[mythtv-users] Xorg nouveau driver vs. nvidia-driver

Yann Lehmann aristide at free-it.ch
Thu Nov 5 10:16:28 UTC 2020

Am 05.11.2020 um 06:04 schrieb Stephen Worthington:> >
> You should check if your TV can be set to have its overscan disabled.
> Some have options for this, and others automatically do it on inputs
> that are identified as a PC rather than a video player device, so if
> the TV manual says to use one specific input for PCs, that will likely
> not have overscan.  Others TVs can do it only via a hidden maintenance
> menu, and then there are some that have no way of disabling it.  And
> in others, it is off in some modes and on in others, so try using
> xrandr to change modes and see if that is what is happening.  It would
> also be good to set full debug output (if that is possible) in the
> Nouveau drivers and keep a copy of the log.  It may well show in there
> exactly what the Nouveau drivers do that removes the overscan.  I have
> also heard of a TV that drops the overscan when you use the menu
> options for naming the inputs and select the name option that has a PC
> like name.  A web search for your exact TV model may be able to help.
> Or is there a manufacturer's help service that you can contact?
> If you need to select from only specific modes to get no overscan,
> then you will probably need to get a copy of all the modes from the
> log file and convert them into modelines and create an xorg.conf file
> from them.  That is very tedious to do, but not horribly complicated.
> I am in the process of doing this at the moment, and have it working
> for all the standard modes I need so far except the 24 Hz ones.  To
> get the log information you need for this, you need to add this:
> Option  "ModeDebug" "true"
> in the Screen section of xorg.conf:
> Section "Screen"
>     Option  "ModeDebug" "true"
> EndSection
> If you are unable to disable the overscan, then you can always use the
> ViewPortOut setting in the Nvidia drivers.  That does reduce the
> resolution of the picture a little bit though, so it is not the
> preferred fix.

I don't know if it helps, but I remember that I had to overwrite a "dpi 
value" in the xorg-settings to fix overscan (with a very old Nvidia 
integrated graphic chip). Unfortunately, I changed the hardware in the 
meantime and don't remember where the settings hat to go.

More information about the mythtv-users mailing list