1 /*
2 * jfdctint.c
3 *
4 * Copyright (C) 1991-1996, Thomas G. Lane.
5 * Modification developed 2003-2009 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains a slow-but-accurate integer implementation of the
10 * forward DCT (Discrete Cosine Transform).
11 *
12 * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
13 * on each column. Direct algorithms are also available, but they are
14 * much more complex and seem not to be any faster when reduced to code.
15 *
16 * This implementation is based on an algorithm described in
17 * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
18 * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
19 * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
20 * The primary algorithm described there uses 11 multiplies and 29 adds.
21 * We use their alternate method with 12 multiplies and 32 adds.
22 * The advantage of this method is that no data path contains more than one
23 * multiplication; this allows a very simple and accurate implementation in
24 * scaled fixed-point arithmetic, with a minimal number of shifts.
25 *
26 * We also provide FDCT routines with various input sample block sizes for
27 * direct resolution reduction or enlargement and for direct resolving the
28 * common 2x1 and 1x2 subsampling cases without additional resampling: NxN
29 * (N=1...16), 2NxN, and Nx2N (N=1...8) pixels for one 8x8 output DCT block.
30 *
31 * For N<8 we fill the remaining block coefficients with zero.
32 * For N>8 we apply a partial N-point FDCT on the input samples, computing
33 * just the lower 8 frequency coefficients and discarding the rest.
34 *
35 * We must scale the output coefficients of the N-point FDCT appropriately
36 * to the standard 8-point FDCT level by 8/N per 1-D pass. This scaling
37 * is folded into the constant multipliers (pass 2) and/or final/initial
38 * shifting.
39 *
40 * CAUTION: We rely on the FIX() macro except for the N=1,2,4,8 cases
41 * since there would be too many additional constants to pre-calculate.
42 */
43
44 #define JPEG_INTERNALS
45 #include "jinclude.h"
46 #include "jpeglib.h"
47 #include "jdct.h" /* Private declarations for DCT subsystem */
48
49 #ifdef DCT_ISLOW_SUPPORTED
50
51
52 /*
53 * This module is specialized to the case DCTSIZE = 8.
54 */
55
56 #if DCTSIZE != 8
57 Sorry, this code only copes with 8x8 DCT blocks. /* deliberate syntax err */
58 #endif
59
60
61 /*
62 * The poop on this scaling stuff is as follows:
63 *
64 * Each 1-D DCT step produces outputs which are a factor of sqrt(N)
65 * larger than the true DCT outputs. The final outputs are therefore
66 * a factor of N larger than desired; since N=8 this can be cured by
67 * a simple right shift at the end of the algorithm. The advantage of
68 * this arrangement is that we save two multiplications per 1-D DCT,
69 * because the y0 and y4 outputs need not be divided by sqrt(N).
70 * In the IJG code, this factor of 8 is removed by the quantization step
71 * (in jcdctmgr.c), NOT in this module.
72 *
73 * We have to do addition and subtraction of the integer inputs, which
74 * is no problem, and multiplication by fractional constants, which is
75 * a problem to do in integer arithmetic. We multiply all the constants
76 * by CONST_SCALE and convert them to integer constants (thus retaining
77 * CONST_BITS bits of precision in the constants). After doing a
78 * multiplication we have to divide the product by CONST_SCALE, with proper
79 * rounding, to produce the correct output. This division can be done
80 * cheaply as a right shift of CONST_BITS bits. We postpone shifting
81 * as long as possible so that partial sums can be added together with
82 * full fractional precision.
83 *
84 * The outputs of the first pass are scaled up by PASS1_BITS bits so that
85 * they are represented to better-than-integral precision. These outputs
86 * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
87 * with the recommended scaling. (For 12-bit sample data, the intermediate
88 * array is INT32 anyway.)
89 *
90 * To avoid overflow of the 32-bit intermediate results in pass 2, we must
91 * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
92 * shows that the values given below are the most effective.
93 */
94
95 #if BITS_IN_JSAMPLE == 8
96 #define CONST_BITS 13
97 #define PASS1_BITS 2
98 #else
99 #define CONST_BITS 13
100 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */
101 #endif
102
103 /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
104 * causing a lot of useless floating-point operations at run time.
105 * To get around this we use the following pre-calculated constants.
106 * If you change CONST_BITS you may want to add appropriate values.
107 * (With a reasonable C compiler, you can just rely on the FIX() macro...)
108 */
109
110 #if CONST_BITS == 13
111 #define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
112 #define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
113 #define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
114 #define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
115 #define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
116 #define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
117 #define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
118 #define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
119 #define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
120 #define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
121 #define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
122 #define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
123 #else
124 #define FIX_0_298631336 FIX(0.298631336)
125 #define FIX_0_390180644 FIX(0.390180644)
126 #define FIX_0_541196100 FIX(0.541196100)
127 #define FIX_0_765366865 FIX(0.765366865)
128 #define FIX_0_899976223 FIX(0.899976223)
129 #define FIX_1_175875602 FIX(1.175875602)
130 #define FIX_1_501321110 FIX(1.501321110)
131 #define FIX_1_847759065 FIX(1.847759065)
132 #define FIX_1_961570560 FIX(1.961570560)
133 #define FIX_2_053119869 FIX(2.053119869)
134 #define FIX_2_562915447 FIX(2.562915447)
135 #define FIX_3_072711026 FIX(3.072711026)
136 #endif
137
138
139 /* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
140 * For 8-bit samples with the recommended scaling, all the variable
141 * and constant values involved are no more than 16 bits wide, so a
142 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
143 * For 12-bit samples, a full 32-bit multiplication will be needed.
144 */
145
146 #if BITS_IN_JSAMPLE == 8
147 #define MULTIPLY(var,const) MULTIPLY16C16(var,const)
148 #else
149 #define MULTIPLY(var,const) ((var) * (const))
150 #endif
151
152
153 /*
154 * Perform the forward DCT on one block of samples.
155 */
156
157 GLOBAL(void)
158 jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
159 {
160 INT32 tmp0, tmp1, tmp2, tmp3;
161 INT32 tmp10, tmp11, tmp12, tmp13;
162 INT32 z1;
163 DCTELEM *dataptr;
164 JSAMPROW elemptr;
165 int ctr;
166 SHIFT_TEMPS
167
168 /* Pass 1: process rows. */
169 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
170 /* furthermore, we scale the results by 2**PASS1_BITS. */
171
172 dataptr = data;
173 for (ctr = 0; ctr < DCTSIZE; ctr++) {
174 elemptr = sample_data[ctr] + start_col;
175
176 /* Even part per LL&M figure 1 --- note that published figure is faulty;
177 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
178 */
179
180 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
181 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
182 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
183 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
184
185 tmp10 = tmp0 + tmp3;
186 tmp12 = tmp0 - tmp3;
187 tmp11 = tmp1 + tmp2;
188 tmp13 = tmp1 - tmp2;
189
190 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
191 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
192 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
193 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
194
195 /* Apply unsigned->signed conversion */
196 dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
197 dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
198
199 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
200 /* Add fudge factor here for final descale. */
201 z1 += ONE << (CONST_BITS-PASS1_BITS-1);
202 dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
203 CONST_BITS-PASS1_BITS);
204 dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
205 CONST_BITS-PASS1_BITS);
206
207 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
208 * cK represents sqrt(2) * cos(K*pi/16).
209 * i0..i3 in the paper are tmp0..tmp3 here.
210 */
211
212 tmp10 = tmp0 + tmp3;
213 tmp11 = tmp1 + tmp2;
214 tmp12 = tmp0 + tmp2;
215 tmp13 = tmp1 + tmp3;
216 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
217 /* Add fudge factor here for final descale. */
218 z1 += ONE << (CONST_BITS-PASS1_BITS-1);
219
220 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
221 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
222 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
223 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
224 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
225 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
226 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
227 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
228
229 tmp12 += z1;
230 tmp13 += z1;
231
232 dataptr[1] = (DCTELEM)
233 RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
234 dataptr[3] = (DCTELEM)
235 RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
236 dataptr[5] = (DCTELEM)
237 RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
238 dataptr[7] = (DCTELEM)
239 RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
240
241 dataptr += DCTSIZE; /* advance pointer to next row */
242 }
243
244 /* Pass 2: process columns.
245 * We remove the PASS1_BITS scaling, but leave the results scaled up
246 * by an overall factor of 8.
247 */
248
249 dataptr = data;
250 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
251 /* Even part per LL&M figure 1 --- note that published figure is faulty;
252 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
253 */
254
255 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
256 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
257 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
258 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
259
260 /* Add fudge factor here for final descale. */
261 tmp10 = tmp0 + tmp3 + (ONE << (PASS1_BITS-1));
262 tmp12 = tmp0 - tmp3;
263 tmp11 = tmp1 + tmp2;
264 tmp13 = tmp1 - tmp2;
265
266 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
267 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
268 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
269 tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
270
271 dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
272 dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
273
274 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
275 /* Add fudge factor here for final descale. */
276 z1 += ONE << (CONST_BITS+PASS1_BITS-1);
277 dataptr[DCTSIZE*2] = (DCTELEM)
278 RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
279 dataptr[DCTSIZE*6] = (DCTELEM)
280 RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
281
282 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
283 * cK represents sqrt(2) * cos(K*pi/16).
284 * i0..i3 in the paper are tmp0..tmp3 here.
285 */
286
287 tmp10 = tmp0 + tmp3;
288 tmp11 = tmp1 + tmp2;
289 tmp12 = tmp0 + tmp2;
290 tmp13 = tmp1 + tmp3;
291 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
292 /* Add fudge factor here for final descale. */
293 z1 += ONE << (CONST_BITS+PASS1_BITS-1);
294
295 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
296 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
297 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
298 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
299 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
300 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
301 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
302 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
303
304 tmp12 += z1;
305 tmp13 += z1;
306
307 dataptr[DCTSIZE*1] = (DCTELEM)
308 RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
309 dataptr[DCTSIZE*3] = (DCTELEM)
310 RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
311 dataptr[DCTSIZE*5] = (DCTELEM)
312 RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
313 dataptr[DCTSIZE*7] = (DCTELEM)
314 RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
315
316 dataptr++; /* advance pointer to next column */
317 }
318 }
319
320 #ifdef DCT_SCALING_SUPPORTED
321
322
323 /*
324 * Perform the forward DCT on a 7x7 sample block.
325 */
326
327 GLOBAL(void)
328 jpeg_fdct_7x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
329 {
330 INT32 tmp0, tmp1, tmp2, tmp3;
331 INT32 tmp10, tmp11, tmp12;
332 INT32 z1, z2, z3;
333 DCTELEM *dataptr;
334 JSAMPROW elemptr;
335 int ctr;
336 SHIFT_TEMPS
337
338 /* Pre-zero output coefficient block. */
339 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
340
341 /* Pass 1: process rows. */
342 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
343 /* furthermore, we scale the results by 2**PASS1_BITS. */
344 /* cK represents sqrt(2) * cos(K*pi/14). */
345
346 dataptr = data;
347 for (ctr = 0; ctr < 7; ctr++) {
348 elemptr = sample_data[ctr] + start_col;
349
350 /* Even part */
351
352 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[6]);
353 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[5]);
354 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[4]);
355 tmp3 = GETJSAMPLE(elemptr[3]);
356
357 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[6]);
358 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[5]);
359 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[4]);
360
361 z1 = tmp0 + tmp2;
362 /* Apply unsigned->signed conversion */
363 dataptr[0] = (DCTELEM)
364 ((z1 + tmp1 + tmp3 - 7 * CENTERJSAMPLE) << PASS1_BITS);
365 tmp3 += tmp3;
366 z1 -= tmp3;
367 z1 -= tmp3;
368 z1 = MULTIPLY(z1, FIX(0.353553391)); /* (c2+c6-c4)/2 */
369 z2 = MULTIPLY(tmp0 - tmp2, FIX(0.920609002)); /* (c2+c4-c6)/2 */
370 z3 = MULTIPLY(tmp1 - tmp2, FIX(0.314692123)); /* c6 */
371 dataptr[2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS-PASS1_BITS);
372 z1 -= z2;
373 z2 = MULTIPLY(tmp0 - tmp1, FIX(0.881747734)); /* c4 */
374 dataptr[4] = (DCTELEM)
375 DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.707106781)), /* c2+c6-c4 */
376 CONST_BITS-PASS1_BITS);
377 dataptr[6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS-PASS1_BITS);
378
379 /* Odd part */
380
381 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(0.935414347)); /* (c3+c1-c5)/2 */
382 tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.170262339)); /* (c3+c5-c1)/2 */
383 tmp0 = tmp1 - tmp2;
384 tmp1 += tmp2;
385 tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.378756276)); /* -c1 */
386 tmp1 += tmp2;
387 tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.613604268)); /* c5 */
388 tmp0 += tmp3;
389 tmp2 += tmp3 + MULTIPLY(tmp12, FIX(1.870828693)); /* c3+c1-c5 */
390
391 dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-PASS1_BITS);
392 dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-PASS1_BITS);
393 dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-PASS1_BITS);
394
395 dataptr += DCTSIZE; /* advance pointer to next row */
396 }
397
398 /* Pass 2: process columns.
399 * We remove the PASS1_BITS scaling, but leave the results scaled up
400 * by an overall factor of 8.
401 * We must also scale the output by (8/7)**2 = 64/49, which we fold
402 * into the constant multipliers:
403 * cK now represents sqrt(2) * cos(K*pi/14) * 64/49.
404 */
405
406 dataptr = data;
407 for (ctr = 0; ctr < 7; ctr++) {
408 /* Even part */
409
410 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*6];
411 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*5];
412 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*4];
413 tmp3 = dataptr[DCTSIZE*3];
414
415 tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*6];
416 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*5];
417 tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*4];
418
419 z1 = tmp0 + tmp2;
420 dataptr[DCTSIZE*0] = (DCTELEM)
421 DESCALE(MULTIPLY(z1 + tmp1 + tmp3, FIX(1.306122449)), /* 64/49 */
422 CONST_BITS+PASS1_BITS);
423 tmp3 += tmp3;
424 z1 -= tmp3;
425 z1 -= tmp3;
426 z1 = MULTIPLY(z1, FIX(0.461784020)); /* (c2+c6-c4)/2 */
427 z2 = MULTIPLY(tmp0 - tmp2, FIX(1.202428084)); /* (c2+c4-c6)/2 */
428 z3 = MULTIPLY(tmp1 - tmp2, FIX(0.411026446)); /* c6 */
429 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS+PASS1_BITS);
430 z1 -= z2;
431 z2 = MULTIPLY(tmp0 - tmp1, FIX(1.151670509)); /* c4 */
432 dataptr[DCTSIZE*4] = (DCTELEM)
433 DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.923568041)), /* c2+c6-c4 */
434 CONST_BITS+PASS1_BITS);
435 dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+PASS1_BITS);
436
437 /* Odd part */
438
439 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.221765677)); /* (c3+c1-c5)/2 */
440 tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.222383464)); /* (c3+c5-c1)/2 */
441 tmp0 = tmp1 - tmp2;
442 tmp1 += tmp2;
443 tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.800824523)); /* -c1 */
444 tmp1 += tmp2;
445 tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.801442310)); /* c5 */
446 tmp0 += tmp3;
447 tmp2 += tmp3 + MULTIPLY(tmp12, FIX(2.443531355)); /* c3+c1-c5 */
448
449 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+PASS1_BITS);
450 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+PASS1_BITS);
451 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+PASS1_BITS);
452
453 dataptr++; /* advance pointer to next column */
454 }
455 }
456
457
458 /*
459 * Perform the forward DCT on a 6x6 sample block.
