NG
noggin
Founding member
Loads of issues here :
1. Almost all TVs - whether LCD, Plasma, DLP or CRT - all still implement overscanning by default (either simulated or actual). Some displays can have this inhibited BUT many will only do this when fed their native resolution. (My Sony 1920x1080 Full HD panels will only inhibit overscan when fed 1080i or 1080p - so 720p and 576i/p sources are still slightly overscanned - and by default very overscanned).
Therefore you have to take overscan into account when devising "graphics safe" areas. And broadcasters official safe area grids DO take this into account. ISTR that the BBC News Channel are a bit "optimistic" though - and a lot of CRTs lose the clock and ticker at least partially...
2. Whilst broadcasters still broadcast an SD service - they have to consider that there are SD viewers watching on 4:3 displays. Almost all digital TV set-top boxes default to 4:3 centre-cut on widescreen broadcasts - though some of the better Freeview boxes will follow AFDs (and thus switch between 4:3 CCO, 14:9 letterbox and 16:9 letterbox on a show-by-show basis) - so it is a fair assumption that a significant number of viewers are watching 4:3 full-screen images. Therefore the broadcast graphics safe areas for 14:9 safe productions are actually within 4:3 picture area (though they would not be conservatively safe in 4:3 CCO mode)
This is pretty important for graphics - as it would be pretty disastrous if the "NOT" of "NOT GUIILTY" were cropped on a graphic, or similarly the small print of an advert became misleading.
Sure - HD content that won't be broadcast in SD can ignore 14:9 safe (though I suspect most broadcasters won't - unless like Sky News HD they can render different versions of their graphics live on transmission) - but you still have to consider 16:9 graphics safe as you should expect your HD broadcast to be overscanned by most domestic displays.
I'd say most HD Ready TVs being fed an HD signal are overscanning - either because they can't have overscanning disabled, or because they default to overscan on and most users don't realise...
1. Almost all TVs - whether LCD, Plasma, DLP or CRT - all still implement overscanning by default (either simulated or actual). Some displays can have this inhibited BUT many will only do this when fed their native resolution. (My Sony 1920x1080 Full HD panels will only inhibit overscan when fed 1080i or 1080p - so 720p and 576i/p sources are still slightly overscanned - and by default very overscanned).
Therefore you have to take overscan into account when devising "graphics safe" areas. And broadcasters official safe area grids DO take this into account. ISTR that the BBC News Channel are a bit "optimistic" though - and a lot of CRTs lose the clock and ticker at least partially...
2. Whilst broadcasters still broadcast an SD service - they have to consider that there are SD viewers watching on 4:3 displays. Almost all digital TV set-top boxes default to 4:3 centre-cut on widescreen broadcasts - though some of the better Freeview boxes will follow AFDs (and thus switch between 4:3 CCO, 14:9 letterbox and 16:9 letterbox on a show-by-show basis) - so it is a fair assumption that a significant number of viewers are watching 4:3 full-screen images. Therefore the broadcast graphics safe areas for 14:9 safe productions are actually within 4:3 picture area (though they would not be conservatively safe in 4:3 CCO mode)
This is pretty important for graphics - as it would be pretty disastrous if the "NOT" of "NOT GUIILTY" were cropped on a graphic, or similarly the small print of an advert became misleading.
Sure - HD content that won't be broadcast in SD can ignore 14:9 safe (though I suspect most broadcasters won't - unless like Sky News HD they can render different versions of their graphics live on transmission) - but you still have to consider 16:9 graphics safe as you should expect your HD broadcast to be overscanned by most domestic displays.
I'd say most HD Ready TVs being fed an HD signal are overscanning - either because they can't have overscanning disabled, or because they default to overscan on and most users don't realise...
IS
They may have the ability - my set, a series 7 Samsung, doesn't allow you to see the whole frame unless you're feeding it a 1080i signal. I'm sure there are plenty of people out there with HD sets but SD STBs.
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
Quote:
as almost everyone has the ability to see the whole 16:9 frame
They may have the ability - my set, a series 7 Samsung, doesn't allow you to see the whole frame unless you're feeding it a 1080i signal. I'm sure there are plenty of people out there with HD sets but SD STBs.
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
DJ
To the OP - if you can find a service manual for your TV, and you're comfortably adept at rooting around the hidden
settings that only technicians would usually understand, you may be able to eliminate the overscan issue altogether.
