[mythtv-users] [ G400 ] Hotwo enable flicker filters

[Cory Papenfuss]

> This defines an interlaced 768x576 mode with 14.76 MHz pixelclock at 50Hz. As 
> far as i know, exactly what PAL is defined at. But: If i use this mode i will 
> get an skewed image. It's displayed two times (at lower and upper half of 
> tv).
 	I have noticed that a large number of video drivers have bugs when 
it comes to displaying interlaced output.  I once tried to use an ATI card 
to generate interlaced output on the framebuffer (so I could see the 
bootup screen).  I ran into limitations of the framebuffer driver on that 
card (although I can't remember specifically what it was).  I'd bet that's 
what you're running into... it seems like it should go.

 	One thing you *might* want to try is different combinations of 
low|high for hsync/vsync/csync.  It sounds like the framebuffer memory 
is being written correctly, but the field-sync isn't being generated.

> Yes i know. But what i've in mind is to enable flicker filtering for the 
> MythTV GUI and disable it for video display.
>
 	I'm not sure exactly what you're trying to do with multiple heads, 
etc.  It sounds overly complicated.

> I think the fonts do not make so big problems like the single lined borders 
> of the mythvideo or mythmusic gui. A simple workaround is to use very big 
> fonts. So there aren't so many single horizontal lines. Maybe there is a 
> workaround for the GUI too. Any suggestions?
>
 	100dpi fonts.  I think MythTV uses the newer vector fonts 
(TrueType), but I'm not sure.  I don't know if those have a notion of 
optimal display on interlaced screens.


 	I don't understand exactly why you're using the framebuffer at 
all.  Unless you *really* want to see the console during bootup, can you 
just wait for X to fire up with the correct timings?  You will have 
unaccelerated video playing if done via a framebuffer, whereas with X (no 
framebuffer) you have the potential of using Xv or XvMC.

-Cory


*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
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