460 */
461
462 GLOBAL(void)
463 jpeg_fdct_6x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
464 {
465 INT32 tmp0, tmp1, tmp2;
466 INT32 tmp10, tmp11, tmp12;
467 DCTELEM *dataptr;
468 JSAMPROW elemptr;
469 int ctr;
470 SHIFT_TEMPS
471
472 /* Pre-zero output coefficient block. */
473 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
474
475 /* Pass 1: process rows. */
476 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
477 /* furthermore, we scale the results by 2**PASS1_BITS. */
478 /* cK represents sqrt(2) * cos(K*pi/12). */
479
480 dataptr = data;
481 for (ctr = 0; ctr < 6; ctr++) {
482 elemptr = sample_data[ctr] + start_col;
483
484 /* Even part */
485
486 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
487 tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
488 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
489
490 tmp10 = tmp0 + tmp2;
491 tmp12 = tmp0 - tmp2;
492
493 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
494 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
495 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
496
497 /* Apply unsigned->signed conversion */
498 dataptr[0] = (DCTELEM)
499 ((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << PASS1_BITS);
500 dataptr[2] = (DCTELEM)
501 DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
502 CONST_BITS-PASS1_BITS);
503 dataptr[4] = (DCTELEM)
504 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
505 CONST_BITS-PASS1_BITS);
506
507 /* Odd part */
508
509 tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
510 CONST_BITS-PASS1_BITS);
511
512 dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << PASS1_BITS));
513 dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << PASS1_BITS);
514 dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << PASS1_BITS));
515
516 dataptr += DCTSIZE; /* advance pointer to next row */
517 }
518
519 /* Pass 2: process columns.
520 * We remove the PASS1_BITS scaling, but leave the results scaled up
521 * by an overall factor of 8.
522 * We must also scale the output by (8/6)**2 = 16/9, which we fold
523 * into the constant multipliers:
524 * cK now represents sqrt(2) * cos(K*pi/12) * 16/9.
525 */
526
527 dataptr = data;
528 for (ctr = 0; ctr < 6; ctr++) {
529 /* Even part */
530
531 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
532 tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
533 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
534
535 tmp10 = tmp0 + tmp2;
536 tmp12 = tmp0 - tmp2;
537
538 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
539 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
540 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
541
542 dataptr[DCTSIZE*0] = (DCTELEM)
543 DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
544 CONST_BITS+PASS1_BITS);
545 dataptr[DCTSIZE*2] = (DCTELEM)
546 DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
547 CONST_BITS+PASS1_BITS);
548 dataptr[DCTSIZE*4] = (DCTELEM)
549 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
550 CONST_BITS+PASS1_BITS);
551
552 /* Odd part */
553
554 tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
555
556 dataptr[DCTSIZE*1] = (DCTELEM)
557 DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
558 CONST_BITS+PASS1_BITS);
559 dataptr[DCTSIZE*3] = (DCTELEM)
560 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
561 CONST_BITS+PASS1_BITS);
562 dataptr[DCTSIZE*5] = (DCTELEM)
563 DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
564 CONST_BITS+PASS1_BITS);
565
566 dataptr++; /* advance pointer to next column */
567 }
568 }
569
570
571 /*
572 * Perform the forward DCT on a 5x5 sample block.
573 */
574
575 GLOBAL(void)
576 jpeg_fdct_5x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
577 {
578 INT32 tmp0, tmp1, tmp2;
579 INT32 tmp10, tmp11;
580 DCTELEM *dataptr;
581 JSAMPROW elemptr;
582 int ctr;
583 SHIFT_TEMPS
584
585 /* Pre-zero output coefficient block. */
586 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
587
588 /* Pass 1: process rows. */
589 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
590 /* furthermore, we scale the results by 2**PASS1_BITS. */
591 /* We scale the results further by 2 as part of output adaption */
592 /* scaling for different DCT size. */
593 /* cK represents sqrt(2) * cos(K*pi/10). */
594
595 dataptr = data;
596 for (ctr = 0; ctr < 5; ctr++) {
597 elemptr = sample_data[ctr] + start_col;
598
599 /* Even part */
600
601 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[4]);
602 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[3]);
603 tmp2 = GETJSAMPLE(elemptr[2]);
604
605 tmp10 = tmp0 + tmp1;
606 tmp11 = tmp0 - tmp1;
607
608 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[4]);
609 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[3]);
610
611 /* Apply unsigned->signed conversion */
612 dataptr[0] = (DCTELEM)
613 ((tmp10 + tmp2 - 5 * CENTERJSAMPLE) << (PASS1_BITS+1));
614 tmp11 = MULTIPLY(tmp11, FIX(0.790569415)); /* (c2+c4)/2 */
615 tmp10 -= tmp2 << 2;
616 tmp10 = MULTIPLY(tmp10, FIX(0.353553391)); /* (c2-c4)/2 */
617 dataptr[2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS-PASS1_BITS-1);
618 dataptr[4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS-PASS1_BITS-1);
619
620 /* Odd part */
621
622 tmp10 = MULTIPLY(tmp0 + tmp1, FIX(0.831253876)); /* c3 */
623
624 dataptr[1] = (DCTELEM)
625 DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.513743148)), /* c1-c3 */
626 CONST_BITS-PASS1_BITS-1);
627 dataptr[3] = (DCTELEM)
628 DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.176250899)), /* c1+c3 */
629 CONST_BITS-PASS1_BITS-1);
630
631 dataptr += DCTSIZE; /* advance pointer to next row */
632 }
633
634 /* Pass 2: process columns.
635 * We remove the PASS1_BITS scaling, but leave the results scaled up
636 * by an overall factor of 8.
637 * We must also scale the output by (8/5)**2 = 64/25, which we partially
638 * fold into the constant multipliers (other part was done in pass 1):
639 * cK now represents sqrt(2) * cos(K*pi/10) * 32/25.
640 */
641
642 dataptr = data;
643 for (ctr = 0; ctr < 5; ctr++) {
644 /* Even part */
645
646 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*4];
647 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*3];
648 tmp2 = dataptr[DCTSIZE*2];
649
650 tmp10 = tmp0 + tmp1;
651 tmp11 = tmp0 - tmp1;
652
653 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*4];
654 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*3];
655
656 dataptr[DCTSIZE*0] = (DCTELEM)
657 DESCALE(MULTIPLY(tmp10 + tmp2, FIX(1.28)), /* 32/25 */
658 CONST_BITS+PASS1_BITS);
659 tmp11 = MULTIPLY(tmp11, FIX(1.011928851)); /* (c2+c4)/2 */
660 tmp10 -= tmp2 << 2;
661 tmp10 = MULTIPLY(tmp10, FIX(0.452548340)); /* (c2-c4)/2 */
662 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS+PASS1_BITS);
663 dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS+PASS1_BITS);
664
665 /* Odd part */
666
667 tmp10 = MULTIPLY(tmp0 + tmp1, FIX(1.064004961)); /* c3 */
668
669 dataptr[DCTSIZE*1] = (DCTELEM)
670 DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.657591230)), /* c1-c3 */
671 CONST_BITS+PASS1_BITS);
672 dataptr[DCTSIZE*3] = (DCTELEM)
673 DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.785601151)), /* c1+c3 */
674 CONST_BITS+PASS1_BITS);
675
676 dataptr++; /* advance pointer to next column */
677 }
678 }
679
680
681 /*
682 * Perform the forward DCT on a 4x4 sample block.
683 */
684
685 GLOBAL(void)
686 jpeg_fdct_4x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
687 {
688 INT32 tmp0, tmp1;
689 INT32 tmp10, tmp11;
690 DCTELEM *dataptr;
691 JSAMPROW elemptr;
692 int ctr;
693 SHIFT_TEMPS
694
695 /* Pre-zero output coefficient block. */
696 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
697
698 /* Pass 1: process rows. */
699 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
700 /* furthermore, we scale the results by 2**PASS1_BITS. */
701 /* We must also scale the output by (8/4)**2 = 2**2, which we add here. */
702 /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
703
704 dataptr = data;
705 for (ctr = 0; ctr < 4; ctr++) {
706 elemptr = sample_data[ctr] + start_col;
707
708 /* Even part */
709
710 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
711 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
712
713 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
714 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
715
716 /* Apply unsigned->signed conversion */
717 dataptr[0] = (DCTELEM)
718 ((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+2));
719 dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+2));
720
721 /* Odd part */
722
723 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
724 /* Add fudge factor here for final descale. */
725 tmp0 += ONE << (CONST_BITS-PASS1_BITS-3);
726
727 dataptr[1] = (DCTELEM)
728 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
729 CONST_BITS-PASS1_BITS-2);
730 dataptr[3] = (DCTELEM)
731 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
732 CONST_BITS-PASS1_BITS-2);
733
734 dataptr += DCTSIZE; /* advance pointer to next row */
735 }
736
737 /* Pass 2: process columns.
738 * We remove the PASS1_BITS scaling, but leave the results scaled up
739 * by an overall factor of 8.
740 */
741
742 dataptr = data;
743 for (ctr = 0; ctr < 4; ctr++) {
744 /* Even part */
745
746 /* Add fudge factor here for final descale. */
747 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3] + (ONE << (PASS1_BITS-1));
748 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
749
750 tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
751 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
752
753 dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
754 dataptr[DCTSIZE*2] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
755
756 /* Odd part */
757
758 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
759 /* Add fudge factor here for final descale. */
760 tmp0 += ONE << (CONST_BITS+PASS1_BITS-1);
761
762 dataptr[DCTSIZE*1] = (DCTELEM)
763 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
764 CONST_BITS+PASS1_BITS);
765 dataptr[DCTSIZE*3] = (DCTELEM)
766 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
767 CONST_BITS+PASS1_BITS);
768
769 dataptr++; /* advance pointer to next column */
770 }
771 }
772
773
774 /*
775 * Perform the forward DCT on a 3x3 sample block.
776 */
777
778 GLOBAL(void)
779 jpeg_fdct_3x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
780 {
781 INT32 tmp0, tmp1, tmp2;
782 DCTELEM *dataptr;
783 JSAMPROW elemptr;
784 int ctr;
785 SHIFT_TEMPS
786
787 /* Pre-zero output coefficient block. */
788 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
789
790 /* Pass 1: process rows. */
791 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
792 /* furthermore, we scale the results by 2**PASS1_BITS. */
793 /* We scale the results further by 2**2 as part of output adaption */
794 /* scaling for different DCT size. */
795 /* cK represents sqrt(2) * cos(K*pi/6). */
796
797 dataptr = data;
798 for (ctr = 0; ctr < 3; ctr++) {
799 elemptr = sample_data[ctr] + start_col;
800
801 /* Even part */
802
803 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[2]);
804 tmp1 = GETJSAMPLE(elemptr[1]);
805
806 tmp2 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[2]);
807
808 /* Apply unsigned->signed conversion */
809 dataptr[0] = (DCTELEM)
810 ((tmp0 + tmp1 - 3 * CENTERJSAMPLE) << (PASS1_BITS+2));
811 dataptr[2] = (DCTELEM)
812 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(0.707106781)), /* c2 */
813 CONST_BITS-PASS1_BITS-2);
814
815 /* Odd part */
816
817 dataptr[1] = (DCTELEM)
818 DESCALE(MULTIPLY(tmp2, FIX(1.224744871)), /* c1 */
819 CONST_BITS-PASS1_BITS-2);
820
821 dataptr += DCTSIZE; /* advance pointer to next row */
822 }
823
824 /* Pass 2: process columns.
825 * We remove the PASS1_BITS scaling, but leave the results scaled up
826 * by an overall factor of 8.
827 * We must also scale the output by (8/3)**2 = 64/9, which we partially
828 * fold into the constant multipliers (other part was done in pass 1):
829 * cK now represents sqrt(2) * cos(K*pi/6) * 16/9.
830 */
831
832 dataptr = data;
833 for (ctr = 0; ctr < 3; ctr++) {
834 /* Even part */
835
836 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*2];
837 tmp1 = dataptr[DCTSIZE*1];
838
839 tmp2 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*2];
840
841 dataptr[DCTSIZE*0] = (DCTELEM)
842 DESCALE(MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
843 CONST_BITS+PASS1_BITS);
844 dataptr[DCTSIZE*2] = (DCTELEM)
845 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(1.257078722)), /* c2 */
846 CONST_BITS+PASS1_BITS);
847
848 /* Odd part */
849
850 dataptr[DCTSIZE*1] = (DCTELEM)
851 DESCALE(MULTIPLY(tmp2, FIX(2.177324216)), /* c1 */
852 CONST_BITS+PASS1_BITS);
853
854 dataptr++; /* advance pointer to next column */
855 }
856 }
857
858
859 /*
860 * Perform the forward DCT on a 2x2 sample block.
861 */
862
863 GLOBAL(void)
864 jpeg_fdct_2x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
865 {
866 INT32 tmp0, tmp1, tmp2, tmp3;
867 JSAMPROW elemptr;
868
869 /* Pre-zero output coefficient block. */
870 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
871
872 /* Pass 1: process rows. */
873 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
874
875 /* Row 0 */
876 elemptr = sample_data[0] + start_col;
877
878 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[1]);
879 tmp1 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[1]);
880
881 /* Row 1 */
882 elemptr = sample_data[1] + start_col;
883
884 tmp2 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[1]);
885 tmp3 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[1]);
886
887 /* Pass 2: process columns.
888 * We leave the results scaled up by an overall factor of 8.
889 * We must also scale the output by (8/2)**2 = 2**4.
890 */
891
892 /* Column 0 */
893 /* Apply unsigned->signed conversion */
894 data[DCTSIZE*0] = (DCTELEM) ((tmp0 + tmp2 - 4 * CENTERJSAMPLE) << 4);
895 data[DCTSIZE*1] = (DCTELEM) ((tmp0 - tmp2) << 4);
896
897 /* Column 1 */
898 data[DCTSIZE*0+1] = (DCTELEM) ((tmp1 + tmp3) << 4);
899 data[DCTSIZE*1+1] = (DCTELEM) ((tmp1 - tmp3) << 4);
900 }
901
902
903 /*
904 * Perform the forward DCT on a 1x1 sample block.
905 */
906
907 GLOBAL(void)
908 jpeg_fdct_1x1 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
909 {
910 /* Pre-zero output coefficient block. */
911 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
912
913 /* We leave the result scaled up by an overall factor of 8. */
914 /* We must also scale the output by (8/1)**2 = 2**6. */
915 /* Apply unsigned->signed conversion */
916 data[0] = (DCTELEM)
917 ((GETJSAMPLE(sample_data[0][start_col]) - CENTERJSAMPLE) << 6);
918 }
919
920
921 /*
922 * Perform the forward DCT on a 9x9 sample block.
923 */
924
925 GLOBAL(void)
926 jpeg_fdct_9x9 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
927 {
928 INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
929 INT32 tmp10, tmp11, tmp12, tmp13;
930 INT32 z1, z2;
931 DCTELEM workspace[8];
932 DCTELEM *dataptr;
933 DCTELEM *wsptr;
934 JSAMPROW elemptr;
935 int ctr;
936 SHIFT_TEMPS
937
938 /* Pass 1: process rows. */
939 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
940 /* we scale the results further by 2 as part of output adaption */
941 /* scaling for different DCT size. */
942 /* cK represents sqrt(2) * cos(K*pi/18). */
943
944 dataptr = data;
945 ctr = 0;
946 for (;;) {
947 elemptr = sample_data[ctr] + start_col;
948
949 /* Even part */
950
951 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[8]);
952 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[7]);
953 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[6]);
954 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[5]);
955 tmp4 = GETJSAMPLE(elemptr[4]);
956
957 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[8]);
958 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[7]);
959 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[6]);
960 tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[5]);
961
962 z1 = tmp0 + tmp2 + tmp3;
963 z2 = tmp1 + tmp4;
964 /* Apply unsigned->signed conversion */
965 dataptr[0] = (DCTELEM) ((z1 + z2 - 9 * CENTERJSAMPLE) << 1);
966 dataptr[6] = (DCTELEM)
967 DESCALE(MULTIPLY(z1 - z2 - z2, FIX(0.707106781)), /* c6 */
968 CONST_BITS-1);
969 z1 = MULTIPLY(tmp0 - tmp2, FIX(1.328926049)); /* c2 */
970 z2 = MULTIPLY(tmp1 - tmp4 - tmp4, FIX(0.707106781)); /* c6 */
971 dataptr[2] = (DCTELEM)
972 DESCALE(MULTIPLY(tmp2 - tmp3, FIX(1.083350441)) /* c4 */
973 + z1 + z2, CONST_BITS-1);
974 dataptr[4] = (DCTELEM)
975 DESCALE(MULTIPLY(tmp3 - tmp0, FIX(0.245575608)) /* c8 */
976 + z1 - z2, CONST_BITS-1);
977
978 /* Odd part */
979
980 dataptr[3] = (DCTELEM)
981 DESCALE(MULTIPLY(tmp10 - tmp12 - tmp13, FIX(1.224744871)), /* c3 */
982 CONST_BITS-1);
983
984 tmp11 = MULTIPLY(tmp11, FIX(1.224744871)); /* c3 */
985 tmp0 = MULTIPLY(tmp10 + tmp12, FIX(0.909038955)); /* c5 */
986 tmp1 = MULTIPLY(tmp10 + tmp13, FIX(0.483689525)); /* c7 */
987
988 dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp0 + tmp1, CONST_BITS-1);
989
990 tmp2 = MULTIPLY(tmp12 - tmp13, FIX(1.392728481)); /* c1 */
991
992 dataptr[5] = (DCTELEM) DESCALE(tmp0 - tmp11 - tmp2, CONST_BITS-1);
993 dataptr[7] = (DCTELEM) DESCALE(tmp1 - tmp11 + tmp2, CONST_BITS-1);
994
995 ctr++;
996
997 if (ctr != DCTSIZE) {
998 if (ctr == 9)
999 break; /* Done. */
1000 dataptr += DCTSIZE; /* advance pointer to next row */
1001 } else
1002 dataptr = workspace; /* switch pointer to extended workspace */
1003 }
1004
1005 /* Pass 2: process columns.
