PC To HDTV curious problem

[Elcs]

I have a Panasonic 42" Plasma HDTV hooked up to my PC (Gainward 7600GT) and on VGA, all is wonderful.

I can use 1366x768 without a problem, everything looks good. Even the text looks decent.

I got curious and tried to hook it up via Component, the Gainward splitter cable has 4 leads coming out of it and my TV has 3 inputs so i did the colour matching thing. PQ is awesome, much much better than VGA but I am having an issue with resolutions.

I have to use Underscanning to a resolution of 1200x676 to make the picture fit my screen and it is extremely difficult to find games which accept that or can be forced into the resolution. In VGA mode at 1200x676, the desktop doesnt fit at at all and my only real solution for most games is to switch back to VGA to play them.

In brief, I want to be able to utilise the Component stream offered to provide me with superior PQ to VGA but at a reasonable resolution which is supported in a wide variety of games ie. 720p.

Im using a Panasonic Viera TH-42PX60B. Dont confuse it with the 600B.

Thanks for any help. If you need any more info to diagnose my problem, just post and Ill try my best.

 

[Elcs]

Bump - Nothing?

 

[Peter]

Well, for one the picture quality on Component is /less/ than on VGA. Doubly so as your screen appears to scale a bit to overscan on Component but leaves the picture alone in VGA.

 

[Elcs]

Originally posted by: Peter
Well, for one the picture quality on Component is /less/ than on VGA. Doubly so as your screen appears to scale a bit to overscan on Component but leaves the picture alone in VGA.

Then why does Component *look* better than VGA? Comparing each at the best tuned I could get them, Component wins hands down.

 

[Peter]

The reproduction of the input signal is more accurate with VGA. Your monitor may run some "image enhancer" on Composite (it obviously does) which make the picture seem "brilliant" or "vibrant" ... but once you figured that all processing inherits a loss, you'll figure that accurate reproduction is better than "enhancements".

 

[Elcs]

is there any way to correct the Composite signal so that it isnt incorrectly scaling the picture?

If not, would using the DVI output on my card to an HDMI port on my TV provide me with a "better" picture than VGA with correct scaling?

 

[Eomer of Aldburg]

I hook up my HDTV via DVI to HDMI. I use a custom resolution of 1360 by 768 and the picture is stunning, way better than if I had it hooked up to VGA

 

[Elcs]

Originally posted by: Eomer of Aldburg
I hook up my HDTV via DVI to HDMI. I use a custom resolution of 1360 by 768 and the picture is stunning, way better than if I had it hooked up to VGA

As a DVI to HDMI cable is only £15 inc delivery, Ive just ordered one to try it out.

Can a DVI connection carry enough signal/quality to be deemed as HDTV quality as my Component Out is on my 7600GT?

If it doesnt work as good as Id like, its no major loss.

 

[jtvang125]

Originally posted by: Elcs

Originally posted by: Eomer of Aldburg
I hook up my HDTV via DVI to HDMI. I use a custom resolution of 1360 by 768 and the picture is stunning, way better than if I had it hooked up to VGA

As a DVI to HDMI cable is only £15 inc delivery, Ive just ordered one to try it out.

Can a DVI connection carry enough signal/quality to be deemed as HDTV quality as my Component Out is on my 7600GT?

If it doesnt work as good as Id like, its no major loss.

DVI is all digital while component is analog. Picture quality difference on my htpc via dvi-hdmi compared to component is night and day. And yes DVI has plenty of bandwidth for hidef content.

 

[Elcs]

So, hooked up my PC via a DVI to HDMI cable.

I cant get a picture. My PC acknowledges that theres a TV connected via the DVI port, it mentions my "Panasonic (Digital)" but if its selected to use as a display, either in Dualview, Clone or Single Display, not a single flicker appears on my TV when set to HDMI.

Can anyone shed some light on this?

 

[imported_TimBob]

I assume there is a separate input for HDMI. Did you switch the input on your TV to HDMI?

edit: nevermind. I didn't read your last post very well.

What resolution and refresh rate is your PC set to? Also, is the VGA connection still hooked up. I have a panasonic projector and I think only one or the other can be used.

 

[Elcs]

Originally posted by: TimBob
I assume there is a separate input for HDMI. Did you switch the input on your TV to HDMI?

edit: nevermind. I didn't read your last post very well.

What resolution and refresh rate is your PC set to? Also, is the VGA connection still hooked up. I have a panasonic projector and I think only one or the other can be used.

i told my PC to use the PANASONIC TV (Digital) feed it found on a clone basis. With either the PTV feed or Component feed as the "leader feed" and VGA disconnected, the TV displayed zero picture when viewing HDMI1 on the TV (I have tried both HDMI1 and HDMI2 on my TV).

Mr PC resolution is 1200x676 (in my first post) and refresh rate is 60hz.

 

[imported_TimBob]

Try setting the resolution to the native resolution of the panel before changing it the HDMI input.
Also, I have a panasonic project and panasonic plasma and the manuals tell me the acceptable resolutions/rates for each input. Does your manual have that information?

 

[Elcs]

Originally posted by: TimBob
Try setting the resolution to the native resolution of the panel before changing it the HDMI input.
Also, I have a panasonic project and panasonic plasma and the manuals tell me the acceptable resolutions/rates for each input. Does your manual have that information?

Im not so sure it provides me with information regarding resolutions and refresh rates for HDMI.

It actually provides me with max resolutions etc. for VGA.

