source: rtems-graphics-toolkit/jpeg-7/jdct.h @ 2abf143

base initial
Last change on this file since 2abf143 was 2abf143, checked in by Joel Sherrill <joel.sherrill@…>, on 12/20/09 at 00:59:55

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