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authorDees_Troy <dees_troy@teamw.in>2013-08-11 15:32:44 +0200
committerGerrit Code Review <gerrit@198.50.184.117>2013-08-11 15:32:44 +0200
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-INSTALLATION INSTRUCTIONS for the Independent JPEG Group's JPEG software
-
-Copyright (C) 1991-1998, Thomas G. Lane.
-This file is part of the Independent JPEG Group's software.
-For conditions of distribution and use, see the accompanying README file.
-
-
-This file explains how to configure and install the IJG software. We have
-tried to make this software extremely portable and flexible, so that it can be
-adapted to almost any environment. The downside of this decision is that the
-installation process is complicated. We have provided shortcuts to simplify
-the task on common systems. But in any case, you will need at least a little
-familiarity with C programming and program build procedures for your system.
-
-If you are only using this software as part of a larger program, the larger
-program's installation procedure may take care of configuring the IJG code.
-For example, Ghostscript's installation script will configure the IJG code.
-You don't need to read this file if you just want to compile Ghostscript.
-
-If you are on a Unix machine, you may not need to read this file at all.
-Try doing
- ./configure
- make
- make test
-If that doesn't complain, do
- make install
-(better do "make -n install" first to see if the makefile will put the files
-where you want them). Read further if you run into snags or want to customize
-the code for your system.
-
-
-TABLE OF CONTENTS
------------------
-
-Before you start
-Configuring the software:
- using the automatic "configure" script
- using one of the supplied jconfig and makefile files
- by hand
-Building the software
-Testing the software
-Installing the software
-Optional stuff
-Optimization
-Hints for specific systems
-
-
-BEFORE YOU START
-================
-
-Before installing the software you must unpack the distributed source code.
-Since you are reading this file, you have probably already succeeded in this
-task. However, there is a potential for error if you needed to convert the
-files to the local standard text file format (for example, if you are on
-MS-DOS you may have converted LF end-of-line to CR/LF). You must apply
-such conversion to all the files EXCEPT those whose names begin with "test".
-The test files contain binary data; if you change them in any way then the
-self-test will give bad results.
-
-Please check the last section of this file to see if there are hints for the
-specific machine or compiler you are using.
-
-
-CONFIGURING THE SOFTWARE
-========================
-
-To configure the IJG code for your system, you need to create two files:
- * jconfig.h: contains values for system-dependent #define symbols.
- * Makefile: controls the compilation process.
-(On a non-Unix machine, you may create "project files" or some other
-substitute for a Makefile. jconfig.h is needed in any environment.)
-
-We provide three different ways to generate these files:
- * On a Unix system, you can just run the "configure" script.
- * We provide sample jconfig files and makefiles for popular machines;
- if your machine matches one of the samples, just copy the right sample
- files to jconfig.h and Makefile.
- * If all else fails, read the instructions below and make your own files.
-
-
-Configuring the software using the automatic "configure" script
----------------------------------------------------------------
-
-If you are on a Unix machine, you can just type
- ./configure
-and let the configure script construct appropriate configuration files.
-If you're using "csh" on an old version of System V, you might need to type
- sh configure
-instead to prevent csh from trying to execute configure itself.
-Expect configure to run for a few minutes, particularly on slower machines;
-it works by compiling a series of test programs.
-
-Configure was created with GNU Autoconf and it follows the usual conventions
-for GNU configure scripts. It makes a few assumptions that you may want to
-override. You can do this by providing optional switches to configure:
-
-* If you want to build libjpeg as a shared library, say
- ./configure --enable-shared
-To get both shared and static libraries, say
- ./configure --enable-shared --enable-static
-Note that these switches invoke GNU libtool to take care of system-dependent
-shared library building methods. If things don't work this way, please try
-running configure without either switch; that should build a static library
-without using libtool. If that works, your problem is probably with libtool
-not with the IJG code. libtool is fairly new and doesn't support all flavors
-of Unix yet. (You might be able to find a newer version of libtool than the
-one included with libjpeg; see ftp.gnu.org. Report libtool problems to
-bug-libtool@gnu.org.)
-
-* Configure will use gcc (GNU C compiler) if it's available, otherwise cc.
-To force a particular compiler to be selected, use the CC option, for example
- ./configure CC='cc'
-The same method can be used to include any unusual compiler switches.
-For example, on HP-UX you probably want to say
- ./configure CC='cc -Aa'
-to get HP's compiler to run in ANSI mode.
-
-* The default CFLAGS setting is "-O" for non-gcc compilers, "-O2" for gcc.
