Computer video resolution for HD 1080i?

[ktalley]

I had been running my graphics output at 1024x768 when using VGA output to my 42" plasma monitor (HD/1080i-capable) -- with GBPVR, of course -- but when I installed an HD tuner (Cat's Eye 150) a couple of days ago, I decided to upgrade my NVidia drivers (and also to change to the DVI/HDMI output on the NVidia card). The NVidia card/drivers detected my plasma and changed my resolution (automatically) to "optimized for HDTV" (1920x1080). Now everything played thru GBPVR plays in a square box in the middle of my plasma panel (vs. a rectangle filling the whole panel).

I guess my general question is -- what resolution should I be running my graphics card to watch full-screen television (both analog with my PVR-150 and OTA ATSC with my Cats' Eye 150)?

I've tried switching to overlay (vs. VMR9), but still get the square in the middle.

Thanks!
Kevin T.

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Specs:
Celeron 3Ghz, 512MB DDR2, two 160GB hard drives
NVidia GeForce 6200 (128MB/64-bit, vga/svideo/dvi out), NVidia PureVideo Decoder
Hauppauge PVR-150
VBox Cat's Eye 150 (DTA-150)
GBPVR
Akai 42" HD-capable (1080i) plasma tv (no internal tuners) -- connected via DVI->HDMI cable to my GeForce card

[Koenie]

In my experience I got the best result when driving the monitor with its native resolution. Anything else will too often result in double scaling of the video (unless only one resolution and aspect ratio is ever used) which causes very unpleasant artifacts.

[ktalley]

Thanks for the response, Koenie...

So you're saying that if my plasma monitor/TV specs state "supports PC image resolutions up to 1024x768 at 60hz" (even though it's HD-capable at 1080i), I should make sure my graphics adapter on computer is set to 1024x768 (vs. 1920x1080) -- even though I'm connected to the plasma with HDMI (vs. the VGA input).

Thanks for the clarification....

Kevin T.

[mikaelgu]

Try changing your TV to a 4:3 in config. Yeah I know it sounds silly, but try it. I've got a 16:9 and when I had that in the config everything looked wrong. Changing back to 4:3 fixed it for me.

[ktalley]

Well, I changed my computer resolution back to 1024x768 (from NVidia driver suggested 1920x1080). ALSO, I changed my Aspect Ratio in GBPVR to 16:9 (funny, I had never changed it from 4:3 -- even though I have a widescreen TV -- and always had a "full" picture for analog channels). I now have crystal clear rectanglular picture in the middle of my screen (and no garbage displaying...).

BUT -- it still does not fill the screen (I'd say it's using 75% of the panel real estate).

So basically, I can watch my OTA HD channels now (even though they don't fill the screen). Perhaps this is expected behavior, but I would think there would be a way to make it use the entire 42" plasma panel.

Any other suggestions would certainly be appreciated. Thanks for the great participation & advice in this forum. And thanks, Sub, for all of your hard work.

[Koenie]

I do not mean that you have to set the display config to the highest supported. I mean it has to be set to the native resolution of the pannel itself. The physically present number of pixels. Practically all plasma's and by for the majority of LCD's can display 1080i but have an effective resolution which is much lower. They simple downscale the image.

A quick look at the Akai website showed that their 42" plasma's have a pannel resolution of 852 x 480 or 1024 x 768. Check which one is yours and set it.

[Koenie]

I see were a few seconds earlier. 1024 x 768 is a 4x3 resolution and will thus not fill you r 16x9 screen unless the monitor streches the image. I guess your pannel res is 852 x 480.

[ktalley]

That's really strange. My plasma panel is definitely 1024x768. But if I use 4:3 setting in GBPVR, I get small square box with HD video (and a lot of other garbage/artifacts on the screen). but if I use 16:9 setting in GBPVR, I get a decent-sized rectangular picture (no garbage/artifacts).

Oh, well. I guess this is part of the joy of building your own PVR! Tweak & learn!

Thanks a lot for your help, Koenie.

Regards,
Kevin T.

[csy]

That's really strange. My plasma panel is definitely 1024x768. But if I use 4:3 setting in GBPVR, I get small square box with HD video (and a lot of other garbage/artifacts on the screen). but if I use 16:9 setting in GBPVR, I get a decent-sized rectangular picture (no garbage/artifacts).

Oh, well. I guess this is part of the joy of building your own PVR! Tweak & learn!

Thanks a lot for your help, Koenie.

Regards,
Kevin T.

There is a well known (and documented in these forums) Nvidia driver bug that when the video doesn't fill the whole screen, then the picture shrinks down to a smallish square with surrounding garbage/artifacts on the screen. The fix is to configure GBPVR to use "VMR9 Custom" renderer.