First of all, thank you to everyone who has helped out this noob. I have learned a lot so far, and I really appreciate all your generous support. I am almost 100% up and running. I have one resolution question:

I am using an infocus 4805 projector and I am trying to 1:1 pixel map my playback. I used the infocus modeline from the wiki which is 848x480 at 60 Hz I disabled all other modelines, and I commented out DPMS = true. When I start the computer, the projector displays that the signal is correctly set to 848x480. By the end of the boot sequence, when the Nvidia splash comes on the screen (just prior to the myth GUI starting) The image flickers and the resolution on the projector changes to 1024x768. I have already gone to the appearance settings and set everything to be viewed at 848x480. I also exited and opened an X shell and typed xrandr. It output that I was at my desired resolution of 848x480, with no other choices to switch to.

So I am stumped can someone tell me what is going on? Is there a why that I can verify the actual pixels being displayed on the screen?


Another question that may be related to the resolution: Sometimes when I was browsing around the mythtv gui, I could not highlight anything with the curser during navigation. The only way around this was pressing the escape button repeatedly until the linux desktop background flashed momentarily and then I was brought back to the main mythtv screen with a working curser. Whats up with that?

Thanks again in advance. You guys are very wise and generous.

open a xterm and type: xwininfo

then click the cursor on the background.

Alright, I tried the xwininfo, and it prints out that it is displaying the 848x480 that I wish to have. I am slightly confused, because when I boot the computer, my projector displays the correct 848x480 resolution. Why would it swithch to the 1024x768 resolution? My fear is that the computer is sending the right resolution, the projector reads it incorrectly as 1024x768, thus actually upconverting the origonal signal, and then downconverts it back again to 848x480. Maybe I am just paranoid, but it kind of bugs me. Plus I am still haveing the curser problems in myth. I dont understand that eithter

I just found the solution to my cursor question here:
http://mysettopbox.tv/phpBB2/viewtopic. ... ght=cursor

Although I am still curious about the resolution thing.

I can think of a few tricks that might tell you what the infocus is thinking.

change inputs while its connected to pc, when you cycle back to the pc input it should pop up
what it thinks it at.. Another trick might be to unplug and replug the pc input.. to see what it
spits up in its confusion..

I have no idea if it will damage the infocus, so please consult the manual first to see if there
is a warning about any of tricks I am suggesting..

The people at the infocus forum seem to think that despite what xrander and xwininfo say, that the computer is still sending the 1024x768. Why would the computer read 848x840 during startup, and then switch to 1024x768 after the Nvidia splash comes on the screen? I tried to go through the NVIDIA settings, but I dont really know what to look for.

By the way mac, I did try your suggestions, still know luck. It switched from the 1024x768 signal to a 480p signal from a regular dvd player. Then when I switched inputs again, it still read 1024x768

look in: /var/log/XFree86.0.log

see if you can see what might be going on..

Alright, I checked /var/log/XFree86.0.log and this is what I got in the relevant section:




Here are some details from my XF86Config-F file



Here are some other details, if I change Display subsection to:

SubSection "Display"
Depth 24
Modes "848x480" "800x600"
EndSubSection

Then when I restart my computer, my projector agin displays 848x480 during the boot, then switches to 800x600 (as opposed to 1024x768) after the Nvidia splash comes on the screen.

So it is almost like that after the boot, it ignores my 848x480 in the modes section, and switches to the default "1024x768" "800x600" "640x480" display resolutions through some 'hidden modeline.

I have also tried to ignore EDID - that did not seem to change the issue.

I also tried "un-commenting" the default modelines to see what xrandr allows. It comes back with:

"848x480"
"1024x768"
"800x600"
"640X480"

And when I switch to any resolution through xrandr, the projector flickers, and displays the correct resolution that I called out. Except when I switch to "848x480", the projector then shows "1024x768"

I know the 848x480 modeline is good. It is posted on the knoppmyth wiki.


Thanks again for all the help everyone.

Alright, this is mainly a bump because I still cannot figure this out. I most recently tried to add these following lines in hope that it would work:


Option "NoDDC" "1"
Option "IgnoreEDID" "true"
Option "UseEdidFreqs" "false"

This still didn’t change my problem. Does anyone know why my projector displays the correct 848x480 modeline during boot up, but then switches to 1024x768 once X starts? I will be eternally grateful to anyone who helps me solve this frustrating problem.

Alright, I seemed to have fixed my problem. Like I said above I used the following options:

Option "NoDDC" "1"
Option "IgnoreEDID" "true"
Option "UseEdidFreqs" "false"
Option “DPMS” “false”


This still did not work. But Then I decided to change my H-sync range from 31.5-80.0 to 25.0-80.0. Doing this with all four options active give me my 848x480 modeline. I am glad it works, but this makes no sense to me.

It scared the crap out of my to change my Hsync with all the safety options turned off. My projector is only rated for Hsync 31.5-80.

http://www.infocus.com/Products/Projectors/SP4805.aspx

And according to my modeline shown above, the Hsync is set to 33.77, so my original Hsync value should have been fine. Anyway, I am just happy that it all works. Maybe this thread can help some other poor noob in the future. Thanks agin.

Glad you got it sorted out, and thanks for coming back to post your solution. Sorry I wasn't much help.