-You can override this by saying, for example,
- ./configure CFLAGS='-g'
-if you want to compile with debugging support.
-
-* Configure will set up the makefile so that "make install" will install files
-into /usr/local/bin, /usr/local/man, etc. You can specify an installation
-prefix other than "/usr/local" by giving configure the option "--prefix=PATH".
-
-* If you don't have a lot of swap space, you may need to enable the IJG
-software's internal virtual memory mechanism. To do this, give the option
-"--enable-maxmem=N" where N is the default maxmemory limit in megabytes.
-This is discussed in more detail under "Selecting a memory manager", below.
-You probably don't need to worry about this on reasonably-sized Unix machines,
-unless you plan to process very large images.
-
-Configure has some other features that are useful if you are cross-compiling
-or working in a network of multiple machine types; but if you need those
-features, you probably already know how to use them.
-
-
-Configuring the software using one of the supplied jconfig and makefile files
------------------------------------------------------------------------------
-
-If you have one of these systems, you can just use the provided configuration
-files:
-
-Makefile jconfig file System and/or compiler
-
-makefile.manx jconfig.manx Amiga, Manx Aztec C
-makefile.sas jconfig.sas Amiga, SAS C
-makeproj.mac jconfig.mac Apple Macintosh, Metrowerks CodeWarrior
-mak*jpeg.st jconfig.st Atari ST/STE/TT, Pure C or Turbo C
-makefile.bcc jconfig.bcc MS-DOS or OS/2, Borland C
-makefile.dj jconfig.dj MS-DOS, DJGPP (Delorie's port of GNU C)
-makefile.mc6 jconfig.mc6 MS-DOS, Microsoft C (16-bit only)
-makefile.wat jconfig.wat MS-DOS, OS/2, or Windows NT, Watcom C
-makefile.vc jconfig.vc Windows NT/95, MS Visual C++
-make*.ds jconfig.vc Windows NT/95, MS Developer Studio
-makefile.mms jconfig.vms Digital VMS, with MMS software
-makefile.vms jconfig.vms Digital VMS, without MMS software
-
-Copy the proper jconfig file to jconfig.h and the makefile to Makefile (or
-whatever your system uses as the standard makefile name). For more info see
-the appropriate system-specific hints section near the end of this file.
-
-
-Configuring the software by hand
---------------------------------
-
-First, generate a jconfig.h file. If you are moderately familiar with C,
-the comments in jconfig.doc should be enough information to do this; just
-copy jconfig.doc to jconfig.h and edit it appropriately. Otherwise, you may
-prefer to use the ckconfig.c program. You will need to compile and execute
-ckconfig.c by hand --- we hope you know at least enough to do that.
-ckconfig.c may not compile the first try (in fact, the whole idea is for it
-to fail if anything is going to). If you get compile errors, fix them by
-editing ckconfig.c according to the directions given in ckconfig.c. Once
-you get it to run, it will write a suitable jconfig.h file, and will also
-print out some advice about which makefile to use.
-
-You may also want to look at the canned jconfig files, if there is one for a
-system similar to yours.
-
-Second, select a makefile and copy it to Makefile (or whatever your system
-uses as the standard makefile name). The most generic makefiles we provide
-are
- makefile.ansi: if your C compiler supports function prototypes
- makefile.unix: if not.
-(You have function prototypes if ckconfig.c put "#define HAVE_PROTOTYPES"
-in jconfig.h.) You may want to start from one of the other makefiles if
-there is one for a system similar to yours.
-
-Look over the selected Makefile and adjust options as needed. In particular
-you may want to change the CC and CFLAGS definitions. For instance, if you
-are using GCC, set CC=gcc. If you had to use any compiler switches to get
-ckconfig.c to work, make sure the same switches are in CFLAGS.
-
-If you are on a system that doesn't use makefiles, you'll need to set up
-project files (or whatever you do use) to compile all the source files and
-link them into executable files cjpeg, djpeg, jpegtran, rdjpgcom, and wrjpgcom.
-See the file lists in any of the makefiles to find out which files go into
-each program. Note that the provided makefiles all make a "library" file
-libjpeg first, but you don't have to do that if you don't want to; the file
-lists identify which source files are actually needed for compression,
-decompression, or both. As a last resort, you can make a batch script that
-just compiles everything and links it all together; makefile.vms is an example
-of this (it's for VMS systems that have no make-like utility).
