I have done some tests by using different combinations of Lucid and
Oneiric for the two steps evince creating the print job (it is already
PDF in Lucid) and Ghostscript rendering the PDF to PCL-XL using the
command line shown in the initial description of this bug.

First off, adding "-dNOINTERPOLATE" does not give any speed advantage
for the "pxlmono" driver which is a vector driver. It seems only to
accelerate rastering as it is done for raster drivers like "cups" or
"ljet4". This is valid for both Lucid and Oneiric.

Then I have let evince generate PDF print output (can be done as
described in "Capturing print job data" on
https://wiki.ubuntu.com/DebuggingPrintingProblems or by selecting "Print
to file" as the printer and PDF as output format) on both Lucid and
Oneiric. In Lucid the file is huge compared to the original PDF:

till@till:~/ghostscript/testfiles$ ll M170931*
-rw-r----- 1 till till 1649229 2011-11-25 12:13 M170931-evince-lucid.pdf
-rw-r--r-- 1 till till   63510 2011-11-25 12:13 M170931-evince-oneiric.pdf
-rw-rw-r-- 1 till till   61019 2011-11-24 18:36 M170931.pdf
till@till:~/ghostscript/testfiles$

Then I ran the resulting PDF of Lucid through the command line of the
bug description on both Lucid and Oneiric. Under Lucid Ghostscript
errored out after around 12 minutes, probably running out of memory
(virtual machine is 64-bit with 2G of RAM). On Oneiric (on the host of
the virtual Lucid machine) the PDF was correctly rendered in around 4
minutes, also not very fast, but one sees at least some acceleration and
higher reliability with the new Ghostscript.

Next step was running Oneiric's print job through Ghostscript on both
systems. The rendering of Ghostscript was significantly faster, on Lucid
I got correct rendering in around five seconds and on Oneiric it took
less than 1/10 of a second.

This means that the best effect will be reached by backporting Oneiric's
Cairo and Poppler. Perhaps it is even enough to only apply the patches
of bug 680628 to the Lucid packages. This could even be issued as an SRU
for all users. It must be tested whether these changes are the only
fixes for output file size and rendering speed issues or whether there
are more fixes in evince/cairo/poppler.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/891026

Title:
  PDF printing from Evince through CUPS is very slow, sometimes fails

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/cups/+bug/891026/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to