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1096 lines
52 KiB
1096 lines
52 KiB
INSTALLATION INSTRUCTIONS for the Independent JPEG Group's JPEG software |
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Copyright (C) 1991-2010, Thomas G. Lane, Guido Vollbeding. |
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This file is part of the Independent JPEG Group's software. |
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For conditions of distribution and use, see the accompanying README file. |
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This file explains how to configure and install the IJG software. We have |
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tried to make this software extremely portable and flexible, so that it can be |
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adapted to almost any environment. The downside of this decision is that the |
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installation process is complicated. We have provided shortcuts to simplify |
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the task on common systems. But in any case, you will need at least a little |
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familiarity with C programming and program build procedures for your system. |
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If you are only using this software as part of a larger program, the larger |
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program's installation procedure may take care of configuring the IJG code. |
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For example, Ghostscript's installation script will configure the IJG code. |
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You don't need to read this file if you just want to compile Ghostscript. |
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If you are on a Unix machine, you may not need to read this file at all. |
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Try doing |
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./configure |
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make |
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make test |
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If that doesn't complain, do |
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make install |
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(better do "make -n install" first to see if the makefile will put the files |
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where you want them). Read further if you run into snags or want to customize |
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the code for your system. |
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TABLE OF CONTENTS |
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----------------- |
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Before you start |
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Configuring the software: |
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using the automatic "configure" script |
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using one of the supplied jconfig and makefile files |
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by hand |
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Building the software |
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Testing the software |
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Installing the software |
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Optional stuff |
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Optimization |
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Hints for specific systems |
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BEFORE YOU START |
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================ |
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Before installing the software you must unpack the distributed source code. |
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Since you are reading this file, you have probably already succeeded in this |
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task. However, there is a potential for error if you needed to convert the |
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files to the local standard text file format (for example, if you are on |
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MS-DOS you may have converted LF end-of-line to CR/LF). You must apply |
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such conversion to all the files EXCEPT those whose names begin with "test". |
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The test files contain binary data; if you change them in any way then the |
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self-test will give bad results. |
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Please check the last section of this file to see if there are hints for the |
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specific machine or compiler you are using. |
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CONFIGURING THE SOFTWARE |
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======================== |
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To configure the IJG code for your system, you need to create two files: |
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* jconfig.h: contains values for system-dependent #define symbols. |
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* Makefile: controls the compilation process. |
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(On a non-Unix machine, you may create "project files" or some other |
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substitute for a Makefile. jconfig.h is needed in any environment.) |
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We provide three different ways to generate these files: |
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* On a Unix system, you can just run the "configure" script. |
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* We provide sample jconfig files and makefiles for popular machines; |
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if your machine matches one of the samples, just copy the right sample |
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files to jconfig.h and Makefile. |
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* If all else fails, read the instructions below and make your own files. |
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Configuring the software using the automatic "configure" script |
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--------------------------------------------------------------- |
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If you are on a Unix machine, you can just type |
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./configure |
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and let the configure script construct appropriate configuration files. |
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If you're using "csh" on an old version of System V, you might need to type |
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sh configure |
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instead to prevent csh from trying to execute configure itself. |
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Expect configure to run for a few minutes, particularly on slower machines; |
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it works by compiling a series of test programs. |
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Configure was created with GNU Autoconf and it follows the usual conventions |
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for GNU configure scripts. It makes a few assumptions that you may want to |
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override. You can do this by providing optional switches to configure: |
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* Configure will build both static and shared libraries, if possible. |
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If you want to build libjpeg only as a static library, say |
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./configure --disable-shared |
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If you want to build libjpeg only as a shared library, say |
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./configure --disable-static |
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Configure uses GNU libtool to take care of system-dependent shared library |
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building methods. |
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* Configure will use gcc (GNU C compiler) if it's available, otherwise cc. |
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To force a particular compiler to be selected, use the CC option, for example |
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./configure CC='cc' |
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The same method can be used to include any unusual compiler switches. |
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For example, on HP-UX you probably want to say |
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./configure CC='cc -Aa' |
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to get HP's compiler to run in ANSI mode. |