-
-Here are comments about some specific configuration decisions you'll
-need to make:
-
-Command line style
-------------------
-
-These programs can use a Unix-like command line style which supports
-redirection and piping, like this:
- cjpeg inputfile >outputfile
- cjpeg <inputfile >outputfile
- source program | cjpeg >outputfile
-The simpler "two file" command line style is just
- cjpeg inputfile outputfile
-You may prefer the two-file style, particularly if you don't have pipes.
-
-You MUST use two-file style on any system that doesn't cope well with binary
-data fed through stdin/stdout; this is true for some MS-DOS compilers, for
-example. If you're not on a Unix system, it's safest to assume you need
-two-file style. (But if your compiler provides either the Posix-standard
-fdopen() library routine or a Microsoft-compatible setmode() routine, you
-can safely use the Unix command line style, by defining USE_FDOPEN or
-USE_SETMODE respectively.)
-
-To use the two-file style, make jconfig.h say "#define TWO_FILE_COMMANDLINE".
-
-Selecting a memory manager
---------------------------
-
-The IJG code is capable of working on images that are too big to fit in main
-memory; data is swapped out to temporary files as necessary. However, the
-code to do this is rather system-dependent. We provide five different
-memory managers:
-
-* jmemansi.c This version uses the ANSI-standard library routine tmpfile(),
- which not all non-ANSI systems have. On some systems
- tmpfile() may put the temporary file in a non-optimal
- location; if you don't like what it does, use jmemname.c.
-
-* jmemname.c This version creates named temporary files. For anything
- except a Unix machine, you'll need to configure the
- select_file_name() routine appropriately; see the comments
- near the head of jmemname.c. If you use this version, define
- NEED_SIGNAL_CATCHER in jconfig.h to make sure the temp files
- are removed if the program is aborted.
-
-* jmemnobs.c (That stands for No Backing Store :-).) This will compile on
- almost any system, but it assumes you have enough main memory
- or virtual memory to hold the biggest images you work with.
-
-* jmemdos.c This should be used with most 16-bit MS-DOS compilers.
- See the system-specific notes about MS-DOS for more info.
- IMPORTANT: if you use this, define USE_MSDOS_MEMMGR in
- jconfig.h, and include the assembly file jmemdosa.asm in the
- programs. The supplied makefiles and jconfig files for
- 16-bit MS-DOS compilers already do both.
-
-* jmemmac.c Custom version for Apple Macintosh; see the system-specific
- notes for Macintosh for more info.
-
-To use a particular memory manager, change the SYSDEPMEM variable in your
-makefile to equal the corresponding object file name (for example, jmemansi.o
-or jmemansi.obj for jmemansi.c).
-
-If you have plenty of (real or virtual) main memory, just use jmemnobs.c.
-"Plenty" means about ten bytes for every pixel in the largest images
-you plan to process, so a lot of systems don't meet this criterion.
-If yours doesn't, try jmemansi.c first. If that doesn't compile, you'll have
-to use jmemname.c; be sure to adjust select_file_name() for local conditions.
-You may also need to change unlink() to remove() in close_backing_store().
-
-Except with jmemnobs.c or jmemmac.c, you need to adjust the DEFAULT_MAX_MEM
-setting to a reasonable value for your system (either by adding a #define for
-DEFAULT_MAX_MEM to jconfig.h, or by adding a -D switch to the Makefile).
-This value limits the amount of data space the program will attempt to
-allocate. Code and static data space isn't counted, so the actual memory
-needs for cjpeg or djpeg are typically 100 to 150Kb more than the max-memory
-setting. Larger max-memory settings reduce the amount of I/O needed to
-process a large image, but too large a value can result in "insufficient
-memory" failures. On most Unix machines (and other systems with virtual
-memory), just set DEFAULT_MAX_MEM to several million and forget it. At the
-other end of the spectrum, for MS-DOS machines you probably can't go much
-above 300K to 400K. (On MS-DOS the value refers to conventional memory only.
-Extended/expanded memory is handled separately by jmemdos.c.)
-
-
-BUILDING THE SOFTWARE
-=====================
-
-Now you should be able to compile the software. Just say "make" (or
-whatever's necessary to start the compilation). Have a cup of coffee.
-
-Here are some things that could go wrong:
-
-If your compiler complains about undefined structures, you should be able to
-shut it up by putting "#define INCOMPLETE_TYPES_BROKEN" in jconfig.h.
-
-If you have trouble with missing system include files or inclusion of the
-wrong ones, read jinclude.h. This shouldn't happen if you used configure
-or ckconfig.c to set up jconfig.h.
-
-There are a fair number of routines that do not use all of their parameters;
-some compilers will issue warnings about this, which you can ignore. There
-are also a few configuration checks that may give "unreachable code" warnings.
