[mythtv-users] Aspect ratio question

[Michael T. Dean]

On 05/30/2013 07:28 AM, Michael T. Dean wrote:
> On 05/30/2013 05:21 AM, Matthias wrote:
>> Hello list,
>>
>> after connecting an hd projector as second display to my frontend, I 
>> have aspect ratio problems. I hope, somebody here on the list can 
>> point me to a solution.
>>
>> I am using a PC with an nvidia graphics card connected via DVI to a 
>> 24" 1920x1080 monitor, everything works nicely.
>>
>> Then I connect an hd projector to the hdmi output of the graphics 
>> card. I have configured xorg.conf with nvidia-settings to start this 
>> configuration as cloned display, the DVI monitor 60Hz, the projector 
>> 50Hz (I am in Europe), sync to the projector.
>>
>> In this configuration, all my 16:9 tv content will be displayed 
>> letter-boxed with black bars on top and bottom of the screen, 
>> squeezed vertically, on both screens. In the preview thumb in the 
>> watch recorded screen, the aspect ratio is drawn correctly. (There 
>> are no black bars in the menus, just when a video is played). Also 
>> mplayer plays the recordings with the correct aspect ratio.
>>
>> I have to set the aspect ratio in myth to 4:3 to get a correct 
>> display. If I do this in the video configuration settings, I will get 
>> 4:3 programs streteched vertically, so this is not the solution I am 
>> looking for.
>>
>> xdpyinfo shows the same information (1920x1080 pixels, 93x94dpi) in 
>> both configurations, with and without the projector.
>>
>> Where do I have to look for a solution for this, has anybody 
>> experienced the same thing?
>
> When using Xinerama or any of its ilk (including Twinview), you must 
> explicitly define the aspect ratio for MythTV to use.
>
> Monitor aspect ratio
> The aspect ratio of a Xinerama display cannot be queried from the 
> display, so it must be specified.
>
> in frontend settings under Appearance.  Are you saying you set that 
> and it's wrong?  If so, it sounds like you may have enabled
>
> Video aspect override
> When enabled, these will override the aspect ratio specified by any 
> broadcaster for all video streams.
>
> which tells MythTV to ignore the display aspect ratio specified inside 
> the video and to assume it's something else (and, really, should never 
> be set by anyone).

Thinking about it, I'm guessing your statement, "I have to set the 
aspect ratio in myth to 4:3 to get a correct display," is saying you set 
"Video aspect override" to 4:3 to get it to display properly.  You need 
to unset that and set "Monitor aspect ratio" properly, instead.  Note 
that you'll only see "Monitor aspect ratio" if Xinerama is enabled in X 
when you start mythfrontend.

Mike