forked from LuaDist/libjpeg
-
Notifications
You must be signed in to change notification settings - Fork 0
/
jdct.h
393 lines (361 loc) · 16.7 KB
/
jdct.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
/*
* jdct.h
*
* Copyright (C) 1994-1996, 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 include file contains common declarations for the forward and
* inverse DCT modules. These declarations are private to the DCT managers
* (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
* The individual DCT algorithms are kept in separate files to ease
* machine-dependent tuning (e.g., assembly coding).
*/
/*
* A forward DCT routine is given a pointer to an input sample array and
* a pointer to a work area of type DCTELEM[]; the DCT is to be performed
* in-place in that buffer. Type DCTELEM is int for 8-bit samples, INT32
* for 12-bit samples. (NOTE: Floating-point DCT implementations use an
* array of type FAST_FLOAT, instead.)
* The input data is to be fetched from the sample array starting at a
* specified column. (Any row offset needed will be applied to the array
* pointer before it is passed to the FDCT code.)
* Note that the number of samples fetched by the FDCT routine is
* DCT_h_scaled_size * DCT_v_scaled_size.
* The DCT outputs are returned scaled up by a factor of 8; they therefore
* have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
* convention improves accuracy in integer implementations and saves some
* work in floating-point ones.
* Quantization of the output coefficients is done by jcdctmgr.c.
*/
#if BITS_IN_JSAMPLE == 8
typedef int DCTELEM; /* 16 or 32 bits is fine */
#else
typedef INT32 DCTELEM; /* must have 32 bits */
#endif
typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data,
JSAMPARRAY sample_data,
JDIMENSION start_col));
typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data,
JSAMPARRAY sample_data,
JDIMENSION start_col));
/*
* An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
* to an output sample array. The routine must dequantize the input data as
* well as perform the IDCT; for dequantization, it uses the multiplier table
* pointed to by compptr->dct_table. The output data is to be placed into the
* sample array starting at a specified column. (Any row offset needed will
* be applied to the array pointer before it is passed to the IDCT code.)
* Note that the number of samples emitted by the IDCT routine is
* DCT_h_scaled_size * DCT_v_scaled_size.
*/
/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
/*
* Each IDCT routine has its own ideas about the best dct_table element type.
*/
typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
#if BITS_IN_JSAMPLE == 8
typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
#else
typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
#endif
typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
/*
* Each IDCT routine is responsible for range-limiting its results and
* converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
* be quite far out of range if the input data is corrupt, so a bulletproof
* range-limiting step is required. We use a mask-and-table-lookup method
* to do the combined operations quickly. See the comments with
* prepare_range_limit_table (in jdmaster.c) for more info.
*/
#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit + CENTERJSAMPLE)
#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
/* Short forms of external names for systems with brain-damaged linkers. */
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_fdct_islow jFDislow
#define jpeg_fdct_ifast jFDifast
#define jpeg_fdct_float jFDfloat
#define jpeg_fdct_7x7 jFD7x7
#define jpeg_fdct_6x6 jFD6x6
#define jpeg_fdct_5x5 jFD5x5
#define jpeg_fdct_4x4 jFD4x4
#define jpeg_fdct_3x3 jFD3x3
#define jpeg_fdct_2x2 jFD2x2
#define jpeg_fdct_1x1 jFD1x1
#define jpeg_fdct_9x9 jFD9x9
#define jpeg_fdct_10x10 jFD10x10
#define jpeg_fdct_11x11 jFD11x11
#define jpeg_fdct_12x12 jFD12x12
#define jpeg_fdct_13x13 jFD13x13
#define jpeg_fdct_14x14 jFD14x14
#define jpeg_fdct_15x15 jFD15x15
#define jpeg_fdct_16x16 jFD16x16
#define jpeg_fdct_16x8 jFD16x8
#define jpeg_fdct_14x7 jFD14x7
#define jpeg_fdct_12x6 jFD12x6
#define jpeg_fdct_10x5 jFD10x5
#define jpeg_fdct_8x4 jFD8x4
#define jpeg_fdct_6x3 jFD6x3
#define jpeg_fdct_4x2 jFD4x2
#define jpeg_fdct_2x1 jFD2x1
#define jpeg_fdct_8x16 jFD8x16
#define jpeg_fdct_7x14 jFD7x14
#define jpeg_fdct_6x12 jFD6x12
#define jpeg_fdct_5x10 jFD5x10
#define jpeg_fdct_4x8 jFD4x8
#define jpeg_fdct_3x6 jFD3x6
#define jpeg_fdct_2x4 jFD2x4
#define jpeg_fdct_1x2 jFD1x2
#define jpeg_idct_islow jRDislow
#define jpeg_idct_ifast jRDifast
#define jpeg_idct_float jRDfloat
#define jpeg_idct_7x7 jRD7x7
#define jpeg_idct_6x6 jRD6x6
#define jpeg_idct_5x5 jRD5x5
#define jpeg_idct_4x4 jRD4x4
#define jpeg_idct_3x3 jRD3x3
#define jpeg_idct_2x2 jRD2x2
#define jpeg_idct_1x1 jRD1x1
#define jpeg_idct_9x9 jRD9x9
#define jpeg_idct_10x10 jRD10x10
#define jpeg_idct_11x11 jRD11x11
#define jpeg_idct_12x12 jRD12x12
#define jpeg_idct_13x13 jRD13x13
#define jpeg_idct_14x14 jRD14x14
#define jpeg_idct_15x15 jRD15x15
#define jpeg_idct_16x16 jRD16x16
#define jpeg_idct_16x8 jRD16x8
#define jpeg_idct_14x7 jRD14x7
#define jpeg_idct_12x6 jRD12x6
#define jpeg_idct_10x5 jRD10x5
#define jpeg_idct_8x4 jRD8x4
#define jpeg_idct_6x3 jRD6x3
#define jpeg_idct_4x2 jRD4x2
#define jpeg_idct_2x1 jRD2x1
#define jpeg_idct_8x16 jRD8x16
#define jpeg_idct_7x14 jRD7x14
#define jpeg_idct_6x12 jRD6x12
#define jpeg_idct_5x10 jRD5x10
#define jpeg_idct_4x8 jRD4x8
#define jpeg_idct_3x6 jRD3x8
#define jpeg_idct_2x4 jRD2x4
#define jpeg_idct_1x2 jRD1x2
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Extern declarations for the forward and inverse DCT routines. */
EXTERN(void) jpeg_fdct_islow