-Any other warning deserves investigation.
-
-If you don't have a getenv() library routine, define NO_GETENV.
-
-Also see the system-specific hints, below.
-
-
-TESTING THE SOFTWARE
-====================
-
-As a quick test of functionality we've included a small sample image in
-several forms:
- testorig.jpg Starting point for the djpeg tests.
- testimg.ppm The output of djpeg testorig.jpg
- testimg.bmp The output of djpeg -bmp -colors 256 testorig.jpg
- testimg.jpg The output of cjpeg testimg.ppm
- testprog.jpg Progressive-mode equivalent of testorig.jpg.
- testimgp.jpg The output of cjpeg -progressive -optimize testimg.ppm
-(The first- and second-generation .jpg files aren't identical since JPEG is
-lossy.) If you can generate duplicates of the testimg* files then you
-probably have working programs.
-
-With most of the makefiles, "make test" will perform the necessary
-comparisons.
-
-If you're using a makefile that doesn't provide the test option, run djpeg
-and cjpeg by hand and compare the output files to testimg* with whatever
-binary file comparison tool you have. The files should be bit-for-bit
-identical.
-
-If the programs complain "MAX_ALLOC_CHUNK is wrong, please fix", then you
-need to reduce MAX_ALLOC_CHUNK to a value that fits in type size_t.
-Try adding "#define MAX_ALLOC_CHUNK 65520L" to jconfig.h. A less likely
-configuration error is "ALIGN_TYPE is wrong, please fix": defining ALIGN_TYPE
-as long should take care of that one.
-
-If the cjpeg test run fails with "Missing Huffman code table entry", it's a
-good bet that you needed to define RIGHT_SHIFT_IS_UNSIGNED. Go back to the
-configuration step and run ckconfig.c. (This is a good plan for any other
-test failure, too.)
-
-If you are using Unix (one-file) command line style on a non-Unix system,
-it's a good idea to check that binary I/O through stdin/stdout actually
-works. You should get the same results from "djpeg <testorig.jpg >out.ppm"
-as from "djpeg -outfile out.ppm testorig.jpg". Note that the makefiles all
-use the latter style and therefore do not exercise stdin/stdout! If this
-check fails, try recompiling with USE_SETMODE or USE_FDOPEN defined.
-If it still doesn't work, better use two-file style.
-
-If you chose a memory manager other than jmemnobs.c, you should test that
-temporary-file usage works. Try "djpeg -bmp -colors 256 -max 0 testorig.jpg"
-and make sure its output matches testimg.bmp. If you have any really large
-images handy, try compressing them with -optimize and/or decompressing with
--colors 256 to make sure your DEFAULT_MAX_MEM setting is not too large.
-
-NOTE: this is far from an exhaustive test of the JPEG software; some modules,
-such as 1-pass color quantization, are not exercised at all. It's just a
-quick test to give you some confidence that you haven't missed something
-major.
-
-
-INSTALLING THE SOFTWARE
-=======================
-
-Once you're done with the above steps, you can install the software by
-copying the executable files (cjpeg, djpeg, jpegtran, rdjpgcom, and wrjpgcom)
-to wherever you normally install programs. On Unix systems, you'll also want
-to put the man pages (cjpeg.1, djpeg.1, jpegtran.1, rdjpgcom.1, wrjpgcom.1)
-in the man-page directory. The pre-fab makefiles don't support this step
-since there's such a wide variety of installation procedures on different
-systems.
-
-If you generated a Makefile with the "configure" script, you can just say
- make install
-to install the programs and their man pages into the standard places.
-(You'll probably need to be root to do this.) We recommend first saying
- make -n install
-to see where configure thought the files should go. You may need to edit
-the Makefile, particularly if your system's conventions for man page
-filenames don't match what configure expects.
-
-If you want to install the IJG library itself, for use in compiling other
-programs besides ours, then you need to put the four include files
- jpeglib.h jerror.h jconfig.h jmorecfg.h
-into your include-file directory, and put the library file libjpeg.a
-(extension may vary depending on system) wherever library files go.
-If you generated a Makefile with "configure", it will do what it thinks
-is the right thing if you say
- make install-lib
-
-
-OPTIONAL STUFF
-==============
-
-Progress monitor:
-
-If you like, you can #define PROGRESS_REPORT (in jconfig.h) to enable display
-of percent-done progress reports. The routine provided in cdjpeg.c merely
-prints percentages to stderr, but you can customize it to do something
-fancier.
