HDTV display problems

[Axeman]

Hi all,

I have my brand new computer with v4.0 of Sage up and running. I am having 2 problems I hope you can help me with. The computer is an 3000+ Athlon 64 with a Gigabyte, Nvidia 6600GT video card and 512mb memory. I am using the component video box that came with the card to connect the card to the TV.

1) My projection TV should handle 1080i (according to the manual). When I select the 1080i output for the TV out in Nvidia's drivers (lastest version from their web site) the screen looks terrible, it flickers about and though you can see the windows desktop it is unwatchable. Perhaps the component output box is not of good quality?

2) So I backed off to 720p resolution. Here the screen looks good but the desktop is much larger than the computer screen. Shouldn't the desktop be the right size to fit in the screen? I have to go into the Nvidia properties screen and work with the overscan settings to get the desktop to fit the TV and that causes the fonts to be very difficult to read (though TV playback looks fine). To fix the problem I played around and finally set the resolution to 1088x612 to make the screen and desktop the same size without playing with the over scan settings. Is this normal, I still think my TV should show the whole desktop when I'm in 720 resolution.

I guess issue 2 won't matter if I can fix issue 1. Then again maybe if I run in 1080 the desktop may still be too big for the screen.

Thanks for any help
Axeman

[mlbdude]

For best video quality you do want to run at your TV's native resolution. Sounds like for you that is 1080i if that projection TV is a CRT. How does the SageTV UI look at that resolution? If you say good, then what you are seeing on the desktop is just the fact of running a 1920x1080 resolution which is interlaced.

If you need to use the desktop for something, try setting up dual resolutions so you don't mess up your video quality.

Either resolution should have some overscan which is normal for a TV. You can use overscan compensation in the drivers to create custom resolutions, but you again can cause image degradation (though not too big a concern on a CRT).

Use the SageTV settings to handle overscan.

[Axeman]

Ok the Sage interface looks much better than the desktop at 1080i. There is a slight but noticable flicker however. I guess related to the interlaced signal and 60hz refresh rate. Though it is more flicker than I would see on a monitor set to 60hz. It is a CRT projection unit BTW. Is the flicker just a fact of life?

Thanks again

[mlbdude]

Yes for 1080i it is. You should not notice it on video playback though.

[thomaszoo]

I wasn't happy with my setup until I started using Powerstrip. It allows you to set up custom resolutions. I view my desktop using a 540p based timing. For you, it would allow you to adjust the desktop overscan for the 720p resolution. There are excellent details on setting it up here:

http://www.avsforum.com/avs-vb/showthread.php?t=206854

This also made it easier for me to connect directly from the PC to the TV with a breakout cable, which IMHO gives me a better picture (I was using ATIs HDTV dongle); YMMV.

Good luck.

[Axeman]

Thanks Thomaszoo, I'll check it out.

[blade]

You don't need powerstrip if you're using a 6600GT.

The nvidia drivers allow you to set the overscan via the control panel. All this does is change the resolution so that it fits the screen properly. If the fonts are too small just change their size. I think mine are set to large, which is around 125% I believe.

My projection crt does 1080i natively but the flicker on the desktop and on the Sage interface is unacceptable to me. So I just run at 720p with the resolution set so that my desktop is displayed perfectly. Then I use the settings in Sage to get the video to fit the screen perfectly. I know for some people not running at the native resolution isn't acceptable, but I'm using analog cable and have a projection crt so I can't really tell any difference in PQ.