From: Branimir Maksimovic on
Alexei A. Frounze wrote:
> On Nov 13, 5:48 am, Herbert Kleebauer <k...(a)unibwm.de> wrote:
>> Branimir Maksimovic wrote:
>>>>> He said decoding 800x600 jpeg pictures is very slow.
>>> I will if we don;t succeed to achieve time of 5 seconds per
>>> picture.
>>> Damn external memory ;)
>> 5 seconds for one 800x600 jpeg? There must be some infinite loop
>> in the code.
>
> 5 secs for a 800x600 pic at 56MHz is ~600 clocks/pixel. A lot, but not
> insane. I'd suggest to look into the algorithm/implementation and
> memory I/O. Perhaps some reordering/caching and algo/impl improvements
> can help.
>
> Alex

Os was dumped. When you do memcpy in linux buffer, you can see lines
comming out on LCD!

Actuall speed is 30 sec per 800x600 picture when executing from
external SDRAM ;)

So we have 512k flash rom and 64kb of ram free on local bus.
So task is to do maximum operations in that ram and
minimise use of 32 MB of sdram.

I think any algorithm will do, shorter the better.

Greets!