[vdr] Re: fonts

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Alessio Sangalli wrote:
> 
> Klaus Schmidinger wrote:
> 
> > Actually the large center part of the OSD has 2 bpp.
> 
> mh... I didn't explained well.
> 
> How many colors are avaiable at a time on a OSD page? let's call this n,
> and I think to understand we have n=4 (2bpp).
> 
> Now each character is coded in a bitmap that can contain 1 or 0: if it's
> 0 the background color will be used, if it's 1 the foreground. We can
> choose bkg and frg from those n (4) colors.

You're forgetting that the four colors are already all used to display
background and foreground for both normal and highlighted (i.e. cursor) mode.
There is no way of having color shades for antialiasing with only 4 colors
in the OSD.

> To have antialiasing for the fonts we should have few different degrees
> of the foreground color when we render a character; for subpixel
> rendering we should have direct access to each rgb component of the pixel.
> 
> > OSD memory is ************EXTREMELY************** limited.
> > You won't be able to use a decent sized OSD with even 4bpp.
> 
> mh...
> in another post you say they only put 2MB (so much? is it perhaps Mbits?
> 2MB would be enough to have a 800x600 true color display) on the board.
> Is there a DVB-board hacker that can find out if we can change the
> memory modules to relase the full potential of the board?

AFAIK that memory is mainly used for the MPEG decoder. It's thanks to Ralph
Metzler that it is at all able to support the degree of OSD that's working
right now.

Klaus
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Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
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