RFC: Xv field order

[Thomas Hilber]

On Tue, Jun 23, 2009 at 03:54:03PM +0200, Krzysztof Halasa wrote:
> DRM level. Unless I'm mistaken the patches don't touch the field order
> and sync, at least on the intel and/or i915 driver.

with a slight modification the patches can output BFF or TFF.
But I'm living in PAL land so I use TFF only ATM.

> going to implement is the BFF/TFF(/progressive) interface at XVideo and

what do you mean with progressive here? Do you mean 2 interlaced
fields in weaved format?

The vga-sync-fields patches effectively use these 2 weaved fields of 
softdecoder output and forward these directly to VGA/DVI output. To keep
synchronicity between stream and video timing the output line frequency
is continuously trimmed in very small steps. This works very well even
for live-TV where you must adopt exactly the stream clock delivered by
the TV station.

Trimming the graphics card video timing ensures that the weaved fields
always appear at the right time in the double buffer of graphics card.
Video output is interlaced. It's the task of the display to take care
of deinterlacing (if needed).
This relieves the PC from CPU intensive deinterlacing. So the patches work
very well with Asus EEE 701 or Intel D945GSEJT.

> DRM level. Unless I'm mistaken the patches don't touch the field order
> and sync, at least on the intel and/or i915 driver.

moving the sync point by 20ms yields in reversed field order output

Cheers
   Thomas