[mythtv-users] auto frame rate change

[blind Pete]

On Tue, 17 Nov 2015 18:40:25 +0000
Jason Kitching <jason at jadrallypix.me.uk> wrote:

It is probably not doing what you think it is doing.  

> 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.
> 
> Cheers
> 
> Jason
> 
> Section "Monitor"
>      Identifier     "Monitor0"
>      VendorName     "Unknown"
>      ModelName      "ONK TX-SR876"
>      HorizSync       28.0 - 83.0
>      VertRefresh     56.0 - 62.0

If this is true (and your computer probably read it from your monitor's
firmware) then your monitor can not display 24 fps or 50 fps.  Mythtv
and / or your graphics card is "performing magic" and sending 60 fps (or
maybe 59.94 fps) signals to your monitor.  

If you really like mucking about, it might be possible to override the
monitor's firmware and drive it at 50 fps; maybe even 48 fps (24 x 2).
But 24 fps or 72 (24 x 3) seems very unlikely.  

>      ModeLine       "1920x1080 at 50" 148.500 1920 2448 2492 2640 1080
> 1084 1089 1125 +hsync +vsync ModeLine       "1920x1080 at 60" 148.500
> 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync ModeLine
> "1920x1080 at 24" 74.250 1920 2558 2602 2750 1080 1084 1089 1125 +hsync
> +vsync ModeLine       "1920x1080 at 23.976" 74.175 1920 2558 2602 2750
> 1080 1084 1089 1125 +hsync +vsync ModeLine       "1920x1080 at 50i"
> 74.250 1920 2448 2492 2640 1080 1085 1095 1125 +hsync +vsync
> interlace ModeLine       "1920x1080 at 60i" 74.250 1920 2008 2052 2200
> 1080 1085 1095 1125 +hsync +vsync interlace ModeLine
> "1920x1080 at 59.94" 148.350 1920 2008 2052 2200 1080 1084 1089 1125
> +hsync +vsync ModeLine       "1920x1080 at 59.94i" 74.175 1920 2008 2052
> 2200 1080 1085 1095 1125 +hsync +vsync interlace Option
> "DPMS" EndSection
> 
> Section "Device"
>      Identifier     "Device0"
>      Driver         "nvidia"
>      VendorName     "NVIDIA Corporation"
>      BoardName      "GeForce GT 430"
>      Option       "FlatPanelProperties" "Scaling = Native"
>      Option       "RegistryDwords" "PerfectLevelSrc=0x3322;
> PowerMixerDefaultAC=0x1" EndSection
> 
> Section "Screen"
>      Identifier     "Screen0"
>      Device         "Device0"
>      Monitor        "Monitor0"
>      DefaultDepth    24
>      Option         "TwinView" "0"
>      Option         "TwinViewXineramaInfoOrder" "DFP-1"
>      Option         "metamodes" "1920x1080_50 +0+0"
>      Option         "NoLogo" "False"
>      SubSection     "Display"
>          Depth       24
>      EndSubSection
> EndSection

-- 
testing
bP