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1 | /* | |
2 | * jmorecfg.h | |
3 | * | |
4 | * Copyright (C) 1991-1997, Thomas G. Lane. | |
5 | * This file is part of the Independent JPEG Group's software. | |
6 | * For conditions of distribution and use, see the accompanying README file. | |
7 | * | |
8 | * This file contains additional configuration options that customize the | |
9 | * JPEG software for special applications or support machine-dependent | |
10 | * optimizations. Most users will not need to touch this file. | |
11 | */ | |
12 | ||
13 | ||
14 | /* | |
15 | * Define BITS_IN_JSAMPLE as either | |
16 | * 8 for 8-bit sample values (the usual setting) | |
17 | * 12 for 12-bit sample values | |
18 | * Only 8 and 12 are legal data precisions for lossy JPEG according to the | |
19 | * JPEG standard, and the IJG code does not support anything else! | |
20 | * We do not support run-time selection of data precision, sorry. | |
21 | */ | |
22 | ||
23 | #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ | |
24 | ||
25 | ||
26 | /* | |
27 | * Maximum number of components (color channels) allowed in JPEG image. | |
28 | * To meet the letter of the JPEG spec, set this to 255. However, darn | |
29 | * few applications need more than 4 channels (maybe 5 for CMYK + alpha | |
30 | * mask). We recommend 10 as a reasonable compromise; use 4 if you are | |
31 | * really short on memory. (Each allowed component costs a hundred or so | |
32 | * bytes of storage, whether actually used in an image or not.) | |
33 | */ | |
34 | ||
35 | #define MAX_COMPONENTS 10 /* maximum number of image components */ | |
36 | ||
37 | ||
38 | /* | |
39 | * Basic data types. | |
40 | * You may need to change these if you have a machine with unusual data | |
41 | * type sizes; for example, "char" not 8 bits, "short" not 16 bits, | |
42 | * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, | |
43 | * but it had better be at least 16. | |
44 | */ | |
45 | ||
46 | /* Representation of a single sample (pixel element value). | |
47 | * We frequently allocate large arrays of these, so it's important to keep | |
48 | * them small. But if you have memory to burn and access to char or short | |
49 | * arrays is very slow on your hardware, you might want to change these. | |
50 | */ | |
51 | ||
52 | #if BITS_IN_JSAMPLE == 8 | |
53 | /* JSAMPLE should be the smallest type that will hold the values 0..255. | |
54 | * You can use a signed char by having GETJSAMPLE mask it with 0xFF. | |
55 | */ | |
56 | ||
57 | #ifdef HAVE_UNSIGNED_CHAR | |
58 | ||
59 | typedef unsigned char JSAMPLE; | |
60 | #define GETJSAMPLE(value) ((int) (value)) | |
61 | ||
62 | #else /* not HAVE_UNSIGNED_CHAR */ | |
63 | ||
64 | typedef char JSAMPLE; | |
65 | #ifdef CHAR_IS_UNSIGNED | |
66 | #define GETJSAMPLE(value) ((int) (value)) | |
67 | #else | |
68 | #define GETJSAMPLE(value) ((int) (value) & 0xFF) | |
69 | #endif /* CHAR_IS_UNSIGNED */ | |
70 | ||
71 | #endif /* HAVE_UNSIGNED_CHAR */ | |
72 | ||
73 | #define MAXJSAMPLE 255 | |
74 | #define CENTERJSAMPLE 128 | |
75 | ||
76 | #endif /* BITS_IN_JSAMPLE == 8 */ | |
77 | ||
78 | ||
79 | #if BITS_IN_JSAMPLE == 12 | |
80 | /* JSAMPLE should be the smallest type that will hold the values 0..4095. | |
81 | * On nearly all machines "short" will do nicely. | |
82 | */ | |
83 | ||
84 | typedef short JSAMPLE; | |
85 | #define GETJSAMPLE(value) ((int) (value)) | |
86 | ||
87 | #define MAXJSAMPLE 4095 | |
88 | #define CENTERJSAMPLE 2048 | |
89 | ||
90 | #endif /* BITS_IN_JSAMPLE == 12 */ | |
91 | ||
92 | ||
93 | /* Representation of a DCT frequency coefficient. | |
94 | * This should be a signed value of at least 16 bits; "short" is usually OK. | |
95 | * Again, we allocate large arrays of these, but you can change to int | |
96 | * if you have memory to burn and "short" is really slow. | |
97 | */ | |
98 | ||
99 | typedef short JCOEF; | |
100 | ||
101 | ||
102 | /* Compressed datastreams are represented as arrays of JOCTET. | |
103 | * These must be EXACTLY 8 bits wide, at least once they are written to | |
