LinHES Forums
http://forums.linhes.org/

Modelines and such
http://forums.linhes.org/viewtopic.php?f=2&t=14748		 Page 1 of 1
Author:  lithuin [ Thu Mar 29, 2007 9:28 am ]
Post subject:  Modelines and such
Hello all,

First time caller, long time... well... not caller.
I've been lurking on these forums on and off for a couple months now, and have read quite a bit about MythTV. I finally took the plunge and put a pretty nice system together. I've installed KnoppMyth R5E50 and everything worked great, so I'll be posting the hardware on the Tier 1 section once I get a couple kinks worked out with the display settings, which is where my question comes in.

I've searched the forums quite a bit, but I can't seem to find anything that quite answers the question I have.

I've got my cable coming in through a Hauppauge PVR-350, and am outputting through VGA, from a GeForce 7300LE to my LCD TV, an LG 42LC2D. The TV has a native resolution of 1366x768, though on boot time the highest resolution detected is 1024x768, so I don't get any widescreen. I can cycle between 4:3 and widescreen on the TV, but it just seems to be scaling the picture. The nVidia drivers do seem to load properly.

I'm a little (lot?) confused when it comes the modelines. This page:
http://knoppmythwiki.org/index.php?page=XModLines
lists what appear to be common, standard modelines.
I'm thinking this would be the one I want to use, as it's quite close to my TVs native resolution:
ModeLine "1360x768" 85.5 1360 1424 1536 1792 768 771 776 794 -hsync -vsync

First, should I need to do anything other than just changing this? I'd just go ahead and do it, I'd like confirmation first if possible.

Do I need to worry about the Option "DPI" line in xorg.conf?

Is there anything else I'm missing?

Thanks in advance for any help. Aside from my widescreen questions, setting up KnoppMyth has been about as simple as it gets. Not that I don't like a challenge, but the developers deserve a congratulations.

EDIT: I should clarify, the TV supports 720p, which is my goal.

EDIT 2: I stumbled upon this page, which seems to imply that the LC2D only does up to 1024x768 over VGA. If this is true, the nVidia card has componant out, so I could switch to that, as the quality should be just as good at 720p. Of course, that brings me back to square 1 on modelines :)
http://pixelmapping.wikispaces.com/Full+List
Author:  Martian [ Thu Mar 29, 2007 11:04 am ]
Post subject: 
I think that modeline should work. If your TV has an HDMI input and your video card has a DVI output you can get a DVI to HDMI cable and should be able to do full 720p that way.

Best of Luck!

Martian
Author:  lithuin [ Thu Mar 29, 2007 11:35 am ]
Post subject: 
I don't normally trust Martians, but I'll try that modeline when I get home. I'm curious to see whether or not widescreen will work over VGA. I'm afraid the video card doesn't have DVI, which sucks because I really want to use one of those HDMI ports for something.

Thanks... unless this is some sort of Martian trick.

EDIT:
OK, I've been thinking about this, and I've got a couple more questions to add here. Please let me know if any of my thinking on this is incorrect.

If the VGA input on my TV only supports 1024x768, I can still set the aspect ratio (through the TV remote) to widescreen, stretching the image. However, the input is still 1024x768. One option? would be to edit the DPI in xorg.conf to a setting that would shrink the dots horizontally, thus making them square when they are stretched to the ratio of my TV's widescreen. Would this actually be increasing the perceived resolution of the image to 1366x768, or would it still be stretching them. Or would the TV chop off the sides of the screen?

The short way of asking the above question, I suppose, would be: Even if I could get the aspect ratio correct so that it looks correct on my TV's widescreen, would I still be getting more pixels, and presumably better quality, on the television by using component cables instead of VGA, presuming that the VGA is still only connecting at 1024x768?

Does any of this make any sense? You'll have to forgive me, as I'm a bit shaky on how the scaling is achieved between the video card and the TV.
Author:  lostmyshape [ Thu Mar 29, 2007 2:15 pm ]
Post subject: 
i dont' see any reason your vga input wouldn't support the tv's max resolution, but i could be wrong. if not, component out is a good option.

the xorg.conf is sort-of confusing when you first encounter it. these two pages helped a lot when i was figuring out my modelines: "xorg.conf demystified" (or, rather the XF86Config... an earlier version and xorg.conf man page, plus the nvidia options.

switching to the component should simply be a matter of specifying the correct output on your video card in the "Device" section.

also, get really familiar with the /var/log/Xorg.0.log file. carefully inspect any (EE)-error or (WW)-warning messages in there. especially those that reference "nvidia". that will tell you what's going wrong and give you an idea of what to search the forums and web for to fix it.

good luck!
Page 1 of 1 All times are UTC - 6 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/