[mythtv-users] Aspect ratio question

Michael T. Dean mtdean at thirdcontact.com
Sun Jun 2 21:39:16 UTC 2013


On 06/01/2013 06:19 AM, Matthias wrote:
> Am 30.05.2013 13:53, schrieb 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.
>>
> Dear Mike,
>
> 1000x thanks for the hint, I had never noticed that setting ( :-( )... 
> fixed it!

Thank you for your post, too.  It reminded me to change the default 
value to 16:9, since that's a more reasonable default in today's world 
than 4:3.  (That change will be in 0.27 and above, but users who enable 
Xinerama should still ensure the setting is correct for their 
systems--this just makes it more likely that a user who enables Xinerama 
will get the right results, even if they don't know about the system, so 
they won't change other settings they had seen before (like aspect 
override) and break their setup more. :)

Mike


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