104 | * external storage. Note that when using the stdio data source/destination | |
105 | * managers, this is also the data type passed to fread/fwrite. | |
106 | */ | |
107 | ||
108 | #ifdef HAVE_UNSIGNED_CHAR | |
109 | ||
110 | typedef unsigned char JOCTET; | |
111 | #define GETJOCTET(value) (value) | |
112 | ||
113 | #else /* not HAVE_UNSIGNED_CHAR */ | |
114 | ||
115 | typedef char JOCTET; | |
116 | #ifdef CHAR_IS_UNSIGNED | |
117 | #define GETJOCTET(value) (value) | |
118 | #else | |
119 | #define GETJOCTET(value) ((value) & 0xFF) | |
120 | #endif /* CHAR_IS_UNSIGNED */ | |
121 | ||
122 | #endif /* HAVE_UNSIGNED_CHAR */ | |
123 | ||
124 | ||
125 | /* These typedefs are used for various table entries and so forth. | |
126 | * They must be at least as wide as specified; but making them too big | |
127 | * won't cost a huge amount of memory, so we don't provide special | |
128 | * extraction code like we did for JSAMPLE. (In other words, these | |
129 | * typedefs live at a different point on the speed/space tradeoff curve.) | |
130 | */ | |
131 | ||
132 | /* UINT8 must hold at least the values 0..255. */ | |
133 | ||
134 | #ifdef HAVE_UNSIGNED_CHAR | |
135 | typedef unsigned char UINT8; | |
136 | #else /* not HAVE_UNSIGNED_CHAR */ | |
137 | #ifdef CHAR_IS_UNSIGNED | |
138 | typedef char UINT8; | |
139 | #else /* not CHAR_IS_UNSIGNED */ | |
140 | typedef short UINT8; | |
141 | #endif /* CHAR_IS_UNSIGNED */ | |
142 | #endif /* HAVE_UNSIGNED_CHAR */ | |
143 | ||
144 | /* UINT16 must hold at least the values 0..65535. */ | |
145 | ||
146 | #ifdef HAVE_UNSIGNED_SHORT | |
147 | typedef unsigned short UINT16; | |
148 | #else /* not HAVE_UNSIGNED_SHORT */ | |
149 | typedef unsigned int UINT16; | |
150 | #endif /* HAVE_UNSIGNED_SHORT */ | |
151 | ||
152 | /* INT16 must hold at least the values -32768..32767. */ | |
153 | ||
154 | #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ | |
155 | typedef short INT16; | |
156 | #endif | |
157 | ||
158 | /* INT32 must hold at least signed 32-bit values. */ | |
159 | ||
160 | /* Modified JACS 23/4/99. 1200 means VC++ 6 */ | |
161 | #if !defined(XMD_H) && !(_MSC_VER >= 1200) && !(__BORLANDC__ >= 0x550) /* X11/xmd.h correctly defines INT32 */ | |
162 | typedef long INT32; | |
163 | #endif | |
164 | ||
165 | /* Added JACS 23/4/99, to get INT32 definition */ | |
166 | #if (_MSC_VER >= 1200) || (__BORLANDC__ >= 0x550) | |
167 | #include <windows.h> | |
168 | #endif | |
169 | ||
170 | /* Datatype used for image dimensions. The JPEG standard only supports | |
171 | * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore | |
172 | * "unsigned int" is sufficient on all machines. However, if you need to | |
173 | * handle larger images and you don't mind deviating from the spec, you | |
174 | * can change this datatype. | |
175 | */ | |
176 | ||
177 | typedef unsigned int JDIMENSION; | |
178 | ||
179 | #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ | |
180 | ||
181 | ||
182 | /* These macros are used in all function definitions and extern declarations. | |
183 | * You could modify them if you need to change function linkage conventions; | |
184 | * in particular, you'll need to do that to make the library a Windows DLL. | |
185 | * Another application is to make all functions global for use with debuggers | |
186 | * or code profilers that require it. | |
187 | */ | |
188 | ||
189 | #if defined(__VISAGECPP__) /* need this for /common/imagjpeg.obj but not loclly */ | |
190 | /* a function called through method pointers: */ | |
191 | #define METHODDEF(type) static type _Optlink | |
192 | /* a function used only in its module: */ | |
193 | #define LOCAL(type) static type _Optlink | |
194 | /* a function referenced thru EXTERNs: */ | |
195 | #define GLOBAL(type) type | |
196 | /* a reference to a GLOBAL function: */ | |
197 | #define EXTERN(type) extern type _Optlink | |
198 | #else | |
199 | /* a function called through method pointers: */ | |
200 | #define METHODDEF(type) static type | |
201 | /* a function used only in its module: */ | |
