359 lines
12 KiB
C
359 lines
12 KiB
C
/*
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* jconfig.h
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*
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* Copyright (C) 1991, 1992, Thomas G. Lane.
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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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*
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* This file contains preprocessor declarations that help customize
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* the JPEG software for a particular application, machine, or compiler.
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* Edit these declarations as needed (or add -D flags to the Makefile).
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*/
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/*
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* These symbols indicate the properties of your machine or compiler.
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* The conditional definitions given may do the right thing already,
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* but you'd best look them over closely, especially if your compiler
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* does not handle full ANSI C. An ANSI-compliant C compiler should
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* provide all the necessary features; __STDC__ is supposed to be
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* predefined by such compilers.
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*/
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/*
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* HAVE_STDC is tested below to see whether ANSI features are available.
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* We avoid testing __STDC__ directly for arcane reasons of portability.
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* (On some compilers, __STDC__ is only defined if a switch is given,
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* but the switch also disables machine-specific features we need to get at.
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* In that case, -DHAVE_STDC in the Makefile is a convenient solution.)
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*/
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#ifdef __STDC__ /* if compiler claims to be ANSI, believe it */
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#define HAVE_STDC
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#endif
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/* Does your compiler support function prototypes? */
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/* (If not, you also need to use ansi2knr, see SETUP) */
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#ifdef HAVE_STDC /* ANSI C compilers always have prototypes */
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#define PROTO
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#else
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#ifdef __cplusplus /* So do C++ compilers */
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#define PROTO
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#endif
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#endif
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/* Does your compiler support the declaration "unsigned char" ? */
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/* How about "unsigned short" ? */
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#ifdef HAVE_STDC /* ANSI C compilers must support both */
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#define HAVE_UNSIGNED_CHAR
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#define HAVE_UNSIGNED_SHORT
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#endif
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/* Define this if an ordinary "char" type is unsigned.
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* If you're not sure, leaving it undefined will work at some cost in speed.
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* If you defined HAVE_UNSIGNED_CHAR then it doesn't matter very much.
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*/
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/* #define CHAR_IS_UNSIGNED */
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/* Define this if your compiler implements ">>" on signed values as a logical
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* (unsigned) shift; leave it undefined if ">>" is a signed (arithmetic) shift,
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* which is the normal and rational definition.
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*/
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/* #define RIGHT_SHIFT_IS_UNSIGNED */
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/* Define "void" as "char" if your compiler doesn't know about type void.
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* NOTE: be sure to define void such that "void *" represents the most general
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* pointer type, e.g., that returned by malloc().
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*/
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/* #define void char */
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/* Define const as empty if your compiler doesn't know the "const" keyword. */
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/* (Even if it does, defining const as empty won't break anything.) */
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#ifndef HAVE_STDC /* ANSI C and C++ compilers should know it. */
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#ifndef __cplusplus
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#define const
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#endif
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#endif
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/* For 80x86 machines, you need to define NEED_FAR_POINTERS,
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* unless you are using a large-data memory model or 80386 flat-memory mode.
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* On less brain-damaged CPUs this symbol must not be defined.
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* (Defining this symbol causes large data structures to be referenced through
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* "far" pointers and to be allocated with a special version of malloc.)
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*/
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#ifdef MSDOS
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#define NEED_FAR_POINTERS
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#endif
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/* The next three symbols only affect the system-dependent user interface
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* modules (jcmain.c, jdmain.c). You can ignore these if you are supplying
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* your own user interface code.
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*/
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/* Define this if you want to name both input and output files on the command
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* line, rather than using stdout and optionally stdin. You MUST do this if
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* your system can't cope with binary I/O to stdin/stdout. See comments at
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* head of jcmain.c or jdmain.c.
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*/
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#ifdef MSDOS /* two-file style is needed for PCs */
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#ifndef USE_SETMODE /* unless you have setmode() */
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#define TWO_FILE_COMMANDLINE
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#endif
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#endif
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#ifdef THINK_C /* it's needed for Macintosh too */
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#define TWO_FILE_COMMANDLINE
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#endif
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/* Define this if your system needs explicit cleanup of temporary files.
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* This is crucial under MS-DOS, where the temporary "files" may be areas
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* of extended memory; on most other systems it's not as important.