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* The default CFLAGS setting is "-g" for non-gcc compilers, "-g -O2" for gcc. |
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You can override this by saying, for example, |
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./configure CFLAGS='-O2' |
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if you want to compile without debugging support. |
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* Configure will set up the makefile so that "make install" will install files |
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into /usr/local/bin, /usr/local/man, etc. You can specify an installation |
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prefix other than "/usr/local" by giving configure the option "--prefix=PATH". |
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* If you don't have a lot of swap space, you may need to enable the IJG |
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software's internal virtual memory mechanism. To do this, give the option |
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"--enable-maxmem=N" where N is the default maxmemory limit in megabytes. |
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This is discussed in more detail under "Selecting a memory manager", below. |
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You probably don't need to worry about this on reasonably-sized Unix machines, |
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unless you plan to process very large images. |
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Configure has some other features that are useful if you are cross-compiling |
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or working in a network of multiple machine types; but if you need those |
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features, you probably already know how to use them. |
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Configuring the software using one of the supplied jconfig and makefile files |
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----------------------------------------------------------------------------- |
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If you have one of these systems, you can just use the provided configuration |
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files: |
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Makefile jconfig file System and/or compiler |
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makefile.manx jconfig.manx Amiga, Manx Aztec C |
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makefile.sas jconfig.sas Amiga, SAS C |
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makeproj.mac jconfig.mac Apple Macintosh, Metrowerks CodeWarrior |
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mak*jpeg.st jconfig.st Atari ST/STE/TT, Pure C or Turbo C |
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makefile.bcc jconfig.bcc MS-DOS or OS/2, Borland C |
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makefile.dj jconfig.dj MS-DOS, DJGPP (Delorie's port of GNU C) |
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makefile.mc6 jconfig.mc6 MS-DOS, Microsoft C (16-bit only) |
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makefile.wat jconfig.wat MS-DOS, OS/2, or Windows NT, Watcom C |
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makefile.vc jconfig.vc Windows NT/95, MS Visual C++ |
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make*.vc6 jconfig.vc Windows NT/95, MS Visual C++ 6 |
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make*.v10 jconfig.vc Windows NT/95, MS Visual C++ 2010 (v10) |
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makefile.mms jconfig.vms Digital VMS, with MMS software |
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makefile.vms jconfig.vms Digital VMS, without MMS software |
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Copy the proper jconfig file to jconfig.h and the makefile to Makefile (or |
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whatever your system uses as the standard makefile name). For more info see |
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the appropriate system-specific hints section near the end of this file. |
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Configuring the software by hand |
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-------------------------------- |
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First, generate a jconfig.h file. If you are moderately familiar with C, |
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the comments in jconfig.txt should be enough information to do this; just |
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copy jconfig.txt to jconfig.h and edit it appropriately. Otherwise, you may |
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prefer to use the ckconfig.c program. You will need to compile and execute |
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ckconfig.c by hand --- we hope you know at least enough to do that. |
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ckconfig.c may not compile the first try (in fact, the whole idea is for it |
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to fail if anything is going to). If you get compile errors, fix them by |
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editing ckconfig.c according to the directions given in ckconfig.c. Once |
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you get it to run, it will write a suitable jconfig.h file, and will also |
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print out some advice about which makefile to use. |
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You may also want to look at the canned jconfig files, if there is one for a |
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system similar to yours. |
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Second, select a makefile and copy it to Makefile (or whatever your system |
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uses as the standard makefile name). The most generic makefiles we provide |
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are |
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makefile.ansi: if your C compiler supports function prototypes |
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makefile.unix: if not. |
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(You have function prototypes if ckconfig.c put "#define HAVE_PROTOTYPES" |
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in jconfig.h.) You may want to start from one of the other makefiles if |
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there is one for a system similar to yours. |
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Look over the selected Makefile and adjust options as needed. In particular |
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you may want to change the CC and CFLAGS definitions. For instance, if you |
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are using GCC, set CC=gcc. If you had to use any compiler switches to get |
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ckconfig.c to work, make sure the same switches are in CFLAGS. |
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If you are on a system that doesn't use makefiles, you'll need to set up |
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project files (or whatever you do use) to compile all the source files and |
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link them into executable files cjpeg, djpeg, jpegtran, rdjpgcom, and wrjpgcom. |
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See the file lists in any of the makefiles to find out which files go into |
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each program. Note that the provided makefiles all make a "library" file |
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libjpeg first, but you don't have to do that if you don't want to; the file |
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lists identify which source files are actually needed for compression, |
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decompression, or both. As a last resort, you can make a batch script that |
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just compiles everything and links it all together; makefile.vms is an example |
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of this (it's for VMS systems that have no make-like utility). |
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Here are comments about some specific configuration decisions you'll |
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need to make: |
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Command line style |
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------------------ |
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These programs can use a Unix-like command line style which supports |
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redirection and piping, like this: |
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cjpeg inputfile >outputfile |
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cjpeg <inputfile >outputfile |
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source program | cjpeg >outputfile |
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The simpler "two file" command line style is just |
