TV Aspect Ratios... question ?

advid · 14-04-2011, 13:23

I've got a 42" Toshiba 'HD READY' (not a full 1080p) TV....

When I plug in my PC to the TV I can get full screen coverage (edge to edge) with a setting of 1280 x 768. The Aspect ratio is correct with circles being perfectly round ect.

When I play BBC iPlayer stuff at 'full screen' setting I get a black line at the top and bottom of the screen aprox 25/30mmm... Why do I not get 'full screen'...? I'm sure faces and circles ect are slighly squashed and it bugs me as I'm annoyed when things are not in their absolutely correct aspect ratio...

Would I also get this if my TV was a full 1080p set ?

(I've used both the D-sub and HDMI on my PC for connection to the TV)

tellytart1 · 14-04-2011, 13:34

Because 768 isn't a valid HD resolution, so iPlayer is putting the bars top and bottom to make the picture 1280x720

advid · 14-04-2011, 14:44

Quote:

Originally Posted by tellytart1

Because 768 isn't a valid HD resolution, so iPlayer is putting the bars top and bottom to make the picture 1280x720

....OK..thanks.that explains it...

However - I can 'Force' my non-'FULL HD' TV to 1080p
(1920 x1080) using the settings on the PC's HDMI card...

Will this do any 'long term' harm to the TV as it's not supposed to do that hi-res mode..(Or does it 'downscale' internally to suit when it get a full 1080p signal) ?

It works but is it doing any damage to the TV..??

tellytart1 · 14-04-2011, 14:48

It'll internally downscale the image to the native resolution of the display.

It won't do it any damage.

advid · 14-04-2011, 16:02

Quote:

Originally Posted by tellytart1

It'll internally downscale the image to the native resolution of the display.

It won't do it any damage.

....many thanks..picture looks slightly better using this full format...perhaps the TV 'downscaler' is doing its job well ?

Only problem at this res is the tiny icons and text on screen...very hard to read....

Not sure of settings in windows to enlarge them - I know where to find them (desktop / properties) but not sure which ones to enlarge or alter...

Why though does the web (Google ect) do totally full screen edge to edge if its not a standard res. and BBC iPlayer and ITV and others scale down to give black bars top and bottom ?

PlayerUK · 14-04-2011, 16:40

Web pages are not usually a fixed vertical size (hence why you have scroll bars). Video has specific horizontal and vertical sizes.

If you keep the aspect ratio locked so that the picture doesn't distort, the upscaler/downscaler will adjust the video size until the largest parameter is at the edge of the screen, be that horizontally (such as cinemascope) or vertically constrained (such as 4:3 on a widescreen TV).

chrisjr · 14-04-2011, 16:42

Quote:

Originally Posted by advid

Why though does the web (Google ect) do totally full screen edge to edge if its not a standard res. and BBC iPlayer and ITV and others scale down to give black bars top and bottom ?

I think you are confusing Broadcast Video resolution with Display Screen resolution. The two are not necessarily related.

Display Screen resolution can be any number of pixels wide and high you like. But video material, especially that sourced from broadcast TV originally, has a limited number of resolutions it can display in.

So you can quite legitimately have a screen resolution that is not a standard broadcast resolution. Which is what you have with your TV. If you then display a broadcast video on that display one of two things can happen.

It can scale the image to fit the screen resolution. Or it can display the video in it's original resolution and add black bars as necessary to fill in the gaps (as it were).

The latter is what is happening when you display an iPlayer video or similar. However applications such as a web browser or word processor or whatever don't have a "size" as such. They simply use whatever bit of screen real estate you let them use. if you let them use full screen then they will.

emptybox · 14-04-2011, 23:18

What is the exact resolution of your TV screen?

You will get the best results if you can match the output from the graphics card to that.

