[mythtv-users] TV Output

Mark Wormgoor mark at wormgoor.com
Fri Dec 24 14:36:22 UTC 2004


Hi,

> >Yeah, I had pretty much the same problem. In the end I got the
> >following numbers directly from the PAL signal specification:
> >
> >Horizontal Frequency = 15.625kHz
> >Vertical Frequency = 50Hz
> >Horizontal lines (total) = 625
> >Horizontal lines (visible) = 576
> >Horizontal Front Porch = 1.5µs
> >Horizontal Sync Width = 4.7µs
> >Horizontal Back Porch = 5.8µs
> >Horizontal blanking period = 12µs
> >Vertical Front Porch = 0.16ms
> >Vertical Sync Width = 0.16ms
> >Vertical Back Porch = 1.28ms
> >Vertical blanking period = 1.6ms
> >
> >As you noticed, Nvidia restrict some of the values in their modelines
> >to multiples of 8. Taking that into account this is the closest
> >possible modeline for 720x576 to the PAL spec:
> >
> >ModeLine "720x576pali" 13.875 720 744 808 888 576 581 586 625 -hsync
> >-vsync interlace

> I don't suppose you have a simliar spec for a progressive PAL image do 
> you?  (I have the Key Digital VGA to Component adapter)
> 
> I generated one based off a Powerstrip mode to get 1024x576 which gives 
> an awesome picture, but I'm not sure whether it's entirely in spec as 
> the TV's input identifier is flashing in the corner, which apart from 
> being really annoying probably means that the signal is not entirely in 
> spec.  (The TV's a Panasonic 36PD30 if it makes any difference)

Progressive PAL is exactly the same as regular PAL, but you need to drop
the "interlace" in that line.  Simple as that.

Kind regards,

Mark Wormgoor




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