Re: [pdf-devel] DCT implemenet

[gerel]

 > Date: Sat, 6 Dec 2008 11:52:42 +0800
 > From: "=?GB2312?B?0e6zo7uq?=" <address@hidden>
 > 
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 > Content-Type: text/plain; charset=ISO-8859-1
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 > Content-Disposition: inline
 > 
 > Hi,
 > 
 > I'm writing DCT filter.I've some issues to discuss with you.
 > 
 > 1. For the base layer, should the input and output  be file or memory? Or
 > both?
 > 
 > 2. How to get the parameters for encode, e.g. the image size? If in the hash
 > table filter_params, should I add the key name of the parameters in
 > pdf-stm.h?
 > 

Hi Yank, for both questions I recommend you to read some already implemented
filter like, pdf-f-ahex. I'll give you some hints anyways.
The input and output are two buffers, whether on disk or memory should not be of
your concern.
You can read more here:
http://gnupdf.org/Lib:Architecture/Base_Layer/Stream_Module#Buffers

Regarding the parameters you only ask for the key, as it's supposed to be 
already
added prior the filter's call.

Hope it helps,

-gerel