Bug 692261

Summary: IJS printer driver interface: "Unsupported color conversion request" in certain print quality modes
Product: Ghostscript Reporter: Till Kamppeter <till.kamppeter>
Component: Printer DriverAssignee: Default assignee <ghostpdl-bugs>
Status: RESOLVED INVALID    
Severity: normal CC: htl10
Priority: P4    
Version: 9.02   
Hardware: PC   
OS: Linux   
Customer: Word Size: ---

Description Till Kamppeter 2011-06-07 22:07:36 UTC
On Ubuntu Natty (Ghostscript 9.01) and Oneiric (Ghostscript 9.02) I have a problem with the IJS printer driver interface when used with the PXLJR driver (http://sourceforge.net/projects/hp-pxl-jetready/, in Ubuntu installed by default). The draft and normal printout modes of the driver make Ghostscript abort with a "Unsupported color conversion request" error, the high quality printout mode works correctly.

The Ghostscript command line for the draft mode is the following:

gs -dFirstPage=1 -q -dBATCH -dPARANOIDSAFER -dQUIET -dNOPAUSE -sDEVICE=ijs -sIjsServer=ijs_pxljr -sDeviceManufacturer="HEWLETT-PACKARD" -sDeviceModel="hp color LaserJet 3550" -dDEVICEWIDTHPOINTS=595 -dDEVICEHEIGHTPOINTS=842 -dDuplex=false -r600 -sIjsParams=Quality:Quality=1,Quality:ColorMode=2,Quality:MediaType=0,Quality:PenSet=2,PS:MediaPosition=7 -dIjsUseOutputFD -sOutputFile=- file.pdf > out.prn

file.pdf is an arbitrary PDF file.

grepping /usr/lib/ for the error message "Unsupported color conversion request" shows that it is only in libjpeg, but the problem occurs also with PDF files which contain only text.

In the case of failure, out.prn contains the following Ghostscript error message:

Error: /ioerror in --showpage--
Operand stack:
   1   true
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push   1910   1   3   %oparray_pop   1909   1   3   %oparray_pop   1893   1   3   %oparray_pop   --nostringval--   --nostringval--   2   1   3   --nostringval--   %for_pos_int_continue   --nostringval--   --nostringval--   1793   0   9   %oparray_pop   --nostringval--   --nostringval--
Dictionary stack:
   --dict:1167/1684(ro)(G)--   --dict:1/20(G)--   --dict:82/200(L)--   --dict:82/200(L)--   --dict:108/127(ro)(G)--   --dict:295/300(ro)(G)--   --dict:23/30(L)--   --dict:6/8(L)--   --dict:21/40(L)--
Current allocation mode is local
Last OS error: 32

For normal mode we have the same command line but with "Quality:Quality=0" and for the (working) high quality mode with "Quality:Quality=2".
Comment 1 Till Kamppeter 2011-06-07 22:10:20 UTC
This problem was originally reported at Ubuntu:

https://bugs.launchpad.net/gs-gpl/+bug/777670
Comment 2 Hin-Tak Leung 2011-06-09 03:55:42 UTC
The "Unsupported color conversion request" string comes from libjpeg. The draft and normal mode of pxljr uses libjpeg but the best quality mode does not, so this appear to be a pxljr<->libjpeg interaction problem. 

Either way, this particular issue does not belong to gs - there seems to be multiple problems in the launchpad report and I will look at that some day... (too busy at the moment).