[mythtv] OpenGL vsync issues

Matt Doran matt.doran at papercut.biz
Mon Jun 4 13:07:43 UTC 2007

Stuart Morgan wrote:
> On Monday 04 June 2007 13:29:08 Matt Doran wrote:
>>> As I've gone over a few times on the users list recently, the
>>> retrace-syncing methods require that your display's framerate be pretty
>>> close to a multiple of the video's framerate.  So watching a 25 Hz PAL
>>> recording on a 60 Hz display is unlikely to be good.
>> It is, I'm watching PAL 25Hz with a 50Hz refresh rate.
> Are you outputting to a TV? Is that an interlaced modeline? Something like the 
> following:
> Modeline "720x576" 12.85 720 752 800 832 576 589 592 605 -hsync -hsync 
> interlace
> I experience no such issues with progressive DVDs, yet I have both bob and  
> and OpenGL vsync enabled.
> I actually only need bob enabled for stuff recorded from my PVR 150. For DVDs 
> and DVB recordings it's not needed and I have noticed that the picture 
> quality drops a small amount on DVB and DVD when I have bob enabled.
Yes, I'm using a TV (Panasonic Plasma).  I'm connecting to the plasma 
over DVI->HDMI.   I'm using a progressive modeline, it's a very slightly 
modified version of the built-in 720p progressive modeline (version of 
the built-in 1280x720 progressive modeline).

I could try an interlaced modeline, but I'm not sure it's possible over 
DVI.  Is it?

If you user an interlaced modeline, I'd be using the TV's deinterlacer 
... which should be of a good quality, right?


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