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cjpeg inputfile outputfile |
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You may prefer the two-file style, particularly if you don't have pipes. |
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You MUST use two-file style on any system that doesn't cope well with binary |
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data fed through stdin/stdout; this is true for some MS-DOS compilers, for |
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example. If you're not on a Unix system, it's safest to assume you need |
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two-file style. (But if your compiler provides either the Posix-standard |
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fdopen() library routine or a Microsoft-compatible setmode() routine, you |
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can safely use the Unix command line style, by defining USE_FDOPEN or |
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USE_SETMODE respectively.) |
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To use the two-file style, make jconfig.h say "#define TWO_FILE_COMMANDLINE". |
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Selecting a memory manager |
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-------------------------- |
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The IJG code is capable of working on images that are too big to fit in main |
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memory; data is swapped out to temporary files as necessary. However, the |
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code to do this is rather system-dependent. We provide five different |
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memory managers: |
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* jmemansi.c This version uses the ANSI-standard library routine tmpfile(), |
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which not all non-ANSI systems have. On some systems |
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tmpfile() may put the temporary file in a non-optimal |
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location; if you don't like what it does, use jmemname.c. |
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* jmemname.c This version creates named temporary files. For anything |
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except a Unix machine, you'll need to configure the |
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select_file_name() routine appropriately; see the comments |
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near the head of jmemname.c. If you use this version, define |
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NEED_SIGNAL_CATCHER in jconfig.h to make sure the temp files |
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are removed if the program is aborted. |
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* jmemnobs.c (That stands for No Backing Store :-).) This will compile on |
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almost any system, but it assumes you have enough main memory |
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or virtual memory to hold the biggest images you work with. |
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* jmemdos.c This should be used with most 16-bit MS-DOS compilers. |
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See the system-specific notes about MS-DOS for more info. |
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IMPORTANT: if you use this, define USE_MSDOS_MEMMGR in |
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jconfig.h, and include the assembly file jmemdosa.asm in the |
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programs. The supplied makefiles and jconfig files for |
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16-bit MS-DOS compilers already do both. |
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* jmemmac.c Custom version for Apple Macintosh; see the system-specific |
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notes for Macintosh for more info. |
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To use a particular memory manager, change the SYSDEPMEM variable in your |
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makefile to equal the corresponding object file name (for example, jmemansi.o |
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or jmemansi.obj for jmemansi.c). |
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If you have plenty of (real or virtual) main memory, just use jmemnobs.c. |
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"Plenty" means about ten bytes for every pixel in the largest images |
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you plan to process, so a lot of systems don't meet this criterion. |
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If yours doesn't, try jmemansi.c first. If that doesn't compile, you'll have |
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to use jmemname.c; be sure to adjust select_file_name() for local conditions. |
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You may also need to change unlink() to remove() in close_backing_store(). |
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Except with jmemnobs.c or jmemmac.c, you need to adjust the DEFAULT_MAX_MEM |
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setting to a reasonable value for your system (either by adding a #define for |
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DEFAULT_MAX_MEM to jconfig.h, or by adding a -D switch to the Makefile). |
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This value limits the amount of data space the program will attempt to |
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allocate. Code and static data space isn't counted, so the actual memory |
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needs for cjpeg or djpeg are typically 100 to 150Kb more than the max-memory |
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setting. Larger max-memory settings reduce the amount of I/O needed to |
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process a large image, but too large a value can result in "insufficient |
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memory" failures. On most Unix machines (and other systems with virtual |
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memory), just set DEFAULT_MAX_MEM to several million and forget it. At the |
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other end of the spectrum, for MS-DOS machines you probably can't go much |
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above 300K to 400K. (On MS-DOS the value refers to conventional memory only. |
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Extended/expanded memory is handled separately by jmemdos.c.) |
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BUILDING THE SOFTWARE |
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===================== |
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Now you should be able to compile the software. Just say "make" (or |
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whatever's necessary to start the compilation). Have a cup of coffee. |
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Here are some things that could go wrong: |
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If your compiler complains about undefined structures, you should be able to |
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shut it up by putting "#define INCOMPLETE_TYPES_BROKEN" in jconfig.h. |
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If you have trouble with missing system include files or inclusion of the |
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wrong ones, read jinclude.h. This shouldn't happen if you used configure |
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or ckconfig.c to set up jconfig.h. |
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There are a fair number of routines that do not use all of their parameters; |
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some compilers will issue warnings about this, which you can ignore. There |
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are also a few configuration checks that may give "unreachable code" warnings. |
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Any other warning deserves investigation. |
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If you don't have a getenv() library routine, define NO_GETENV. |
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Also see the system-specific hints, below. |
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TESTING THE SOFTWARE |
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==================== |
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As a quick test of functionality we've included a small sample image in |
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several forms: |
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testorig.jpg Starting point for the djpeg tests. |
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testimg.ppm The output of djpeg testorig.jpg |
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testimg.bmp The output of djpeg -bmp -colors 256 testorig.jpg |