-
-Utah RLE file format support:
-
-We distribute the software with support for RLE image files (Utah Raster
-Toolkit format) disabled, because the RLE support won't compile without the
-Utah library. If you have URT version 3.1 or later, you can enable RLE
-support as follows:
- 1. #define RLE_SUPPORTED in jconfig.h.
- 2. Add a -I option to CFLAGS in the Makefile for the directory
- containing the URT .h files (typically the "include"
- subdirectory of the URT distribution).
- 3. Add -L... -lrle to LDLIBS in the Makefile, where ... specifies
- the directory containing the URT "librle.a" file (typically the
- "lib" subdirectory of the URT distribution).
-
-Support for 12-bit-deep pixel data:
-
-The JPEG standard allows either 8-bit or 12-bit data precision. (For color,
-this means 8 or 12 bits per channel, of course.) If you need to work with
-deeper than 8-bit data, you can compile the IJG code for 12-bit operation.
-To do so:
- 1. In jmorecfg.h, define BITS_IN_JSAMPLE as 12 rather than 8.
- 2. In jconfig.h, undefine BMP_SUPPORTED, RLE_SUPPORTED, and TARGA_SUPPORTED,
- because the code for those formats doesn't handle 12-bit data and won't
- even compile. (The PPM code does work, as explained below. The GIF
- code works too; it scales 8-bit GIF data to and from 12-bit depth
- automatically.)
- 3. Compile. Don't expect "make test" to pass, since the supplied test
- files are for 8-bit data.
-
-Currently, 12-bit support does not work on 16-bit-int machines.
-
-Note that a 12-bit version will not read 8-bit JPEG files, nor vice versa;
-so you'll want to keep around a regular 8-bit compilation as well.
-(Run-time selection of data depth, to allow a single copy that does both,
-is possible but would probably slow things down considerably; it's very low
-on our to-do list.)
-
-The PPM reader (rdppm.c) can read 12-bit data from either text-format or
-binary-format PPM and PGM files. Binary-format PPM/PGM files which have a
-maxval greater than 255 are assumed to use 2 bytes per sample, LSB first
-(little-endian order). As of early 1995, 2-byte binary format is not
-officially supported by the PBMPLUS library, but it is expected that a
-future release of PBMPLUS will support it. Note that the PPM reader will
-read files of any maxval regardless of the BITS_IN_JSAMPLE setting; incoming
-data is automatically rescaled to either maxval=255 or maxval=4095 as
-appropriate for the cjpeg bit depth.
-
-The PPM writer (wrppm.c) will normally write 2-byte binary PPM or PGM
-format, maxval 4095, when compiled with BITS_IN_JSAMPLE=12. Since this
-format is not yet widely supported, you can disable it by compiling wrppm.c
-with PPM_NORAWWORD defined; then the data is scaled down to 8 bits to make a
-standard 1-byte/sample PPM or PGM file. (Yes, this means still another copy
-of djpeg to keep around. But hopefully you won't need it for very long.
-Poskanzer's supposed to get that new PBMPLUS release out Real Soon Now.)
-
-Of course, if you are working with 12-bit data, you probably have it stored
-in some other, nonstandard format. In that case you'll probably want to
-write your own I/O modules to read and write your format.
-
-Note that a 12-bit version of cjpeg always runs in "-optimize" mode, in
-order to generate valid Huffman tables. This is necessary because our
-default Huffman tables only cover 8-bit data.
-
-Removing code:
-
-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.doc 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@uunet.uu.net 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@uunet.uu.net. 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.doc 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.
-
-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.
-
-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.doc 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.)
-
-Some users feel that it's easier to call the library from C++ code if you
-force VC++ to treat the library as C++ code, which you can do by renaming
-all the *.c files to *.cpp (and adjusting the makefile to match). This
-avoids the need to put extern "C" { ... } around #include "jpeglib.h" in
-your C++ application.
-
-
-Microsoft Windows, Microsoft Developer Studio:
-
-We include makefiles that should work as project files in DevStudio 4.2 or
-later. There is a library makefile that builds the IJG library as a static
-Win32 library, and an application makefile that builds 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. Copy jconfig.vc to jconfig.h, makelib.ds to jpeg.mak, and
- makeapps.ds to apps.mak. (Note that the renaming is critical!)
-2. Click on the .mak files to construct project workspaces.
- (If you are using DevStudio more recent than 4.2, you'll probably
- get a message saying that the makefiles are being updated.)
-3. Build the library project, then the applications project.
-4. Move the application .exe files from `app`\Release to an
- appropriate location on your path.
-5. To perform the self-test, execute the command line
- NMAKE /f makefile.vc test
-
-
-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.