I am afraid to tell you that your TV overscan *is* too much.

The only reason, when you compared "fullscreen" to the analogue broadcast and noticed that the analogue broadcast didn't chop off the writing on that comparison you did is that often the analogue broadcast doesn't take a 4:3 centre cut (or as you say your option is, "full screen") of widescreen material. It also doesn't fully letterbox 16:9 material, as too many people would complain about the dirty big black strops top and bottom on analogue (you know, the people who have no idea about what widescreen is really offering them). So the broadcasters take a compromise image for analogue if the source is meant to be widescreen, doing a little bit of slicing off of the sides, and only a little bit of letterboxing. This is called a 14:9 cut, and the black strips on analogue are far less obvious (especially if your TV has a dirty large amount of overscan, sometimes the black strips are almost totally hidden away in overscan on some TVs I have seen showing broadcasted 14:9 material!)

Regards

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Guest gumpystb

Tonymy01

Why is it then that overscan does not stuff up foxtel text bars ie on the cricket ? Does that mean that the foxtel image is slightly shorter than the digital fta image ?

If I did get to the hidden menu and reduced overscan would that result in vertically shrinking all other sources ie foxtel, analogue, videos etc

If so then I will choose the aspect button as the solution.

From your response I assume what I am getting is not normal as you are suggesting there is a fault or calibration issue that is causing it.

Does overscan affect both vertical and horizontal or only vertical ?

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The reasons some text isn't getting chopped off for you is:

1. Most stuff is shot/overlayed with safe areas that shouldn't have important stuff in it, as all TVs have *some* overscan. However, I guess that if your overscan is say, 12% per edge rather than 5%, then you may start losing the edges of 4:3 broadcasts where they push the writing right to the edge of this "safe" area.

2. You may be watching a 14:9 analogue image (where it has small black strips top and bottom).

Also, like I have said in a previous message on this thread, overscan is normally on all 4 edges. We have been focussing on the bottom (and I suppose the top) in this thread, because this was the contention we are trying to discuss (as trying to explain why letterbox doesn't have this problem for you is due to letterbox mode *shrinking* the vertical height of the image).

I don't know how to adjust your TV, google my friend. If you do manage to get in there, be very very very careful about which settings you fiddle with. You only really want to change vertical height, vertical position, horizontal height, horizontal position settings. Write down EVERY setting before you start.

Don't try and adjust all the overscan out to the nearest mm, as quite often there is junk on the top and bottom few lines of a broadcast (out of the 576lines), and junk on the left/right. Overscan is also there so you don't seen any nasty edge non-linearities (where the edge can look wobbly/not straight), so leave a little bit there.

Regards

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I think he's comparing cricket on 4:3 foxtel to recorded file footage of the same cricket footage as shown on 7 news analogue that they've cropped to 14:9 (ie. sliced the top and bottom off), and comparing it with digital cropped 4:3 of the 7 news already-cropped 14:9 picture.

I don't believe overscan is the issue. I have now seen shows with 4:3 as the natural mode and it comes out perfect. Digital and analogue pictures are the same.

This means overscan isn't a problem, probably not worth tampering with if theres nothing wrong with the current setting.

It's ch7, I think they cropped the foxtel 4:3 footage to a 14:9 frame by slicing the top and bottom off. This is highly unorthodox and I've seen them do this before with their footage, it looks zoomed in, and will look even more so on digital cropped to 4:3.

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Guest gumpystb

What I am going to do is watch a foxtel show and use the tvs shrink mode (I think it is 16:9) to see if anything is missing at the edges of the picture. If so I may do something about overscan. If not I will just use the aspect button on the remote.

The tv's modes just do vertical shrink and expand. When watching fta channels it needs to be 4:3 because 4:3 expand makes things look tall and skinny, whereas 16:9 makes them look short and fat.

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