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testimg.jpg The output of cjpeg testimg.ppm |
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testprog.jpg Progressive-mode equivalent of testorig.jpg. |
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testimgp.jpg The output of cjpeg -progressive -optimize testimg.ppm |
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(The first- and second-generation .jpg files aren't identical since JPEG is |
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lossy.) If you can generate duplicates of the testimg* files then you |
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probably have working programs. |
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With most of the makefiles, "make test" will perform the necessary |
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comparisons. |
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If you're using a makefile that doesn't provide the test option, run djpeg |
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and cjpeg by hand and compare the output files to testimg* with whatever |
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binary file comparison tool you have. The files should be bit-for-bit |
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identical. |
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If the programs complain "MAX_ALLOC_CHUNK is wrong, please fix", then you |
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need to reduce MAX_ALLOC_CHUNK to a value that fits in type size_t. |
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Try adding "#define MAX_ALLOC_CHUNK 65520L" to jconfig.h. A less likely |
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configuration error is "ALIGN_TYPE is wrong, please fix": defining ALIGN_TYPE |
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as long should take care of that one. |
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If the cjpeg test run fails with "Missing Huffman code table entry", it's a |
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good bet that you needed to define RIGHT_SHIFT_IS_UNSIGNED. Go back to the |
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configuration step and run ckconfig.c. (This is a good plan for any other |
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test failure, too.) |
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If you are using Unix (one-file) command line style on a non-Unix system, |
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it's a good idea to check that binary I/O through stdin/stdout actually |
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works. You should get the same results from "djpeg <testorig.jpg >out.ppm" |
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as from "djpeg -outfile out.ppm testorig.jpg". Note that the makefiles all |
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use the latter style and therefore do not exercise stdin/stdout! If this |
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check fails, try recompiling with USE_SETMODE or USE_FDOPEN defined. |
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If it still doesn't work, better use two-file style. |
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If you chose a memory manager other than jmemnobs.c, you should test that |
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temporary-file usage works. Try "djpeg -bmp -colors 256 -max 0 testorig.jpg" |
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and make sure its output matches testimg.bmp. If you have any really large |
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images handy, try compressing them with -optimize and/or decompressing with |
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-colors 256 to make sure your DEFAULT_MAX_MEM setting is not too large. |
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NOTE: this is far from an exhaustive test of the JPEG software; some modules, |
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such as 1-pass color quantization, are not exercised at all. It's just a |
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quick test to give you some confidence that you haven't missed something |
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major. |
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INSTALLING THE SOFTWARE |
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======================= |
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Once you're done with the above steps, you can install the software by |
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copying the executable files (cjpeg, djpeg, jpegtran, rdjpgcom, and wrjpgcom) |
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to wherever you normally install programs. On Unix systems, you'll also want |
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to put the man pages (cjpeg.1, djpeg.1, jpegtran.1, rdjpgcom.1, wrjpgcom.1) |
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in the man-page directory. The pre-fab makefiles don't support this step |
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since there's such a wide variety of installation procedures on different |
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systems. |
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If you generated a Makefile with the "configure" script, you can just say |
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make install |
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to install the programs and their man pages into the standard places. |
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(You'll probably need to be root to do this.) We recommend first saying |
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make -n install |
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to see where configure thought the files should go. You may need to edit |
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the Makefile, particularly if your system's conventions for man page |
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filenames don't match what configure expects. |
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If you want to install the IJG library itself, for use in compiling other |
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programs besides ours, then you need to put the four include files |
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jpeglib.h jerror.h jconfig.h jmorecfg.h |
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into your include-file directory, and put the library file libjpeg.a |
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(extension may vary depending on system) wherever library files go. |
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If you generated a Makefile with "configure", it will do what it thinks |
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is the right thing if you say |
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make install-lib |
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OPTIONAL STUFF |
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============== |
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Progress monitor: |
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If you like, you can #define PROGRESS_REPORT (in jconfig.h) to enable display |
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of percent-done progress reports. The routine provided in cdjpeg.c merely |
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prints percentages to stderr, but you can customize it to do something |
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fancier. |
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Utah RLE file format support: |
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We distribute the software with support for RLE image files (Utah Raster |
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Toolkit format) disabled, because the RLE support won't compile without the |
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Utah library. If you have URT version 3.1 or later, you can enable RLE |
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support as follows: |
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1. #define RLE_SUPPORTED in jconfig.h. |
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2. Add a -I option to CFLAGS in the Makefile for the directory |
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containing the URT .h files (typically the "include" |
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subdirectory of the URT distribution). |
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3. Add -L... -lrle to LDLIBS in the Makefile, where ... specifies |
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the directory containing the URT "librle.a" file (typically the |
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"lib" subdirectory of the URT distribution). |
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Support for 12-bit-deep pixel data: |
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The JPEG standard allows either 8-bit or 12-bit data precision. (For color, |
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this means 8 or 12 bits per channel, of course.) If you need to work with |
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deeper than 8-bit data, you can compile the IJG code for 12-bit operation. |
