[mythtv-users] Overscan issue SOLVED! Yea!

A. F. Cano afc at shibaya.lonestar.org
Mon Oct 2 02:09:29 UTC 2017

On Sun, Sep 17, 2017 at 06:17:33PM -0400, Peter Bennett wrote:
> On 09/17/2017 04:57 PM, A. F. Cano wrote:
> >I don't understand why I'm getting myth displayed too big on the TV.
> >All 4 edges are cut off, the clock and date on the bottom edge are cut off
> >in half and only the top half is visible.  The same happens with video.
> >
> >Is there anything I can do in myth to tell it to conform to the display
> >size that xrandr reports? (1920x1080)  Or do I have to set some
> >parameter in some X config file?  Keep in mind that this has to be
> >specific to the HDMI screen.  Like I said, when running on the
> >primary screen (VGA-1) it works like it should.
> What I do with TVs with overscan is use the Frontend setup,
> appearance, to set the GUI size and x and y coordinates. It is a
> trial-and-error process, changing the settings a bit at a time until
> it looks right. Also use the "Use GUI size for TV playback" setting
> to ensure the video playback conforms as well.

Since the VGA screen displays correctly, I was not too sure about
messing with settings that might affect that.  I went looking for
some settings that might be HDMI specific, and then I found this:


This is the relevant part: (quoted from the long thread)

  In the end it turns out the solution was exactly what all the forums
  said, you need to plug the PC in to the HDMI port labeled DVI and then
  change the name of that port to PC/DVI. The secret sauce, of course, was
  to figure out how the hell to do that. Select HDMI1 in the sources list
  and hit the info button and then you get a menu which lets you give
  sources names. Yay for inscrutable, undocumented, procedures which the
  support staff don't know anything about. (Even knowing I probably had to
  rename the source they couldn't tell me how to do that).

On my TV, the myth machine was plugged into the "HDMI 1" port, so the
first thing was to change that to the "HDMI 2/DVI" port.

Then, on my TV it's not the "info" button that gets you to the relevant
menu, it's the "tools" button.  When the menu comes up, I had to scroll
down to "DVI PC" (which is not even visible when the menu first comes
up) and select that.  After that: no more overscan.

> If you have two different type screens on the same computer then I

They're both 1920 x 1080, side by side on the same desktop.

> suggest you set a different name for one of them so that the screen
> size adjustments only apply to the correct screen. If your two
> screens are logged onto different user ids, then in the user id for

This approach is problematic because the way Debian/Kde dynamically
allocate the displays is by placing the tv to the right of the VGA
display to make one large desktop.  I'm logged in as one user.

> the second screen .mythtv/config.xml, change the setting
> <LocalHostName>my-unique-identifier-goes-here</LocalHostName> . This
> normally defaults to the machine name, set a different name for the
> second screen for example your machine name with a 1 at the end.

I also looked at kernel boot options.  There are ways to compensate for
the overscan as specified here:


in the video section.  But as I'm glad to have found out, the proper way
is to tell the TV to do its job properly.

I also looked at video driver options accessible via xrandr, but the
built-in video of the Liva X is quite limited as far as what can be
configured: no overscan or underscan options for instance.

In any case, thank you for taking the time to respond.  The more I
thought about it, the more it seemed that this was a problem specific to
either the tv or the hdmi interface so I was reluctant to have myth
contort in ways that it shouldn't have to to compensate.  Like the author
of tha quote above said: not very intuitive.


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