home *** CD-ROM | disk | FTP | other *** search
- xpdf
- ====
- and pdftops
-
- version 0.6 (beta)
- 96-nov-12
-
- The xpdf and pdftops software and documentation are
- copyright 1996 Derek B. Noonburg.
-
- Email: derekn@ece.cmu.edu
- WWW: http://www.contrib.andrew.cmu.edu/usr/dn0o/xpdf/xpdf.html
-
- The PDF data structures, operators, and specification
- are copyright 1995 Adobe Systems Inc.
-
-
- What is xpdf?
- -------------
-
- Xpdf is a viewer for Portable Document Format (PDF) files. (These are
- also sometimes also called 'Acrobat' files, from the name of Adobe's
- PDF software.) Xpdf runs under UNIX or VMS and the X Window System.
-
- Xpdf is designed to be small and efficient. It does not use the Motif
- or Xt libraries. It uses standard X fonts. Xpdf is quite usable on a
- 486-66 PC running Linux.
-
-
- Compatibility
- -------------
-
- Xpdf is known to work on the following systems:
-
- * x86, Linux 2.0 ELF, gcc 2.7.2
- * PowerPC, AIX 4.1, gcc 2.7.0
- * SPARC, Solaris 2.5, gcc 2.7.2
- * Alpha, OSF/1 3.2, gcc 2.7.2
- * HP-PA, HP-UX 9.05, gcc 2.7.2
-
- It should work on pretty much any UNIX or VMS system which runs X11.
- You'll need ANSI C++ and C compilers to compile it. If you compile it
- for a system not listed on the xpdf web page, please let me know. If
- you're willing to make your binary available by ftp or on the web,
- I'll add a pointer to the web page. If you can't get it to compile on
- your system, I'll try to help.
-
-
- Getting xpdf
- ------------
-
- The latest version is available from:
-
- http://www.contrib.andrew.cmu.edu/usr/dn0o/xpdf/xpdf.html
-
- or:
-
- ftp://ftp.andrew.cmu.edu/pub/xpdf/
-
- Source code and several precompiled executables are available.
-
- Announcements of new versions are posted to several newsgroups
- (comp.text.pdf, comp.os.linux.announce, and others) and emailed to a
- list of people. If you'd like to receive email notification of new
- versions, just let me know.
-
-
- Running xpdf
- ------------
-
- To run xpdf, simply type:
-
- xpdf file.pdf
-
- To generate a PostScript file, hit the "print" button in xpdf, or run
- pdftops:
-
- pdftops file.pdf
-
- Command line options and many other details are described in the man
- pages (xpdf.1 and pdftops.1) and the VMS help files (xpdf.hlp and
- pdftops.hlp).
-
-
- Fonts
- -----
-
- Xpdf uses X server fonts. It requires the following fonts:
-
- * Courier: medium-r, bold-r, medium-o, and bold-o
- * Helvetica: medium-r, bold-r, medium-o, and bold-o
- * Times: medium-r, bold-r, medium-i, and bold-i
- * Symbol: medium-r
- * Zapf Dingbats: medium-r
-
- Most X installations should already have all of these fonts, except
- Zapf Dingbats. You can install a Type 1 Zapf Dingbats font -- see the
- mkfontdir(1) man page for details. Use this font descriptor in your
- fonts.scale file:
-
- -itc-zapfdingbats-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific
-
- You can get a Type 1 font file from the ghostscript 4.x distribution
- (look for d050000l.pfb).
-
- X servers, starting at R5, support font scaling. Xpdf will
- automatically take advantage of this. There are two types of scaling.
- The first type uses standard bitmap fonts: if a font doesn't exist in
- the requested size, the server will scale the bitmapped characters.
- This is reasonably fast, and the results are readable but not very
- pretty. X servers can also handle true scalable, e.g., Type-1, fonts.
- (See the mkfontdir(1) man page for details on setting these up.)
- Scalable fonts are slower, especially since PDF documents tend to use
- lots of fonts, but they look much nicer.
-
- Some X servers also support font rotation. Xpdf will use this feature
- if available.