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To do so: |
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1. In jmorecfg.h, define BITS_IN_JSAMPLE as 12 rather than 8. |
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2. In jconfig.h, undefine BMP_SUPPORTED, RLE_SUPPORTED, and TARGA_SUPPORTED, |
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because the code for those formats doesn't handle 12-bit data and won't |
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even compile. (The PPM code does work, as explained below. The GIF |
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code works too; it scales 8-bit GIF data to and from 12-bit depth |
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automatically.) |
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3. Compile. Don't expect "make test" to pass, since the supplied test |
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files are for 8-bit data. |
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Currently, 12-bit support does not work on 16-bit-int machines. |
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Note that a 12-bit version will not read 8-bit JPEG files, nor vice versa; |
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so you'll want to keep around a regular 8-bit compilation as well. |
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(Run-time selection of data depth, to allow a single copy that does both, |
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is possible but would probably slow things down considerably; it's very low |
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on our to-do list.) |
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The PPM reader (rdppm.c) can read 12-bit data from either text-format or |
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binary-format PPM and PGM files. Binary-format PPM/PGM files which have a |
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maxval greater than 255 are assumed to use 2 bytes per sample, MSB first |
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(big-endian order). As of early 1995, 2-byte binary format is not |
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officially supported by the PBMPLUS library, but it is expected that a |
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future release of PBMPLUS will support it. Note that the PPM reader will |
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read files of any maxval regardless of the BITS_IN_JSAMPLE setting; incoming |
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data is automatically rescaled to either maxval=255 or maxval=4095 as |
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appropriate for the cjpeg bit depth. |
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The PPM writer (wrppm.c) will normally write 2-byte binary PPM or PGM |
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format, maxval 4095, when compiled with BITS_IN_JSAMPLE=12. Since this |
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format is not yet widely supported, you can disable it by compiling wrppm.c |
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with PPM_NORAWWORD defined; then the data is scaled down to 8 bits to make a |
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standard 1-byte/sample PPM or PGM file. (Yes, this means still another copy |
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of djpeg to keep around. But hopefully you won't need it for very long. |
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Poskanzer's supposed to get that new PBMPLUS release out Real Soon Now.) |
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Of course, if you are working with 12-bit data, you probably have it stored |
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in some other, nonstandard format. In that case you'll probably want to |
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write your own I/O modules to read and write your format. |
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Note that a 12-bit version of cjpeg always runs in "-optimize" mode, in |
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order to generate valid Huffman tables. This is necessary because our |
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default Huffman tables only cover 8-bit data. |
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Removing code: |
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|
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If you need to make a smaller version of the JPEG software, some optional |
|
functions can be removed at compile time. See the xxx_SUPPORTED #defines in |
|
jconfig.h and jmorecfg.h. If at all possible, we recommend that you leave in |
|
decoder support for all valid JPEG files, to ensure that you can read anyone's |
|
output. Taking out support for image file formats that you don't use is the |
|
most painless way to make the programs smaller. Another possibility is to |
|
remove some of the DCT methods: in particular, the "IFAST" method may not be |
|
enough faster than the others to be worth keeping on your machine. (If you |
|
do remove ISLOW or IFAST, be sure to redefine JDCT_DEFAULT or JDCT_FASTEST |
|
to a supported method, by adding a #define in jconfig.h.) |
|
|
|
|
|
OPTIMIZATION |
|
============ |
|
|
|
Unless you own a Cray, you'll probably be interested in making the JPEG |
|
software go as fast as possible. This section covers some machine-dependent |
|
optimizations you may want to try. We suggest that before trying any of |
|
this, you first get the basic installation to pass the self-test step. |
|
Repeat the self-test after any optimization to make sure that you haven't |
|
broken anything. |
|
|
|
The integer DCT routines perform a lot of multiplications. These |
|
multiplications must yield 32-bit results, but none of their input values |
|
are more than 16 bits wide. On many machines, notably the 680x0 and 80x86 |
|
CPUs, a 16x16=>32 bit multiply instruction is faster than a full 32x32=>32 |
|
bit multiply. Unfortunately there is no portable way to specify such a |
|
multiplication in C, but some compilers can generate one when you use the |
|
right combination of casts. See the MULTIPLYxxx macro definitions in |
|
jdct.h. If your compiler makes "int" be 32 bits and "short" be 16 bits, |
|
defining SHORTxSHORT_32 is fairly likely to work. When experimenting with |
|
alternate definitions, be sure to test not only whether the code still works |
|
(use the self-test), but also whether it is actually faster --- on some |
|
compilers, alternate definitions may compute the right answer, yet be slower |
|
than the default. Timing cjpeg on a large PGM (grayscale) input file is the |
|
best way to check this, as the DCT will be the largest fraction of the runtime |
|
in that mode. (Note: some of the distributed compiler-specific jconfig files |
|
already contain #define switches to select appropriate MULTIPLYxxx |
|
definitions.) |
|
|
|
If your machine has sufficiently fast floating point hardware, you may find |
|
that the float DCT method is faster than the integer DCT methods, even |
|
after tweaking the integer multiply macros. In that case you may want to |
|
make the float DCT be the default method. (The only objection to this is |
|
that float DCT results may vary slightly across machines.) To do that, add |
|
"#define JDCT_DEFAULT JDCT_FLOAT" to jconfig.h. Even if you don't change |
|
the default, you should redefine JDCT_FASTEST, which is the method selected |
|
by djpeg's -fast switch. Don't forget to update the documentation files |
|
(usage.txt and/or cjpeg.1, djpeg.1) to agree with what you've done. |
|
|
|
If access to "short" arrays is slow on your machine, it may be a win to |
|
define type JCOEF as int rather than short. This will cost a good deal of |
|
memory though, particularly in some multi-pass modes, so don't do it unless |
|
you have memory to burn and short is REALLY slow. |
|
|
|
If your compiler can compile function calls in-line, make sure the INLINE |
|
macro in jmorecfg.h is defined as the keyword that marks a function |
|
inline-able. Some compilers have a switch that tells the compiler to inline |
|
any function it thinks is profitable (e.g., -finline-functions for gcc). |
|
Enabling such a switch is likely to make the compiled code bigger but faster. |
|
|
|
In general, it's worth trying the maximum optimization level of your compiler, |
|
and experimenting with any optional optimizations such as loop unrolling. |
|
(Unfortunately, far too many compilers have optimizer bugs ... be prepared to |
|
back off if the code fails self-test.) If you do any experimentation along |
|
these lines, please report the optimal settings to jpeg-info@uc.ag so we |
|
can mention them in future releases. Be sure to specify your machine |
|
and compiler version. |
|
|
|
|
|
HINTS FOR SPECIFIC SYSTEMS |
|
========================== |
|
|
|
We welcome reports on changes needed for systems not mentioned here. Submit |
|
'em to jpeg-info@uc.ag. Also, if configure or ckconfig.c is wrong about how |
|
to configure the JPEG software for your system, please let us know. |
|
|
|
|
|
Acorn RISC OS: |
|
|
|
(Thanks to Simon Middleton for these hints on compiling with Desktop C.) |
|
After renaming the files according to Acorn conventions, take a copy of |
|
makefile.ansi, change all occurrences of 'libjpeg.a' to 'libjpeg.o' and |
