INTERACT FORUM

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: DVI to HDMI tv-out overscan problems. Any help appreciated.  (Read 15569 times)

marko

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 9124

our TV died this weekend. deep joy :D
While we could have done without purchasing a new TV, buying new toys like TV's turns me on a lot more than buying a new sofa, if you know what I mean ;)

Anyhoo, after a whistle-stop tour of review sites, we bought a 32" Sony Bravia LCD TV and very nice it is too.

I'm seriously considering ditching our VirginMedia cable TV package. The picture quality is really quite poor in comparison with the freeview digital channels coming in via a 15 year old ariel up on the roof somewhere, which is producing absolutely stunning picture quality. The cable pictures are something akin to an over-compressed XviD movie :( Perhaps Sky Digital offers better picture quality...

Of primary concern atm, and the main reason for this post, is MC and theatre view on this TV.

I've connected the TV and the PC using the second DVI port on my evga 8800 GTX card and one of the HDMI inputs on the TV. Resolution is set at 1920 x 1080 and things look superb.
The problem is that I'm getting what I'd describe as cropping.
If I place MC maximised in standard view on the TV, I cannot see the top toolbar or the bottom status bar, and at the sides, it cuts off all but a fraction of the 'previous' button and most of the search field.

empty desktops:


with MC on the TV:

as you can see, it's all there, but for some reason, it's not all showing? The highlighted area is what I actually see.

The WOW factor of our new TV has kind of faded a little because of this, theatre does not look nice with this cropping going on :(
I cannot work out why this is, and have had no joy with my attempts to correct the problem.
Can anyone out there help me out with a solution?

As far as display driver settings are concerned:
The desktop has been extended onto the second display (aka the TV)
The two displays are in 'Dual View' mode (settings independant of each other)
They are both using 32 bit colour
the primary monitor is running @ 1680 x 1050 with a 60 Hz refresh rate
the TV is running @ 1920 x 1080 with a 50 Hz refresh rate

-marko.

EDIT:Changed thread title as it would appear that my problem is something rather common called "overscan"

raym

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 3583
Re: DVI to HDMI tv-out cropping problems. Any help appreciated.
« Reply #1 on: July 09, 2007, 10:36:48 pm »

Quote
theatre does not look nice with this cropping going on


Take a look at the Overscan setting under the advanced options for Theater View. This may help correct some of what you're seeing. Worth a try....
Logged
RKM Smart Home - www.rkmsmarthome.com.au
Z-Wave Home Automation

marko

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 9124
Re: DVI to HDMI tv-out cropping problems. Any help appreciated.
« Reply #2 on: July 10, 2007, 06:33:59 am »

Worth a try indeed. I'd had a look there yesterday, wound up with a blank screen and figured I'd broke something... I think I must have hit ctrl+5 instead of 4 and detached the display instead.

Anyways, setting overscan to 3% takes care of the clipping in theatre view rather well. Thanks for sending me back there.



I went back to the forum search page again too and have been reading all about my problem for a while now.

Larry helps with this explanation:
Quote
The problem is that adjusting overscan at the driver level does NOT solve the issue -- it can "help" since you lose less information, but it's definitely not the proper way to fix this since when an NTSC TV is properly calibrated, the image is SUPPOSED to have the edges of the full scan cut off a bit.  This is part of the NTSC standard.  In other words, the concept of overscan is to not not put any "necessary" image information right up against the edge of the full scan area since this area will be cut off when an NTSC monitor is properly adjusted.  This is done because the very edges of the full scan image are not "clean" on an NTSC monitor -- they're a bit grungy due to the way NTSC TVs are designed.  When you adjust the overscan in the drivers to show the full image, you end up cutting into this "unclean" part of the image along the borders, which defeats the purpose of overscan.  It's the SOURCE image that needs to be adjusted in order to properly adjust for overscan, NOT the output image.  Drivers can only adjust the output image.
But I'm in PAL land...  ?

