[maemo-developers] [maemo-developers] SDL vertical blank (vbl) sync.

[From: Visti Andresen]

On Mon, 29 May 2006 16:50:50 +0200
Frantisek Dufka <dufkaf at seznam.cz> wrote:

> Juha Yrjölä wrote:
> 
> > Unfortunately we don't provide user-space with the vsync information (or 
> > "Tearing Effect" signal, as it's called in LCD land).
> > 
> > If there's large enough need for this, we might consider implementing 
> > the support.  The tearing effects should be minimal on the 770, however, 
> > because of the high (around 55 Hz) refresh rate of the display.
> > 
> 
> Hello,
> 
> well the effect is visible even when playing the Ice Age Trailer (I 
> suppose it is not already in the movie data). I think such feature is 
> quite useful for games and movie playback. BTW how big is the 
> framebuffer memory? Is there space for 2 frames so double-buffering is 
> possible? Also is there some datasheet for the Epson hwa742 chip? Can 
> you make it public? I tried to google for it (and for lph8923 too) but 
> found nothing useful. Thanks.

My "flashingTest" reports that:
It got a hardware surface (I should be writing directly to "video memory" accordingly to the SDL docs)
And the surface is double buffered.

The size of the surface is 800x480 16 bit (R5G6B5)
So there should be at least 1536000 bytes of video memory

I suppose the kernel display driver is open-source? 

> 
> Frantisek
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