Be careful though, it can be all too easy to screw up the display on your TV using the hidden technician settings.
That said, back in 2003, I managed to eliminate about 99% of the overscan on a (now 10 year old) Thomson CRT
widescreen TV, and it's possible to view the full picture on all 16:9 broadcasts and downloaded 16:9 video files.
settings that only technicians would usually understand, you may be able to eliminate the overscan issue altogether.
Be careful though, it can be all too easy to screw up the display on your TV using the hidden technician settings.
That said, back in 2003, I managed to eliminate about 99% of the overscan on a (now 10 year old) Thomson CRT
widescreen TV, and it's possible to view the full picture on all 16:9 broadcasts and downloaded 16:9 video files.
DA
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA, but a 576i signal, such as would be generated by an SD STB (whether it's 4:3 or 16:9, that's just a flag) will, on most if not all TVs of any type, be displayed with some overscan cropped out. Broadcasters know this, though, and shoot (and generate graphics) accordingly.
David
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA, but a 576i signal, such as would be generated by an SD STB (whether it's 4:3 or 16:9, that's just a flag) will, on most if not all TVs of any type, be displayed with some overscan cropped out. Broadcasters know this, though, and shoot (and generate graphics) accordingly.
David
DB
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA,
Full Height Anamorphic
http://en.wikipedia.org/wiki/Anamorphic_widescreen
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA,
Full Height Anamorphic
http://en.wikipedia.org/wiki/Anamorphic_widescreen
IS
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA, but a 576i signal, such as would be generated by an SD STB (whether it's 4:3 or 16:9, that's just a flag)
Yes, that's FHA - Full Height Anamorphic, in this case a 576 line SD video signal containing a 16:9 image. If you view it on a 4:3 screen it'll look tall and thin, if you view it on a 16:9 screen it looks correct. As you say the TV set cannot tell if the image is 4:3 or 16:9, except with a flag either signalled on the SCART or in the VBI.
Looking back at your original post, is it that your TV presents the SD signal from the STB as a 4:3 image or is it just the underscan you don't get?
Eh? even if your STB is outputting a 16:9 FHA image, it won't show you the whole thing?
I don't know what you mean by FHA, but a 576i signal, such as would be generated by an SD STB (whether it's 4:3 or 16:9, that's just a flag)
Yes, that's FHA - Full Height Anamorphic, in this case a 576 line SD video signal containing a 16:9 image. If you view it on a 4:3 screen it'll look tall and thin, if you view it on a 16:9 screen it looks correct. As you say the TV set cannot tell if the image is 4:3 or 16:9, except with a flag either signalled on the SCART or in the VBI.
Looking back at your original post, is it that your TV presents the SD signal from the STB as a 4:3 image or is it just the underscan you don't get?
OV
I can't say I've seen that problem on the CRTs I have, the graphics fit on screen quite comfortably. First thing I would check is the aspect ratio setting the TV is on, as it may have accidentally been switched to one of the zoom modes.
It might help if you tell us what brand of CRT you have.
It might help if you tell us what brand of CRT you have.
E1
E180
I can't say I've seen that problem on the CRTs I have, the graphics fit on screen quite comfortably. First thing I would check is the aspect ratio setting the TV is on, as it may have accidentally been switched to one of the zoom modes.
It might help if you tell us what brand of CRT you have.
It might help if you tell us what brand of CRT you have.
It's a Sanyo CE28WN7-B and I've checked to see if it's zoomed by accident and it isn't. The colour setting is a little too saturated for my liking, but I can't change it because I've lost the remote control. I change channel with the sky remote.
IT
Well that could be why then - it's stuck in a zooming aspect ratio option, and you don't have a remote to deactivate it.
It's a Sanyo CE28WN7-B and I've checked to see if it's zoomed by accident and it isn't. The colour setting is a little too saturated for my liking, but I can't change it because I've lost the remote control. I change channel with the sky remote.
Well that could be why then - it's stuck in a zooming aspect ratio option, and you don't have a remote to deactivate it.
BO
I notice that a lot of programmes that originate from European broadcasters are now using the full-frame. I.e. Wallander on BBC Four (Swedish) and that uses text and graphics on the full frame, German football on ESPN uses the full screen and so on...
If you watch the likes of Sweden's SVT, nearly every programme appears to ignore the 4:3 and 14:9 safe-areas.
If you watch the likes of Sweden's SVT, nearly every programme appears to ignore the 4:3 and 14:9 safe-areas.