Should the CUPS Raster outputdevice ofGhostscript output compressed or uncompressed Raster data?

Heino Goldenstein heino.goldenstein at microplex.de
Wed Jul 7 15:32:06 PDT 2010


On Jul 7 13:34 Till Kamppeter wrote (shortened):

> If the printer understands CUPS Raster by default or can auto-detect
> CUPS Raster, you could use "-" as driver filter name, which means no filter:
>
> *cupsFilter:    "application/vnd.cups-raster 0 -"
>
> This makes CUPS sending CUPS Raster to the backend.

As IDOL supports greater than thirty emulations and the incoming
print data is mainly a stream of bytes with no explicit start
markers your chance to auto-detect the right emulation is quite
small. Better set it explicit prior with a command or if you
only need one emulation set it as power up default in the printer.
The solution with the rastertoidol script gives you here the
greatest flexability. And as it is only a script it is quite
easy to set up. Put it at the right destination and you are done.
An now there is also the possibility to remove the filter for
e.g. greatest performance.

> I also suggest to either add a PPD extention to select CUPS Raster v2
> output or to output CUPS Raster v2 in the case that there is no filter
> afterwards (final format is CUPS Raster). As IPP Everywhere defines CUPS
> Raster as a standard input format for printers, there will be more CUPS
> Raster printers in the future. So we will need support for compressed
> CUPS Raster.

That was the reason I filed
http://bugs.ghostscript.com/show_bug.cgi?id=689885
I found that the code for the output of cups-raster version 2 was
already there and only a mechanism to select it was missing.
There are situations where the compressed data is larger than
the uncompressed data so it is better to be able select it
explicit.

Kind Regards
Heino Goldenstein




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