[mythtv-users] HDPVR HD Recordings are in 4:3 format

[Michael T. Dean]

On 12/13/2013 04:39 AM, Stuart Morgan wrote:
> On Thursday 12 Dec 2013 22:07:20 Michael T. Dean wrote:
>> On 12/12/2013 07:15 PM, Raymond Wagner wrote:
>>> On 12/12/13 18:24, Scott Smith wrote:
>>>> I have this problem or one simiar to it. All my HD content appears to be
>>>> in a 4:3 aspect. It is compressed horizontally. Forcing the aspect can
>>>> make it better.
>>>> Im not sure what changed.
>>>>
>>>> But i did notice the output from the frontend is reporting the desktop
>>>> as 2560x1080. Maybe the frontend thinks it needs to compress the
>>>> 1920x1080 into this?
>>> If your monitor is reporting its dimensions accurately, that should not
>>> matter.
>> Except, based on that screen resolution, I'd bet that Scott is using X
>> configured with Xinerama (or one of its ilk, such as TwinView) enabled
>> (even if he thinks there's only one monitor) /and/ using an old version
>> of MythTV (not 0.27).
> We've never had this problem with TwinView, I didn't think it was a problem
> with xinerama either but it's been so long since I last tried it that I'm
> can't be certain.


It should be just as visible with TwinView as with Xinerama. TwinView 
creates a single display area that the card then displays onto 2 
monitors, and as far as the X server is concerned, there's only a single 
screen (with some crazy dimensions).  However, nvidia "fakes" a Xinerama 
configuration***, even providing Xinerama information about the multiple 
screens (including reporting that Xinerama is active).  In Xinerama (or 
with the faked Xinerama information from TwinView), the server will 
report information about the multiple monitors, so with the right 
(low-level, Xcb or Xlib or maybe Xrandr, not-Qt) code, we should be able 
to determine how many monitors are displaying portions of the single 
logical screen and which portion of the screen each monitor is 
displaying (but whether it's worth doing that is a whole other topic).  
However, we don't have such code, so if we notice that Xinerama is 
active, we ignore the reported dimensions and use the user-specified 
(or, default-specified, if the user never specified the setting) 
aspect.  (See videooutbase.cpp, around line 1807.)

So, again, if anyone is using a Xinerama or TwinView configuration and 
aspect ratio of displayed video is correct, but they haven't set the 
settings, the only reason it's working right is because the MythTV 
defaults happened to be right for their configuration when they first 
started using MythTV with Xinerama.  Or, it's also possible that you've 
also set the "Video aspect override" setting and combined 2 incorrect 
settings values to make it appear that things are working properly.  So, 
please set (all 3**** of) the settings properly if you are using Xinerama.

Mike

*** I think you can actually disable TwinView's reporting faked Xinerama 
information with the NoTwinViewXineramaInfo configuration setting for 
the nvidia drivers, at which point, we would think Xinerama is not 
enabled and use the size/aspect information reported about the one 
screen the X server knows about (which is strangely sized due to the 
multi-monitor configuration).  This would actually make things worse in 
that the user wouldn't be able to override the reported (but incorrect, 
due to multiple monitors, unless he's actually displaying the video 
across all those multiple monitors) information about the display.

**** "Display on screen", "Monitor aspect ratio", and "Video aspect 
override" all in Appearance settings.