Glynor chips in with the following help:
Quote
1. Make sure the TV has appropriate inputs.  You'll want DVI or HDMI (which can be converted to from DVI).  A VGA input would be needed if your computer's video card only has analog outs.
I've got 2 HDMI inputs plus a VGA input, also, an s-video/composite input that I don't want to use as they are on the side of the TV.

Quote
2. I'd look for a 1080p TV.  You'll get much better resolution (1920 x 1080), and generally better build quality.  My Westinghouse is a 1080p TV, and as I said, the text is crisp and sharp.  I couldn't say the same for a 720p TV (though many might be fine).  You'll certainly want to enable and configure ClearType to fix the fonts, but it isn't difficult with a good quality HDTV.
The TV tells me "1080i" here. Overscan aside, pc output over HDMI is wonderful.

Quote
3. Overscan compensation.  Unlike computer monitors, many (though not all) TVs have "overscan".  This means a portion of the image around the edges of the screen is hidden by the plastic bezel of the TV's case and can't be seen.  This is typically done because of distortion at the very edges of the screen, and most videos are designed with this taken into account.  This is NOT what you'll want for a computer display though, or the Start button might be missing.  Modern ATI and nVidia video cards have the ability to compensate for this via their control panels.  If you have an older video card, you might want to research this before making the purchase.
Here we go. I've got that and it's 'orrible!!
Thing is, I've not got an older video card, I've got an eVGA GeForce8800 GTX, and using nVidia's 158.22 drivers, I cannot find the control panel option that allows me to control this 'overscan'. I've got their 162.18 beta driver here which I'll install after this post to see if there's anything there that might help.

Larry, again, in this thread, the first quote is from Matt:
Quote
Quote
You'll get better quality, eliminate overscan, and have true 16x9 resolutions with DVI, HDMI, VGA, or even component connections. (assuming your display supports it)

Better quality yes, but using DVI/HDMI does not mean that overscan is eliminated, and component, which is an analogue signal, has the same overscan issues that composite does.
I can confirm that using DVI > HDMI does not eliminate overscan!!

Although we are at opposite ends of the globe, it would appear that Nathan and I have pretty similar problems if I've understood this post correctly. Nathan, I'll go and have another look, but I don't recall seeing this "underscan" option you mention. Where should I look to find that?

It would seem that I've joined a club with a rapidly expanding membership  :)

-marko.

jmone

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 14409
  • I won! I won!
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #3 on: July 19, 2007, 01:00:47 am »

Hi Marko,  Sorry I missed you thread but just got back in the last couple of days:
1) NTSC & PAL both use Overscan so Larry's explenation applies to us PAL users as well
2) NVIDIA's XP drivers have an Overscan feature BUT it does not work with 50HZ timing (you can have overscan and 60hz or no overscan and 50hz).  50HZ is preferable for PAL based media....  From Memory, if you are using XP go into their control panel (make sure Advanced View is on) and you should see it under the HDTV section.
3) NVIDIA's offical Vista drivers do NOT yet have the Overscan feature  >:( and the beta ones don't work...

As I'm on Vista I'm using the MC12 Overscan feature for T'View but I've still got the problem in Windows, Std View, any full screen Viz etc till NVIDIA get the drivers sorted.....

Thanks
Nathan
Logged
JRiver CEO Elect

lepa

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 2033
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #4 on: July 19, 2007, 05:49:29 am »

Is your 32" bravia native resolution really 1920x1080 or is is 1366x768? If latter then you should try 1360x768
resolution from your graphic card to get picture which is not scaled. There should be black 3 pixels on both sides
of the picture. If not the image is scaled. Don't know if it helps with the overscan problem though.
Logged

raym

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 3583
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #5 on: July 25, 2007, 09:42:51 pm »

Is your 32" bravia native resolution really 1920x1080 or is is 1366x768? If latter then you should try 1360x768
resolution from your graphic card to get picture which is not scaled.

But 1366x768 is not a HDMI supported resolution so it will probably not work.


