[Intel-gfx] VGA to PAL RGB

[Thomas Hilber]

[ SORRY MY PREVIOUS POST IS VOID, IF POSSIBLE PLEASE REMOVE IT FROM THE
LIST - THANK YOU ]

On Tue, Jul 22, 2008 at 10:46:39PM +0200, Thomas Elsen wrote:
> 
> The problem with the current drivers is that the minimal dot clock is 
> defined as 25Mhz. I'd like to know if this is a hardware limitation and, 
> if not, what should be done to run the clock at 14,76Mhz.

For my current project

english:
http://linuxtv.org/pipermail/vdr/2008-July/017347.html

german:
http://www.vdr-portal.de/board/thread.php?threadid=78480

I experiment a lot with VGA->SCART adaptors. In the meantime I
get excellent picture quality on Radeons like (7000, 9200SE, 9250,
9600SE, IGP-9100). This is because no deinterlacing at all takes place any
more. I route the untouched fields from softdecoder straight to the VGA
port! A new synchronization mechanism avoids any field loss. Please see
links above for more information.

Yesterday I started to port this thing to intel DDX. Please find
attached a patch that allows you to use such low dot clocks on intel 
hardware. I don't know what these limits in the standard intel code are good
for. BTW I use a thinkpad with mobile GM965/GL960 chipset for my tests.
Maybe you must adapt the patch to your needs.

But there exist still some issues with intel-gfx and interlaced modes:

Using the overlay XV adaptor I only get a green picture...
Using the textured XV adaptor the picture is vertically stretched (if not
doubled)...

So for the moment I stopped further activities with intel-gfx.

Maybe the situation has improved since xf86-video-intel 2.4.0. I haven't had
the time yet to give it a try.

-Thomas
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