202 | #define LOCAL(type) static type | |
203 | /* a function referenced thru EXTERNs: */ | |
204 | #define GLOBAL(type) type | |
205 | /* a reference to a GLOBAL function: */ | |
206 | #define EXTERN(type) extern type | |
207 | #endif | |
208 | ||
209 | /* This macro is used to declare a "method", that is, a function pointer. | |
210 | * We want to supply prototype parameters if the compiler can cope. | |
211 | * Note that the arglist parameter must be parenthesized! | |
212 | * Again, you can customize this if you need special linkage keywords. | |
213 | */ | |
214 | ||
215 | #if defined(__VISAGECPP__) /* need this for /common/imagjpeg.obj but not loclly */ | |
216 | #ifdef HAVE_PROTOTYPES | |
217 | #define JMETHOD(type,methodname,arglist) type (_Optlink *methodname) arglist | |
218 | #else | |
219 | #define JMETHOD(type,methodname,arglist) type (_Optlink *methodname) () | |
220 | #endif | |
221 | ||
222 | #else | |
223 | ||
224 | #ifdef HAVE_PROTOTYPES | |
225 | #define JMETHOD(type,methodname,arglist) type (*methodname) arglist | |
226 | #else | |
227 | #define JMETHOD(type,methodname,arglist) type (*methodname) () | |
228 | #endif | |
229 | ||
230 | #endif | |
231 | ||
232 | /* Here is the pseudo-keyword for declaring pointers that must be "far" | |
233 | * on 80x86 machines. Most of the specialized coding for 80x86 is handled | |
234 | * by just saying "FAR *" where such a pointer is needed. In a few places | |
235 | * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. | |
236 | */ | |
237 | ||
238 | #ifdef NEED_FAR_POINTERS | |
239 | #define FAR far | |
240 | #else | |
241 | #define FAR | |
242 | #endif | |
243 | ||
244 | ||
245 | /* | |
246 | * On a few systems, type boolean and/or its values FALSE, TRUE may appear | |
247 | * in standard header files. Or you may have conflicts with application- | |
248 | * specific header files that you want to include together with these files. | |
249 | * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. | |
250 | */ | |
251 | ||
252 | #ifndef HAVE_BOOLEAN | |
253 | typedef int boolean; | |
254 | #endif | |
255 | #ifndef FALSE /* in case these macros already exist */ | |
256 | #define FALSE 0 /* values of boolean */ | |
257 | #endif | |
258 | #ifndef TRUE | |
259 | #define TRUE 1 | |
260 | #endif | |
261 | ||
262 | ||
263 | /* | |
264 | * The remaining options affect code selection within the JPEG library, | |
265 | * but they don't need to be visible to most applications using the library. | |
266 | * To minimize application namespace pollution, the symbols won't be | |
267 | * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. | |
268 | */ | |
269 | ||
270 | #ifdef JPEG_INTERNALS | |
271 | #define JPEG_INTERNAL_OPTIONS | |
272 | #endif | |
273 | ||
274 | #ifdef JPEG_INTERNAL_OPTIONS | |
275 | ||
276 | ||
277 | /* | |
278 | * These defines indicate whether to include various optional functions. | |
279 | * Undefining some of these symbols will produce a smaller but less capable | |
280 | * library. Note that you can leave certain source files out of the | |
281 | * compilation/linking process if you've #undef'd the corresponding symbols. | |
282 | * (You may HAVE to do that if your compiler doesn't like null source files.) | |
283 | */ | |
284 | ||
285 | /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ | |
286 | ||
287 | /* Capability options common to encoder and decoder: */ | |
288 | ||
289 | #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ | |
290 | #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ | |
291 | #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ | |
292 | ||
293 | /* Encoder capability options: */ | |
294 | ||
295 | #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ | |
296 | #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ | |
297 | #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ | |
298 | #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ | |
299 | /* Note: if you selected 12-bit data precision, it is dangerous to turn off | |
300 | * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit | |
301 | * precision, so jchuff.c normally uses entropy optimization to compute | |
302 | * usable tables for higher precision. If you don't want to do optimization, | |
303 | * you'll have to supply different default Huffman tables. | |
304 | * The exact same statements apply for progressive JPEG: the default tables | |
305 | * don't work for progressive mode. (This may get fixed, however.) | |
306 | */ | |
307 | #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ | |
308 | ||
309 | /* Decoder capability options: */ | |
310 | ||
311 | #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ | |
312 | #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ | |
313 | #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ | |
314 | #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ | |
315 | #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ | |
316 | #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ | |
317 | #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ | |
318 | #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ | |
319 | #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ | |
320 | #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ | |
321 | ||
322 | /* more capability options later, no doubt */ | |
323 | ||
324 | ||
325 | /* | |
326 | * Ordering of RGB data in scanlines passed to or from the application. | |
327 | * If your application wants to deal with data in the order B,G,R, just | |
328 | * change these macros. You can also deal with formats such as R,G,B,X | |
329 | * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing | |
330 | * the offsets will also change the order in which colormap data is organized. | |
331 | * RESTRICTIONS: | |
332 | * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. | |
333 | * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not | |
334 | * useful if you are using JPEG color spaces other than YCbCr or grayscale. | |
335 | * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE | |
336 | * is not 3 (they don't understand about dummy color components!). So you | |
337 | * can't use color quantization if you change that value. | |
338 | */ | |
339 | ||
340 | #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ | |
341 | #define RGB_GREEN 1 /* Offset of Green */ | |
342 | #define RGB_BLUE 2 /* Offset of Blue */ | |
343 | #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ | |
344 | ||
345 | ||
346 | /* Definitions for speed-related optimizations. */ | |
347 | ||
348 | ||
349 | /* If your compiler supports inline functions, define INLINE | |
350 | * as the inline keyword; otherwise define it as empty. | |
351 | */ | |
352 | ||
353 | #ifndef INLINE | |
354 | #ifdef __GNUC__ /* for instance, GNU C knows about inline */ | |
355 | #define INLINE __inline__ | |
356 | #endif | |
357 | #ifndef INLINE | |
358 | #define INLINE /* default is to define it as empty */ | |
359 | #endif | |
360 | #endif | |
361 | ||
362 | ||
363 | /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying | |
364 | * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER | |
365 | * as short on such a machine. MULTIPLIER must be at least 16 bits wide. | |
366 | */ | |
367 | ||
368 | #ifndef MULTIPLIER | |
369 | #define MULTIPLIER int /* type for fastest integer multiply */ | |
370 | #endif | |
371 | ||
372 | ||
373 | /* FAST_FLOAT should be either float or double, whichever is done faster | |
374 | * by your compiler. (Note that this type is only used in the floating point | |
375 | * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) | |
376 | * Typically, float is faster in ANSI C compilers, while double is faster in | |
377 | * pre-ANSI compilers (because they insist on converting to double anyway). | |
378 | * The code below therefore chooses float if we have ANSI-style prototypes. | |
379 | */ | |
380 | ||
381 | #ifndef FAST_FLOAT | |
382 | #ifdef HAVE_PROTOTYPES | |
383 | #define FAST_FLOAT float | |
384 | #else | |
385 | #define FAST_FLOAT double | |
386 | #endif | |
387 | #endif | |
388 | ||
389 | #endif /* JPEG_INTERNAL_OPTIONS */ |