|
change these definitions as indicated: |
|
|
|
CFLAGS= -throwback -IC: -Wn |
|
LDLIBS=C:o.Stubs |
|
SYSDEPMEM=jmemansi.o |
|
LN=Link |
|
AR=LibFile -c -o |
|
|
|
Also add a new line '.c.o:; $(cc) $< $(cflags) -c -o $@'. Remove the |
|
lines '$(RM) libjpeg.o' and '$(AR2) libjpeg.o' and the 'jconfig.h' |
|
dependency section. |
|
|
|
Copy jconfig.txt to jconfig.h. Edit jconfig.h to define TWO_FILE_COMMANDLINE |
|
and CHAR_IS_UNSIGNED. |
|
|
|
Run the makefile using !AMU not !Make. If you want to use the 'clean' and |
|
'test' makefile entries then you will have to fiddle with the syntax a bit |
|
and rename the test files. |
|
|
|
|
|
Amiga: |
|
|
|
SAS C 6.50 reportedly is too buggy to compile the IJG code properly. |
|
A patch to update to 6.51 is available from SAS or AmiNet FTP sites. |
|
|
|
The supplied config files are set up to use jmemname.c as the memory |
|
manager, with temporary files being created on the device named by |
|
"JPEGTMP:". |
|
|
|
|
|
Atari ST/STE/TT: |
|
|
|
Copy the project files makcjpeg.st, makdjpeg.st, maktjpeg.st, and makljpeg.st |
|
to cjpeg.prj, djpeg.prj, jpegtran.prj, and libjpeg.prj respectively. The |
|
project files should work as-is with Pure C. For Turbo C, change library |
|
filenames "pc..." to "tc..." in each project file. Note that libjpeg.prj |
|
selects jmemansi.c as the recommended memory manager. You'll probably want to |
|
adjust the DEFAULT_MAX_MEM setting --- you want it to be a couple hundred K |
|
less than your normal free memory. Put "#define DEFAULT_MAX_MEM nnnn" into |
|
jconfig.h to do this. |
|
|
|
To use the 68881/68882 coprocessor for the floating point DCT, add the |
|
compiler option "-8" to the project files and replace pcfltlib.lib with |
|
pc881lib.lib in cjpeg.prj and djpeg.prj. Or if you don't have a |
|
coprocessor, you may prefer to remove the float DCT code by undefining |
|
DCT_FLOAT_SUPPORTED in jmorecfg.h (since without a coprocessor, the float |
|
code will be too slow to be useful). In that case, you can delete |
|
pcfltlib.lib from the project files. |
|
|
|
Note that you must make libjpeg.lib before making cjpeg.ttp, djpeg.ttp, |
|
or jpegtran.ttp. You'll have to perform the self-test by hand. |
|
|
|
We haven't bothered to include project files for rdjpgcom and wrjpgcom. |
|
Those source files should just be compiled by themselves; they don't |
|
depend on the JPEG library. You can use the default.prj project file |
|
of the Pure C distribution to make the programs. |
|
|
|
There is a bug in some older versions of the Turbo C library which causes the |
|
space used by temporary files created with "tmpfile()" not to be freed after |
|
an abnormal program exit. If you check your disk afterwards, you will find |
|
cluster chains that are allocated but not used by a file. This should not |
|
happen in cjpeg/djpeg/jpegtran, since we enable a signal catcher to explicitly |
|
close temp files before exiting. But if you use the JPEG library with your |
|
own code, be sure to supply a signal catcher, or else use a different |
|
system-dependent memory manager. |
|
|
|
|
|
Cray: |
|
|
|
Should you be so fortunate as to be running JPEG on a Cray YMP, there is a |
|
compiler bug in old versions of Cray's Standard C (prior to 3.1). If you |
|
still have an old compiler, you'll need to insert a line reading |
|
"#pragma novector" just before the loop |
|
for (i = 1; i <= (int) htbl->bits[l]; i++) |
|
huffsize[p++] = (char) l; |
|
in fix_huff_tbl (in V5beta1, line 204 of jchuff.c and line 176 of jdhuff.c). |
|
[This bug may or may not still occur with the current IJG code, but it's |
|
probably a dead issue anyway...] |
|
|
|
|
|
HP-UX: |
|
|
|
If you have HP-UX 7.05 or later with the "software development" C compiler, |
|
you should run the compiler in ANSI mode. If using the configure script, |
|
say |
|
./configure CC='cc -Aa' |
|
(or -Ae if you prefer). If configuring by hand, use makefile.ansi and add |
|
"-Aa" to the CFLAGS line in the makefile. |
|
|
|
If you have a pre-7.05 system, or if you are using the non-ANSI C compiler |
|
delivered with a minimum HP-UX system, then you must use makefile.unix |
|
(and do NOT add -Aa); or just run configure without the CC option. |
|
|
|
On HP 9000 series 800 machines, the HP C compiler is buggy in revisions prior |
|
to A.08.07. If you get complaints about "not a typedef name", you'll have to |
|
use makefile.unix, or run configure without the CC option. |
|
|
|
|
|
Macintosh, generic comments: |
|
|
|
The supplied user-interface files (cjpeg.c, djpeg.c, etc) are set up to |
|
provide a Unix-style command line interface. You can use this interface on |
|
the Mac by means of the ccommand() library routine provided by Metrowerks |
|
CodeWarrior or Think C. This is only appropriate for testing the library, |
|
however; to make a user-friendly equivalent of cjpeg/djpeg you'd really want |
|
to develop a Mac-style user interface. There isn't a complete example |
|
available at the moment, but there are some helpful starting points: |
|
1. Sam Bushell's free "To JPEG" applet provides drag-and-drop conversion to |
|
JPEG under System 7 and later. This only illustrates how to use the |
|
compression half of the library, but it does a very nice job of that part. |
|
The CodeWarrior source code is available from http://www.pobox.com/~jsam. |
|
2. Jim Brunner prepared a Mac-style user interface for both compression and |
|
decompression. Unfortunately, it hasn't been updated since IJG v4, and |
|
the library's API has changed considerably since then. Still it may be of |
|
some help, particularly as a guide to compiling the IJG code under Think C. |
|
Jim's code is available from the Info-Mac archives, at sumex-aim.stanford.edu |
|
or mirrors thereof; see file /info-mac/dev/src/jpeg-convert-c.hqx. |
|
|
|
jmemmac.c is the recommended memory manager back end for Macintosh. It uses |
|
NewPtr/DisposePtr instead of malloc/free, and has a Mac-specific |
|
implementation of jpeg_mem_available(). It also creates temporary files that |
|
follow Mac conventions. (That part of the code relies on System-7-or-later OS |
|
functions. See the comments in jmemmac.c if you need to run it on System 6.) |
|
NOTE that USE_MAC_MEMMGR must be defined in jconfig.h to use jmemmac.c. |
|
|
|
You can also use jmemnobs.c, if you don't care about handling images larger |
|
than available memory. If you use any memory manager back end other than |
|
jmemmac.c, we recommend replacing "malloc" and "free" by "NewPtr" and |
|
"DisposePtr", because Mac C libraries often have peculiar implementations of |
|
malloc/free. (For instance, free() may not return the freed space to the |
|
Mac Memory Manager. This is undesirable for the IJG code because jmemmgr.c |
|
already clumps space requests.) |
|
|
|
|
|
Macintosh, Metrowerks CodeWarrior: |
|
|
|
The Unix-command-line-style interface can be used by defining USE_CCOMMAND. |
|
You'll also need to define TWO_FILE_COMMANDLINE to avoid stdin/stdout. |
|
This means that when using the cjpeg/djpeg programs, you'll have to type the |
|
input and output file names in the "Arguments" text-edit box, rather than |
|
using the file radio buttons. (Perhaps USE_FDOPEN or USE_SETMODE would |
|
eliminate the problem, but I haven't heard from anyone who's tried it.) |
|
|
|
On 680x0 Macs, Metrowerks defines type "double" as a 10-byte IEEE extended |
|
float. jmemmgr.c won't like this: it wants sizeof(ALIGN_TYPE) to be a power |
|
of 2. Add "#define ALIGN_TYPE long" to jconfig.h to eliminate the complaint. |
|
|
|
The supplied configuration file jconfig.mac can be used for your jconfig.h; |
|
it includes all the recommended symbol definitions. If you have AppleScript |
|
installed, you can run the supplied script makeproj.mac to create CodeWarrior |
|
project files for the library and the testbed applications, then build the |
|
library and applications. (Thanks to Dan Sears and Don Agro for this nifty |
|
hack, which saves us from trying to maintain CodeWarrior project files as part |
|
of the IJG distribution...) |
|
|
|
|
|
Macintosh, Think C: |
|
|
|
The documentation in Jim Brunner's "JPEG Convert" source code (see above) |
|
includes detailed build instructions for Think C; it's probably somewhat |
|
out of date for the current release, but may be helpful. |
|
|
|
If you want to build the minimal command line version, proceed as follows. |
|
You'll have to prepare project files for the programs; we don't include any |
|
in the distribution since they are not text files. Use the file lists in |
|
any of the supplied makefiles as a guide. Also add the ANSI and Unix C |
|
libraries in a separate segment. You may need to divide the JPEG files into |
|
more than one segment; we recommend dividing compression and decompression |
|
modules. Define USE_CCOMMAND in jconfig.h so that the ccommand() routine is |
|
called. You must also define TWO_FILE_COMMANDLINE because stdin/stdout |
|
don't handle binary data correctly. |
|
|
|
On 680x0 Macs, Think C defines type "double" as a 12-byte IEEE extended float. |
|
jmemmgr.c won't like this: it wants sizeof(ALIGN_TYPE) to be a power of 2. |
|
Add "#define ALIGN_TYPE long" to jconfig.h to eliminate the complaint. |
|
|
|
jconfig.mac should work as a jconfig.h configuration file for Think C, |
|
but the makeproj.mac AppleScript script is specific to CodeWarrior. Sorry. |
|
|
|
|
|
MIPS R3000: |
|
|
|
MIPS's cc version 1.31 has a rather nasty optimization bug. Don't use -O |
