[mythtv-users] Strange resolution problem

[Damian]

On 14/07/2015 23:29, Hika van den Hoven wrote:
> Hoi Damian,
>
> Wednesday, July 15, 2015, 12:14:12 AM, you wrote:
>
>> On 14/07/2015 23:07, Damian wrote:
>>> 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
>
>> OK, I'm assuming that this is the aswer:
>
>> # 1920x1080 @60Hz 67.5KHz 148.5MHz +HSync +VSync
>> Modeline "1920x1080" 148.5 1920 2008 2052 2200 1080 1084 1089 1125
>> +HSync +VSync
>
>> I'll give it a try tomorrow
>
>> Damian
>> _______________________________________________
>
> Looks like a valid modeline.
> But you also have to disable all other modes, so it can't switch to
> them anymore. I earlier gave some suggestions I think, but look in the
> readme coming with the nvidia driver for how to diable EDID modes etc.

Thanks Hika,

It seems to have worked.

It didn't initially, but then I added .. Option "PreferredMode" 
"1920x1080_60.00" (and renamed the modeline "1920x1080_60.00"). That 
seems to have done the trick.

I don't know how to disable the other modes that are not compatible with 
my projector. I have Intel graphics.

However, this is working for now and there's rarely a need for the 
resolution to switch. If I come across a better solution I will 
implement it.

Thanks again,
Damian