-
-
- The Unisys LZW Patent
- ---------------------
-
- Nearly all PDF files include data which has been compressed with the
- LZW compression algorithm. Unfortunately, LZW is covered by a
- software patent which is owned by Unisys Corporation. Unisys refuses
- to license this patent for PDF-related use in software such as xpdf
- which is released for free and which may be freely redistributed.
- (This is same algorithm which is used by GIF. However, Unisys is not
- doing licensing for free PDF viwers in the same way as for free GIF
- viewers.)
-
- As a workaround, xpdf converts PDF-format LZW data to compress-format
- LZW data. (The standard UNIX compress utility also uses LZW, but with
- a slightly different file format.) This conversion does *not*
- decompress the data; it simply converts it to a different file format.
- Xpdf then calls uncompress to actually decompress the data.
-
- I have been told by several notable people that the LZW patent covers
- compression only, and does not cover decompression. This seems pretty
- fuzzy to me, so I'm going to stick with my workaround, at least for
- now.
-
- Software patents in general are a bad idea. Consider supporting the
- League for Programming Freedom <http://www.lpf.org/>.
-
- For Unisys's slant on things (mostly regarding GIF), see
- <http://www.unisys.com/LeadStory/lzwterms.html> and
- <http://www.unisys.com/LeadStory/lzwfaq.html>. These pages mention
- an email address for feedback.
-
-
- Compiling xpdf
- --------------
-
- Xpdf is written in C++ (with a little bit of C). It should work with
- any ANSI-compliant C++ and C compilers. The systems and compilers
- it's been tested with are listed on the xpdf web page.
-
- To compile xpdf for UNIX:
-
- * Edit Makefile.config in the top-level directory. Set the compilers
- you want to use (e.g., gcc and g++) and add any necessary switches
- and options (e.g., include and library directories). You can also
- set the installation directory here (the PREFIX variable).
-
- * If neither 'uncompress -c file.Z' nor 'gzip -d -c file.Z' decompress
- a standard UNIX .Z file to stdout on your system, you'll need to
- change uncompressCmd in xpdf/config.h. This should not be necessary
- on most systems.
-
- * Type 'make' in the top-level directory to compile both xpdf and
- pdftops. If you only want to make one of the executables, type
- 'make xpdf' or 'make pdftops'.
-
- * If nothing goes wrong, the executables will be left in xpdf/xpdf and
- xpdf/pdftops. There are no runtime configuration or support files;
- the binary can be moved to any directory.
-
- * If desired, type 'make install' to install the binaries and man
- pages.
-
- To compile xpdf for VMS:
-
- * There are two sets of scripts: vmscomp.com (for gcc on VAX) and
- vmsdecccomp.com (for DEC C on Alpha). There are four of each: in
- the top-level directory, [.goo], [.ltk], and [.xpdf]. You may need
- to edit these scripts as appropriate for your system.
-
- * The 'stddef.h' include file which comes with older versions of gcc
- may be missing a definition for wchar_t. In this case, add the
- following lines:
- -----
- File GNU_CC:[INCLUDE]STDDEF.H;2
- 44 /* Wide characters, not yet supported by VAXCRTL [match VAXC's <stddef.
- 45 #if !defined(_WCHAR_T) && !defined(_WCHAR_T_)
- 46 typedef unsigned int wchar_t;
- 47 #endif
- 48 #define _WCHAR_T
- 49 #define _WCHAR_T_
- 50
- -----
-
- * Type '@vmscomp' or '@vmsdecccomp' in the top-level directory.
-
- * The executables will be left in '[.xpdf]xpdf' and '[.xpdf]pdftops'.
-
-
- Distribution
- ------------
-
- Xpdf may be distributed under the following conditions:
-
- 1. This file ('README') is included, unmodified, in the distribution.
-
- 2. The distribution includes:
- a. all of the xpdf source code and documentation, unmodified; OR
- b. one or more xpdf executables, compiled from the unmodified
- source code, plus the associated documentation (UNIX man pages
- or VMS help files); OR
- c. both of the above.
-
- If you distribute xpdf, I would appreciate receiving a pointer (ftp
- site, BBS phone number, etc.) or a copy (disk, CD-ROM, etc.).