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*/
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#ifdef MSDOS
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#define NEED_SIGNAL_CATCHER
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#endif
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/* By default, we open image files with fopen(...,"rb") or fopen(...,"wb").
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* This is necessary on systems that distinguish text files from binary files,
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* and is harmless on most systems that don't. If you have one of the rare
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* systems that complains about the "b" spec, define this symbol.
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*/
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/* #define DONT_USE_B_MODE */
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/* If you're getting bored, that's the end of the symbols you HAVE to
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* worry about. Go fix the makefile and compile.
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*/
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/* If your compiler supports inline functions, define INLINE
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* as the inline keyword; otherwise define it as empty.
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*/
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#ifdef __GNUC__ /* for instance, GNU C knows about inline */
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#define INLINE __inline__
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#endif
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#ifndef INLINE /* default is to define it as empty */
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#define INLINE
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#endif
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/* On a few systems, type boolean and/or macros FALSE, TRUE may appear
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* in standard header files. Or you may have conflicts with application-
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* specific header files that you want to include together with these files.
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* In that case you need only comment out these definitions.
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*/
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typedef int boolean;
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#undef FALSE /* in case these macros already exist */
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#undef TRUE
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#define FALSE 0 /* values of boolean */
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#define TRUE 1
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/* This defines the size of the I/O buffers for entropy compression
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* and decompression; you could reduce it if memory is tight.
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*/
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#define JPEG_BUF_SIZE 4096 /* bytes */
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/* These symbols determine the JPEG functionality supported. */
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/*
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* These defines indicate whether to include various optional functions.
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* Undefining some of these symbols will produce a smaller but less capable
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* program file. Note that you can leave certain source files out of the
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* compilation/linking process if you've #undef'd the corresponding symbols.
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* (You may HAVE to do that if your compiler doesn't like null source files.)
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*/
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/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */
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/* Encoder capability options: */
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#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
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#undef C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? (NYI) */
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#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */
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#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */
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/* Decoder capability options: */
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#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
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#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
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#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing during decoding? */
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#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */
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#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */
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/* these defines indicate which JPEG file formats are allowed */
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#define JFIF_SUPPORTED /* JFIF or "raw JPEG" files */
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#undef JTIFF_SUPPORTED /* JPEG-in-TIFF (not yet implemented) */
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/* these defines indicate which image (non-JPEG) file formats are allowed */
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#define GIF_SUPPORTED /* GIF image file format */
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/* #define RLE_SUPPORTED */ /* RLE image file format (by default, no) */
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#define PPM_SUPPORTED /* PPM/PGM image file format */
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#define TARGA_SUPPORTED /* Targa image file format */
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#undef TIFF_SUPPORTED /* TIFF image file format (not yet impl.) */
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/* more capability options later, no doubt */
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/*
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* Define exactly one of these three symbols to indicate whether you want
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* 8-bit, 12-bit, or 16-bit sample (pixel component) values. 8-bit is the
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* default and is nearly always the right thing to use. You can use 12-bit if
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* you need to support image formats with more than 8 bits of resolution in a
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* color value. 16-bit should only be used for the lossless JPEG mode (not
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* currently supported). Note that 12- and 16-bit values take up twice as
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* much memory as 8-bit!
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* Note: if you select 12- or 16-bit precision, it is dangerous to turn off
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* ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit
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* precision, so jchuff.c normally uses entropy optimization to compute
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* usable tables for higher precision. If you don't want to do optimization,
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* you'll have to supply different default Huffman tables.
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*/
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#define EIGHT_BIT_SAMPLES
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#undef TWELVE_BIT_SAMPLES
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#undef SIXTEEN_BIT_SAMPLES
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/*
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* The remaining definitions don't need to be hand-edited in most cases.
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* You may need to change these if you have a machine with unusual data
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* types; for example, "char" not 8 bits, "short" not 16 bits,
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* or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits,
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* but it had better be at least 16.
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*/
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/* First define the representation of a single pixel element value. */
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#ifdef EIGHT_BIT_SAMPLES
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/* JSAMPLE should be the smallest type that will hold the values 0..255.
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* You can use a signed char by having GETJSAMPLE mask it with 0xFF.
