[cups.development] Pseudo duplex mode for several printers

Aurélien Croc aurelien at ap2c.com
Thu Oct 18 13:51:48 PDT 2007

I'm quite agre with you and i'm waiting for PDF as a standard in the  
UNIXes printing systems!!
But like you said, if rastertospl2 makes that work, it would take a  
LOT of space on disk and lot of time to process.
About the rotation of the page, it's not a problem. But i would  
prefer to use an extern program to reorder the postscript.

Currently, since my printer doesn't support duplex, i simulate the  
duplex by printing manually the even pages then the odd one. It's a  
common option available in lots of applications. So does it exist an  
application that can extract the odd and next the even pages and then  
give the result to ghostscript to convert it to CMYK?


Le 18 oct. 07 à 22:37, Till Kamppeter a écrit :

> Probably it is more reliable to let the rastertospl2 driver do this  
> work
> (you probably thought in delegating it to pstops).
> Page reordering, scaling, and so on is currently done by the pstops
> filter. Unfortunately PostScript is not designed well enough to force
> every Postscript file to have easily distinguishable pages. Later the
> DSC comments were defined to have the possibility to make a
> well-structured Postscript where one really can distinguish the pages,
> but many applications produce a PostScript which is not DSC- 
> conforming.
> To solve this problem in the future, PostScript will be replaced by  
> as standard print job format (decided on the Printing Summit in April
> 2006 in Atlanta). In PDF files you can always separate the pages.
> So for now it is better to go to a later step of the filter chain,  
> where
> the data is already in the CUPS raster format or even in the printer's
> native format. Here it is very well defined where one page ends and  
> the
> next one starts, only disadvantage is that the data chunks  
> representing
> the pages are much bigger than in the PostScript stage, so more disk
> space for temporary files is needed for the reordering. This would  
> mean
> that you reorder the pages in rastertospl2. Also rotating pages by 180
> degrees is probably more reliable with bitmaps. You could stream the
> incoming data into two temporary files, one with the even and one with
> the odd pages, after that you stream out one file and then the other.
>     Till
> Aurélien Croc wrote:
>> Hi,
>> I'm the main developer of the SpliX CUPS driver (driver for QPDL
>> printers (Samsung, Xerox, Dell, Ricoh) and i'm working on the "pseudo
>> duplex" mode which is available in several samsung printers.
>> This pseudo duplex mode prints the even inversed pages, waits the  
>> user
>> get the printed sheets, puts them in the printer and press a button,
>> then prints the odd pages.
>> Unfortunatly, this options needs that the document struct must be
>> "altered": the inverted even pages must be placed before the odd  
>> pages..
>> Finally the driver needs to know where is the first odd page to  
>> change
>> several bytes sent to the printer (to specify to the printer that the
>> next pages are odd pages).
>> So, i'm wondering how CUPS can help my driver by giving to it  
>> pages in
>> this special order (and rotation) ?
>> Is it a way to do that? Is it "impossible"?
>> Regards,
>> Aurélien
>> -- 
>> M. Aurélien Croc
>> Projet AP²C - http://www.ap2c.org
>> Clef Publique : http://www.ap2c.org/aurelien.gpg
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M. Aurélien Croc
Projet AP²C - http://www.ap2c.org
Clef Publique : http://www.ap2c.org/aurelien.gpg

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