ref: 2c6cc121339ade33ac5aa4b46356df1cd5469fbe
dir: /sys/src/cmd/gs/jpeg/jmorecfg.h.save/
/* * jmorecfg.h * * Copyright (C) 1991-1997, 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 additional configuration options that customize the * JPEG software for special applications or support machine-dependent * optimizations. Most users will not need to touch this file. */ /* * Define BITS_IN_JSAMPLE as either * 8 for 8-bit sample values (the usual setting) * 12 for 12-bit sample values * Only 8 and 12 are legal data precisions for lossy JPEG according to the * JPEG standard, and the IJG code does not support anything else! * We do not support run-time selection of data precision, sorry. */ #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ /* * Maximum number of components (color channels) allowed in JPEG image. * To meet the letter of the JPEG spec, set this to 255. However, darn * few applications need more than 4 channels (maybe 5 for CMYK + alpha * mask). We recommend 10 as a reasonable compromise; use 4 if you are * really short on memory. (Each allowed component costs a hundred or so * bytes of storage, whether actually used in an image or not.) */ #define MAX_COMPONENTS 10 /* maximum number of image components */ /* * Basic data types. * You may need to change these if you have a machine with unusual data * type sizes; 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. */ /* Representation of a single sample (pixel element value). * We frequently allocate large arrays of these, so it's important to keep * them small. But if you have memory to burn and access to char or short * arrays is very slow on your hardware, you might want to change these. */ #if BITS_IN_JSAMPLE == 8 /* 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. */ #ifdef HAVE_UNSIGNED_CHAR typedef unsigned char JSAMPLE; #define GETJSAMPLE(value) ((int) (value)) #else /* not HAVE_UNSIGNED_CHAR */ typedef char JSAMPLE; #ifdef CHAR_IS_UNSIGNED #define GETJSAMPLE(value) ((int) (value)) #else #define GETJSAMPLE(value) ((int) (value) & 0xFF) #endif /* CHAR_IS_UNSIGNED */ #endif /* HAVE_UNSIGNED_CHAR */ #define MAXJSAMPLE 255 #define CENTERJSAMPLE 128 #endif /* BITS_IN_JSAMPLE == 8 */ #if BITS_IN_JSAMPLE == 12 /* 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) ((int) (value)) #define MAXJSAMPLE 4095 #define CENTERJSAMPLE 2048 #endif /* BITS_IN_JSAMPLE == 12 */ /* Representation of a DCT frequency coefficient. * This should be a signed value of at least 16 bits; "short" is usually OK. * Again, we allocate large arrays of these, but you can change to int * if you have memory to burn and "short" is really slow. */ typedef short JCOEF; /* Compressed datastreams are represented as arrays of JOCTET. * These must be EXACTLY 8 bits wide, at least once they are written to * external storage. Note that when using the stdio data source/destination * managers, this is also the data type passed to fread/fwrite. */ #ifdef HAVE_UNSIGNED_CHAR typedef unsigned char JOCTET; #define GETJOCTET(value) (value) #else /* not HAVE_UNSIGNED_CHAR */ typedef char JOCTET; #ifdef CHAR_IS_UNSIGNED #define GETJOCTET(value) (value) #else #define GETJOCTET(value) ((value) & 0xFF) #endif /* CHAR_IS_UNSIGNED */ #endif /* HAVE_UNSIGNED_CHAR */ /* These 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. */ #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ typedef short INT16; #endif /* INT32 must hold at least signed 32-bit values. */ #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ typedef long INT32; #endif /* Datatype used for image dimensions. The JPEG standard only supports * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore * "unsigned int" is sufficient on all machines. However, if you need to * handle larger images and you don't mind deviating from the spec, you * can change this datatype. */ typedef unsigned int JDIMENSION; #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ /* These macros are used in all function definitions and extern declarations. * You could modify them if you need to change function linkage conventions; * in particular, you'll need to do that to make the library a Windows DLL. * Another application is to make all functions global for use with debuggers * or code profilers that require it. */ /* a function called through method pointers: */ #define METHODDEF(type) static type /* a function used only in its module: */ #define LOCAL(type) static type /* a function referenced thru EXTERNs: */ #define GLOBAL(type) type /* a reference to a GLOBAL function: */ #define EXTERN(type) extern type /* This macro is used to declare