1006 * We leave the results scaled up by an overall factor of 8.
1007 * We must also scale the output by (8/9)**2 = 64/81, which we partially
1008 * fold into the constant multipliers and final/initial shifting:
1009 * cK now represents sqrt(2) * cos(K*pi/18) * 128/81.
1010 */
1011
1012 dataptr = data;
1013 wsptr = workspace;
1014 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1015 /* Even part */
1016
1017 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*0];
1018 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*7];
1019 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*6];
1020 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*5];
1021 tmp4 = dataptr[DCTSIZE*4];
1022
1023 tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*0];
1024 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*7];
1025 tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*6];
1026 tmp13 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*5];
1027
1028 z1 = tmp0 + tmp2 + tmp3;
1029 z2 = tmp1 + tmp4;
1030 dataptr[DCTSIZE*0] = (DCTELEM)
1031 DESCALE(MULTIPLY(z1 + z2, FIX(1.580246914)), /* 128/81 */
1032 CONST_BITS+2);
1033 dataptr[DCTSIZE*6] = (DCTELEM)
1034 DESCALE(MULTIPLY(z1 - z2 - z2, FIX(1.117403309)), /* c6 */
1035 CONST_BITS+2);
1036 z1 = MULTIPLY(tmp0 - tmp2, FIX(2.100031287)); /* c2 */
1037 z2 = MULTIPLY(tmp1 - tmp4 - tmp4, FIX(1.117403309)); /* c6 */
1038 dataptr[DCTSIZE*2] = (DCTELEM)
1039 DESCALE(MULTIPLY(tmp2 - tmp3, FIX(1.711961190)) /* c4 */
1040 + z1 + z2, CONST_BITS+2);
1041 dataptr[DCTSIZE*4] = (DCTELEM)
1042 DESCALE(MULTIPLY(tmp3 - tmp0, FIX(0.388070096)) /* c8 */
1043 + z1 - z2, CONST_BITS+2);
1044
1045 /* Odd part */
1046
1047 dataptr[DCTSIZE*3] = (DCTELEM)
1048 DESCALE(MULTIPLY(tmp10 - tmp12 - tmp13, FIX(1.935399303)), /* c3 */
1049 CONST_BITS+2);
1050
1051 tmp11 = MULTIPLY(tmp11, FIX(1.935399303)); /* c3 */
1052 tmp0 = MULTIPLY(tmp10 + tmp12, FIX(1.436506004)); /* c5 */
1053 tmp1 = MULTIPLY(tmp10 + tmp13, FIX(0.764348879)); /* c7 */
1054
1055 dataptr[DCTSIZE*1] = (DCTELEM)
1056 DESCALE(tmp11 + tmp0 + tmp1, CONST_BITS+2);
1057
1058 tmp2 = MULTIPLY(tmp12 - tmp13, FIX(2.200854883)); /* c1 */
1059
1060 dataptr[DCTSIZE*5] = (DCTELEM)
1061 DESCALE(tmp0 - tmp11 - tmp2, CONST_BITS+2);
1062 dataptr[DCTSIZE*7] = (DCTELEM)
1063 DESCALE(tmp1 - tmp11 + tmp2, CONST_BITS+2);
1064
1065 dataptr++; /* advance pointer to next column */
1066 wsptr++; /* advance pointer to next column */
1067 }
1068 }
1069
1070
1071 /*
1072 * Perform the forward DCT on a 10x10 sample block.
1073 */
1074
1075 GLOBAL(void)
1076 jpeg_fdct_10x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1077 {
1078 INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
1079 INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
1080 DCTELEM workspace[8*2];
1081 DCTELEM *dataptr;
1082 DCTELEM *wsptr;
1083 JSAMPROW elemptr;
1084 int ctr;
1085 SHIFT_TEMPS
1086
1087 /* Pass 1: process rows. */
1088 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
1089 /* we scale the results further by 2 as part of output adaption */
1090 /* scaling for different DCT size. */
1091 /* cK represents sqrt(2) * cos(K*pi/20). */
1092
1093 dataptr = data;
1094 ctr = 0;
1095 for (;;) {
1096 elemptr = sample_data[ctr] + start_col;
1097
1098 /* Even part */
1099
1100 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[9]);
1101 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[8]);
1102 tmp12 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[7]);
1103 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[6]);
1104 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[5]);
1105
1106 tmp10 = tmp0 + tmp4;
1107 tmp13 = tmp0 - tmp4;
1108 tmp11 = tmp1 + tmp3;
1109 tmp14 = tmp1 - tmp3;
1110
1111 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[9]);
1112 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[8]);
1113 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[7]);
1114 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[6]);
1115 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[5]);
1116
1117 /* Apply unsigned->signed conversion */
1118 dataptr[0] = (DCTELEM)
1119 ((tmp10 + tmp11 + tmp12 - 10 * CENTERJSAMPLE) << 1);
1120 tmp12 += tmp12;
1121 dataptr[4] = (DCTELEM)
1122 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.144122806)) - /* c4 */
1123 MULTIPLY(tmp11 - tmp12, FIX(0.437016024)), /* c8 */
1124 CONST_BITS-1);
1125 tmp10 = MULTIPLY(tmp13 + tmp14, FIX(0.831253876)); /* c6 */
1126 dataptr[2] = (DCTELEM)
1127 DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.513743148)), /* c2-c6 */
1128 CONST_BITS-1);
1129 dataptr[6] = (DCTELEM)
1130 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.176250899)), /* c2+c6 */
1131 CONST_BITS-1);
1132
1133 /* Odd part */
1134
1135 tmp10 = tmp0 + tmp4;
1136 tmp11 = tmp1 - tmp3;
1137 dataptr[5] = (DCTELEM) ((tmp10 - tmp11 - tmp2) << 1);
1138 tmp2 <<= CONST_BITS;
1139 dataptr[1] = (DCTELEM)
1140 DESCALE(MULTIPLY(tmp0, FIX(1.396802247)) + /* c1 */
1141 MULTIPLY(tmp1, FIX(1.260073511)) + tmp2 + /* c3 */
1142 MULTIPLY(tmp3, FIX(0.642039522)) + /* c7 */
1143 MULTIPLY(tmp4, FIX(0.221231742)), /* c9 */
1144 CONST_BITS-1);
1145 tmp12 = MULTIPLY(tmp0 - tmp4, FIX(0.951056516)) - /* (c3+c7)/2 */
1146 MULTIPLY(tmp1 + tmp3, FIX(0.587785252)); /* (c1-c9)/2 */
1147 tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.309016994)) + /* (c3-c7)/2 */
1148 (tmp11 << (CONST_BITS - 1)) - tmp2;
1149 dataptr[3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS-1);
1150 dataptr[7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS-1);
1151
1152 ctr++;
1153
1154 if (ctr != DCTSIZE) {
1155 if (ctr == 10)
1156 break; /* Done. */
1157 dataptr += DCTSIZE; /* advance pointer to next row */
1158 } else
1159 dataptr = workspace; /* switch pointer to extended workspace */
1160 }
1161
1162 /* Pass 2: process columns.
1163 * We leave the results scaled up by an overall factor of 8.
1164 * We must also scale the output by (8/10)**2 = 16/25, which we partially
1165 * fold into the constant multipliers and final/initial shifting:
1166 * cK now represents sqrt(2) * cos(K*pi/20) * 32/25.
1167 */
1168
1169 dataptr = data;
1170 wsptr = workspace;
1171 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1172 /* Even part */
1173
1174 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*1];
1175 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*0];
1176 tmp12 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*7];
1177 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*6];
1178 tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
1179
1180 tmp10 = tmp0 + tmp4;
1181 tmp13 = tmp0 - tmp4;
1182 tmp11 = tmp1 + tmp3;
1183 tmp14 = tmp1 - tmp3;
1184
1185 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*1];
1186 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*0];
1187 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*7];
1188 tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*6];
1189 tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
1190
1191 dataptr[DCTSIZE*0] = (DCTELEM)
1192 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(1.28)), /* 32/25 */
1193 CONST_BITS+2);
1194 tmp12 += tmp12;
1195 dataptr[DCTSIZE*4] = (DCTELEM)
1196 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.464477191)) - /* c4 */
1197 MULTIPLY(tmp11 - tmp12, FIX(0.559380511)), /* c8 */
1198 CONST_BITS+2);
1199 tmp10 = MULTIPLY(tmp13 + tmp14, FIX(1.064004961)); /* c6 */
1200 dataptr[DCTSIZE*2] = (DCTELEM)
1201 DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.657591230)), /* c2-c6 */
1202 CONST_BITS+2);
1203 dataptr[DCTSIZE*6] = (DCTELEM)
1204 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.785601151)), /* c2+c6 */
1205 CONST_BITS+2);
1206
1207 /* Odd part */
1208
1209 tmp10 = tmp0 + tmp4;
1210 tmp11 = tmp1 - tmp3;
1211 dataptr[DCTSIZE*5] = (DCTELEM)
1212 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp2, FIX(1.28)), /* 32/25 */
1213 CONST_BITS+2);
1214 tmp2 = MULTIPLY(tmp2, FIX(1.28)); /* 32/25 */
1215 dataptr[DCTSIZE*1] = (DCTELEM)
1216 DESCALE(MULTIPLY(tmp0, FIX(1.787906876)) + /* c1 */
1217 MULTIPLY(tmp1, FIX(1.612894094)) + tmp2 + /* c3 */
1218 MULTIPLY(tmp3, FIX(0.821810588)) + /* c7 */
1219 MULTIPLY(tmp4, FIX(0.283176630)), /* c9 */
1220 CONST_BITS+2);
1221 tmp12 = MULTIPLY(tmp0 - tmp4, FIX(1.217352341)) - /* (c3+c7)/2 */
1222 MULTIPLY(tmp1 + tmp3, FIX(0.752365123)); /* (c1-c9)/2 */
1223 tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.395541753)) + /* (c3-c7)/2 */
1224 MULTIPLY(tmp11, FIX(0.64)) - tmp2; /* 16/25 */
1225 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS+2);
1226 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS+2);
1227
1228 dataptr++; /* advance pointer to next column */
1229 wsptr++; /* advance pointer to next column */
1230 }
1231 }
1232
1233
1234 /*
1235 * Perform the forward DCT on an 11x11 sample block.
1236 */
1237
1238 GLOBAL(void)
1239 jpeg_fdct_11x11 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1240 {
1241 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
1242 INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
1243 INT32 z1, z2, z3;
1244 DCTELEM workspace[8*3];
1245 DCTELEM *dataptr;
1246 DCTELEM *wsptr;
1247 JSAMPROW elemptr;
1248 int ctr;
1249 SHIFT_TEMPS
1250
1251 /* Pass 1: process rows. */
1252 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
1253 /* we scale the results further by 2 as part of output adaption */
1254 /* scaling for different DCT size. */
1255 /* cK represents sqrt(2) * cos(K*pi/22). */
1256
1257 dataptr = data;
1258 ctr = 0;
1259 for (;;) {
1260 elemptr = sample_data[ctr] + start_col;
1261
1262 /* Even part */
1263
1264 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[10]);
1265 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[9]);
1266 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[8]);
1267 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[7]);
1268 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[6]);
1269 tmp5 = GETJSAMPLE(elemptr[5]);
1270
1271 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[10]);
1272 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[9]);
1273 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[8]);
1274 tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[7]);
1275 tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[6]);
1276
1277 /* Apply unsigned->signed conversion */
1278 dataptr[0] = (DCTELEM)
1279 ((tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 - 11 * CENTERJSAMPLE) << 1);
1280 tmp5 += tmp5;
1281 tmp0 -= tmp5;
1282 tmp1 -= tmp5;
1283 tmp2 -= tmp5;
1284 tmp3 -= tmp5;
1285 tmp4 -= tmp5;
1286 z1 = MULTIPLY(tmp0 + tmp3, FIX(1.356927976)) + /* c2 */
1287 MULTIPLY(tmp2 + tmp4, FIX(0.201263574)); /* c10 */
1288 z2 = MULTIPLY(tmp1 - tmp3, FIX(0.926112931)); /* c6 */
1289 z3 = MULTIPLY(tmp0 - tmp1, FIX(1.189712156)); /* c4 */
1290 dataptr[2] = (DCTELEM)
1291 DESCALE(z1 + z2 - MULTIPLY(tmp3, FIX(1.018300590)) /* c2+c8-c6 */
1292 - MULTIPLY(tmp4, FIX(1.390975730)), /* c4+c10 */
1293 CONST_BITS-1);
1294 dataptr[4] = (DCTELEM)
1295 DESCALE(z2 + z3 + MULTIPLY(tmp1, FIX(0.062335650)) /* c4-c6-c10 */
1296 - MULTIPLY(tmp2, FIX(1.356927976)) /* c2 */
1297 + MULTIPLY(tmp4, FIX(0.587485545)), /* c8 */
1298 CONST_BITS-1);
1299 dataptr[6] = (DCTELEM)
1300 DESCALE(z1 + z3 - MULTIPLY(tmp0, FIX(1.620527200)) /* c2+c4-c6 */
1301 - MULTIPLY(tmp2, FIX(0.788749120)), /* c8+c10 */
1302 CONST_BITS-1);
1303
1304 /* Odd part */
1305
1306 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.286413905)); /* c3 */
1307 tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.068791298)); /* c5 */
1308 tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.764581576)); /* c7 */
1309 tmp0 = tmp1 + tmp2 + tmp3 - MULTIPLY(tmp10, FIX(1.719967871)) /* c7+c5+c3-c1 */
1310 + MULTIPLY(tmp14, FIX(0.398430003)); /* c9 */
1311 tmp4 = MULTIPLY(tmp11 + tmp12, - FIX(0.764581576)); /* -c7 */
1312 tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.399818907)); /* -c1 */
1313 tmp1 += tmp4 + tmp5 + MULTIPLY(tmp11, FIX(1.276416582)) /* c9+c7+c1-c3 */
1314 - MULTIPLY(tmp14, FIX(1.068791298)); /* c5 */
1315 tmp10 = MULTIPLY(tmp12 + tmp13, FIX(0.398430003)); /* c9 */
1316 tmp2 += tmp4 + tmp10 - MULTIPLY(tmp12, FIX(1.989053629)) /* c9+c5+c3-c7 */
1317 + MULTIPLY(tmp14, FIX(1.399818907)); /* c1 */
1318 tmp3 += tmp5 + tmp10 + MULTIPLY(tmp13, FIX(1.305598626)) /* c1+c5-c9-c7 */
1319 - MULTIPLY(tmp14, FIX(1.286413905)); /* c3 */
1320
1321 dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-1);
1322 dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-1);
1323 dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-1);
1324 dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS-1);
1325
1326 ctr++;
1327
1328 if (ctr != DCTSIZE) {
1329 if (ctr == 11)
1330 break; /* Done. */
1331 dataptr += DCTSIZE; /* advance pointer to next row */
1332 } else
1333 dataptr = workspace; /* switch pointer to extended workspace */
1334 }
1335
1336 /* Pass 2: process columns.
