[mythtv-users] bob deinterlace and 50Hz refresh rate questions

Magnus Sandin magnus at sandin.cx
Wed May 17 05:14:37 UTC 2006


Hello!

I've been using MythTV for quite some time now on my PAL TV which works 
great.
However I also have a projector with the native resolution 1024x576 
which I've previously feed with a S-Video signal. It would however be 
really nice to feed it with DVI or VGA with its native resolution 
(1024x576).

Since I live in PAL land I would like to have 1024 x 576 @ 50Hz to get 
the picture smooth.

The problem is that when using the modeline that looks nice on the 
projector (the pixels from the output signal line up correctly with the 
ones in the projector), BOB DeInterlacing wont work.

The message from the frontend is: "frame rate (refresh rate too low for 
bob deint)".

* What determines if the refresh rate is high enough in MythTV to do BOB 
DeInterlace (the vertical refresh rate is 50Hz in both modelines, right?)?

I'm going to split my system, so the current combined frontend and 
backend will be backend only and I will build a completely new frontend.
Any suggestions on which video card, etc. to put into the new frontend 
would be apriciated.

Information about my system:

This is the modeline which looks good, but without bob deinterlace.
Modeline "1024x576 at 50Hz"  37.95  1024 1048 1152 1280  576 577 580 593  
-HSync +Vsync # 50Hz no bob

This is the modeline where the pixels don't line up, but where bob 
deinterlace works.
Modeline "1024x576x50Hz"   39.5 1024 1056 1152 1264 576 581 586 625 
+hsync +vsync  # 50 Hz

* Ubuntu Breezy Badger, kernel 2.6.15.7
* MythTV 0.19.1 SVN (9409)
* nVidia GeForce4 MX 4000 AGP
* nVidia driver version 7676
* Using OpenGL VSynch


Regards
// Magnus Sandin


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