a "method", that is, a function pointer. * We want to supply prototype parameters if the compiler can cope. * Note that the arglist parameter must be parenthesized! * Again, you can customize this if you need special linkage keywords. */ #ifdef HAVE_PROTOTYPES #define JMETHOD(type,methodname,arglist) type (*methodname) arglist #else #define JMETHOD(type,methodname,arglist) type (*methodname) () #endif /* Here is the pseudo-keyword for declaring pointers that must be "far" * on 80x86 machines. Most of the specialized coding for 80x86 is handled * by just saying "FAR *" where such a pointer is needed. In a few places * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. */ #ifdef NEED_FAR_POINTERS #define FAR far #else #define FAR #endif /* * On a few systems, type boolean and/or its values 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. * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. */ #ifndef HAVE_BOOLEAN typedef int boolean; #endif #ifndef FALSE /* in case these macros already exist */ #define FALSE 0 /* values of boolean */ #endif #ifndef TRUE #define TRUE 1 #endif /* * The remaining options affect code selection within the JPEG library, * but they don't need to be visible to most applications using the library. * To minimize application namespace pollution, the symbols won't be * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. */ #ifdef JPEG_INTERNALS #define JPEG_INTERNAL_OPTIONS #endif #ifdef JPEG_INTERNAL_OPTIONS /* * These defines indicate whether to include various optional functions. * Undefining some of these symbols will produce a smaller but less capable * library. 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. */ /* Capability options common to encoder and decoder: */ #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ /* Encoder capability options: */ #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ /* Note: if you selected 12-bit data precision, it is dangerous to turn off * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit * precision, so jchuff.c normally uses entropy optimization to compute * usable tables for higher precision. If you don't want to do optimization, * you'll have to supply different default Huffman tables. * The exact same statements apply for progressive JPEG: the default tables * don't work for progressive mode. (This may get fixed, however.) */ #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ /* Decoder capability options: */ #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ /* more capability options later, no doubt */ /* * Ordering of RGB data in scanlines passed to or from the application. * If your application wants to deal with data in the order B,G,R, just * change these macros. You can also deal with formats such as R,G,B,X * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing * the offsets will also change the order in which colormap data is organized. * RESTRICTIONS: * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not * useful if you are using JPEG color spaces other than YCbCr or grayscale. * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE * is not 3 (they don't understand about dummy color components!). So you * can't use color quantization if you change that value. */ #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ #define RGB_GREEN 1 /* Offset of Green */ #define RGB_BLUE 2 /* Offset of Blue */ #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ /* Definitions for speed-related optimizations. */ /* If your compiler supports inline functions, define INLINE * as the inline keyword; otherwise define it as empty. */ #ifndef INLINE #ifdef __GNUC__ /* for instance, GNU C knows about inline */ #define INLINE __inline__ #endif #ifndef INLINE #define INLINE /* default is to define it as empty */ #endif #endif /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER * as short on such a machine. MULTIPLIER must be at least 16 bits wide. */ #ifndef MULTIPLIER #define MULTIPLIER int /* type for fastest integer multiply */ #endif /* FAST_FLOAT should be either float or double, whichever is done faster * by your compiler. (Note that this type is only used in the floating point * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) * Typically, float is faster in ANSI C compilers, while double is faster in * pre-ANSI compilers (because they insist on converting to double anyway). * The code below therefore chooses float if we have ANSI-style prototypes. */ #ifndef FAST_FLOAT #ifdef HAVE_PROTOTYPES #define FAST_FLOAT float #else #define FAST_FLOAT double #endif #endif #endif /* JPEG_INTERNAL_OPTIONS */