bitblitting

Kristoffer Ericson kristoffer.ericson at gmail.com
Sun Nov 22 05:38:11 EST 2009


On Sun, 22 Nov 2009 06:04:15 +0100
Lars-Peter Clausen <lars at metafoo.de> wrote:

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> Kristoffer Ericson wrote:
> > Greetings,
> >
> > Could anyone point me in the direction of the video datasheets.
> > Noticed that we are using softbitblitting. Could be worth to see
> > what it offers.
> >
> > Best wishes Kristoffer
> Hi
> 
> The jz4740 has no gpu or whatever to accelerate graphics opertions.
> The video memory can be any arbitrary memory region in the system ram.
> Which is then written to by the cpu and read by the lcd controller,
> which sends the data to the lcd.

I noticed this when reading the datasheets last night.
> 
> One could try to use the dma engine and do mem-to-mem operations, but
> unless your image has the same width then the screen you'll have to
> transfer each line by itself. And I highly doubt that with that
> overhead there would be any significant performance gain.

I pretty much came to the same conclusion. 

> 
> But there is an ipu which does scaling and YUV to RGB conversion and
> can be used for video playback acceleration.
> 

Yeppers, that would be worth looking at.

> - - Lars
> 
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-- 
Kristoffer Ericson <kristoffer.ericson at gmail.com>




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