1337 * We leave the results scaled up by an overall factor of 8.
1338 * We must also scale the output by (8/11)**2 = 64/121, which we partially
1339 * fold into the constant multipliers and final/initial shifting:
1340 * cK now represents sqrt(2) * cos(K*pi/22) * 128/121.
1341 */
1342
1343 dataptr = data;
1344 wsptr = workspace;
1345 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1346 /* Even part */
1347
1348 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*2];
1349 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*1];
1350 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*0];
1351 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*7];
1352 tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*6];
1353 tmp5 = dataptr[DCTSIZE*5];
1354
1355 tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*2];
1356 tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*1];
1357 tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*0];
1358 tmp13 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*7];
1359 tmp14 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*6];
1360
1361 dataptr[DCTSIZE*0] = (DCTELEM)
1362 DESCALE(MULTIPLY(tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5,
1363 FIX(1.057851240)), /* 128/121 */
1364 CONST_BITS+2);
1365 tmp5 += tmp5;
1366 tmp0 -= tmp5;
1367 tmp1 -= tmp5;
1368 tmp2 -= tmp5;
1369 tmp3 -= tmp5;
1370 tmp4 -= tmp5;
1371 z1 = MULTIPLY(tmp0 + tmp3, FIX(1.435427942)) + /* c2 */
1372 MULTIPLY(tmp2 + tmp4, FIX(0.212906922)); /* c10 */
1373 z2 = MULTIPLY(tmp1 - tmp3, FIX(0.979689713)); /* c6 */
1374 z3 = MULTIPLY(tmp0 - tmp1, FIX(1.258538479)); /* c4 */
1375 dataptr[DCTSIZE*2] = (DCTELEM)
1376 DESCALE(z1 + z2 - MULTIPLY(tmp3, FIX(1.077210542)) /* c2+c8-c6 */
1377 - MULTIPLY(tmp4, FIX(1.471445400)), /* c4+c10 */
1378 CONST_BITS+2);
1379 dataptr[DCTSIZE*4] = (DCTELEM)
1380 DESCALE(z2 + z3 + MULTIPLY(tmp1, FIX(0.065941844)) /* c4-c6-c10 */
1381 - MULTIPLY(tmp2, FIX(1.435427942)) /* c2 */
1382 + MULTIPLY(tmp4, FIX(0.621472312)), /* c8 */
1383 CONST_BITS+2);
1384 dataptr[DCTSIZE*6] = (DCTELEM)
1385 DESCALE(z1 + z3 - MULTIPLY(tmp0, FIX(1.714276708)) /* c2+c4-c6 */
1386 - MULTIPLY(tmp2, FIX(0.834379234)), /* c8+c10 */
1387 CONST_BITS+2);
1388
1389 /* Odd part */
1390
1391 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.360834544)); /* c3 */
1392 tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.130622199)); /* c5 */
1393 tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.808813568)); /* c7 */
1394 tmp0 = tmp1 + tmp2 + tmp3 - MULTIPLY(tmp10, FIX(1.819470145)) /* c7+c5+c3-c1 */
1395 + MULTIPLY(tmp14, FIX(0.421479672)); /* c9 */
1396 tmp4 = MULTIPLY(tmp11 + tmp12, - FIX(0.808813568)); /* -c7 */
1397 tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.480800167)); /* -c1 */
1398 tmp1 += tmp4 + tmp5 + MULTIPLY(tmp11, FIX(1.350258864)) /* c9+c7+c1-c3 */
1399 - MULTIPLY(tmp14, FIX(1.130622199)); /* c5 */
1400 tmp10 = MULTIPLY(tmp12 + tmp13, FIX(0.421479672)); /* c9 */
1401 tmp2 += tmp4 + tmp10 - MULTIPLY(tmp12, FIX(2.104122847)) /* c9+c5+c3-c7 */
1402 + MULTIPLY(tmp14, FIX(1.480800167)); /* c1 */
1403 tmp3 += tmp5 + tmp10 + MULTIPLY(tmp13, FIX(1.381129125)) /* c1+c5-c9-c7 */
1404 - MULTIPLY(tmp14, FIX(1.360834544)); /* c3 */
1405
1406 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+2);
1407 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+2);
1408 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+2);
1409 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+2);
1410
1411 dataptr++; /* advance pointer to next column */
1412 wsptr++; /* advance pointer to next column */
1413 }
1414 }
1415
1416
1417 /*
1418 * Perform the forward DCT on a 12x12 sample block.
1419 */
1420
1421 GLOBAL(void)
1422 jpeg_fdct_12x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1423 {
1424 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
1425 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
1426 DCTELEM workspace[8*4];
1427 DCTELEM *dataptr;
1428 DCTELEM *wsptr;
1429 JSAMPROW elemptr;
1430 int ctr;
1431 SHIFT_TEMPS
1432
1433 /* Pass 1: process rows. */
1434 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1435 /* cK represents sqrt(2) * cos(K*pi/24). */
1436
1437 dataptr = data;
1438 ctr = 0;
1439 for (;;) {
1440 elemptr = sample_data[ctr] + start_col;
1441
1442 /* Even part */
1443
1444 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[11]);
1445 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[10]);
1446 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[9]);
1447 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[8]);
1448 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[7]);
1449 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[6]);
1450
1451 tmp10 = tmp0 + tmp5;
1452 tmp13 = tmp0 - tmp5;
1453 tmp11 = tmp1 + tmp4;
1454 tmp14 = tmp1 - tmp4;
1455 tmp12 = tmp2 + tmp3;
1456 tmp15 = tmp2 - tmp3;
1457
1458 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[11]);
1459 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[10]);
1460 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[9]);
1461 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[8]);
1462 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[7]);
1463 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[6]);
1464
1465 /* Apply unsigned->signed conversion */
1466 dataptr[0] = (DCTELEM) (tmp10 + tmp11 + tmp12 - 12 * CENTERJSAMPLE);
1467 dataptr[6] = (DCTELEM) (tmp13 - tmp14 - tmp15);
1468 dataptr[4] = (DCTELEM)
1469 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.224744871)), /* c4 */
1470 CONST_BITS);
1471 dataptr[2] = (DCTELEM)
1472 DESCALE(tmp14 - tmp15 + MULTIPLY(tmp13 + tmp15, FIX(1.366025404)), /* c2 */
1473 CONST_BITS);
1474
1475 /* Odd part */
1476
1477 tmp10 = MULTIPLY(tmp1 + tmp4, FIX_0_541196100); /* c9 */
1478 tmp14 = tmp10 + MULTIPLY(tmp1, FIX_0_765366865); /* c3-c9 */
1479 tmp15 = tmp10 - MULTIPLY(tmp4, FIX_1_847759065); /* c3+c9 */
1480 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.121971054)); /* c5 */
1481 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.860918669)); /* c7 */
1482 tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.580774953)) /* c5+c7-c1 */
1483 + MULTIPLY(tmp5, FIX(0.184591911)); /* c11 */
1484 tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.184591911)); /* -c11 */
1485 tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.339493912)) /* c1+c5-c11 */
1486 + MULTIPLY(tmp5, FIX(0.860918669)); /* c7 */
1487 tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.725788011)) /* c1+c11-c7 */
1488 - MULTIPLY(tmp5, FIX(1.121971054)); /* c5 */
1489 tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.306562965)) /* c3 */
1490 - MULTIPLY(tmp2 + tmp5, FIX_0_541196100); /* c9 */
1491
1492 dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS);
1493 dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS);
1494 dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS);
1495 dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS);
1496
1497 ctr++;
1498
1499 if (ctr != DCTSIZE) {
1500 if (ctr == 12)
1501 break; /* Done. */
1502 dataptr += DCTSIZE; /* advance pointer to next row */
1503 } else
1504 dataptr = workspace; /* switch pointer to extended workspace */
1505 }
1506
1507 /* Pass 2: process columns.
1508 * We leave the results scaled up by an overall factor of 8.
1509 * We must also scale the output by (8/12)**2 = 4/9, which we partially
1510 * fold into the constant multipliers and final shifting:
1511 * cK now represents sqrt(2) * cos(K*pi/24) * 8/9.
1512 */
1513
1514 dataptr = data;
1515 wsptr = workspace;
1516 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1517 /* Even part */
1518
1519 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*3];
1520 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*2];
1521 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*1];
1522 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*0];
1523 tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*7];
1524 tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*6];
1525
1526 tmp10 = tmp0 + tmp5;
1527 tmp13 = tmp0 - tmp5;
1528 tmp11 = tmp1 + tmp4;
1529 tmp14 = tmp1 - tmp4;
1530 tmp12 = tmp2 + tmp3;
1531 tmp15 = tmp2 - tmp3;
1532
1533 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*3];
1534 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*2];
1535 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*1];
1536 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*0];
1537 tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*7];
1538 tmp5 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*6];
1539
1540 dataptr[DCTSIZE*0] = (DCTELEM)
1541 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(0.888888889)), /* 8/9 */
1542 CONST_BITS+1);
1543 dataptr[DCTSIZE*6] = (DCTELEM)
1544 DESCALE(MULTIPLY(tmp13 - tmp14 - tmp15, FIX(0.888888889)), /* 8/9 */
1545 CONST_BITS+1);
1546 dataptr[DCTSIZE*4] = (DCTELEM)
1547 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.088662108)), /* c4 */
1548 CONST_BITS+1);
1549 dataptr[DCTSIZE*2] = (DCTELEM)
1550 DESCALE(MULTIPLY(tmp14 - tmp15, FIX(0.888888889)) + /* 8/9 */
1551 MULTIPLY(tmp13 + tmp15, FIX(1.214244803)), /* c2 */
1552 CONST_BITS+1);
1553
1554 /* Odd part */
1555
1556 tmp10 = MULTIPLY(tmp1 + tmp4, FIX(0.481063200)); /* c9 */
1557 tmp14 = tmp10 + MULTIPLY(tmp1, FIX(0.680326102)); /* c3-c9 */
1558 tmp15 = tmp10 - MULTIPLY(tmp4, FIX(1.642452502)); /* c3+c9 */
1559 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(0.997307603)); /* c5 */
1560 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.765261039)); /* c7 */
1561 tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.516244403)) /* c5+c7-c1 */
1562 + MULTIPLY(tmp5, FIX(0.164081699)); /* c11 */
1563 tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.164081699)); /* -c11 */
1564 tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.079550144)) /* c1+c5-c11 */
1565 + MULTIPLY(tmp5, FIX(0.765261039)); /* c7 */
1566 tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.645144899)) /* c1+c11-c7 */
1567 - MULTIPLY(tmp5, FIX(0.997307603)); /* c5 */
1568 tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.161389302)) /* c3 */
1569 - MULTIPLY(tmp2 + tmp5, FIX(0.481063200)); /* c9 */
1570
1571 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+1);
1572 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+1);
1573 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+1);
1574 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+1);
1575
1576 dataptr++; /* advance pointer to next column */
1577 wsptr++; /* advance pointer to next column */
1578 }
1579 }
1580
1581
1582 /*
1583 * Perform the forward DCT on a 13x13 sample block.
1584 */
1585
1586 GLOBAL(void)
1587 jpeg_fdct_13x13 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1588 {
1589 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
1590 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
1591 INT32 z1, z2;
1592 DCTELEM workspace[8*5];
1593 DCTELEM *dataptr;
1594 DCTELEM *wsptr;
1595 JSAMPROW elemptr;
1596 int ctr;
1597 SHIFT_TEMPS
1598
1599 /* Pass 1: process rows. */
1600 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1601 /* cK represents sqrt(2) * cos(K*pi/26). */
1602
1603 dataptr = data;
1604 ctr = 0;
1605 for (;;) {
1606 elemptr = sample_data[ctr] + start_col;
1607
1608 /* Even part */
1609
1610 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[12]);
1611 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[11]);
1612 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[10]);
1613 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[9]);
1614 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[8]);
1615 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[7]);
1616 tmp6 = GETJSAMPLE(elemptr[6]);
1617
1618 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[12]);
1619 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[11]);
1620 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[10]);
1621 tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[9]);
1622 tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[8]);
1623 tmp15 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[7]);
1624
1625 /* Apply unsigned->signed conversion */
1626 dataptr[0] = (DCTELEM)
1627 (tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 + tmp6 - 13 * CENTERJSAMPLE);
1628 tmp6 += tmp6;
1629 tmp0 -= tmp6;
1630 tmp1 -= tmp6;
1631 tmp2 -= tmp6;
1632 tmp3 -= tmp6;
1633 tmp4 -= tmp6;
1634 tmp5 -= tmp6;
1635 dataptr[2] = (DCTELEM)
1636 DESCALE(MULTIPLY(tmp0, FIX(1.373119086)) + /* c2 */
1637 MULTIPLY(tmp1, FIX(1.058554052)) + /* c6 */
1638 MULTIPLY(tmp2, FIX(0.501487041)) - /* c10 */
1639 MULTIPLY(tmp3, FIX(0.170464608)) - /* c12 */
1640 MULTIPLY(tmp4, FIX(0.803364869)) - /* c8 */
1641 MULTIPLY(tmp5, FIX(1.252223920)), /* c4 */
1642 CONST_BITS);
1643 z1 = MULTIPLY(tmp0 - tmp2, FIX(1.155388986)) - /* (c4+c6)/2 */
1644 MULTIPLY(tmp3 - tmp4, FIX(0.435816023)) - /* (c2-c10)/2 */
1645 MULTIPLY(tmp1 - tmp5, FIX(0.316450131)); /* (c8-c12)/2 */
1646 z2 = MULTIPLY(tmp0 + tmp2, FIX(0.096834934)) - /* (c4-c6)/2 */
1647 MULTIPLY(tmp3 + tmp4, FIX(0.937303064)) + /* (c2+c10)/2 */
1648 MULTIPLY(tmp1 + tmp5, FIX(0.486914739)); /* (c8+c12)/2 */
1649
1650 dataptr[4] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS);
1651 dataptr[6] = (DCTELEM) DESCALE(z1 - z2, CONST_BITS);
1652
1653 /* Odd part */
1654
1655 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.322312651)); /* c3 */
1656 tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.163874945)); /* c5 */
1657 tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.937797057)) + /* c7 */
1658 MULTIPLY(tmp14 + tmp15, FIX(0.338443458)); /* c11 */
1659 tmp0 = tmp1 + tmp2 + tmp3 -
1660 MULTIPLY(tmp10, FIX(2.020082300)) + /* c3+c5+c7-c1 */
1661 MULTIPLY(tmp14, FIX(0.318774355)); /* c9-c11 */
1662 tmp4 = MULTIPLY(tmp14 - tmp15, FIX(0.937797057)) - /* c7 */
1663 MULTIPLY(tmp11 + tmp12, FIX(0.338443458)); /* c11 */
1664 tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.163874945)); /* -c5 */
1665 tmp1 += tmp4 + tmp5 +
1666 MULTIPLY(tmp11, FIX(0.837223564)) - /* c5+c9+c11-c3 */
1667 MULTIPLY(tmp14, FIX(2.341699410)); /* c1+c7 */
1668 tmp6 = MULTIPLY(tmp12 + tmp13, - FIX(0.657217813)); /* -c9 */
1669 tmp2 += tmp4 + tmp6 -
1670 MULTIPLY(tmp12, FIX(1.572116027)) + /* c1+c5-c9-c11 */
1671 MULTIPLY(tmp15, FIX(2.260109708)); /* c3+c7 */
1672 tmp3 += tmp5 + tmp6 +
1673 MULTIPLY(tmp13, FIX(2.205608352)) - /* c3+c5+c9-c7 */
1674 MULTIPLY(tmp15, FIX(1.742345811)); /* c1+c11 */
1675
1676 dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS);
1677 dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS);
1678 dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS);
1679 dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS);
1680
1681 ctr++;
1682
1683 if (ctr != DCTSIZE) {
1684 if (ctr == 13)
1685 break; /* Done. */
1686 dataptr += DCTSIZE; /* advance pointer to next row */
1687 } else
1688 dataptr = workspace; /* switch pointer to extended workspace */
1689 }
1690
1691 /* Pass 2: process columns.
1692 * We leave the results scaled up by an overall factor of 8.
1693 * We must also scale the output by (8/13)**2 = 64/169, which we partially
1694 * fold into the constant multipliers and final shifting:
1695 * cK now represents sqrt(2) * cos(K*pi/26) * 128/169.
