Hi everybody,

I just bought an Acer Aspire 3003 WLMI laptop which has a 10/6 native resolution (1280x800). When I switch to a 4/3 resolution (800/600 for example), I get all my images wider than the true images (For example if I draw a square, I get a rectangle).
I tried tu use xvidtune program, which theoretically can resize a screen, but apparently it cannot do it for a LCD screen, because I couldn't change anything with this program.

Does somebody know of a program which can resize a LCD screen under LINUX (I am running with UBUNTU 6.06) ? Or does somebody know if that is possible or not ?

Thank you very much in advance for any reply.

I think if you edit config file for your X, you can do almost everything. However, I cannot figure out what you want to do....

Hi,

Thanks for your reply and your interest for my problem.

I only want to use XVIDTUNE with the 800x600 resolution, in order that the screen gets right sizes (4/3 ratio instead of 10/6 one, which is the native ratio). XVIDTUNE has WIDER and NARROWER options which allow to change width of the screen, and AUTO and TEST options which must apply immediately the changes. I tried many times to use those options without any effect.

That is my problem and my question is : does XVIDTUNE work with LCD screens, or only with CRT ones ? If not, does another similar program work with LCD ?

Anyway, I didn't see anywhere that one can directly and easily change the screen sizes only changing manually config file parameters. ModeLine parameter is not easy to change manually : one doesn't see what one does...

Thanks again for your time,

The problem you have is that the physical dimensions of your display are 8 by 5 aspect ratio (not quite 10 by 6 as you stated), but you're trying to use a resolution with a different aspect ratio (assuming square pixels). This by simple reasoning cannot be done without stretching, any more than it's possible to make a perfect flat map of a curved surface.

Do you want to leave unused black bands on the sides, so that 800x600 is expanded to fill as much of the display as possible without changing it's ratio?

Or maybe what you actually want to do is have a height of 600 pixels, in which case you want a width of 960 to fill the entire display.

Of course you should realise that the pixels in LCD panels are fixed, in that there are exactly 1280x800 pixels on the screen, and any other resolution will cause some virtual pixels to be stretched across actual pixels, generally making the display blurry.

Hi,

Thank you very much for your reply. You have quite understood my problem. I tried the 960x600 resolution, but it gives me a very small screen. The other solution (keep 800x600 with black bands) should be better and I thought XVIDTUNE could do it, but apparently it doesn't, at least for a LCD.

Well, the only difference I would see between 960x600 and 800x600 with black bands would be the black bands - the part of the screen in the middle should be the same size. That means that if you want a height of 600 pixels there's really no reason to have the bands.

Do you intend to use 1280x800 for the most part, but be able to zoom in using CTRL-ALT-+ while keeping images from being stretched? I would recommend just sticking with 960x600 if it worked.

1280x800 and 960x600 have the same ratio (8/5, or 10/6, that is to say 1.6). So they give jpg and other images with right proportions. The two resolutions use actual pixels. It's of no interest to use the smaller.

On another hand, 800x600 resolution is using expanded pixels, 600 pixels expanded on 800 actual pixels of the screen height, and 800 expanded on 1280 actual pixels of the screen width. Of course images can't have right proportions (expansion ratio is not the same for height and width : 600/800 is not = 800/1280).

Proportions would be right if the 800 pixels were expanded on 1067 actual pixels instead of 1280 (expansion ratio = 600/800 = 800/1067 or near).

For now I'm using the native 1280x800 with good glasses... :-)

Yes, but why expand 800 pixels across 1067 and leave the others black, when you could just use 960x600? The "zoom level" would be exactly the same, just with more screen real estate (what would be the black bars otherwise are useable space). Using 960x600 on a 1280x800 lcd display would NOT be using "actual pixels" - there are exactly 1280x800 pixels on the panel. No more, no less. Anything other than the native resolution or integer factors of those dimensions will result in pixels being blended across pixel borders.

Oh, and 8/5 (which is exactly 1.6:1) is not quite equal to 10/6 (which is 1.66666667:1). Similarly a 5:4 display is not the same as a 4:3 display, but some people use 1024x768 on the former which isn't the proper aspect ratio.

Anyway, as I said I think 960x600 is probably what you're looking for (but expect blurriness)

Of course you are right for 10/6, it's a (repeated !!!) mistake of my own, because I wanted to say 16/10... I'm very sorry...

About 960x600, I can certify (it's not a mistake) that this resolution gives on my laptop a desktop which leaves 4 black bands, the too small desktop (960x600 actual - I insist ! - pixels) on the center. I was very amazed of that : why 800x600 gives an expanded desktop recovering all the screen and not 960x600 ? I tried other resolution with the same 1.6 ratio (1120x700), but I didn't succeed to reconfigure. What you are saying is certainly right, so I think I have a problem with the distro I'am using (Ubuntu 6.06). As soon as I can, I'll try other distros. On a 4/3 screen (and also on this 8/5 screen), every resolution with the same ratio (1.33333) is expanding on all the screen (640x480, 800x600, 1024x768) : why on this 8/5 screen, the things would not work the same way with every 1.6 resolution ?...

Finally I resolved my problem. I found the Web Page of the SIS driver's author, which displays a wonderful documentation, and allows to download a nice tool (SISCTRL). This tool detects the screen(s) connected to the video card, and possible resolutions, and allows to change "on the fly" the resolution and other parameters. Here below is this address :

http://www.winischhofer.at/linuxsispart1.shtml

I think it could be very useful to everybody who has a SIS video card and has problem with it.

Again thanks for your help !