[mythtv-users] Custom Modeline

Cory Papenfuss papenfuss at juneau.me.vt.edu
Sun Jun 20 12:34:23 EDT 2004

> Useful stuff to understand what's going on - I know I found it interesting so 
> I've added it for those who want to know
> see :
> http://www.mythtv.info/moin.cgi/ModeLinesHowTo/DoItByHand

 	OK... it looks hauntingly familiar... :)
> I'm afraid I agree with JDS on the usefulness of tools though - be it 
> videogen, a calculator or even those most primitive tools: pen and paper - 
> I'll bet you don't really advocate noobs do this stuff in their head do you?

 	Tools are good, and in general I'm a big fan.  I usually use one of the 
online "modeline generators" to either cook one up, or use a standard VESA mode 
as a starting point.  If someone is doing something as "advanced" as custom 
modelines to interface with finicky hardware, it's best they understand what 
they're doing so it doesn't melt.  Once upon a time I damaged my mac monitor by 
convincing the mac it could do 1024x768 at 75, when in reality it could only do it 
at 70Hz... never did sync right after that.

 	Definately not a noob maneuver.  Modelines aren't that complicated 
though, and it seems like many people blindly paste them into the file to see 
if they work.  In most cases, the hardware is idiot-proof, but sometimes it's 

 	It gets really ugly when you're using a TVOUT vidcard, because the 
modeline is only loosely related to what comes out the TV.  After all, there's 
scan conversion going on, often with little or no knowledge or configurability. 
I had to get the modeline absolutely correct for my setup, as the output is 
going straight to the TV.  I'm sure it wouldn't like running at 16kHz instead 
of 15.7kHz.  It might sync on it and run.... for a little while.


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