1696 */
1697
1698 dataptr = data;
1699 wsptr = workspace;
1700 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1701 /* Even part */
1702
1703 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*4];
1704 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*3];
1705 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*2];
1706 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*1];
1707 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*0];
1708 tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*7];
1709 tmp6 = dataptr[DCTSIZE*6];
1710
1711 tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*4];
1712 tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*3];
1713 tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*2];
1714 tmp13 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*1];
1715 tmp14 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*0];
1716 tmp15 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*7];
1717
1718 dataptr[DCTSIZE*0] = (DCTELEM)
1719 DESCALE(MULTIPLY(tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 + tmp6,
1720 FIX(0.757396450)), /* 128/169 */
1721 CONST_BITS+1);
1722 tmp6 += tmp6;
1723 tmp0 -= tmp6;
1724 tmp1 -= tmp6;
1725 tmp2 -= tmp6;
1726 tmp3 -= tmp6;
1727 tmp4 -= tmp6;
1728 tmp5 -= tmp6;
1729 dataptr[DCTSIZE*2] = (DCTELEM)
1730 DESCALE(MULTIPLY(tmp0, FIX(1.039995521)) + /* c2 */
1731 MULTIPLY(tmp1, FIX(0.801745081)) + /* c6 */
1732 MULTIPLY(tmp2, FIX(0.379824504)) - /* c10 */
1733 MULTIPLY(tmp3, FIX(0.129109289)) - /* c12 */
1734 MULTIPLY(tmp4, FIX(0.608465700)) - /* c8 */
1735 MULTIPLY(tmp5, FIX(0.948429952)), /* c4 */
1736 CONST_BITS+1);
1737 z1 = MULTIPLY(tmp0 - tmp2, FIX(0.875087516)) - /* (c4+c6)/2 */
1738 MULTIPLY(tmp3 - tmp4, FIX(0.330085509)) - /* (c2-c10)/2 */
1739 MULTIPLY(tmp1 - tmp5, FIX(0.239678205)); /* (c8-c12)/2 */
1740 z2 = MULTIPLY(tmp0 + tmp2, FIX(0.073342435)) - /* (c4-c6)/2 */
1741 MULTIPLY(tmp3 + tmp4, FIX(0.709910013)) + /* (c2+c10)/2 */
1742 MULTIPLY(tmp1 + tmp5, FIX(0.368787494)); /* (c8+c12)/2 */
1743
1744 dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+1);
1745 dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 - z2, CONST_BITS+1);
1746
1747 /* Odd part */
1748
1749 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.001514908)); /* c3 */
1750 tmp2 = MULTIPLY(tmp10 + tmp12, FIX(0.881514751)); /* c5 */
1751 tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.710284161)) + /* c7 */
1752 MULTIPLY(tmp14 + tmp15, FIX(0.256335874)); /* c11 */
1753 tmp0 = tmp1 + tmp2 + tmp3 -
1754 MULTIPLY(tmp10, FIX(1.530003162)) + /* c3+c5+c7-c1 */
1755 MULTIPLY(tmp14, FIX(0.241438564)); /* c9-c11 */
1756 tmp4 = MULTIPLY(tmp14 - tmp15, FIX(0.710284161)) - /* c7 */
1757 MULTIPLY(tmp11 + tmp12, FIX(0.256335874)); /* c11 */
1758 tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(0.881514751)); /* -c5 */
1759 tmp1 += tmp4 + tmp5 +
1760 MULTIPLY(tmp11, FIX(0.634110155)) - /* c5+c9+c11-c3 */
1761 MULTIPLY(tmp14, FIX(1.773594819)); /* c1+c7 */
1762 tmp6 = MULTIPLY(tmp12 + tmp13, - FIX(0.497774438)); /* -c9 */
1763 tmp2 += tmp4 + tmp6 -
1764 MULTIPLY(tmp12, FIX(1.190715098)) + /* c1+c5-c9-c11 */
1765 MULTIPLY(tmp15, FIX(1.711799069)); /* c3+c7 */
1766 tmp3 += tmp5 + tmp6 +
1767 MULTIPLY(tmp13, FIX(1.670519935)) - /* c3+c5+c9-c7 */
1768 MULTIPLY(tmp15, FIX(1.319646532)); /* c1+c11 */
1769
1770 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+1);
1771 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+1);
1772 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+1);
1773 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+1);
1774
1775 dataptr++; /* advance pointer to next column */
1776 wsptr++; /* advance pointer to next column */
1777 }
1778 }
1779
1780
1781 /*
1782 * Perform the forward DCT on a 14x14 sample block.
1783 */
1784
1785 GLOBAL(void)
1786 jpeg_fdct_14x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1787 {
1788 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
1789 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
1790 DCTELEM workspace[8*6];
1791 DCTELEM *dataptr;
1792 DCTELEM *wsptr;
1793 JSAMPROW elemptr;
1794 int ctr;
1795 SHIFT_TEMPS
1796
1797 /* Pass 1: process rows. */
1798 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1799 /* cK represents sqrt(2) * cos(K*pi/28). */
1800
1801 dataptr = data;
1802 ctr = 0;
1803 for (;;) {
1804 elemptr = sample_data[ctr] + start_col;
1805
1806 /* Even part */
1807
1808 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[13]);
1809 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[12]);
1810 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[11]);
1811 tmp13 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[10]);
1812 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[9]);
1813 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[8]);
1814 tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[7]);
1815
1816 tmp10 = tmp0 + tmp6;
1817 tmp14 = tmp0 - tmp6;
1818 tmp11 = tmp1 + tmp5;
1819 tmp15 = tmp1 - tmp5;
1820 tmp12 = tmp2 + tmp4;
1821 tmp16 = tmp2 - tmp4;
1822
1823 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[13]);
1824 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[12]);
1825 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[11]);
1826 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[10]);
1827 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[9]);
1828 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[8]);
1829 tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[7]);
1830
1831 /* Apply unsigned->signed conversion */
1832 dataptr[0] = (DCTELEM)
1833 (tmp10 + tmp11 + tmp12 + tmp13 - 14 * CENTERJSAMPLE);
1834 tmp13 += tmp13;
1835 dataptr[4] = (DCTELEM)
1836 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.274162392)) + /* c4 */
1837 MULTIPLY(tmp11 - tmp13, FIX(0.314692123)) - /* c12 */
1838 MULTIPLY(tmp12 - tmp13, FIX(0.881747734)), /* c8 */
1839 CONST_BITS);
1840
1841 tmp10 = MULTIPLY(tmp14 + tmp15, FIX(1.105676686)); /* c6 */
1842
1843 dataptr[2] = (DCTELEM)
1844 DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.273079590)) /* c2-c6 */
1845 + MULTIPLY(tmp16, FIX(0.613604268)), /* c10 */
1846 CONST_BITS);
1847 dataptr[6] = (DCTELEM)
1848 DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.719280954)) /* c6+c10 */
1849 - MULTIPLY(tmp16, FIX(1.378756276)), /* c2 */
1850 CONST_BITS);
1851
1852 /* Odd part */
1853
1854 tmp10 = tmp1 + tmp2;
1855 tmp11 = tmp5 - tmp4;
1856 dataptr[7] = (DCTELEM) (tmp0 - tmp10 + tmp3 - tmp11 - tmp6);
1857 tmp3 <<= CONST_BITS;
1858 tmp10 = MULTIPLY(tmp10, - FIX(0.158341681)); /* -c13 */
1859 tmp11 = MULTIPLY(tmp11, FIX(1.405321284)); /* c1 */
1860 tmp10 += tmp11 - tmp3;
1861 tmp11 = MULTIPLY(tmp0 + tmp2, FIX(1.197448846)) + /* c5 */
1862 MULTIPLY(tmp4 + tmp6, FIX(0.752406978)); /* c9 */
1863 dataptr[5] = (DCTELEM)
1864 DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(2.373959773)) /* c3+c5-c13 */
1865 + MULTIPLY(tmp4, FIX(1.119999435)), /* c1+c11-c9 */
1866 CONST_BITS);
1867 tmp12 = MULTIPLY(tmp0 + tmp1, FIX(1.334852607)) + /* c3 */
1868 MULTIPLY(tmp5 - tmp6, FIX(0.467085129)); /* c11 */
1869 dataptr[3] = (DCTELEM)
1870 DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.424103948)) /* c3-c9-c13 */
1871 - MULTIPLY(tmp5, FIX(3.069855259)), /* c1+c5+c11 */
1872 CONST_BITS);
1873 dataptr[1] = (DCTELEM)
1874 DESCALE(tmp11 + tmp12 + tmp3 + tmp6 -
1875 MULTIPLY(tmp0 + tmp6, FIX(1.126980169)), /* c3+c5-c1 */
1876 CONST_BITS);
1877
1878 ctr++;
1879
1880 if (ctr != DCTSIZE) {
1881 if (ctr == 14)
1882 break; /* Done. */
1883 dataptr += DCTSIZE; /* advance pointer to next row */
1884 } else
1885 dataptr = workspace; /* switch pointer to extended workspace */
1886 }
1887
1888 /* Pass 2: process columns.
1889 * We leave the results scaled up by an overall factor of 8.
1890 * We must also scale the output by (8/14)**2 = 16/49, which we partially
1891 * fold into the constant multipliers and final shifting:
1892 * cK now represents sqrt(2) * cos(K*pi/28) * 32/49.
1893 */
1894
1895 dataptr = data;
1896 wsptr = workspace;
1897 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
1898 /* Even part */
1899
1900 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*5];
1901 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*4];
1902 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*3];
1903 tmp13 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*2];
1904 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*1];
1905 tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*0];
1906 tmp6 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
1907
1908 tmp10 = tmp0 + tmp6;
1909 tmp14 = tmp0 - tmp6;
1910 tmp11 = tmp1 + tmp5;
1911 tmp15 = tmp1 - tmp5;
1912 tmp12 = tmp2 + tmp4;
1913 tmp16 = tmp2 - tmp4;
1914
1915 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*5];
1916 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*4];
1917 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*3];
1918 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*2];
1919 tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*1];
1920 tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*0];
1921 tmp6 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
1922
1923 dataptr[DCTSIZE*0] = (DCTELEM)
1924 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12 + tmp13,
1925 FIX(0.653061224)), /* 32/49 */
1926 CONST_BITS+1);
1927 tmp13 += tmp13;
1928 dataptr[DCTSIZE*4] = (DCTELEM)
1929 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(0.832106052)) + /* c4 */
1930 MULTIPLY(tmp11 - tmp13, FIX(0.205513223)) - /* c12 */
1931 MULTIPLY(tmp12 - tmp13, FIX(0.575835255)), /* c8 */
1932 CONST_BITS+1);
1933
1934 tmp10 = MULTIPLY(tmp14 + tmp15, FIX(0.722074570)); /* c6 */
1935
1936 dataptr[DCTSIZE*2] = (DCTELEM)
1937 DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.178337691)) /* c2-c6 */
1938 + MULTIPLY(tmp16, FIX(0.400721155)), /* c10 */
1939 CONST_BITS+1);
1940 dataptr[DCTSIZE*6] = (DCTELEM)
1941 DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.122795725)) /* c6+c10 */
1942 - MULTIPLY(tmp16, FIX(0.900412262)), /* c2 */
1943 CONST_BITS+1);
1944
1945 /* Odd part */
1946
1947 tmp10 = tmp1 + tmp2;
1948 tmp11 = tmp5 - tmp4;
1949 dataptr[DCTSIZE*7] = (DCTELEM)
1950 DESCALE(MULTIPLY(tmp0 - tmp10 + tmp3 - tmp11 - tmp6,
1951 FIX(0.653061224)), /* 32/49 */
1952 CONST_BITS+1);
1953 tmp3 = MULTIPLY(tmp3 , FIX(0.653061224)); /* 32/49 */
1954 tmp10 = MULTIPLY(tmp10, - FIX(0.103406812)); /* -c13 */
1955 tmp11 = MULTIPLY(tmp11, FIX(0.917760839)); /* c1 */
1956 tmp10 += tmp11 - tmp3;
1957 tmp11 = MULTIPLY(tmp0 + tmp2, FIX(0.782007410)) + /* c5 */
1958 MULTIPLY(tmp4 + tmp6, FIX(0.491367823)); /* c9 */
1959 dataptr[DCTSIZE*5] = (DCTELEM)
1960 DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(1.550341076)) /* c3+c5-c13 */
1961 + MULTIPLY(tmp4, FIX(0.731428202)), /* c1+c11-c9 */
1962 CONST_BITS+1);
1963 tmp12 = MULTIPLY(tmp0 + tmp1, FIX(0.871740478)) + /* c3 */
1964 MULTIPLY(tmp5 - tmp6, FIX(0.305035186)); /* c11 */
1965 dataptr[DCTSIZE*3] = (DCTELEM)
1966 DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.276965844)) /* c3-c9-c13 */
1967 - MULTIPLY(tmp5, FIX(2.004803435)), /* c1+c5+c11 */
1968 CONST_BITS+1);
1969 dataptr[DCTSIZE*1] = (DCTELEM)
1970 DESCALE(tmp11 + tmp12 + tmp3
1971 - MULTIPLY(tmp0, FIX(0.735987049)) /* c3+c5-c1 */
1972 - MULTIPLY(tmp6, FIX(0.082925825)), /* c9-c11-c13 */
1973 CONST_BITS+1);
1974
1975 dataptr++; /* advance pointer to next column */
1976 wsptr++; /* advance pointer to next column */
1977 }
1978 }
1979
1980
1981 /*
1982 * Perform the forward DCT on a 15x15 sample block.
1983 */
1984
1985 GLOBAL(void)
1986 jpeg_fdct_15x15 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
1987 {
1988 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
1989 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
1990 INT32 z1, z2, z3;
1991 DCTELEM workspace[8*7];
1992 DCTELEM *dataptr;
1993 DCTELEM *wsptr;
1994 JSAMPROW elemptr;
1995 int ctr;
1996 SHIFT_TEMPS
1997
1998 /* Pass 1: process rows. */
1999 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
2000 /* cK represents sqrt(2) * cos(K*pi/30). */
2001
2002 dataptr = data;
2003 ctr = 0;
2004 for (;;) {
2005 elemptr = sample_data[ctr] + start_col;
2006
2007 /* Even part */
2008
2009 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[14]);
2010 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[13]);
2011 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[12]);
2012 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[11]);
2013 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[10]);
2014 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[9]);
2015 tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[8]);
2016 tmp7 = GETJSAMPLE(elemptr[7]);
2017
2018 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[14]);
2019 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[13]);
2020 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[12]);
2021 tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[11]);
2022 tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[10]);
2023 tmp15 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[9]);
2024 tmp16 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[8]);
2025
2026 z1 = tmp0 + tmp4 + tmp5;
2027 z2 = tmp1 + tmp3 + tmp6;
2028 z3 = tmp2 + tmp7;
2029 /* Apply unsigned->signed conversion */
2030 dataptr[0] = (DCTELEM) (z1 + z2 + z3 - 15 * CENTERJSAMPLE);
2031 z3 += z3;
2032 dataptr[6] = (DCTELEM)
2033 DESCALE(MULTIPLY(z1 - z3, FIX(1.144122806)) - /* c6 */
2034 MULTIPLY(z2 - z3, FIX(0.437016024)), /* c12 */
2035 CONST_BITS);
2036 tmp2 += ((tmp1 + tmp4) >> 1) - tmp7 - tmp7;
2037 z1 = MULTIPLY(tmp3 - tmp2, FIX(1.531135173)) - /* c2+c14 */
2038 MULTIPLY(tmp6 - tmp2, FIX(2.238241955)); /* c4+c8 */
2039 z2 = MULTIPLY(tmp5 - tmp2, FIX(0.798468008)) - /* c8-c14 */
2040 MULTIPLY(tmp0 - tmp2, FIX(0.091361227)); /* c2-c4 */
2041 z3 = MULTIPLY(tmp0 - tmp3, FIX(1.383309603)) + /* c2 */
2042 MULTIPLY(tmp6 - tmp5, FIX(0.946293579)) + /* c8 */
2043 MULTIPLY(tmp1 - tmp4, FIX(0.790569415)); /* (c6+c12)/2 */
2044
2045 dataptr[2] = (DCTELEM) DESCALE(z1 + z3, CONST_BITS);
2046 dataptr[4] = (DCTELEM) DESCALE(z2 + z3, CONST_BITS);
2047
2048 /* Odd part */
2049
2050 tmp2 = MULTIPLY(tmp10 - tmp12 - tmp13 + tmp15 + tmp16,
2051 FIX(1.224744871)); /* c5 */
2052 tmp1 = MULTIPLY(tmp10 - tmp14 - tmp15, FIX(1.344997024)) + /* c3 */
2053 MULTIPLY(tmp11 - tmp13 - tmp16, FIX(0.831253876)); /* c9 */
2054 tmp12 = MULTIPLY(tmp12, FIX(1.224744871)); /* c5 */
2055 tmp4 = MULTIPLY(tmp10 - tmp16, FIX(1.406466353)) + /* c1 */
2056 MULTIPLY(tmp11 + tmp14, FIX(1.344997024)) + /* c3 */
2057 MULTIPLY(tmp13 + tmp15, FIX(0.575212477)); /* c11 */
2058 tmp0 = MULTIPLY(tmp13, FIX(0.475753014)) - /* c7-c11 */
2059 MULTIPLY(tmp14, FIX(0.513743148)) + /* c3-c9 */
2060 MULTIPLY(tmp16, FIX(1.700497885)) + tmp4 + tmp12; /* c1+c13 */
2061 tmp3 = MULTIPLY(tmp10, - FIX(0.355500862)) - /* -(c1-c7) */
2062 MULTIPLY(tmp11, FIX(2.176250899)) - /* c3+c9 */
2063 MULTIPLY(tmp15, FIX(0.869244010)) + tmp4 - tmp12; /* c11+c13 */
2064
2065 dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS);
2066 dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS);
2067 dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS);
2068 dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS);
2069
2070 ctr++;
2071
2072 if (ctr != DCTSIZE) {
2073 if (ctr == 15)
2074 break; /* Done. */
2075 dataptr += DCTSIZE; /* advance pointer to next row */
2076 } else
2077 dataptr = workspace; /* switch pointer to extended workspace */
2078 }
2079
2080 /* Pass 2: process columns.
