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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
59typedef unsigned char JSAMPLE;
60#define GETJSAMPLE(value) ((int) (value))
61
62#else /* not HAVE_UNSIGNED_CHAR */
63
64typedef 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
84typedef 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
99typedef 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
110typedef unsigned char JOCTET;
111#define GETJOCTET(value) (value)
112
113#else /* not HAVE_UNSIGNED_CHAR */
114
115typedef 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
135typedef unsigned char UINT8;
136#else /* not HAVE_UNSIGNED_CHAR */
137#ifdef CHAR_IS_UNSIGNED
138typedef char UINT8;
139#else /* not CHAR_IS_UNSIGNED */
140typedef 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
147typedef unsigned short UINT16;
148#else /* not HAVE_UNSIGNED_SHORT */
149typedef 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 */
155typedef short INT16;
156#endif
157
158/* INT32 must hold at least signed 32-bit values. */
159
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160/*
161 VZ: due to the horrible mess resulting in INT32 being defined in windows.h
162 for some compilers but not for the other ones, I have globally replace
163 INT32 with JPEG_INT32 in libjpeg code to avoid the eight level ifdef
164 which used to be here. The problem is that, of course, now we'll have
165 conflicts when upgrading to the next libjpeg release -- however
166 considering their frequency (1 in the last 5 years) it seems that
167 it is not too high a price to pay for the clean compilation with all
168 versions of mingw32 and cygwin
169 */
170typedef long JPEG_INT32;
ae128b35 171
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172/* Datatype used for image dimensions. The JPEG standard only supports
173 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore
174 * "unsigned int" is sufficient on all machines. However, if you need to
175 * handle larger images and you don't mind deviating from the spec, you
176 * can change this datatype.
177 */
178
179typedef unsigned int JDIMENSION;
180
181#define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */
182
183
184/* These macros are used in all function definitions and extern declarations.
185 * You could modify them if you need to change function linkage conventions;
186 * in particular, you'll need to do that to make the library a Windows DLL.
187 * Another application is to make all functions global for use with debuggers
188 * or code profilers that require it.
189 */
190
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191#if defined(__VISAGECPP__)
192#define JPEG_CALLING_CONV _Optlink
193#else /* !Visual Age C++ */
194#define JPEG_CALLING_CONV
195#endif
196
197/* We can't declare a static function as extern "C" as we need to do in C++
198 * programs, so suppress static in METHODDEF when using C++.
199 */
200#if defined(__cplusplus)
201#define JPEG_METHOD_LINKAGE
202#else /* !__cplusplus */
203#define JPEG_METHOD_LINKAGE static
204#endif
205
e1929140 206/* a function called through method pointers: */
d7c42914 207#define METHODDEF(type) JPEG_METHOD_LINKAGE type JPEG_CALLING_CONV
e1929140 208/* a function used only in its module: */
d7c42914 209#define LOCAL(type) static type JPEG_CALLING_CONV
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210/* a function referenced thru EXTERNs: */
211#define GLOBAL(type) type
212/* a reference to a GLOBAL function: */
d7c42914 213#define EXTERN(type) extern type JPEG_CALLING_CONV
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214
215/* This macro is used to declare a "method", that is, a function pointer.
216 * We want to supply prototype parameters if the compiler can cope.
217 * Note that the arglist parameter must be parenthesized!
218 * Again, you can customize this if you need special linkage keywords.
219 */
220
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221#if defined(__VISAGECPP__) /* need this for /common/imagjpeg.obj but not loclly */
222#ifdef HAVE_PROTOTYPES
223#define JMETHOD(type,methodname,arglist) type (_Optlink *methodname) arglist
224#else
225#define JMETHOD(type,methodname,arglist) type (_Optlink *methodname) ()
226#endif
227
228#else
229
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230#ifdef HAVE_PROTOTYPES
231#define JMETHOD(type,methodname,arglist) type (*methodname) arglist
232#else
233#define JMETHOD(type,methodname,arglist) type (*methodname) ()
234#endif
235
413098d0 236#endif
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237
238/* Here is the pseudo-keyword for declaring pointers that must be "far"
239 * on 80x86 machines. Most of the specialized coding for 80x86 is handled
240 * by just saying "FAR *" where such a pointer is needed. In a few places
241 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
242 */
243
244#ifdef NEED_FAR_POINTERS
245#define FAR far
246#else
9c824f29 247#ifndef FAR
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248#define FAR
249#endif
9c824f29 250#endif
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251
252
253/*
254 * On a few systems, type boolean and/or its values FALSE, TRUE may appear
255 * in standard header files. Or you may have conflicts with application-
256 * specific header files that you want to include together with these files.
