[mythtv-users] Match display refresh rate to video framerate

[Mark Schuren]

Am Donnerstag, den 07.01.2010, 22:07 +0100 schrieb Rene H. Larsen:
> man, 28 12 2009 kl. 12:17 +0100, skrev Schuren, Mark:
> > Hi Jean-Yves,
> > 
> > I followed your suggestions and now use the predefined
> > modelines from the example I found in the archives of
> > your site. Still no luck :( 
> > 
> > Here's my frontend log with -v playback:
> > http://mythtv-users.pastebin.ca/1729349
> > 
> > It shows 3 playbacks, first with 25fps, second with 24
> > fps, and the third with a 60i video. Myth still detects
> > (or calculates) exactly '49.832 Hz' for the 50Hz mode,
> > and then picks the wrong one ('59.798 Hz') for 25fps video.
> > I'm pretty sure that is the cause of the problem.
> > 
> > Here is my xorg.conf:
> > http://mythtv-users.pastebin.ca/1729357
> > My TV does not support 25Hz or 30Hz modes, just 24, 50
> > and 60. But even when ignoring the EDID values, I get
> > the exact same results :(
> > 
> > I really wonder what is different between your setup
> > and mine. I currently run NVIDIA 195.30.
> > 
> > Mark
> 
> 
> Hi Mark,
> 
> I had the exact same problem with the frame rates that you had, and I
> believe that I tracked down the problem.  It relates to the use of ","
> as the decimal point in many European countries vs. the way the
> modelines are parsed by MythTV.
> 
> I would appreciate it if you would test the patch from
> http://svn.mythtv.org/trac/ticket/7874 (which I created only a few
> minutes ago).
> 
> It works very well for me.
> 

This is really interesting. I've managed to solve my original problem by

1. using the recent patch from JYA (changeset 23030 for 0.22-fixes).
Myth now also picks an available 49.8xx mode for 25fps, instead of only
picking 49.9xx or (when 50.0+-0.1 is not available like in my setup)
59.9xx.

2. tweaking my xorg.conf so that the X server ONLY validates the modes I
manually define:
Option "ModeValidation" "NoEdidModes, NoVesaModes, NoXServerModes,
NoPredefinedModes"
Otherwise I got a bunch of available modes, including a weird 60Hz mode
that my TV did not like, and which Mythtv often picked for some 29,9fps
videos resulting in my TV showing "unsupported signal" instead of the
video.

Actually, after the above 2 changes, I have no problem anymore, and
automatic refresh rate selection works like a charm for me for any video
content i throw at it.

Nevertheless, I'll give your patch a try - it sounds logic to me that it
might have to do with locale setting. Yes, we use ',' as the decimal
point in Germany... And this might be indeed what makes the magic
difference between my setup and JYA's. JYA said it all worked ok for him
BEFORE changeset 23023...

So I'll first revert both changes mentioned above, then apply your patch
and recompile and then see what happens.

Since I'm quite busy, it might take me a day or two before I can report
back on the results.

Mark