|
if you have that compiler version. (Use "cc -V" to check the version.) |
|
Note that the R3000 chip is found in workstations from DEC and others. |
|
|
|
|
|
MS-DOS, generic comments for 16-bit compilers: |
|
|
|
The IJG code is designed to work well in 80x86 "small" or "medium" memory |
|
models (i.e., data pointers are 16 bits unless explicitly declared "far"; |
|
code pointers can be either size). You may be able to use small model to |
|
compile cjpeg or djpeg by itself, but you will probably have to use medium |
|
model for any larger application. This won't make much difference in |
|
performance. You *will* take a noticeable performance hit if you use a |
|
large-data memory model, and you should avoid "huge" model if at all |
|
possible. Be sure that NEED_FAR_POINTERS is defined in jconfig.h if you use |
|
a small-data memory model; be sure it is NOT defined if you use a large-data |
|
model. (The supplied makefiles and jconfig files for Borland and Microsoft C |
|
compile in medium model and define NEED_FAR_POINTERS.) |
|
|
|
The DOS-specific memory manager, jmemdos.c, should be used if possible. |
|
It needs some assembly-code routines which are in jmemdosa.asm; make sure |
|
your makefile assembles that file and includes it in the library. If you |
|
don't have a suitable assembler, you can get pre-assembled object files for |
|
jmemdosa by FTP from ftp.uu.net:/graphics/jpeg/jdosaobj.zip. (DOS-oriented |
|
distributions of the IJG source code often include these object files.) |
|
|
|
When using jmemdos.c, jconfig.h must define USE_MSDOS_MEMMGR and must set |
|
MAX_ALLOC_CHUNK to less than 64K (65520L is a typical value). If your |
|
C library's far-heap malloc() can't allocate blocks that large, reduce |
|
MAX_ALLOC_CHUNK to whatever it can handle. |
|
|
|
If you can't use jmemdos.c for some reason --- for example, because you |
|
don't have an assembler to assemble jmemdosa.asm --- you'll have to fall |
|
back to jmemansi.c or jmemname.c. You'll probably still need to set |
|
MAX_ALLOC_CHUNK in jconfig.h, because most DOS C libraries won't malloc() |
|
more than 64K at a time. IMPORTANT: if you use jmemansi.c or jmemname.c, |
|
you will have to compile in a large-data memory model in order to get the |
|
right stdio library. Too bad. |
|
|
|
wrjpgcom needs to be compiled in large model, because it malloc()s a 64KB |
|
work area to hold the comment text. If your C library's malloc can't |
|
handle that, reduce MAX_COM_LENGTH as necessary in wrjpgcom.c. |
|
|
|
Most MS-DOS compilers treat stdin/stdout as text files, so you must use |
|
two-file command line style. But if your compiler has either fdopen() or |
|
setmode(), you can use one-file style if you like. To do this, define |
|
USE_SETMODE or USE_FDOPEN so that stdin/stdout will be set to binary mode. |
|
(USE_SETMODE seems to work with more DOS compilers than USE_FDOPEN.) You |
|
should test that I/O through stdin/stdout produces the same results as I/O |
|
to explicitly named files... the "make test" procedures in the supplied |
|
makefiles do NOT use stdin/stdout. |
|
|
|
|
|
MS-DOS, generic comments for 32-bit compilers: |
|
|
|
None of the above comments about memory models apply if you are using a |
|
32-bit flat-memory-space environment, such as DJGPP or Watcom C. (And you |
|
should use one if you have it, as performance will be much better than |
|
8086-compatible code!) For flat-memory-space compilers, do NOT define |
|
NEED_FAR_POINTERS, and do NOT use jmemdos.c. Use jmemnobs.c if the |
|
environment supplies adequate virtual memory, otherwise use jmemansi.c or |
|
jmemname.c. |
|
|
|
You'll still need to be careful about binary I/O through stdin/stdout. |
|
See the last paragraph of the previous section. |
|
|
|
|
|
MS-DOS, Borland C: |
|
|
|
Be sure to convert all the source files to DOS text format (CR/LF newlines). |
|
Although Borland C will often work OK with unmodified Unix (LF newlines) |
|
source files, sometimes it will give bogus compile errors. |
|
"Illegal character '#'" is the most common such error. (This is true with |
|
Borland C 3.1, but perhaps is fixed in newer releases.) |
|
|
|
If you want one-file command line style, just undefine TWO_FILE_COMMANDLINE. |
|
jconfig.bcc already includes #define USE_SETMODE to make this work. |
|
(fdopen does not work correctly.) |
|
|
|
|
|
MS-DOS, Microsoft C: |
|
|
|
makefile.mc6 works with Microsoft C, DOS Visual C++, etc. It should only |
|
be used if you want to build a 16-bit (small or medium memory model) program. |
|
|
|
If you want one-file command line style, just undefine TWO_FILE_COMMANDLINE. |
|
jconfig.mc6 already includes #define USE_SETMODE to make this work. |
|
(fdopen does not work correctly.) |
|
|
|
Note that this makefile assumes that the working copy of itself is called |
|
"makefile". If you want to call it something else, say "makefile.mak", |
|
be sure to adjust the dependency line that reads "$(RFILE) : makefile". |
|
Otherwise the make will fail because it doesn't know how to create "makefile". |
|
Worse, some releases of Microsoft's make utilities give an incorrect error |
|
message in this situation. |
|
|
|
Old versions of MS C fail with an "out of macro expansion space" error |
|
because they can't cope with the macro TRACEMS8 (defined in jerror.h). |
|
If this happens to you, the easiest solution is to change TRACEMS8 to |
|
expand to nothing. You'll lose the ability to dump out JPEG coefficient |
|
tables with djpeg -debug -debug, but at least you can compile. |
|
|
|
Original MS C 6.0 is very buggy; it compiles incorrect code unless you turn |
|
off optimization entirely (remove -O from CFLAGS). 6.00A is better, but it |
|
still generates bad code if you enable loop optimizations (-Ol or -Ox). |
|
|
|
MS C 8.0 crashes when compiling jquant1.c with optimization switch /Oo ... |
|
which is on by default. To work around this bug, compile that one file |
|
with /Oo-. |
|
|
|
|
|
Microsoft Windows (all versions), generic comments: |
|
|
|
Some Windows system include files define typedef boolean as "unsigned char". |
|
The IJG code also defines typedef boolean, but we make it "int" by default. |
|
This doesn't affect the IJG programs because we don't import those Windows |
|
include files. But if you use the JPEG library in your own program, and some |
|
of your program's files import one definition of boolean while some import the |
|
other, you can get all sorts of mysterious problems. A good preventive step |
|
is to make the IJG library use "unsigned char" for boolean. To do that, |
|
add something like this to your jconfig.h file: |
|
/* Define "boolean" as unsigned char, not int, per Windows custom */ |
|
#ifndef __RPCNDR_H__ /* don't conflict if rpcndr.h already read */ |
|
typedef unsigned char boolean; |
|
#endif |
|
#define HAVE_BOOLEAN /* prevent jmorecfg.h from redefining it */ |
|
(This is already in jconfig.vc, by the way.) |
|
|
|
windef.h contains the declarations |
|
#define far |
|
#define FAR far |
|
Since jmorecfg.h tries to define FAR as empty, you may get a compiler |
|
warning if you include both jpeglib.h and windef.h (which windows.h |
|
includes). To suppress the warning, you can put "#ifndef FAR"/"#endif" |
|
around the line "#define FAR" in jmorecfg.h. |
|
(Something like this is already in jmorecfg.h, by the way.) |
|
|
|
When using the library in a Windows application, you will almost certainly |
|
want to modify or replace the error handler module jerror.c, since our |
|
default error handler does a couple of inappropriate things: |
|
1. it tries to write error and warning messages on stderr; |
|
2. in event of a fatal error, it exits by calling exit(). |
|
|
|
A simple stopgap solution for problem 1 is to replace the line |
|
fprintf(stderr, "%s\n", buffer); |
|
(in output_message in jerror.c) with |
|
MessageBox(GetActiveWindow(),buffer,"JPEG Error",MB_OK|MB_ICONERROR); |
|
It's highly recommended that you at least do that much, since otherwise |
|
error messages will disappear into nowhere. (Beginning with IJG v6b, this |
|
code is already present in jerror.c; just define USE_WINDOWS_MESSAGEBOX in |
|
jconfig.h to enable it.) |
|
|
|
The proper solution for problem 2 is to return control to your calling |
|
application after a library error. This can be done with the setjmp/longjmp |
|
technique discussed in libjpeg.txt and illustrated in example.c. (NOTE: |
|
some older Windows C compilers provide versions of setjmp/longjmp that |
|
don't actually work under Windows. You may need to use the Windows system |
|
functions Catch and Throw instead.) |
|
|
|
The recommended memory manager under Windows is jmemnobs.c; in other words, |
|
let Windows do any virtual memory management needed. You should NOT use |
|
jmemdos.c nor jmemdosa.asm under Windows. |
|
|
|
For Windows 3.1, we recommend compiling in medium or large memory model; |
|
for newer Windows versions, use a 32-bit flat memory model. (See the MS-DOS |
|
sections above for more info about memory models.) In the 16-bit memory |
|
models only, you'll need to put |
|
#define MAX_ALLOC_CHUNK 65520L /* Maximum request to malloc() */ |
|
into jconfig.h to limit allocation chunks to 64Kb. (Without that, you'd |
|
have to use huge memory model, which slows things down unnecessarily.) |
|
jmemnobs.c works without modification in large or flat memory models, but to |
|
use medium model, you need to modify its jpeg_get_large and jpeg_free_large |
|
