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