Marko,
I'm just amazed that you were able to get HDMI from a PC to work at all! I have an ATI x1600 video card with a dedicated HDMI out connector and no matter what I try, I cannot get an image out to my Samsung R series TV (which I believe has virtually the same specs as your Bravia). I'm in PAL land also. VGA (D-sub) works fine so I've basically given up on HDMI out from the PC. The only issue is that VGA is locked at 60Hz so I get some jitter.
Logged
RKM Smart Home - www.rkmsmarthome.com.au
Z-Wave Home Automation

marko

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 9124
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #6 on: July 26, 2007, 01:49:22 am »

I spent £49.99 in Maplins on a DVI --> HDMI cable and it just worked, no messing!

The TV has two HDMI inputs. 1 with seperate audio inputs and one without.

I have had absolutely no joy whatsoever from messing around with the nVidia control panel. No matter what I change the refresh rate to, be it 50Hz or 60Hz, no further options open up to me.
Life on the bleeding edge eh?  ::)

-marko.

jmone

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 14409
  • I won! I won!
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #7 on: July 26, 2007, 02:02:35 am »

Nope just poor nVidia Drivers.....I especially like their comments on the latest 158.24 Beta Drivers (just gives you a way to big black box around the lot!)

Quote
Overscan/Underscan Support
The ability to display the entire desktop on a TV is not supported—the
desktop will be masked instead.
NVIDIA has not implemented full underscan compensation control in the
drivers yet. However, end users can access 8% underscan compensation
from the Windows Vista Display Properies Control Panel on an HDTV as
follows:
1 Open the Windows Control Panel, click Classic View, then double‐click
Personalization
2 Click Display Settings, then click Advanced Settings.
3 Click the Monitor Tab.
4 Clear (uncheck) the Hide modes that this monitor cannot display
checkbox, then click OK.
Once this is done, HDTV users will now see up to two new ʺunderscannedʺ
modes on the Windows Display Settings Control Panel, depending on their
HDTV–1176x656 for 720p modes and 1768x992 for 1080i/1080p modes.
To switch between the interlaced and progressive modes for 1768x992,
1 Click Advanced Settings, then click the Adapter Tab.
2 Click List all modes, then locate the modes that are appended with
ʺinterlacedʺ or ʺprogressiveʺ and click the appropriate mode.
3 Click OK, then click OK or Apply.
Logged
JRiver CEO Elect

jmone

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 14409
  • I won! I won!
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #8 on: July 29, 2007, 05:29:14 pm »

There are new Vista-32 Bit drivers on the nVidia Site that apparantly now support overscan correction  :) (but so far I can not get the overscan correction to work  :'( )

EDIT - I've got them to work  :) (mostly - some of the goemetry is not quite right but MUCH better than what it was)...As a result I can now see my desktop correctly but still find a 1% Overscan in MC12 is still good for Theater View spacing
Logged
JRiver CEO Elect

marko

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 9124
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #9 on: August 05, 2007, 02:35:32 pm »

got things working here too :D

I reinstalled Vista this weekend for a look-see, and managed to get it going. Strange thing (to me) was that the refresh rate options given for the TV were 25Hz, 29Hz or 30Hz. 25Hz was selected by default, and simply changing that to 30Hz brought the desktop display into view properly.

I've yet to try theatre view, or video playback on the TV as I've still got a fair old way to go with setting windows up etc. etc.
Wasted far too much time this afternoon trying to figure out why drive letter changes to my virtual cd drive refuse to stick after a reboot. I've given up for now and settled for the default "next letter" it keeps getting despite my choices made in disk management!

Nice to see things as expected (so far) on the TV though.

-marko.

jmone

  • Administrator
  • Citizen of the Universe
  • *****
  • Posts: 14409
  • I won! I won!
Re: DVI to HDMI tv-out overscan problems. Any help appreciated.
« Reply #10 on: August 05, 2007, 03:12:35 pm »

I saw that in 1080i you only had 25/29/30 Hz - I'm currently running in 720p & can get 50/59/60 Hz (being PAL I''m in Multiples of 25).  For once the overscan correction is working OK but it is a little off centered so I still have some overscan so as not to see the boarders on two sides, and use 1% in MC12 so the edge text does not get cut off.

Better than where we were!
Nathan
Logged
JRiver CEO Elect
Pages: [1]   Go Up