[gs-devel] Re: [Gimp-print-devel] IJS breaks with large raster images

[Robert L Krawitz]

   Date: Fri, 31 May 2002 19:53:48 +0200
   From: Till Kamppeter <till.kamppeter@gmx.net>

   Now both times with "export STP_DEBUG=-1", once with and once without 
   "strace -f":

   wget http://www.linuxprinting.org/till/tmp/GS-IJS-A1-strace-f-DEBUG.txt
   wget http://www.linuxprinting.org/till/tmp/GS-IJS-A1-DEBUG.txt

   I hope this helps.

Never mind.  It isn't dumping core.  It's getting an IJS_ERANGE error:

#define IJS_ERANGE         -4  /* out of range */

This is actually a bug in (at least) the ijsgimpprint driver.  It's
overflowing 31 bits.  How do you like that?

      img.total_bytes = ((ph.n_chan * ph.bps * ph.width + 7) >> 3) 
	* ph.height;

So let's plug in some numbers -- 24" wide, 33" long, 1440x720 DPI, 3
channels, 8 bps:

[2(rlk)||{!13}<dsl092-065-009>/home/rlk/sandbox]
$ expr 1440 \* 720 \* 24 \* 33
821145600
[2(rlk)||{!14}<dsl092-065-009>/home/rlk/sandbox]
$ expr 1440 \* 720 \* 24 \* 33 \* 3
-1831530496

Oops.  This should fix it (at least on the ijsgimpprint side).
However, it's a rather ugly fix, and I really don't know why I did it
this way, rather than doing it in terms of rows.  It really should
count rows.

*** ijsgimpprint.c.~1.10.~	Wed Apr  3 19:08:35 2002
--- ijsgimpprint.c	Fri May 31 19:21:55 2002
***************
*** 83,90 ****
    int row;		/* row number in buffer */
    int row_width;	/* length of a row */
    char *row_buf;	/* buffer for raster */
!   int total_bytes;	/* total size of raster */
!   int bytes_left;	/* bytes remaining to be read */
    GimpParamList *params;
  } IMAGE;
  
--- 83,90 ----
    int row;		/* row number in buffer */
    int row_width;	/* length of a row */
    char *row_buf;	/* buffer for raster */
!   double total_bytes;	/* total size of raster */
!   double bytes_left;	/* bytes remaining to be read */
    GimpParamList *params;
  } IMAGE;
  
***************
*** 664,680 ****
  image_next_row(IMAGE *img)
  {
    int status = 0;
!   int n_bytes = img->bytes_left;
    if (img->bytes_left)
      {
  
        if (n_bytes > img->row_width)
  	n_bytes = img->row_width;
  #ifdef VERBOSE
!       STP_DEBUG(fprintf(stderr, "%d bytes left, reading %d, on row %d\n", 
! 			bytes_left, n_bytes, img->row));
  #endif
!       status = ijs_server_get_data(img->ctx, img->row_buf, n_bytes);
        if (status)
  	{
  	  STP_DEBUG(fprintf(stderr, "page aborted!\n"));
--- 664,680 ----
  image_next_row(IMAGE *img)
  {
    int status = 0;
!   double n_bytes = img->bytes_left;
    if (img->bytes_left)
      {
  
        if (n_bytes > img->row_width)
  	n_bytes = img->row_width;
  #ifdef VERBOSE
!       STP_DEBUG(fprintf(stderr, "%.0f bytes left, reading %.d, on row %d\n",
! 			img->bytes_left, (int) n_bytes, img->row));
  #endif
!       status = ijs_server_get_data(img->ctx, img->row_buf, (int) n_bytes);
        if (status)
  	{
  	  STP_DEBUG(fprintf(stderr, "page aborted!\n"));

-- 
Robert Krawitz <rlk@alum.mit.edu>      http://www.tiac.net/users/rlk/

Tall Clubs International  --  http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom -- mail lpf@uunet.uu.net
Project lead for Gimp Print/stp --  http://gimp-print.sourceforge.net

"Linux doesn't dictate how I work, I dictate how Linux works."
--Eric Crampton