2081 * We leave the results scaled up by an overall factor of 8.
2082 * We must also scale the output by (8/15)**2 = 64/225, which we partially
2083 * fold into the constant multipliers and final shifting:
2084 * cK now represents sqrt(2) * cos(K*pi/30) * 256/225.
2085 */
2086
2087 dataptr = data;
2088 wsptr = workspace;
2089 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2090 /* Even part */
2091
2092 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*6];
2093 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*5];
2094 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*4];
2095 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*3];
2096 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*2];
2097 tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*1];
2098 tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*0];
2099 tmp7 = dataptr[DCTSIZE*7];
2100
2101 tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*6];
2102 tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*5];
2103 tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*4];
2104 tmp13 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*3];
2105 tmp14 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*2];
2106 tmp15 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*1];
2107 tmp16 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*0];
2108
2109 z1 = tmp0 + tmp4 + tmp5;
2110 z2 = tmp1 + tmp3 + tmp6;
2111 z3 = tmp2 + tmp7;
2112 dataptr[DCTSIZE*0] = (DCTELEM)
2113 DESCALE(MULTIPLY(z1 + z2 + z3, FIX(1.137777778)), /* 256/225 */
2114 CONST_BITS+2);
2115 z3 += z3;
2116 dataptr[DCTSIZE*6] = (DCTELEM)
2117 DESCALE(MULTIPLY(z1 - z3, FIX(1.301757503)) - /* c6 */
2118 MULTIPLY(z2 - z3, FIX(0.497227121)), /* c12 */
2119 CONST_BITS+2);
2120 tmp2 += ((tmp1 + tmp4) >> 1) - tmp7 - tmp7;
2121 z1 = MULTIPLY(tmp3 - tmp2, FIX(1.742091575)) - /* c2+c14 */
2122 MULTIPLY(tmp6 - tmp2, FIX(2.546621957)); /* c4+c8 */
2123 z2 = MULTIPLY(tmp5 - tmp2, FIX(0.908479156)) - /* c8-c14 */
2124 MULTIPLY(tmp0 - tmp2, FIX(0.103948774)); /* c2-c4 */
2125 z3 = MULTIPLY(tmp0 - tmp3, FIX(1.573898926)) + /* c2 */
2126 MULTIPLY(tmp6 - tmp5, FIX(1.076671805)) + /* c8 */
2127 MULTIPLY(tmp1 - tmp4, FIX(0.899492312)); /* (c6+c12)/2 */
2128
2129 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z3, CONST_BITS+2);
2130 dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(z2 + z3, CONST_BITS+2);
2131
2132 /* Odd part */
2133
2134 tmp2 = MULTIPLY(tmp10 - tmp12 - tmp13 + tmp15 + tmp16,
2135 FIX(1.393487498)); /* c5 */
2136 tmp1 = MULTIPLY(tmp10 - tmp14 - tmp15, FIX(1.530307725)) + /* c3 */
2137 MULTIPLY(tmp11 - tmp13 - tmp16, FIX(0.945782187)); /* c9 */
2138 tmp12 = MULTIPLY(tmp12, FIX(1.393487498)); /* c5 */
2139 tmp4 = MULTIPLY(tmp10 - tmp16, FIX(1.600246161)) + /* c1 */
2140 MULTIPLY(tmp11 + tmp14, FIX(1.530307725)) + /* c3 */
2141 MULTIPLY(tmp13 + tmp15, FIX(0.654463974)); /* c11 */
2142 tmp0 = MULTIPLY(tmp13, FIX(0.541301207)) - /* c7-c11 */
2143 MULTIPLY(tmp14, FIX(0.584525538)) + /* c3-c9 */
2144 MULTIPLY(tmp16, FIX(1.934788705)) + tmp4 + tmp12; /* c1+c13 */
2145 tmp3 = MULTIPLY(tmp10, - FIX(0.404480980)) - /* -(c1-c7) */
2146 MULTIPLY(tmp11, FIX(2.476089912)) - /* c3+c9 */
2147 MULTIPLY(tmp15, FIX(0.989006518)) + tmp4 - tmp12; /* c11+c13 */
2148
2149 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+2);
2150 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+2);
2151 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+2);
2152 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+2);
2153
2154 dataptr++; /* advance pointer to next column */
2155 wsptr++; /* advance pointer to next column */
2156 }
2157 }
2158
2159
2160 /*
2161 * Perform the forward DCT on a 16x16 sample block.
2162 */
2163
2164 GLOBAL(void)
2165 jpeg_fdct_16x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2166 {
2167 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
2168 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
2169 DCTELEM workspace[DCTSIZE2];
2170 DCTELEM *dataptr;
2171 DCTELEM *wsptr;
2172 JSAMPROW elemptr;
2173 int ctr;
2174 SHIFT_TEMPS
2175
2176 /* Pass 1: process rows. */
2177 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2178 /* furthermore, we scale the results by 2**PASS1_BITS. */
2179 /* cK represents sqrt(2) * cos(K*pi/32). */
2180
2181 dataptr = data;
2182 ctr = 0;
2183 for (;;) {
2184 elemptr = sample_data[ctr] + start_col;
2185
2186 /* Even part */
2187
2188 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[15]);
2189 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[14]);
2190 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[13]);
2191 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[12]);
2192 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[11]);
2193 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[10]);
2194 tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[9]);
2195 tmp7 = GETJSAMPLE(elemptr[7]) + GETJSAMPLE(elemptr[8]);
2196
2197 tmp10 = tmp0 + tmp7;
2198 tmp14 = tmp0 - tmp7;
2199 tmp11 = tmp1 + tmp6;
2200 tmp15 = tmp1 - tmp6;
2201 tmp12 = tmp2 + tmp5;
2202 tmp16 = tmp2 - tmp5;
2203 tmp13 = tmp3 + tmp4;
2204 tmp17 = tmp3 - tmp4;
2205
2206 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[15]);
2207 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[14]);
2208 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[13]);
2209 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[12]);
2210 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[11]);
2211 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[10]);
2212 tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[9]);
2213 tmp7 = GETJSAMPLE(elemptr[7]) - GETJSAMPLE(elemptr[8]);
2214
2215 /* Apply unsigned->signed conversion */
2216 dataptr[0] = (DCTELEM)
2217 ((tmp10 + tmp11 + tmp12 + tmp13 - 16 * CENTERJSAMPLE) << PASS1_BITS);
2218 dataptr[4] = (DCTELEM)
2219 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
2220 MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
2221 CONST_BITS-PASS1_BITS);
2222
2223 tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
2224 MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
2225
2226 dataptr[2] = (DCTELEM)
2227 DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
2228 + MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
2229 CONST_BITS-PASS1_BITS);
2230 dataptr[6] = (DCTELEM)
2231 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
2232 - MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
2233 CONST_BITS-PASS1_BITS);
2234
2235 /* Odd part */
2236
2237 tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
2238 MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
2239 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
2240 MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
2241 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
2242 MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
2243 tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
2244 MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
2245 tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
2246 MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
2247 tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
2248 MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
2249 tmp10 = tmp11 + tmp12 + tmp13 -
2250 MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2251 MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
2252 tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
2253 - MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
2254 tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
2255 + MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
2256 tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
2257 + MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
2258
2259 dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
2260 dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
2261 dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
2262 dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
2263
2264 ctr++;
2265
2266 if (ctr != DCTSIZE) {
2267 if (ctr == DCTSIZE * 2)
2268 break; /* Done. */
2269 dataptr += DCTSIZE; /* advance pointer to next row */
2270 } else
2271 dataptr = workspace; /* switch pointer to extended workspace */
2272 }
2273
2274 /* Pass 2: process columns.
2275 * We remove the PASS1_BITS scaling, but leave the results scaled up
2276 * by an overall factor of 8.
2277 * We must also scale the output by (8/16)**2 = 1/2**2.
2278 */
2279
2280 dataptr = data;
2281 wsptr = workspace;
2282 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2283 /* Even part */
2284
2285 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*7];
2286 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*6];
2287 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*5];
2288 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*4];
2289 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*3];
2290 tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*2];
2291 tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*1];
2292 tmp7 = dataptr[DCTSIZE*7] + wsptr[DCTSIZE*0];
2293
2294 tmp10 = tmp0 + tmp7;
2295 tmp14 = tmp0 - tmp7;
2296 tmp11 = tmp1 + tmp6;
2297 tmp15 = tmp1 - tmp6;
2298 tmp12 = tmp2 + tmp5;
2299 tmp16 = tmp2 - tmp5;
2300 tmp13 = tmp3 + tmp4;
2301 tmp17 = tmp3 - tmp4;
2302
2303 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*7];
2304 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*6];
2305 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*5];
2306 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*4];
2307 tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*3];
2308 tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*2];
2309 tmp6 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*1];
2310 tmp7 = dataptr[DCTSIZE*7] - wsptr[DCTSIZE*0];
2311
2312 dataptr[DCTSIZE*0] = (DCTELEM)
2313 DESCALE(tmp10 + tmp11 + tmp12 + tmp13, PASS1_BITS+2);
2314 dataptr[DCTSIZE*4] = (DCTELEM)
2315 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
2316 MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
2317 CONST_BITS+PASS1_BITS+2);
2318
2319 tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
2320 MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
2321
2322 dataptr[DCTSIZE*2] = (DCTELEM)
2323 DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
2324 + MULTIPLY(tmp16, FIX(2.172734804)), /* c2+10 */
2325 CONST_BITS+PASS1_BITS+2);
2326 dataptr[DCTSIZE*6] = (DCTELEM)
2327 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
2328 - MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
2329 CONST_BITS+PASS1_BITS+2);
2330
2331 /* Odd part */
2332
2333 tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
2334 MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
2335 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
2336 MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
2337 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
2338 MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
2339 tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
2340 MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
2341 tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
2342 MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
2343 tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
2344 MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
2345 tmp10 = tmp11 + tmp12 + tmp13 -
2346 MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2347 MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
2348 tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
2349 - MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
2350 tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
2351 + MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
2352 tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
2353 + MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
2354
2355 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS+2);
2356 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS+2);
2357 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS+2);
2358 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS+2);
2359
2360 dataptr++; /* advance pointer to next column */
2361 wsptr++; /* advance pointer to next column */
2362 }
2363 }
2364
2365
2366 /*
2367 * Perform the forward DCT on a 16x8 sample block.
2368 *
2369 * 16-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
2370 */
2371
2372 GLOBAL(void)
2373 jpeg_fdct_16x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2374 {
2375 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
2376 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
2377 INT32 z1;
2378 DCTELEM *dataptr;
2379 JSAMPROW elemptr;
2380 int ctr;
2381 SHIFT_TEMPS
2382
2383 /* Pass 1: process rows. */
2384 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2385 /* furthermore, we scale the results by 2**PASS1_BITS. */
2386 /* 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32). */
2387
2388 dataptr = data;
2389 ctr = 0;
2390 for (ctr = 0; ctr < DCTSIZE; ctr++) {
2391 elemptr = sample_data[ctr] + start_col;
2392
2393 /* Even part */
2394
2395 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[15]);
2396 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[14]);
2397 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[13]);
2398 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[12]);
2399 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[11]);
2400 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[10]);
2401 tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[9]);
2402 tmp7 = GETJSAMPLE(elemptr[7]) + GETJSAMPLE(elemptr[8]);
2403
2404 tmp10 = tmp0 + tmp7;
2405 tmp14 = tmp0 - tmp7;
2406 tmp11 = tmp1 + tmp6;
2407 tmp15 = tmp1 - tmp6;
2408 tmp12 = tmp2 + tmp5;
2409 tmp16 = tmp2 - tmp5;
2410 tmp13 = tmp3 + tmp4;
2411 tmp17 = tmp3 - tmp4;
2412
2413 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[15]);
2414 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[14]);
2415 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[13]);
2416 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[12]);
2417 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[11]);
2418 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[10]);
2419 tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[9]);
2420 tmp7 = GETJSAMPLE(elemptr[7]) - GETJSAMPLE(elemptr[8]);
2421
2422 /* Apply unsigned->signed conversion */
2423 dataptr[0] = (DCTELEM)
2424 ((tmp10 + tmp11 + tmp12 + tmp13 - 16 * CENTERJSAMPLE) << PASS1_BITS);
2425 dataptr[4] = (DCTELEM)
2426 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
2427 MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
2428 CONST_BITS-PASS1_BITS);
2429
2430 tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
2431 MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
2432
2433 dataptr[2] = (DCTELEM)
2434 DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
2435 + MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
2436 CONST_BITS-PASS1_BITS);
2437 dataptr[6] = (DCTELEM)
2438 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
2439 - MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
2440 CONST_BITS-PASS1_BITS);
2441
2442 /* Odd part */
2443
2444 tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
2445 MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
2446 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
2447 MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
2448 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
2449 MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
2450 tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
2451 MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
2452 tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
2453 MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
2454 tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
2455 MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
2456 tmp10 = tmp11 + tmp12 + tmp13 -
2457 MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2458 MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
2459 tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
2460 - MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
2461 tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
2462 + MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
2463 tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
2464 + MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
2465
2466 dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
2467 dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
2468 dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
2469 dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
2470
2471 dataptr += DCTSIZE; /* advance pointer to next row */
2472 }
2473
2474 /* Pass 2: process columns.
2475 * We remove the PASS1_BITS scaling, but leave the results scaled up
2476 * by an overall factor of 8.
2477 * We must also scale the output by 8/16 = 1/2.
2478 */
2479
2480 dataptr = data;
2481 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2482 /* Even part per LL&M figure 1 --- note that published figure is faulty;
2483 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
2484 */
2485
2486 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
2487 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
2488 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
2489 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
2490
2491 tmp10 = tmp0 + tmp3;
2492 tmp12 = tmp0 - tmp3;
2493 tmp11 = tmp1 + tmp2;
2494 tmp13 = tmp1 - tmp2;
2495
2496 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
2497 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
2498 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
2499 tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
2500
2501 dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS+1);
2502 dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS+1);
2503
2504 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
2505 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
2506 CONST_BITS+PASS1_BITS+1);
2507 dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
2508 CONST_BITS+PASS1_BITS+1);
2509
2510 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
2511 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
2512 * i0..i3 in the paper are tmp0..tmp3 here.