14-04-2011, 13:23	#1
advid Forum Member Join Date: Sep 2003 Posts: 560	TV Aspect Ratios... question ? I've got a 42" Toshiba 'HD READY' (not a full 1080p) TV.... When I plug in my PC to the TV I can get full screen coverage (edge to edge) with a setting of 1280 x 768. The Aspect ratio is correct with circles being perfectly round ect. When I play BBC iPlayer stuff at 'full screen' setting I get a black line at the top and bottom of the screen aprox 25/30mmm... Why do I not get 'full screen'...? I'm sure faces and circles ect are slighly squashed and it bugs me as I'm annoyed when things are not in their absolutely correct aspect ratio... Would I also get this if my TV was a full 1080p set ? (I've used both the D-sub and HDMI on my PC for connection to the TV)

14-04-2011, 14:44	#3
advid Forum Member Join Date: Sep 2003 Posts: 560	reply -from originator of this thread... Quote: Originally Posted by tellytart1 Because 768 isn't a valid HD resolution, so iPlayer is putting the bars top and bottom to make the picture 1280x720 ....OK..thanks.that explains it... However - I can 'Force' my non-'FULL HD' TV to 1080p (1920 x1080) using the settings on the PC's HDMI card... Will this do any 'long term' harm to the TV as it's not supposed to do that hi-res mode..(Or does it 'downscale' internally to suit when it get a full 1080p signal) ? It works but is it doing any damage to the TV..??

14-04-2011, 16:02	#5
advid Forum Member Join Date: Sep 2003 Posts: 560	reply -from originator of this thread... Quote: Originally Posted by tellytart1 It'll internally downscale the image to the native resolution of the display. It won't do it any damage. ....many thanks..picture looks slightly better using this full format...perhaps the TV 'downscaler' is doing its job well ? Only problem at this res is the tiny icons and text on screen...very hard to read.... Not sure of settings in windows to enlarge them - I know where to find them (desktop / properties) but not sure which ones to enlarge or alter... Why though does the web (Google ect) do totally full screen edge to edge if its not a standard res. and BBC iPlayer and ITV and others scale down to give black bars top and bottom ?

14-04-2011, 13:34	#2
tellytart1 Forum Member Join Date: Sep 2003 Location: London Posts: 3,638	Because 768 isn't a valid HD resolution, so iPlayer is putting the bars top and bottom to make the picture 1280x720

14-04-2011, 14:48	#4
tellytart1 Forum Member Join Date: Sep 2003 Location: London Posts: 3,638	It'll internally downscale the image to the native resolution of the display. It won't do it any damage.

14-04-2011, 16:40	#6
PlayerUK Forum Member Join Date: Dec 2009 Posts: 702	Web pages are not usually a fixed vertical size (hence why you have scroll bars). Video has specific horizontal and vertical sizes. If you keep the aspect ratio locked so that the picture doesn't distort, the upscaler/downscaler will adjust the video size until the largest parameter is at the edge of the screen, be that horizontally (such as cinemascope) or vertically constrained (such as 4:3 on a widescreen TV).

14-04-2011, 16:42	#7
chrisjr Forum Member Join Date: May 2004 Location: Reading Posts: 27,916	Quote: Originally Posted by advid Why though does the web (Google ect) do totally full screen edge to edge if its not a standard res. and BBC iPlayer and ITV and others scale down to give black bars top and bottom ? I think you are confusing Broadcast Video resolution with Display Screen resolution. The two are not necessarily related. Display Screen resolution can be any number of pixels wide and high you like. But video material, especially that sourced from broadcast TV originally, has a limited number of resolutions it can display in. So you can quite legitimately have a screen resolution that is not a standard broadcast resolution. Which is what you have with your TV. If you then display a broadcast video on that display one of two things can happen. It can scale the image to fit the screen resolution. Or it can display the video in it's original resolution and add black bars as necessary to fill in the gaps (as it were). The latter is what is happening when you display an iPlayer video or similar. However applications such as a web browser or word processor or whatever don't have a "size" as such. They simply use whatever bit of screen real estate you let them use. if you let them use full screen then they will.

14-04-2011, 23:18	#8
emptybox Forum Member Join Date: Mar 2006 Location: Scottish Borders Posts: 11,995	What is the exact resolution of your TV screen? You will get the best results if you can match the output from the graphics card to that.

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TV Aspect Ratios... question ?