[vdr] RGB/PAL over VGA at variable frame rate

Torgeir Veimo torgeir at pobox.com
Wed Jul 23 10:04:29 CEST 2008


On 23 Jul 2008, at 02:37, Thomas Hilber wrote:

> To a certain degree you can workaround this by software deinterlacing.

> After some further experimenting I finally found a solution to fine  
> adjust the
> frame rate of my elderly Radeon type card.

> Just trimming the length of a few scanlines during vertical retrace
> period does the trick.
>
> Then I tried to implement the new functionality by applying only  
> minimum
> changes to my current VDR development system. Radeon DRM driver is  
> perfectly
> suited for that.

> I finally ended up in a small patch against Radeon DRM driver and a  
> even
> smaller one against xine-lib.

Your approach is very interesting, I myself have seen the problems  
that clock drift has on judder when using softdevice with vdr.

Have you considered applying your approach to DirectFB? There's a  
radeon driver which is not too hard to change, it also has a kernel  
module which could be augmented by using an ioctl command.

In addition, you might want to try out your approach with a matrox  
G550 card. These have field perfect interlaced output using DirectFB,  
so you'd have that part of the problem solved already.

-- 
Torgeir Veimo
torgeir at pobox.com







More information about the vdr mailing list