2513 */
2514
2515 tmp10 = tmp0 + tmp3;
2516 tmp11 = tmp1 + tmp2;
2517 tmp12 = tmp0 + tmp2;
2518 tmp13 = tmp1 + tmp3;
2519 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
2520
2521 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
2522 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
2523 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
2524 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
2525 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
2526 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
2527 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
2528 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
2529
2530 tmp12 += z1;
2531 tmp13 += z1;
2532
2533 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12,
2534 CONST_BITS+PASS1_BITS+1);
2535 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13,
2536 CONST_BITS+PASS1_BITS+1);
2537 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12,
2538 CONST_BITS+PASS1_BITS+1);
2539 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13,
2540 CONST_BITS+PASS1_BITS+1);
2541
2542 dataptr++; /* advance pointer to next column */
2543 }
2544 }
2545
2546
2547 /*
2548 * Perform the forward DCT on a 14x7 sample block.
2549 *
2550 * 14-point FDCT in pass 1 (rows), 7-point in pass 2 (columns).
2551 */
2552
2553 GLOBAL(void)
2554 jpeg_fdct_14x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2555 {
2556 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
2557 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
2558 INT32 z1, z2, z3;
2559 DCTELEM *dataptr;
2560 JSAMPROW elemptr;
2561 int ctr;
2562 SHIFT_TEMPS
2563
2564 /* Zero bottom row of output coefficient block. */
2565 MEMZERO(&data[DCTSIZE*7], SIZEOF(DCTELEM) * DCTSIZE);
2566
2567 /* Pass 1: process rows. */
2568 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2569 /* furthermore, we scale the results by 2**PASS1_BITS. */
2570 /* 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28). */
2571
2572 dataptr = data;
2573 for (ctr = 0; ctr < 7; ctr++) {
2574 elemptr = sample_data[ctr] + start_col;
2575
2576 /* Even part */
2577
2578 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[13]);
2579 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[12]);
2580 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[11]);
2581 tmp13 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[10]);
2582 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[9]);
2583 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[8]);
2584 tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[7]);
2585
2586 tmp10 = tmp0 + tmp6;
2587 tmp14 = tmp0 - tmp6;
2588 tmp11 = tmp1 + tmp5;
2589 tmp15 = tmp1 - tmp5;
2590 tmp12 = tmp2 + tmp4;
2591 tmp16 = tmp2 - tmp4;
2592
2593 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[13]);
2594 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[12]);
2595 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[11]);
2596 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[10]);
2597 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[9]);
2598 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[8]);
2599 tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[7]);
2600
2601 /* Apply unsigned->signed conversion */
2602 dataptr[0] = (DCTELEM)
2603 ((tmp10 + tmp11 + tmp12 + tmp13 - 14 * CENTERJSAMPLE) << PASS1_BITS);
2604 tmp13 += tmp13;
2605 dataptr[4] = (DCTELEM)
2606 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.274162392)) + /* c4 */
2607 MULTIPLY(tmp11 - tmp13, FIX(0.314692123)) - /* c12 */
2608 MULTIPLY(tmp12 - tmp13, FIX(0.881747734)), /* c8 */
2609 CONST_BITS-PASS1_BITS);
2610
2611 tmp10 = MULTIPLY(tmp14 + tmp15, FIX(1.105676686)); /* c6 */
2612
2613 dataptr[2] = (DCTELEM)
2614 DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.273079590)) /* c2-c6 */
2615 + MULTIPLY(tmp16, FIX(0.613604268)), /* c10 */
2616 CONST_BITS-PASS1_BITS);
2617 dataptr[6] = (DCTELEM)
2618 DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.719280954)) /* c6+c10 */
2619 - MULTIPLY(tmp16, FIX(1.378756276)), /* c2 */
2620 CONST_BITS-PASS1_BITS);
2621
2622 /* Odd part */
2623
2624 tmp10 = tmp1 + tmp2;
2625 tmp11 = tmp5 - tmp4;
2626 dataptr[7] = (DCTELEM) ((tmp0 - tmp10 + tmp3 - tmp11 - tmp6) << PASS1_BITS);
2627 tmp3 <<= CONST_BITS;
2628 tmp10 = MULTIPLY(tmp10, - FIX(0.158341681)); /* -c13 */
2629 tmp11 = MULTIPLY(tmp11, FIX(1.405321284)); /* c1 */
2630 tmp10 += tmp11 - tmp3;
2631 tmp11 = MULTIPLY(tmp0 + tmp2, FIX(1.197448846)) + /* c5 */
2632 MULTIPLY(tmp4 + tmp6, FIX(0.752406978)); /* c9 */
2633 dataptr[5] = (DCTELEM)
2634 DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(2.373959773)) /* c3+c5-c13 */
2635 + MULTIPLY(tmp4, FIX(1.119999435)), /* c1+c11-c9 */
2636 CONST_BITS-PASS1_BITS);
2637 tmp12 = MULTIPLY(tmp0 + tmp1, FIX(1.334852607)) + /* c3 */
2638 MULTIPLY(tmp5 - tmp6, FIX(0.467085129)); /* c11 */
2639 dataptr[3] = (DCTELEM)
2640 DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.424103948)) /* c3-c9-c13 */
2641 - MULTIPLY(tmp5, FIX(3.069855259)), /* c1+c5+c11 */
2642 CONST_BITS-PASS1_BITS);
2643 dataptr[1] = (DCTELEM)
2644 DESCALE(tmp11 + tmp12 + tmp3 + tmp6 -
2645 MULTIPLY(tmp0 + tmp6, FIX(1.126980169)), /* c3+c5-c1 */
2646 CONST_BITS-PASS1_BITS);
2647
2648 dataptr += DCTSIZE; /* advance pointer to next row */
2649 }
2650
2651 /* Pass 2: process columns.
2652 * We remove the PASS1_BITS scaling, but leave the results scaled up
2653 * by an overall factor of 8.
2654 * We must also scale the output by (8/14)*(8/7) = 32/49, which we
2655 * partially fold into the constant multipliers and final shifting:
2656 * 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14) * 64/49.
2657 */
2658
2659 dataptr = data;
2660 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2661 /* Even part */
2662
2663 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*6];
2664 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*5];
2665 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*4];
2666 tmp3 = dataptr[DCTSIZE*3];
2667
2668 tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*6];
2669 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*5];
2670 tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*4];
2671
2672 z1 = tmp0 + tmp2;
2673 dataptr[DCTSIZE*0] = (DCTELEM)
2674 DESCALE(MULTIPLY(z1 + tmp1 + tmp3, FIX(1.306122449)), /* 64/49 */
2675 CONST_BITS+PASS1_BITS+1);
2676 tmp3 += tmp3;
2677 z1 -= tmp3;
2678 z1 -= tmp3;
2679 z1 = MULTIPLY(z1, FIX(0.461784020)); /* (c2+c6-c4)/2 */
2680 z2 = MULTIPLY(tmp0 - tmp2, FIX(1.202428084)); /* (c2+c4-c6)/2 */
2681 z3 = MULTIPLY(tmp1 - tmp2, FIX(0.411026446)); /* c6 */
2682 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS+PASS1_BITS+1);
2683 z1 -= z2;
2684 z2 = MULTIPLY(tmp0 - tmp1, FIX(1.151670509)); /* c4 */
2685 dataptr[DCTSIZE*4] = (DCTELEM)
2686 DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.923568041)), /* c2+c6-c4 */
2687 CONST_BITS+PASS1_BITS+1);
2688 dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+PASS1_BITS+1);
2689
2690 /* Odd part */
2691
2692 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.221765677)); /* (c3+c1-c5)/2 */
2693 tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.222383464)); /* (c3+c5-c1)/2 */
2694 tmp0 = tmp1 - tmp2;
2695 tmp1 += tmp2;
2696 tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.800824523)); /* -c1 */
2697 tmp1 += tmp2;
2698 tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.801442310)); /* c5 */
2699 tmp0 += tmp3;
2700 tmp2 += tmp3 + MULTIPLY(tmp12, FIX(2.443531355)); /* c3+c1-c5 */
2701
2702 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+PASS1_BITS+1);
2703 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+PASS1_BITS+1);
2704 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+PASS1_BITS+1);
2705
2706 dataptr++; /* advance pointer to next column */
2707 }
2708 }
2709
2710
2711 /*
2712 * Perform the forward DCT on a 12x6 sample block.
2713 *
2714 * 12-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
2715 */
2716
2717 GLOBAL(void)
2718 jpeg_fdct_12x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2719 {
2720 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
2721 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
2722 DCTELEM *dataptr;
2723 JSAMPROW elemptr;
2724 int ctr;
2725 SHIFT_TEMPS
2726
2727 /* Zero 2 bottom rows of output coefficient block. */
2728 MEMZERO(&data[DCTSIZE*6], SIZEOF(DCTELEM) * DCTSIZE * 2);
2729
2730 /* Pass 1: process rows. */
2731 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2732 /* furthermore, we scale the results by 2**PASS1_BITS. */
2733 /* 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24). */
2734
2735 dataptr = data;
2736 for (ctr = 0; ctr < 6; ctr++) {
2737 elemptr = sample_data[ctr] + start_col;
2738
2739 /* Even part */
2740
2741 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[11]);
2742 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[10]);
2743 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[9]);
2744 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[8]);
2745 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[7]);
2746 tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[6]);
2747
2748 tmp10 = tmp0 + tmp5;
2749 tmp13 = tmp0 - tmp5;
2750 tmp11 = tmp1 + tmp4;
2751 tmp14 = tmp1 - tmp4;
2752 tmp12 = tmp2 + tmp3;
2753 tmp15 = tmp2 - tmp3;
2754
2755 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[11]);
2756 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[10]);
2757 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[9]);
2758 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[8]);
2759 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[7]);
2760 tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[6]);
2761
2762 /* Apply unsigned->signed conversion */
2763 dataptr[0] = (DCTELEM)
2764 ((tmp10 + tmp11 + tmp12 - 12 * CENTERJSAMPLE) << PASS1_BITS);
2765 dataptr[6] = (DCTELEM) ((tmp13 - tmp14 - tmp15) << PASS1_BITS);
2766 dataptr[4] = (DCTELEM)
2767 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.224744871)), /* c4 */
2768 CONST_BITS-PASS1_BITS);
2769 dataptr[2] = (DCTELEM)
2770 DESCALE(tmp14 - tmp15 + MULTIPLY(tmp13 + tmp15, FIX(1.366025404)), /* c2 */
2771 CONST_BITS-PASS1_BITS);
2772
2773 /* Odd part */
2774
2775 tmp10 = MULTIPLY(tmp1 + tmp4, FIX_0_541196100); /* c9 */
2776 tmp14 = tmp10 + MULTIPLY(tmp1, FIX_0_765366865); /* c3-c9 */
2777 tmp15 = tmp10 - MULTIPLY(tmp4, FIX_1_847759065); /* c3+c9 */
2778 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.121971054)); /* c5 */
2779 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.860918669)); /* c7 */
2780 tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.580774953)) /* c5+c7-c1 */
2781 + MULTIPLY(tmp5, FIX(0.184591911)); /* c11 */
2782 tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.184591911)); /* -c11 */
2783 tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.339493912)) /* c1+c5-c11 */
2784 + MULTIPLY(tmp5, FIX(0.860918669)); /* c7 */
2785 tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.725788011)) /* c1+c11-c7 */
2786 - MULTIPLY(tmp5, FIX(1.121971054)); /* c5 */
2787 tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.306562965)) /* c3 */
2788 - MULTIPLY(tmp2 + tmp5, FIX_0_541196100); /* c9 */
2789
2790 dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
2791 dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
2792 dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
2793 dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
2794
2795 dataptr += DCTSIZE; /* advance pointer to next row */
2796 }
2797
2798 /* Pass 2: process columns.
2799 * We remove the PASS1_BITS scaling, but leave the results scaled up
2800 * by an overall factor of 8.
2801 * We must also scale the output by (8/12)*(8/6) = 8/9, which we
2802 * partially fold into the constant multipliers and final shifting:
2803 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
2804 */
2805
2806 dataptr = data;
2807 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2808 /* Even part */
2809
2810 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
2811 tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
2812 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
2813
2814 tmp10 = tmp0 + tmp2;
2815 tmp12 = tmp0 - tmp2;
2816
2817 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
2818 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
2819 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
2820
2821 dataptr[DCTSIZE*0] = (DCTELEM)
2822 DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
2823 CONST_BITS+PASS1_BITS+1);
2824 dataptr[DCTSIZE*2] = (DCTELEM)
2825 DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
2826 CONST_BITS+PASS1_BITS+1);
2827 dataptr[DCTSIZE*4] = (DCTELEM)
2828 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
2829 CONST_BITS+PASS1_BITS+1);
2830
2831 /* Odd part */
2832
2833 tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
2834
2835 dataptr[DCTSIZE*1] = (DCTELEM)
2836 DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
2837 CONST_BITS+PASS1_BITS+1);
2838 dataptr[DCTSIZE*3] = (DCTELEM)
2839 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
2840 CONST_BITS+PASS1_BITS+1);
2841 dataptr[DCTSIZE*5] = (DCTELEM)
2842 DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
2843 CONST_BITS+PASS1_BITS+1);
2844
2845 dataptr++; /* advance pointer to next column */
2846 }
2847 }
2848
2849
2850 /*
2851 * Perform the forward DCT on a 10x5 sample block.
2852 *
2853 * 10-point FDCT in pass 1 (rows), 5-point in pass 2 (columns).
2854 */
2855
2856 GLOBAL(void)
2857 jpeg_fdct_10x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2858 {
2859 INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
2860 INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
2861 DCTELEM *dataptr;
2862 JSAMPROW elemptr;
2863 int ctr;
2864 SHIFT_TEMPS
2865
2866 /* Zero 3 bottom rows of output coefficient block. */
2867 MEMZERO(&data[DCTSIZE*5], SIZEOF(DCTELEM) * DCTSIZE * 3);
2868
2869 /* Pass 1: process rows. */
2870 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2871 /* furthermore, we scale the results by 2**PASS1_BITS. */
2872 /* 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20). */
2873
2874 dataptr = data;
2875 for (ctr = 0; ctr < 5; ctr++) {
2876 elemptr = sample_data[ctr] + start_col;
2877
2878 /* Even part */
2879
2880 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[9]);
2881 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[8]);
2882 tmp12 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[7]);
2883 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[6]);
2884 tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[5]);
2885
2886 tmp10 = tmp0 + tmp4;
2887 tmp13 = tmp0 - tmp4;
2888 tmp11 = tmp1 + tmp3;
2889 tmp14 = tmp1 - tmp3;
2890
2891 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[9]);
2892 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[8]);
2893 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[7]);
2894 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[6]);
2895 tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[5]);
2896
2897 /* Apply unsigned->signed conversion */
2898 dataptr[0] = (DCTELEM)
2899 ((tmp10 + tmp11 + tmp12 - 10 * CENTERJSAMPLE) << PASS1_BITS);
2900 tmp12 += tmp12;
2901 dataptr[4] = (DCTELEM)
2902 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.144122806)) - /* c4 */
2903 MULTIPLY(tmp11 - tmp12, FIX(0.437016024)), /* c8 */
2904 CONST_BITS-PASS1_BITS);
2905 tmp10 = MULTIPLY(tmp13 + tmp14, FIX(0.831253876)); /* c6 */
2906 dataptr[2] = (DCTELEM)
2907 DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.513743148)), /* c2-c6 */
2908 CONST_BITS-PASS1_BITS);
2909 dataptr[6] = (DCTELEM)
2910 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.176250899)), /* c2+c6 */
2911 CONST_BITS-PASS1_BITS);
2912
2913 /* Odd part */
2914
2915 tmp10 = tmp0 + tmp4;
2916 tmp11 = tmp1 - tmp3;
2917 dataptr[5] = (DCTELEM) ((tmp10 - tmp11 - tmp2) << PASS1_BITS);
2918 tmp2 <<= CONST_BITS;
2919 dataptr[1] = (DCTELEM)
2920 DESCALE(MULTIPLY(tmp0, FIX(1.396802247)) + /* c1 */
2921 MULTIPLY(tmp1, FIX(1.260073511)) + tmp2 + /* c3 */
2922 MULTIPLY(tmp3, FIX(0.642039522)) + /* c7 */
2923 MULTIPLY(tmp4, FIX(0.221231742)), /* c9 */
2924 CONST_BITS-PASS1_BITS);
2925 tmp12 = MULTIPLY(tmp0 - tmp4, FIX(0.951056516)) - /* (c3+c7)/2 */
2926 MULTIPLY(tmp1 + tmp3, FIX(0.587785252)); /* (c1-c9)/2 */
2927 tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.309016994)) + /* (c3-c7)/2 */
2928 (tmp11 << (CONST_BITS - 1)) - tmp2;
2929 dataptr[3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS-PASS1_BITS);
2930 dataptr[7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS-PASS1_BITS);
2931
2932 dataptr += DCTSIZE; /* advance pointer to next row */
2933 }
2934
2935 /* Pass 2: process columns.