Component strangely allows me to go up to 1080i and display a picture even if the scaling is out of whack and doesnt particularly fit the screen correctly.

I'll give it a read and try to set the native resolutions it mentions for VGA before swapping to HDMI.

TV's and PC's are rather unforgiving and I feel a little out of my depth here, despite ripping apart PC's for fun and fiddling around with software/overclocking on a regular basis.

 

[L00PY]

Originally posted by: Elcs
is there any way to correct the Composite signal so that it isnt incorrectly scaling the picture?

If not, would using the DVI output on my card to an HDMI port on my TV provide me with a "better" picture than VGA with correct scaling?

I suspect your TV will always scale any signal you send it. Your TV has a native resolution of 1024x768 with rectangular pixels. It has an internal scaler to interpolate the square pixels you send it.

Your best bet will be to try a whole mess of resolutions to figure out the one that scales best. Go ahead and start from 1080p and work your way down through all the 16:9 AR resolutions (including the interlaced variants).

 

[Elcs]

Anyone got any idea why my PC picks up my HDTV via DVI -> HDMI cable but wont allow me to view HDMI? Ive tried both HDMI ports on my TV to the same effect and tried the suggested 1024x768 @50/60hz to no avail.

I am using a Clone Monitor set up. VGA on a 19" LCD Monitor and DVI -> HDMI to the TV.

The three things I can think of:

1) Dodgy cable/ports
2) HDCP -> dont know what all the fuss is about but Im guessing it could be this
3) My TV just doeesnt like PC signals through HDMI

 

[bigpow]

I doubt HDCP would prevent the TV from displaying the picture from DVI, since I also run DVI w/o HDCP and it works Fine.

I'd check avsforum's Pany 42" plasma thread for more setup details if I were you

 

[madh83]

I have a hdtv being used as a 2ndary monitor with a geforce 6800(DOES NOT HAVE HDCP). DVI to HDMI works great, and vga works well too. There's no technical reason why component shouldn't be visually as pleasing as HDMI. w/e people see is due to the way certain components in their setup process analog and digital differently. To answer your question though, it is definitely not the HDCP that's messing things up. Sometimes if a HDMI cable is too long the signal might degrade(i'm talking about over 25ft)

The most probable reason that everything looks better over component is that most tvs don't do processing over VGA(you can check by seeing that some options are missing in vga mode). The viera has a really nice video processor, so the better image over component is probably due to its enhancements.

Ultimately, I don't think you can really do much to get a full 720p resolution. The only thing I can think of is if you try to change aspect/zoom settings to get the whole image to fit. Otherwise, check that your tv does support 720p input from those sources and if it does you could create custom resolutions and see how that works.

Edit: I 2nd the avsforum recommendation, this is really right up their alley

 

[L00PY]

It wouldn't surprise me if it's a HDCP handshaking issue. Does you video card have HDCP? Have you tried powering up your PC with it connected and the TV already on?

And AFAIK, all video cards use square pixels so it'd be neigh impossible to send your TV a widescreen 1024x768 signal with rectangular pixels.

 

[Elcs]

Originally posted by: L00PY
It wouldn't surprise me if it's a HDCP handshaking issue. Does you video card have HDCP? Have you tried powering up your PC with it connected and the TV already on?

And AFAIK, all video cards use square pixels so it'd be neigh impossible to send your TV a widescreen 1024x768 signal with rectangular pixels.

After reading into it, it doesnt look like the card supports HDCP.

 

[Elcs]

A November 2004 (old) article linked from AVS Forums notes that some displays have problems when the source output is dual link DVI. However upon inspection, this should not prove to be a problem.

The Manual for the TV tells me that it accepts 720p through the HDMI inputs so Im completely stumped. The Panasonic Thread is 217 pages long and most of it seems to be about the American version of my TV... which is of no use to myself.

 

[xtknight]

Looks like this person has a similar problem:

http://www.highdefforum.com/showthread.php?t=44629

The supported resolutions are listed there. 1024x768 definitely isn't, though.

You might try "force detection as HDTV" or whatever it is, in the NVIDIA control panel. May be a faulty cable too.

 

[Elcs]

Originally posted by: xtknight
Looks like this person has a similar problem:

http://www.highdefforum.com/showthread.php?t=44629

The supported resolutions are listed there. 1024x768 definitely isn't, though.

You might try "force detection as HDTV" or whatever it is, in the NVIDIA control panel. May be a faulty cable too.

Brilliant link. From a basic scan, he's getting a picture over DVI->HDMI whereas Im not but it may unlock something there.

1024x768 is noted, as the thread owner mentioned, in the manual and the TV even has an XGA (1024x768) setting. This is what I am using now on VGA in fact. WXGA (1366x768) is an option of the TV also.

Force Detection as an HDTV was selected. I have tried both On and Off for this setting.

My issue is over on the AVS Forum. Their Panasonic Plasma HDTV thread is monster but mainly talking about the US version of the TV in more day to day uses.

I will try and sift through the thread and keep this up to date. My problem might help someone else.

A dodgy cable is what I thought all along but theres so many possibilities it seems with TV's.

 

[Elcs]

Bump - Posted on AVS Forums and nothing so far.

My head is currently bouncing against some wall.

 

[DaveBC]

Originally posted by: Eomer of Aldburg
I hook up my HDTV via DVI to HDMI. I use a custom resolution of 1360 by 768 and the picture is stunning, way better than if I had it hooked up to VGA

Me too, DVI rocks. You can get games to run fine at 1360x768 too. Most of the newer games support that res. And you can get work arounds for others here.