[mythtv-users] auto frame rate change

[Jason Kitching]

> Message: 4
> Date: Thu, 19 Nov 2015 08:46:26 +1300
> From: HP-mini <blm-ubunet at slingshot.co.nz>
> To: mythtv-users at mythtv.org
> Subject: Re: [mythtv-users] mythtv-users Digest, Vol 152, Issue 28
> Message-ID: <1447875986.3802.14.camel at hp-mini-laptop>
> Content-Type: text/plain; charset="UTF-8"
> 
> 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
---------------------

Followed that Blm, thanks, can see the default change to 60Hz but 24fps 
still being forced so I checked /var/log/Xorg.0.log and found that 
nvidia-auto-select kicks in and sets the res to 1920_1080_24.

Strange though as the auto select line isn't present in the xorg.conf 
file. Quick search about disabling auto-select lead me to the ubuntu 
forum where another user had a similar problem with auto-select kicking 
in and the xorg.conf file was being ignored. Instead one of the conf 
files in /usr/share/X11/xorg.conf.d was being used.

I will have a look later in that directory and see if I can figure out 
what exactly is causing nvidia-auto-select to run.

Thanks.

Jason