257 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
258 */
259
260#ifndef HAVE_BOOLEAN
261typedef int boolean;
262#endif
263#ifndef FALSE /* in case these macros already exist */
264#define FALSE 0 /* values of boolean */
265#endif
266#ifndef TRUE
267#define TRUE 1
268#endif
269
270
271/*
272 * The remaining options affect code selection within the JPEG library,
273 * but they don't need to be visible to most applications using the library.
274 * To minimize application namespace pollution, the symbols won't be
275 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
276 */
277
278#ifdef JPEG_INTERNALS
279#define JPEG_INTERNAL_OPTIONS
280#endif
281
282#ifdef JPEG_INTERNAL_OPTIONS
283
284
285/*
286 * These defines indicate whether to include various optional functions.
287 * Undefining some of these symbols will produce a smaller but less capable
288 * library. Note that you can leave certain source files out of the
289 * compilation/linking process if you've #undef'd the corresponding symbols.
290 * (You may HAVE to do that if your compiler doesn't like null source files.)
291 */
292
293/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */
294
295/* Capability options common to encoder and decoder: */
296
297#define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */
298#define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */
299#define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */
300
301/* Encoder capability options: */
302
303#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
304#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
305#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
306#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */
307/* Note: if you selected 12-bit data precision, it is dangerous to turn off
308 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit
309 * precision, so jchuff.c normally uses entropy optimization to compute
310 * usable tables for higher precision. If you don't want to do optimization,
311 * you'll have to supply different default Huffman tables.
312 * The exact same statements apply for progressive JPEG: the default tables
313 * don't work for progressive mode. (This may get fixed, however.)
314 */
315#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */
316
317/* Decoder capability options: */
318
319#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
320#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
321#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
322#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */
323#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */
324#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */
325#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */
326#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */
327#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */
328#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */
329
330/* more capability options later, no doubt */
331
332
333/*
334 * Ordering of RGB data in scanlines passed to or from the application.
335 * If your application wants to deal with data in the order B,G,R, just
336 * change these macros. You can also deal with formats such as R,G,B,X
337 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing
338 * the offsets will also change the order in which colormap data is organized.
339 * RESTRICTIONS:
340 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
341 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
342 * useful if you are using JPEG color spaces other than YCbCr or grayscale.
343 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
344 * is not 3 (they don't understand about dummy color components!). So you
345 * can't use color quantization if you change that value.
346 */
347
348#define RGB_RED 0 /* Offset of Red in an RGB scanline element */
349#define RGB_GREEN 1 /* Offset of Green */
350#define RGB_BLUE 2 /* Offset of Blue */
351#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */
352
353
354/* Definitions for speed-related optimizations. */
355
356
357/* If your compiler supports inline functions, define INLINE
358 * as the inline keyword; otherwise define it as empty.
359 */
360
361#ifndef INLINE
362#ifdef __GNUC__ /* for instance, GNU C knows about inline */
363#define INLINE __inline__
364#endif
365#ifndef INLINE
366#define INLINE /* default is to define it as empty */
367#endif
368#endif
369
370
371/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
372 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER
373 * as short on such a machine. MULTIPLIER must be at least 16 bits wide.
374 */
375
376#ifndef MULTIPLIER
377#define MULTIPLIER int /* type for fastest integer multiply */
378#endif
379
380
381/* FAST_FLOAT should be either float or double, whichever is done faster
382 * by your compiler. (Note that this type is only used in the floating point
383 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
384 * Typically, float is faster in ANSI C compilers, while double is faster in
385 * pre-ANSI compilers (because they insist on converting to double anyway).
386 * The code below therefore chooses float if we have ANSI-style prototypes.
387 */
388
389#ifndef FAST_FLOAT
390#ifdef HAVE_PROTOTYPES
391#define FAST_FLOAT float
392#else
393#define FAST_FLOAT double
394#endif
395#endif
396
397#endif /* JPEG_INTERNAL_OPTIONS */