What video mode fits XGA screen best?

[poppa_f]

Hi,

I'm trying to connect my shuttle SN45G into my Panasonic Viera 37" LCD via a DVI->Component YPrPb. The native resolution of the LCD is XGA (1024 x 768 with a 15:9 aspect ratio).

The connector I've got offers video modes of

480i, 480p, 540p, 720p and 1080i


My question is, what setting should I use to fit best with the 1024 x 768 15:9 resolution?

Fred

[stevelup]

Hi

Exactly which panel have you got?

I'm not aware of any LCD's with non-square pixels, nor am I aware of any Viera set which is not true 16:9...

Assuming you mean you've got the 37" Plasma (which is 16:9 and 1024x768), you've got two options.

1) Set your PC to output 1366 x 768 - this will give you the correct aspect ratio and no vertical scaling will be required. You will however be scaling slightly in the horizontal ratio.

2) Set your PC to output 1024x768 - this will give you a proper pixel mapped signal and the sharpest possible resolution from your PC, however the aspect ratio for windows apps will be incorrect. This should not cause you a problem for video playback though so long as your video player software can accept an aspect ratio modifier. (All the high end DVD player software can do this, as can MediaPlayer classic and I believe the later versions of Windows Media Player)

Steve

[stevelup]

Ah, I see you are using component, not VGA.

Your best option will be 720P in that case although it's not ideal as you cannot get a pixel matched video mode.

Is there any reason you cannot connect via VGA or DVI?

[poppa_f]

The panel I'm using is a Panasonic Viera TX32LXD1. Unfortunately it does not have VGA / DVI / HDMI inputs, just Scart and Component YPrPb.

Originally I tried running S-Video in via Scart at 1024 x 768 resolution. The picture fitted the screen nicely, but the picture quality was shockingly bad.

I've since invested £10 in an ATI DVI -> Component YPrPb adapter (for some reason only places in the US seem to sell these). The picture quality with this is superb, but I'm struggling a bit to get a decent the resolution (read decent as 1024 x 768 or close to it).

I thought it would be fairly straightforward to get a decent resolution on the TV, as the TV's native resolution is 1024 x 768, which is one of the standard windows resolutions. However, the DVI -> Component YPrPb adapter only outputs to certain video modes -> 480i, 480p, 540p, 720p and 1080i.

480p works, but is fairly low res (640 x 480ish). By the sounds of it I should use 720p and then fiddle around with powerstrip to get the picture to fit on the screen properly.

Does this sound like my best option then?

Fred

[richjthorpe]

Your TV is actually 1280x768 which is a 15:9 format. Use 720p and let the TV scale the rest of it.

Richie.

[poppa_f]

Originally Posted by richjthorpe

Your TV is actually 1280x768 which is a 15:9 format. Use 720p and let the TV scale the rest of it.

Richie.

<slaps head>

yes you're right. Ok so 720p is almost bang on.

Thanks for the help,

Fred

[poppa_f]

Ok, I'm having big problems with this. I have the ATI connector set to 540i, 720p and 16:9 (when I go into the Catalyst control centre I can see those boxes ticked). The PC is defaulting to 720 x 400 resolution on startup. For some reason, if I try and set it to anything different from this in control panel then I lose the image (like a TV not tuned in properly).

I've tried experimenting using Powerstrip, but it is very difficult as when I change the settings, the image goes and then I have to re-start in safe-mode and uninstall powerstrip and ATI CCC to get the pictue back
(for some reason using the shift+ctrl+s shortcut doesn't get the old pictue back )

It's very annoying as the TV should be able to take a much higher res than 720 x 400 but I just can't get it to work.

Does anyone have a solution to this?

[poppa_f]

update - I've been mucking about with the CCC and powerstip settings and I've found out that if I go in to CCC and set the "desktop size" to 1280x720, then instead of the picture breaking up, it zooms in, so I can only see about a 1/4 of my desktop.

Not sure if this is any closer to the correct answer. I'm sure there musr be some permutation of CCC setting and powerstrip setting that will get me to to a higher resolution. Damned if I can figure it out though

[richjthorpe]

Hmmmmm....I haven't used Catalyst drivers but I do know that Powerstrip over rides any other resolution. Try removing Powerstrip altogether and just use the Catlyst drivers set at 720p.

Richie.

[poppa_f]

Originally Posted by richjthorpe

Hmmmmm....I haven't used Catalyst drivers but I do know that Powerstrip over rides any other resolution. Try removing Powerstrip altogether and just use the Catlyst drivers set at 720p.

Richie.

I'll give that a try tonight.

Thanks