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

Martin Emrich emme at emmes-world.de
Wed Jul 23 15:06:59 CEST 2008


Hi!

Thomas Hilber schrieb:
> On Wed, Jul 23, 2008 at 12:12:46AM +0200, Martin Emrich wrote:
>> I have connected my VDR box to my TV via a DVI-to-HDMI cable, set the
>> resolution to 1920x1080 and let the graphics card do the upscaling
>> instead of the TV, because the quality looks IMHO better this way. But
> 
> ok. But if doing so you still have to continue deinterlacing in
> software. This is because any scaling in Y dimension intermixes even/odd
> fields in the frame buffer. Finally producing a totally messed VGA output 
> signal.

Of course. As I also use other applications on the box (mplayer, photo
viewing), neither reducing the resolution nor enabling interlacing
(1080i) is desired.

Software deinterlacing is no problem, from time to time I experiment
with all the interlacer options. (I wonder why there's no simple "TV
simulator" that upmixes 50 fields/s to 50 frames/s just like a CRT TV?).

> right. Even if you still must use software deinterlacing for some reason
> you benefit from the 'sync_fields' patch. You then can enable
> sync-to-vblank and the patch dynamically synchronizes graphics card's vblanks
> and TV signal's field updates. Thus avoiding unsteady frame rates at
> VGA/DVI/HDMI output.

Ok. I'm really busy currently (but your project looked so cool that I
just *had* to write an email to the list), but as soon as I get to it,
I'll try to make it work.

Does anyone have a 1080p at 50Hz modeline ready? Currently, I use the
settings provided by the TV via EDID, and I guess it defaults to 60Hz :(

>> I wonder if your patch could be applied to a DVI/HDMI connection, too?
>> Its a Radeon X850 currently with xf86-video-ati 6.6.3 and xorg-server 1.4.
> 
> In your case the only prerequisite is support of your Radeon X850 by Radeon 
> DRM driver. DRM normally is shipped with kernel. So this is a kernel/driver
> issue. But I don't expect problems here though I not yet testet the 
> X850 myself (yet).

As the box runs a home-built netboot mini distro, I am quite flexible
regarding kernel versions. As soon as I have some spare time (probably
after I finished my BA thesis :(, I get to it...

Ciao

Martin



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