[mythtv] Ticket #2903 is necessary to achieve perfect playback with an interleaved display mode.

[mythtv-dev at toh.cx]

On Mon, Mar 23, 2009 at 12:50:40PM +0000, Paul Gardiner wrote:
> I've just started working on the one remaining problem, which
> is that there is nothing keeping the interlaces in sync between
> content and display. Half the time I get perfection, half the time
> I get terrible combs. I believe this is a well known problem. I can
> hit "back" a few times when this happens and get it back in sync.

I'm experimenting with VGA2SCART for various graphics cards since a while.
In the course of that I solved the issue to keep in sync with current 
field polarity.

Since August 2008 patches are available for ATI Radeon cards. Newer 
versions of my patch called 'vga-sync-fields' are also suitable for 
Intel i9xx chipsets.

With D945GCLF or D945GCLF2 you can setup a very cheap but high quality 
SCART DVB receiver.

Current field status is monitored continuously by the 'vga-sync-fields' patch.
VGA output frequency is adjusted dynamically in very small degrees to keep
in sync with DVB stream.

The patch will be integral part of easy-vdr distribution soon. It is
primarily written for VDR running xine. But it should't be a big deal to
port it to mythtv. 

Most references to my project are in German. Here are 3 of them:
http://www.vdr-portal.de/board/thread.php?threadid=78480
http://www.vdr-portal.de/board/thread.php?threadid=79536
http://www.easy-vdr.de/forum/index.php?topic=6072.msg45309#msg45309

Further references in English:
http://vga2scart.gw90.de/
http://www.spinics.net/lists/vdr/msg17317.html
http://lowbyte.de/vga-sync-fields/vga-sync-fields/README

Snapshots:
http://lowbyte.de/vga-sync-fields/

Current development:
git clone git://vga2scart.gw90.de/git/vga2scart

Cheers 
  Thomas