routines to allocate far memory. In any case, you might like to replace |
|
its calls to malloc and free with direct calls on Windows memory allocation |
|
functions. |
|
|
|
You may also want to modify jdatasrc.c and jdatadst.c to use Windows file |
|
operations rather than fread/fwrite. This is only necessary if your C |
|
compiler doesn't provide a competent implementation of C stdio functions. |
|
|
|
You might want to tweak the RGB_xxx macros in jmorecfg.h so that the library |
|
will accept or deliver color pixels in BGR sample order, not RGB; BGR order |
|
is usually more convenient under Windows. Note that this change will break |
|
the sample applications cjpeg/djpeg, but the library itself works fine. |
|
|
|
|
|
Many people want to convert the IJG library into a DLL. This is reasonably |
|
straightforward, but watch out for the following: |
|
|
|
1. Don't try to compile as a DLL in small or medium memory model; use |
|
large model, or even better, 32-bit flat model. Many places in the IJG code |
|
assume the address of a local variable is an ordinary (not FAR) pointer; |
|
that isn't true in a medium-model DLL. |
|
|
|
2. Microsoft C cannot pass file pointers between applications and DLLs. |
|
(See Microsoft Knowledge Base, PSS ID Number Q50336.) So jdatasrc.c and |
|
jdatadst.c don't work if you open a file in your application and then pass |
|
the pointer to the DLL. One workaround is to make jdatasrc.c/jdatadst.c |
|
part of your main application rather than part of the DLL. |
|
|
|
3. You'll probably need to modify the macros GLOBAL() and EXTERN() to |
|
attach suitable linkage keywords to the exported routine names. Similarly, |
|
you'll want to modify METHODDEF() and JMETHOD() to ensure function pointers |
|
are declared in a way that lets application routines be called back through |
|
the function pointers. These macros are in jmorecfg.h. Typical definitions |
|
for a 16-bit DLL are: |
|
#define GLOBAL(type) type _far _pascal _loadds _export |
|
#define EXTERN(type) extern type _far _pascal _loadds |
|
#define METHODDEF(type) static type _far _pascal |
|
#define JMETHOD(type,methodname,arglist) \ |
|
type (_far _pascal *methodname) arglist |
|
For a 32-bit DLL you may want something like |
|
#define GLOBAL(type) __declspec(dllexport) type |
|
#define EXTERN(type) extern __declspec(dllexport) type |
|
Although not all the GLOBAL routines are actually intended to be called by |
|
the application, the performance cost of making them all DLL entry points is |
|
negligible. |
|
|
|
The unmodified IJG library presents a very C-specific application interface, |
|
so the resulting DLL is only usable from C or C++ applications. There has |
|
been some talk of writing wrapper code that would present a simpler interface |
|
usable from other languages, such as Visual Basic. This is on our to-do list |
|
but hasn't been very high priority --- any volunteers out there? |
|
|
|
|
|
Microsoft Windows, Borland C: |
|
|
|
The provided jconfig.bcc should work OK in a 32-bit Windows environment, |
|
but you'll need to tweak it in a 16-bit environment (you'd need to define |
|
NEED_FAR_POINTERS and MAX_ALLOC_CHUNK). Beware that makefile.bcc will need |
|
alteration if you want to use it for Windows --- in particular, you should |
|
use jmemnobs.c not jmemdos.c under Windows. |
|
|
|
Borland C++ 4.5 fails with an internal compiler error when trying to compile |
|
jdmerge.c in 32-bit mode. If enough people complain, perhaps Borland will fix |
|
it. In the meantime, the simplest known workaround is to add a redundant |
|
definition of the variable range_limit in h2v1_merged_upsample(), at the head |
|
of the block that handles odd image width (about line 268 in v6 jdmerge.c): |
|
/* If image width is odd, do the last output column separately */ |
|
if (cinfo->output_width & 1) { |
|
register JSAMPLE * range_limit = cinfo->sample_range_limit; /* ADD THIS */ |
|
cb = GETJSAMPLE(*inptr1); |
|
Pretty bizarre, especially since the very similar routine h2v2_merged_upsample |
|
doesn't trigger the bug. |
|
Recent reports suggest that this bug does not occur with "bcc32a" (the |
|
Pentium-optimized version of the compiler). |
|
|
|
Another report from a user of Borland C 4.5 was that incorrect code (leading |
|
to a color shift in processed images) was produced if any of the following |
|
optimization switch combinations were used: |
|
-Ot -Og |
|
-Ot -Op |
|
-Ot -Om |
|
So try backing off on optimization if you see such a problem. (Are there |
|
several different releases all numbered "4.5"??) |
|
|
|
|
|
Microsoft Windows, Microsoft Visual C++: |
|
|
|
jconfig.vc should work OK with any Microsoft compiler for a 32-bit memory |
|
model. makefile.vc is intended for command-line use. (If you are using |
|
the Developer Studio environment, you may prefer the DevStudio project |
|
files; see below.) |
|
|
|
IJG JPEG 7 adds extern "C" to jpeglib.h. This avoids the need to put |
|
extern "C" { ... } around #include "jpeglib.h" in your C++ application. |
|
You can also force VC++ to treat the library as C++ code by renaming |
|
all the *.c files to *.cpp (and adjusting the makefile to match). |
|
In this case you also need to define the symbol DONT_USE_EXTERN_C in |
|
the configuration to prevent jpeglib.h from using extern "C". |
|
|
|
|
|
Microsoft Windows, Microsoft Visual C++ 6 Developer Studio: |
|
|
|
We include makefiles that should work as project files in DevStudio 6.0 or |
|
later. There is a library makefile that builds the IJG library as a static |
|
Win32 library, and application makefiles that build the sample applications |
|
as Win32 console applications. (Even if you only want the library, we |
|
recommend building the applications so that you can run the self-test.) |
|
|
|
To use: |
|
1. Open the command prompt, change to the main directory and execute the |
|
command line |
|
NMAKE /f makefile.vc setup-vc6 |
|
This will move jconfig.vc to jconfig.h and makefiles to project files. |
|
(Note that the renaming is critical!) |
|
2. Open the workspace file jpeg.dsw, build the library project. |
|
(If you are using DevStudio more recent than 6.0, you'll probably |
|
get a message saying that the project files are being updated.) |
|
3. Open the workspace file apps.dsw, build the application projects. |
|
4. To perform the self-test, execute the command line |
|
NMAKE /f makefile.vc test-build |
|
5. Move the application .exe files from `app`\Release to an |
|
appropriate location on your path. |
|
|
|
|
|
Microsoft Windows, Microsoft Visual C++ 2010 Developer Studio (v10): |
|
|
|
We include makefiles that should work as project files in Visual Studio |
|
2010 or later. There is a library makefile that builds the IJG library |
|
as a static Win32 library, and application makefiles that build the sample |
|
applications as Win32 console applications. (Even if you only want the |
|
library, we recommend building the applications so that you can run the |
|
self-test.) |
|
|
|
To use: |
|
1. Open the command prompt, change to the main directory and execute the |
|
command line |
|
NMAKE /f makefile.vc setup-v10 |
|
This will move jconfig.vc to jconfig.h and makefiles to project files. |
|
(Note that the renaming is critical!) |
|
2. Open the solution file jpeg.sln, build the library project. |
|
(If you are using Visual Studio more recent than 2010 (v10), you'll |
|
probably get a message saying that the project files are being updated.) |
|
3. Open the solution file apps.sln, build the application projects. |
|
4. To perform the self-test, execute the command line |
|
NMAKE /f makefile.vc test-build |
|
5. Move the application .exe files from `app`\Release to an |
|
appropriate location on your path. |
|
|
|
Note: |
|
There seems to be an optimization bug in the compiler which causes the |
|
self-test to fail with the color quantization option. |
|
We have disabled optimization for the file jquant2.c in the library |
|
project file which causes the self-test to pass properly. |
|
|
|
|
|
OS/2, Borland C++: |
|
|
|
Watch out for optimization bugs in older Borland compilers; you may need |
|
to back off the optimization switch settings. See the comments in |
|
makefile.bcc. |
|
|
|
|
|
SGI: |
|
|
|
On some SGI systems, you may need to set "AR2= ar -ts" in the Makefile. |
|
If you are using configure, you can do this by saying |
|
./configure RANLIB='ar -ts' |
|
This change is not needed on all SGIs. Use it only if the make fails at the |
|
stage of linking the completed programs. |
|
|
|
On the MIPS R4000 architecture (Indy, etc.), the compiler option "-mips2" |
|
reportedly speeds up the float DCT method substantially, enough to make it |
|
faster than the default int method (but still slower than the fast int |
|
method). If you use -mips2, you may want to alter the default DCT method to |
|
be float. To do this, put "#define JDCT_DEFAULT JDCT_FLOAT" in jconfig.h. |
|
|
|
|
|
VMS: |
|
|
|
On an Alpha/VMS system with MMS, be sure to use the "/Marco=Alpha=1" |
|
qualifier with MMS when building the JPEG package. |
|
|
|
VAX/VMS v5.5-1 may have problems with the test step of the build procedure |
|
reporting differences when it compares the original and test images. If the |
|
error points to the last block of the files, it is most likely bogus and may |
|
be safely ignored. It seems to be because the files are Stream_LF and |
|
Backup/Compare has difficulty with the (presumably) null padded files. |
|
This problem was not observed on VAX/VMS v6.1 or AXP/VMS v6.1.
|
|
|