[mythtv-users] Strange resolution problem

[Damian]

On 07/07/2015 09:46, Damian wrote:
> On 06/07/2015 16:01, Michael T. Dean wrote:
>> On 07/06/2015 06:32 AM, Damian wrote:
>>> 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). 
>>
>> The fact that the annoying mode is 1 pixel less than your 
>> normal/desired mode leads me to assume that this may be related to 
>> the Window Manager you're using "scaling away" some 1-pixel-wide 
>> auto-hidden bar on the side of your screen every once in a while. I'd 
>> guess it's one of those fancy, compositing Window Managers. That 
>> said, if I'm correct, it won't help you fix the issue with your 
>> projector disliking mode changes (and/or prevent mode changes), but 
>> it may help find ways to avoid the changes (even it means just 
>> switching to a different, 
>> less-fancy-but-much-better-for-MythTV-type-usage Window Manager).
>>
>> Note, too, that MythTV will only change the mode if you enable:
>>
>> Separate video modes for GUI and TV playback
>> Switch X Window video modes for TV. Requires "xrandr" support.
>>
>> and set the appropriate related settings.  So, if your mode is 
>> changing and you have that disabled, it's not MythTV that's doing the 
>> changing.
>>
>> Mike
>
> I fixed it!
>
> I too was thinking that it must be something to do with the window 
> manager or something, but I'm using XFCE, the default WM that comes 
> with Mythbuntu.
>
> Then I remembered that I edited the DPI setting to make everything a 
> bit bigger on screen.
>
> I had it set to 100, which must have resulted in things not quite 
> fitting to 1920x1080 right. So, it was kind of flickering between 1920 
> and 1919 resolution.
>
> I'm not quite sure why this was only happening on scene changes, but 
> don't really care as it's fixed now :-) I've even deleted the xorg 
> file (why had been the only thing that had made it at all bearable) 
> and all is still good.
>
> Thanks for the help everyone.
>
> Is there any other way to make everything a bit bigger on screen 
> without messing with the DPI? I've increased the default font size and 
> the height of the default mythbutu/xfce panel, but some things are 
> still too small.
>
> Thanks again,
> Damian
Here's part of the output of ... xrandr -q --verbose

1920x1080 (0xb9)  172.8MHz -HSync +VSync *current
         h: width  1920 start 2040 end 2248 total 2576 skew    0 clock   
67.1KHz
         v: height 1080 start 1081 end 1084 total 1118 clock   60.0Hz
   1920x1080 (0xba)  148.5MHz +HSync +VSync
         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   
67.5KHz
         v: height 1080 start 1084 end 1089 total 1125 clock   60.0Hz
   1920x1080 (0xbb)  148.5MHz +HSync +VSync
         h: width  1920 start 2448 end 2492 total 2640 skew    0 clock   
56.2KHz
         v: height 1080 start 1084 end 1089 total 1125 clock   50.0Hz
   1920x1080 (0xbc)  148.4MHz +HSync +VSync
         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   
67.4KHz
         v: height 1080 start 1084 end 1089 total 1125 clock   59.9Hz
   1920x1080i (0xbd)   74.2MHz +HSync +VSync Interlace
         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   
33.8KHz
         v: height 1080 start 1084 end 1094 total 1125 clock   60.1Hz
   1920x1080i (0xbe)   74.2MHz +HSync +VSync Interlace
         h: width  1920 start 2448 end 2492 total 2640 skew    0 clock   
28.1KHz
         v: height 1080 start 1084 end 1094 total 1125 clock   50.0Hz
   1920x1080i (0xbf)   74.2MHz +HSync +VSync Interlace
         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   
33.7KHz
         v: height 1080 start 1084 end 1094 total 1125 clock   60.0Hz

 From that list, this one ...
   1920x1080 (0xba)  148.5MHz +HSync +VSync
         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock   
67.5KHz
         v: height 1080 start 1084 end 1089 total 1125 clock   60.0Hz
... looks most like the settings I need for my projector at 1920x1080 
(67.5 H-freq and 148.5 Pixel Frequency)

How can I make the machine use this setting instead of the 'current' one 
it is using?

I assume I need to make a modeline out of those numbers, bot how do I do 
that?

Damian