[mythtv-users] mythtv-users Digest, Vol 152, Issue 28

[HP-mini]

On Wed, 2015-11-18 at 12:38 +0000, Jason Kitching wrote:
> > Hoi Jason,
> > 
> > Wednesday, November 18, 2015, 11:19:46 AM, you wrote:
> > 
> > 
> >>> Hoi Jason,
> >>> 
> >>> Tuesday, November 17, 2015, 7:40:25 PM, you wrote:
> >>> 
> >>>> I have a mixture of 50/60/24fps recordings/videos and at present my
> >>>> xorg.conf file is set up to auto change the screen res accordingly 
> >>>> as
> >>>> per the myth judder free entry in the wiki, and it does a fine job
> >>> 
> >>>> However, due to the nature of how my screen hands 24fps, I'd prefer
> >>>> that
> >>>> 24fps to be broadcast as 60fps and have messed around in the xorg 
> >>>> file
> >>>> to try and do this but failed miserablly. Is it even possible?
> >>> 
> >>>> I can at present, manually change the res in either the frontend 
> >>>> setup
> >>>> so it broadcasts at 60Hz rather than Auto or change it in
> >>>> nvidia-settings and that works ok, but would prefer an automatic
> >>>> resolution change to make things a little easier and to make it a 
> >>>> bit
> >>>> more other half and kids friendly
> >>> 
> >>>> I've included my xorg.conf to see if anyone can think of any entries
> >>>> that need adding or amending.
> >>> 
> >>> 
> >> It's not that it judders on 24fps, far from it, very smooth, the panel
> >> performs better at 60fps when showing 24fps content (known issue on 
> >> the
> >> panasonic plasma forums).
> > 
> >> I can manually make the switch to run on 60fps, but my query is 
> >> whether
> >> I can get the xorg to automatically send 24fps out as 60fps, to save 
> >> me
> >> having to manually update everytime I swtich from 24fps to 50fps.
> >> 
> The "Monitor" on the xorg is in fact my AV Receiver, which is set to 
> just pass through the video signal. This is then hooked up to the Plasma 
> tv and both accept and run 24fps. Possible i've completely messed up the 
> HorizSync and VertRefresh the amount of manual editing I've been doing 
> to the file recently.
> 
> As for losing any quality, the picture is exactly the same quality (that 
> I can see anyway) whether it's 24hz or 60hz in nvidia-settings. The only 
> difference being that the plasma telly handles posterization better on 
> 60hz than it does on 24hz. That's the only reason why I now switch to 
> 60hz when any 24fps material is being shown.
> 

The driver will just add your custom modelines to the total pool of
available modes unless you tell it to ignore the others..

Unless this "VertRefresh     56.0 - 62.0" is being ignored because it
does not compute with the custom modelines then you're getting 60Hz
output only.
You can read thru' /var/log/Xorg.0.log file to find out..

If you remove the 24p modeline & have 60p (59.xx) mode the default then
video card will convert 24->60p with pull-down. Change the metamode in
device section to be 60Hz.
Sadly VDPAU does not (yet) have a 24p frame rate doubler..

Remove (comment out) the interlaced modelines because the video card
should be better than the TV.

The remaining 2 modelines are not right, they are just made up for some
old projector (VGA possibly).
The ~60Hz one should be using reduced vertical blank timing:
Modeline "1920x1080R"  138.50  1920 1968 2000 2080  1080 1083 1088 1111
+hsync -vsync
 and the 50Hz one:
Modeline "1920x1080_50.00"  141.50  1920 2032 2232 2544  1080 1083 1088
1114 -hsync +vsync

Blm