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_ifast
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_float
JPP((FAST_FLOAT * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_7x7
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_6x6
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_5x5
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_4x4
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_3x3
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_2x2
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_1x1
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_9x9
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_10x10
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_11x11
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_12x12
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_13x13
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_14x14
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_15x15
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_16x16
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_16x8
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_14x7
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_12x6
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_10x5
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_8x4
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_6x3
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_4x2
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_2x1
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_8x16
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_7x14
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_6x12
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_5x10
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_4x8
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_3x6
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_2x4
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_fdct_1x2
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
EXTERN(void) jpeg_idct_islow
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_ifast
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_float
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_7x7
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_6x6
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_5x5
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_4x4
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_3x3
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_2x2
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_1x1
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_9x9
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_10x10
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_11x11
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_12x12
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_13x13
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_14x14
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_15x15
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_16x16
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_16x8
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_14x7
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_12x6
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_10x5
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_8x4
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_6x3
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_4x2
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_2x1
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_8x16
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_7x14
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_6x12
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_5x10
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_4x8
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_3x6
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_2x4
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_1x2
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
/*
* Macros for handling fixed-point arithmetic; these are used by many
* but not all of the DCT/IDCT modules.
*
* All values are expected to be of type INT32.
* Fractional constants are scaled left by CONST_BITS bits.
* CONST_BITS is defined within each module using these macros,
* and may differ from one module to the next.
*/
#define ONE ((INT32) 1)
#define CONST_SCALE (ONE << CONST_BITS)
/* Convert a positive real constant to an integer scaled by CONST_SCALE.
* Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
* thus causing a lot of useless floating-point operations at run time.
*/
#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
/* Descale and correctly round an INT32 value that's scaled by N bits.
* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
* the fudge factor is correct for either sign of X.
*/
#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
* This macro is used only when the two inputs will actually be no more than
* 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
* full 32x32 multiply. This provides a useful speedup on many machines.
* Unfortunately there is no way to specify a 16x16->32 multiply portably
* in C, but some C compilers will do the right thing if you provide the
* correct combination of casts.
*/
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
#endif
#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
#endif
#ifndef MULTIPLY16C16 /* default definition */
#define MULTIPLY16C16(var,const) ((var) * (const))
#endif
/* Same except both inputs are variables. */
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
#endif
#ifndef MULTIPLY16V16 /* default definition */
#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
#endif