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* If you have only signed chars, and you are more worried about speed than
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* memory usage, it might be a win to make JSAMPLE be short.
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*/
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#ifdef HAVE_UNSIGNED_CHAR
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typedef unsigned char JSAMPLE;
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#define GETJSAMPLE(value) (value)
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#else /* not HAVE_UNSIGNED_CHAR */
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#ifdef CHAR_IS_UNSIGNED
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typedef char JSAMPLE;
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#define GETJSAMPLE(value) (value)
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#else /* not CHAR_IS_UNSIGNED */
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typedef char JSAMPLE;
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#define GETJSAMPLE(value) ((value) & 0xFF)
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#endif /* CHAR_IS_UNSIGNED */
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#endif /* HAVE_UNSIGNED_CHAR */
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#define BITS_IN_JSAMPLE 8
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#define MAXJSAMPLE 255
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#define CENTERJSAMPLE 128
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#endif /* EIGHT_BIT_SAMPLES */
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#ifdef TWELVE_BIT_SAMPLES
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/* JSAMPLE should be the smallest type that will hold the values 0..4095. */
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/* On nearly all machines "short" will do nicely. */
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typedef short JSAMPLE;
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#define GETJSAMPLE(value) (value)
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#define BITS_IN_JSAMPLE 12
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#define MAXJSAMPLE 4095
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#define CENTERJSAMPLE 2048
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#endif /* TWELVE_BIT_SAMPLES */
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#ifdef SIXTEEN_BIT_SAMPLES
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/* JSAMPLE should be the smallest type that will hold the values 0..65535. */
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#ifdef HAVE_UNSIGNED_SHORT
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typedef unsigned short JSAMPLE;
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#define GETJSAMPLE(value) (value)
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#else /* not HAVE_UNSIGNED_SHORT */
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/* If int is 32 bits this'll be horrendously inefficient storage-wise.
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* But since we don't actually support 16-bit samples (ie lossless coding) yet,
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* I'm not going to worry about making a smarter definition ...
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*/
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typedef unsigned int JSAMPLE;
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#define GETJSAMPLE(value) (value)
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#endif /* HAVE_UNSIGNED_SHORT */
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#define BITS_IN_JSAMPLE 16
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#define MAXJSAMPLE 65535
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#define CENTERJSAMPLE 32768
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#endif /* SIXTEEN_BIT_SAMPLES */
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/* Here we define the representation of a DCT frequency coefficient.
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* This should be a signed 16-bit value; "short" is usually right.
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* It's important that this be exactly 16 bits, no more and no less;
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* more will cost you a BIG hit of memory, less will give wrong answers.
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*/
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typedef short JCOEF;
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/* The remaining typedefs are used for various table entries and so forth.
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* They must be at least as wide as specified; but making them too big
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* won't cost a huge amount of memory, so we don't provide special
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* extraction code like we did for JSAMPLE. (In other words, these
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* typedefs live at a different point on the speed/space tradeoff curve.)
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*/
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/* UINT8 must hold at least the values 0..255. */
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#ifdef HAVE_UNSIGNED_CHAR
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typedef unsigned char UINT8;
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#else /* not HAVE_UNSIGNED_CHAR */
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#ifdef CHAR_IS_UNSIGNED
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typedef char UINT8;
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#else /* not CHAR_IS_UNSIGNED */
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typedef short UINT8;
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#endif /* CHAR_IS_UNSIGNED */
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#endif /* HAVE_UNSIGNED_CHAR */
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/* UINT16 must hold at least the values 0..65535. */
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#ifdef HAVE_UNSIGNED_SHORT
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typedef unsigned short UINT16;
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#else /* not HAVE_UNSIGNED_SHORT */
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typedef unsigned int UINT16;
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#endif /* HAVE_UNSIGNED_SHORT */
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/* INT16 must hold at least the values -32768..32767. */
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#ifndef XMD_H /* X11/xmd.h correctly defines INT16 */
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typedef short INT16;
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#endif
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/* INT32 must hold signed 32-bit values; if your machine happens */
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/* to have 64-bit longs, you might want to change this. */
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#ifndef XMD_H /* X11/xmd.h correctly defines INT32 */
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typedef long INT32;
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#endif
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