[mythtv-users] Strange resolution problem

[Damian]

On 04/07/2015 08:29, Alec Leamas wrote:
> On 04/07/15 08:57, Andréas Kühne wrote:
>> What I would do is check the EDID properties of the projector, also
>> perhaps change the settings in mythbuntu to not care about the EDID
>> values. I don't know how to do that however.
>
> I did this long time ago for a monitor with a long cable, long enough 
> to make EDID fail. The solution was to add a modeline to xorg.conf, in 
> my case it looks like this (mind the email linebreaks). It still works.
>
> Section "Monitor"
>     Identifier     "Monitor0"
>     VendorName     "IBM"
>     ModelName      "ThinkVision L190"
>     HorizSync       15.0 - 70.0
>     VertRefresh     58.0 - 64.0
>     ModeLine     "1280x1024_60.00" 108.9 1280 1360 1496 1712 1024 1025 
> 1028 1060 -hsync +vsync
>     Option         "DPMS"
> EndSection
>
>
> Part of this lesson was that a cable can work in the video sense while 
> still not having bandwidth enough for EDID.
>
>> Of course, I could be totally wrong, but it was the only thing I 
>> could think of.
>
>
> OTOH, perhaps you're right :)
OK, so here's an update.

I created an empty xorg.conf file and entered the following:

Section "Monitor"
Identifier "Monitor0"
VendorName "BenQ"
ModelName "W1300"
# 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHz
Modeline "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 
1118 -HSync +Vsync
# 1920x1080 @ 50.00 Hz (GTF) hsync: 55.60 kHz; pclk: 141.45 MHz
Modeline "1920x1080_50.00" 141.45 1920 2032 2232 2544 1080 1081 1084 
1112 -HSync +Vsync
EndSection

And it has improved things a lot, but not completely. Maybe 75% better.

The first thing I did was test a particularly bad scene from a program I 
watched a few nights ago. That would now play without any problems. So, 
I decided to watch a full film last night. It was pretty good 
throughout, but at about 3 points throughout the film, it had two or 
three of these 'black and searching' screens, then after a couple of 
seconds it pops back up having found the resolution again (switching 
between 1920x1080 and 1919x1080).

Also, this morning, I plugged my office windows PC into the projector. 
That seemed to play everything fine and 1920x1020. The 'searching' thing 
didn't happen once.

Any more ideas to fix that final 25%?

I'm wondering if theres a way to remove any ability to go to the 
1919x1080 resolution? Although maybe that would leave me with a 
completely blank screen?

One thing I did notice is that I was expecting the monitor name in the 
GUI display settings to have changed to BenQ or W1300. It haddn't, it 
was still on whatever the default of automated setting thought that the 
monitor was. Maybe this means that the monitor identifier value is wrong?

Thanks,
Damian