-
- Modified versions of xpdf or applications using some or all of the
- xpdf code (i.e., 'derivative works' under copyright law) may not be
- distributed without explicit permission.
-
-
- Bugs
- ----
-
- This is an beta release of xpdf, and there are still a bunch of PDF
- features which I have yet to implement.
-
- At this point, the biggest problem is that embedded fonts are not
- handled correctly.
-
- If you find a bug in xpdf, i.e., if it prints an error message,
- crashes, or incorrectly displays a document, and you don't see that
- bug listed here, please send me email, with a pointer (URL, ftp site,
- etc.) to the PDF file.
-
-
- Acknowledgments
- ---------------
-
- Thanks to:
-
- * Patrick Voigt for help with the remote server code.
- * Patrick Moreau for the VMS port.
- * David Boldt and Rick Rodgers for sample man pages.
-
-
- References
- ----------
-
- Adobe Systems Inc., _Portable Document Format Reference Manual_.
- Addison-Wesley, 1993, ISBN 0-201-62628-4.
- [The manual for PDF version 1.0. The updated version (for PDF 1.1) is
- available on the net from http://www.adobe.com/Support/TechNotes.html
- or ftp://ftp.adobe.com/pub/adobe/Acrobat/SDK/TECHDOC/PDFSPEC.PDF.]
-
- Adobe Systems Inc., _Updates to the Portable Document Format Reference
- Manual_, Adobe Developer Support Technical Note #5156. 1995.
- [Updates for PDF version 1.1. Available on the WWW as
- http://www.adobe.com/PDFs/TN/5156.PDF_UPD.PDF.]
-
- Adobe Systems Inc., _Updates to the Portable Document Format Reference
- Manual_.
- [Update for Sections 5.7 and 6.12 (encryption), emailed to developers
- July 24, 1996.]
-
- Adobe Systems Inc., _PostScript Language Reference Manual_, 2nd ed.
- Addison-Wesley, 1990, ISBN 0-201-18127-4.
- [The official PostScript manual.]
-
- Adobe Systems Inc., _Supporting the DCT Filters in PostScript Level
- 2_, Adobe Developer Support Technical Note #5116. 1992.
- [Description of the DCTDecode filter parameters.]
-
- Anonymous, RC4 source code.
- [This is the algorithm used to encrypt PDF files. Available on
- various ftp sites, e.g., ftp://ftp.ox.ac.uk/pub/crypto/misc/rc4.tar.gz
- or ftp://idea.sec.dsi.unimi.it/pub/crypt/code/rc4.tar.gz.]
-
- CCITT, _Blue Book_, Volume VII Fascicle 3: "Terminal Equipment and
- Protocols for Telematic Services", Recommendations T.4 and T.6.
- [The official Group 3 and 4 fax standards. These are available on the
- net (but misformatted) as
- ftp://ftp.uu.net/doc/standards/ccitt/1988/7_3_01.ps and 7_3_02.ps.]
-
- Foley, van Dam, Feiner, and Hughes, _Computer Graphics: Principles and
- Practice_, 2nd ed. Addison-Wesley, 1990, ISBN 0-201-12110-7.
- [Colorspace conversion functions, Bezier spline math.]
-
- Robert L. Hummel, _Programmer's Technical Reference: Data and Fax
- Communications_. Ziff-Davis Press, 1993, ISBN 1-56276-077-7.
- [CCITT Group 3 and 4 fax decoding.]
-
- Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz, "Practical
- Fast 1-D DCT Algorithms with 11 Multiplications". IEEE Intl. Conf. on
- Acoustics, Speech & Signal Processing, 1989, 988-991.
- [The fast IDCT algorithm used in the DCTDecode filter.]
-
- R. Rivest, "The MD5 Message-Digest Algorithm". RFC 1321.
- [MD5 is used in PDF document encryption.]
-
- Gregory K. Wallace, "The JPEG Still Picture Compression Standard".
- [Good description of the JPEG standard. Available on the net as
- ftp://ftp.uu.net/graphics/jpeg/wallace.ps.gz. Also published in CACM,
- April 1991, and submitted to IEEE Transactions on Consumer
- Electronics.]
-