[mythtv-users] Advice on using Nvidia Cards for Highest Quality Video

Jean-Yves Avenard jyavenard at gmail.com
Tue May 27 03:07:20 UTC 2014


Hi

On 27 May 2014 12:18, OM Ugarcina <mo.ucina at gmail.com> wrote:
> Hello Guys,
>
> A recent upgrade to the latest nvidia long term driver rev 331.79 prompted a
> revisit to my xorg.conf as I noticed that certain features have disappeared
> . So I have ended up with a xorg.conf that has a bit of clutter which is no
> longer supported such as "flatpanelproperties" scaling . This opened a

Funny, I went through exactly the same problem last night after I
upgraded my machine...
I updated the wiki page with my findings
http://www.mythtv.org/wiki/User_Manual:JudderFree

it still does..
ftp://download.nvidia.com/XFree86/Linux-x86/337.19/README/xconfigoptions.html

format has changed, however and instead of "native" you use

 Option "FlatPanelProperties" "Dithering = Disabled"

having said that, the only reason you needed it IMHO before was
because without this option, you couldn't change refresh rates.
That is not the case anymore, you can so this option isn't really relevant today


> re-think of what other carry overs I have which do not fit into new driver
> or even myth 0.27 . Over the years I have been sticking things in that
> seemed a good idea at the time . I have a late model nvidia card and use
> VDPAU on Centos6 and use a Sony Bravia KDL46X3100 TV as a monitor via HDMI .
> So I would like ask a bit of advice from the more knowledgeable members on a
> few aspects :
>
> 1) Colour space conversion : I am using  vdpaucolorspace=auto  as part of my
> playback profile additional settings . Is this a good idea , should I use
> xorg.conf settigs of Option "ColorSpace" and Option "ColorRange" instead or

no, let myth do it, it will use BT-709 for HD and BT-601 for SD.

> 2) Modelines . I use JYA modelines instead of EDID to make sure that timing
> is 100% spot on . I have the first line duplicated to overcome a bug in the
> Nvidia driver , which used to loose this line . Is that still the case with
> the latest driver, is it still needed ?

unfortunately, yes, it is still the case, the 2nd modeline for a given
resolution is always dropped.
Note that the bug also exists with modeline retrieved from the EDID,
that means without defining your own modelines, and only use the EDID
one, you will always miss an available refresh rate.
On mine machine, it means I never get 50Hz, only 60 and 24.. damn annoying.

With 233.xx drivers, I have found that you can't disable EDID
modelines with Ubuntu Unity (it works with XFce), I've updated the
wiki yesterday about it.

So if X doesn't start and appears hung, make sure you remove the line

Option "ModeValidation" "NoEdidModes"



>     Anandtech mentions that Nvidia clocks 24p as 23.971 Hz instead of 23.976
> Hz , some people have suggested a change to the modeline to force the clock
> up to 23.976 . Do you guys know what needs to be changed ? Would there be a
> need to use Option "ModeValidation"

if you follow the wiki, and you add your own modeline, you will have
both and myth will pick the right one (23.976)

The xorg.conf on the wiki will work for your TV (I have the same, and I use it)


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