2936 * We remove the PASS1_BITS scaling, but leave the results scaled up
2937 * by an overall factor of 8.
2938 * We must also scale the output by (8/10)*(8/5) = 32/25, which we
2939 * fold into the constant multipliers:
2940 * 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10) * 32/25.
2941 */
2942
2943 dataptr = data;
2944 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
2945 /* Even part */
2946
2947 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*4];
2948 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*3];
2949 tmp2 = dataptr[DCTSIZE*2];
2950
2951 tmp10 = tmp0 + tmp1;
2952 tmp11 = tmp0 - tmp1;
2953
2954 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*4];
2955 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*3];
2956
2957 dataptr[DCTSIZE*0] = (DCTELEM)
2958 DESCALE(MULTIPLY(tmp10 + tmp2, FIX(1.28)), /* 32/25 */
2959 CONST_BITS+PASS1_BITS);
2960 tmp11 = MULTIPLY(tmp11, FIX(1.011928851)); /* (c2+c4)/2 */
2961 tmp10 -= tmp2 << 2;
2962 tmp10 = MULTIPLY(tmp10, FIX(0.452548340)); /* (c2-c4)/2 */
2963 dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS+PASS1_BITS);
2964 dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS+PASS1_BITS);
2965
2966 /* Odd part */
2967
2968 tmp10 = MULTIPLY(tmp0 + tmp1, FIX(1.064004961)); /* c3 */
2969
2970 dataptr[DCTSIZE*1] = (DCTELEM)
2971 DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.657591230)), /* c1-c3 */
2972 CONST_BITS+PASS1_BITS);
2973 dataptr[DCTSIZE*3] = (DCTELEM)
2974 DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.785601151)), /* c1+c3 */
2975 CONST_BITS+PASS1_BITS);
2976
2977 dataptr++; /* advance pointer to next column */
2978 }
2979 }
2980
2981
2982 /*
2983 * Perform the forward DCT on an 8x4 sample block.
2984 *
2985 * 8-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
2986 */
2987
2988 GLOBAL(void)
2989 jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
2990 {
2991 INT32 tmp0, tmp1, tmp2, tmp3;
2992 INT32 tmp10, tmp11, tmp12, tmp13;
2993 INT32 z1;
2994 DCTELEM *dataptr;
2995 JSAMPROW elemptr;
2996 int ctr;
2997 SHIFT_TEMPS
2998
2999 /* Zero 4 bottom rows of output coefficient block. */
3000 MEMZERO(&data[DCTSIZE*4], SIZEOF(DCTELEM) * DCTSIZE * 4);
3001
3002 /* Pass 1: process rows. */
3003 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3004 /* furthermore, we scale the results by 2**PASS1_BITS. */
3005 /* We must also scale the output by 8/4 = 2, which we add here. */
3006
3007 dataptr = data;
3008 for (ctr = 0; ctr < 4; ctr++) {
3009 elemptr = sample_data[ctr] + start_col;
3010
3011 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3012 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
3013 */
3014
3015 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
3016 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
3017 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
3018 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
3019
3020 tmp10 = tmp0 + tmp3;
3021 tmp12 = tmp0 - tmp3;
3022 tmp11 = tmp1 + tmp2;
3023 tmp13 = tmp1 - tmp2;
3024
3025 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
3026 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
3027 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
3028 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
3029
3030 /* Apply unsigned->signed conversion */
3031 dataptr[0] = (DCTELEM)
3032 ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << (PASS1_BITS+1));
3033 dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << (PASS1_BITS+1));
3034
3035 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
3036 /* Add fudge factor here for final descale. */
3037 z1 += ONE << (CONST_BITS-PASS1_BITS-2);
3038 dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
3039 CONST_BITS-PASS1_BITS-1);
3040 dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
3041 CONST_BITS-PASS1_BITS-1);
3042
3043 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3044 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3045 * i0..i3 in the paper are tmp0..tmp3 here.
3046 */
3047
3048 tmp10 = tmp0 + tmp3;
3049 tmp11 = tmp1 + tmp2;
3050 tmp12 = tmp0 + tmp2;
3051 tmp13 = tmp1 + tmp3;
3052 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
3053 /* Add fudge factor here for final descale. */
3054 z1 += ONE << (CONST_BITS-PASS1_BITS-2);
3055
3056 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
3057 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
3058 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
3059 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
3060 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
3061 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
3062 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
3063 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
3064
3065 tmp12 += z1;
3066 tmp13 += z1;
3067
3068 dataptr[1] = (DCTELEM)
3069 RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS-1);
3070 dataptr[3] = (DCTELEM)
3071 RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS-1);
3072 dataptr[5] = (DCTELEM)
3073 RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS-1);
3074 dataptr[7] = (DCTELEM)
3075 RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS-1);
3076
3077 dataptr += DCTSIZE; /* advance pointer to next row */
3078 }
3079
3080 /* Pass 2: process columns.
3081 * We remove the PASS1_BITS scaling, but leave the results scaled up
3082 * by an overall factor of 8.
3083 * 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3084 */
3085
3086 dataptr = data;
3087 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
3088 /* Even part */
3089
3090 /* Add fudge factor here for final descale. */
3091 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3] + (ONE << (PASS1_BITS-1));
3092 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
3093
3094 tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
3095 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
3096
3097 dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
3098 dataptr[DCTSIZE*2] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
3099
3100 /* Odd part */
3101
3102 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
3103 /* Add fudge factor here for final descale. */
3104 tmp0 += ONE << (CONST_BITS+PASS1_BITS-1);
3105
3106 dataptr[DCTSIZE*1] = (DCTELEM)
3107 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
3108 CONST_BITS+PASS1_BITS);
3109 dataptr[DCTSIZE*3] = (DCTELEM)
3110 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
3111 CONST_BITS+PASS1_BITS);
3112
3113 dataptr++; /* advance pointer to next column */
3114 }
3115 }
3116
3117
3118 /*
3119 * Perform the forward DCT on a 6x3 sample block.
3120 *
3121 * 6-point FDCT in pass 1 (rows), 3-point in pass 2 (columns).
3122 */
3123
3124 GLOBAL(void)
3125 jpeg_fdct_6x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3126 {
3127 INT32 tmp0, tmp1, tmp2;
3128 INT32 tmp10, tmp11, tmp12;
3129 DCTELEM *dataptr;
3130 JSAMPROW elemptr;
3131 int ctr;
3132 SHIFT_TEMPS
3133
3134 /* Pre-zero output coefficient block. */
3135 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3136
3137 /* Pass 1: process rows. */
3138 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3139 /* furthermore, we scale the results by 2**PASS1_BITS. */
3140 /* We scale the results further by 2 as part of output adaption */
3141 /* scaling for different DCT size. */
3142 /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
3143
3144 dataptr = data;
3145 for (ctr = 0; ctr < 3; ctr++) {
3146 elemptr = sample_data[ctr] + start_col;
3147
3148 /* Even part */
3149
3150 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
3151 tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
3152 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
3153
3154 tmp10 = tmp0 + tmp2;
3155 tmp12 = tmp0 - tmp2;
3156
3157 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
3158 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
3159 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
3160
3161 /* Apply unsigned->signed conversion */
3162 dataptr[0] = (DCTELEM)
3163 ((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << (PASS1_BITS+1));
3164 dataptr[2] = (DCTELEM)
3165 DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
3166 CONST_BITS-PASS1_BITS-1);
3167 dataptr[4] = (DCTELEM)
3168 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
3169 CONST_BITS-PASS1_BITS-1);
3170
3171 /* Odd part */
3172
3173 tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
3174 CONST_BITS-PASS1_BITS-1);
3175
3176 dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << (PASS1_BITS+1)));
3177 dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << (PASS1_BITS+1));
3178 dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << (PASS1_BITS+1)));
3179
3180 dataptr += DCTSIZE; /* advance pointer to next row */
3181 }
3182
3183 /* Pass 2: process columns.
3184 * We remove the PASS1_BITS scaling, but leave the results scaled up
3185 * by an overall factor of 8.
3186 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
3187 * fold into the constant multipliers (other part was done in pass 1):
3188 * 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6) * 16/9.
3189 */
3190
3191 dataptr = data;
3192 for (ctr = 0; ctr < 6; ctr++) {
3193 /* Even part */
3194
3195 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*2];
3196 tmp1 = dataptr[DCTSIZE*1];
3197
3198 tmp2 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*2];
3199
3200 dataptr[DCTSIZE*0] = (DCTELEM)
3201 DESCALE(MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
3202 CONST_BITS+PASS1_BITS);
3203 dataptr[DCTSIZE*2] = (DCTELEM)
3204 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(1.257078722)), /* c2 */
3205 CONST_BITS+PASS1_BITS);
3206
3207 /* Odd part */
3208
3209 dataptr[DCTSIZE*1] = (DCTELEM)
3210 DESCALE(MULTIPLY(tmp2, FIX(2.177324216)), /* c1 */
3211 CONST_BITS+PASS1_BITS);
3212
3213 dataptr++; /* advance pointer to next column */
3214 }
3215 }
3216
3217
3218 /*
3219 * Perform the forward DCT on a 4x2 sample block.
3220 *
3221 * 4-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
3222 */
3223
3224 GLOBAL(void)
3225 jpeg_fdct_4x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3226 {
3227 INT32 tmp0, tmp1;
3228 INT32 tmp10, tmp11;
3229 DCTELEM *dataptr;
3230 JSAMPROW elemptr;
3231 int ctr;
3232 SHIFT_TEMPS
3233
3234 /* Pre-zero output coefficient block. */
3235 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3236
3237 /* Pass 1: process rows. */
3238 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3239 /* furthermore, we scale the results by 2**PASS1_BITS. */
3240 /* We must also scale the output by (8/4)*(8/2) = 2**3, which we add here. */
3241 /* 4-point FDCT kernel, */
3242 /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
3243
3244 dataptr = data;
3245 for (ctr = 0; ctr < 2; ctr++) {
3246 elemptr = sample_data[ctr] + start_col;
3247
3248 /* Even part */
3249
3250 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
3251 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
3252
3253 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
3254 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
3255
3256 /* Apply unsigned->signed conversion */
3257 dataptr[0] = (DCTELEM)
3258 ((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+3));
3259 dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+3));
3260
3261 /* Odd part */
3262
3263 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
3264 /* Add fudge factor here for final descale. */
3265 tmp0 += ONE << (CONST_BITS-PASS1_BITS-4);
3266
3267 dataptr[1] = (DCTELEM)
3268 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
3269 CONST_BITS-PASS1_BITS-3);
3270 dataptr[3] = (DCTELEM)
3271 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
3272 CONST_BITS-PASS1_BITS-3);
3273
3274 dataptr += DCTSIZE; /* advance pointer to next row */
3275 }
3276
3277 /* Pass 2: process columns.
3278 * We remove the PASS1_BITS scaling, but leave the results scaled up
3279 * by an overall factor of 8.
3280 */
3281
3282 dataptr = data;
3283 for (ctr = 0; ctr < 4; ctr++) {
3284 /* Even part */
3285
3286 /* Add fudge factor here for final descale. */
3287 tmp0 = dataptr[DCTSIZE*0] + (ONE << (PASS1_BITS-1));
3288 tmp1 = dataptr[DCTSIZE*1];
3289
3290 dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
3291
3292 /* Odd part */
3293
3294 dataptr[DCTSIZE*1] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
3295
3296 dataptr++; /* advance pointer to next column */
3297 }
3298 }
3299
3300
3301 /*
3302 * Perform the forward DCT on a 2x1 sample block.
3303 *
3304 * 2-point FDCT in pass 1 (rows), 1-point in pass 2 (columns).
3305 */
3306
3307 GLOBAL(void)
3308 jpeg_fdct_2x1 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3309 {
3310 INT32 tmp0, tmp1;
3311 JSAMPROW elemptr;
3312
3313 /* Pre-zero output coefficient block. */
3314 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3315
3316 elemptr = sample_data[0] + start_col;
3317
3318 tmp0 = GETJSAMPLE(elemptr[0]);
3319 tmp1 = GETJSAMPLE(elemptr[1]);
3320
3321 /* We leave the results scaled up by an overall factor of 8.
3322 * We must also scale the output by (8/2)*(8/1) = 2**5.
3323 */
3324
3325 /* Even part */
3326 /* Apply unsigned->signed conversion */
3327 data[0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
3328
3329 /* Odd part */
3330 data[1] = (DCTELEM) ((tmp0 - tmp1) << 5);
3331 }
3332
3333
3334 /*
3335 * Perform the forward DCT on an 8x16 sample block.
3336 *
3337 * 8-point FDCT in pass 1 (rows), 16-point in pass 2 (columns).
3338 */
3339
3340 GLOBAL(void)
3341 jpeg_fdct_8x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3342 {
3343 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
3344 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
3345 INT32 z1;
3346 DCTELEM workspace[DCTSIZE2];
3347 DCTELEM *dataptr;
3348 DCTELEM *wsptr;
3349 JSAMPROW elemptr;
3350 int ctr;
3351 SHIFT_TEMPS
3352
3353 /* Pass 1: process rows. */
3354 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3355 /* furthermore, we scale the results by 2**PASS1_BITS. */
3356
3357 dataptr = data;
3358 ctr = 0;
3359 for (;;) {
3360 elemptr = sample_data[ctr] + start_col;
3361
3362 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3363 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
3364 */
3365
3366 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
3367 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
3368 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
3369 tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
3370
3371 tmp10 = tmp0 + tmp3;
3372 tmp12 = tmp0 - tmp3;
3373 tmp11 = tmp1 + tmp2;
3374 tmp13 = tmp1 - tmp2;
3375
3376 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
3377 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
3378 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
3379 tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
3380
3381 /* Apply unsigned->signed conversion */
3382 dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
3383 dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
3384
3385 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
3386 dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
3387 CONST_BITS-PASS1_BITS);
3388 dataptr[6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
3389 CONST_BITS-PASS1_BITS);
3390
3391 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3392 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3393 * i0..i3 in the paper are tmp0..tmp3 here.
3394 */
3395
3396 tmp10 = tmp0 + tmp3;
3397 tmp11 = tmp1 + tmp2;
3398 tmp12 = tmp0 + tmp2;
3399 tmp13 = tmp1 + tmp3;
3400 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
3401
3402 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
3403 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
3404 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
3405 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
3406 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
3407 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
3408 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
3409 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
3410
3411 tmp12 += z1;
3412 tmp13 += z1;
3413
3414 dataptr[1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
3415 dataptr[3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
3416 dataptr[5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
3417 dataptr[7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
3418
3419 ctr++;
3420
3421 if (ctr != DCTSIZE) {
3422 if (ctr == DCTSIZE * 2)
3423 break; /* Done. */
3424 dataptr += DCTSIZE; /* advance pointer to next row */
3425 } else
3426 dataptr = workspace; /* switch pointer to extended workspace */
3427 }
3428
3429 /* Pass 2: process columns.
3430 * We remove the PASS1_BITS scaling, but leave the results scaled up
3431 * by an overall factor of 8.
3432 * We must also scale the output by 8/16 = 1/2.
3433 * 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
3434 */
3435
3436 dataptr = data;
3437 wsptr = workspace;
3438 for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
3439 /* Even part */
3440
3441 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*7];
3442 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*6];
3443 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*5];
3444 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*4];
3445 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*3];
3446 tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*2];
3447 tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*1];
3448 tmp7 = dataptr[DCTSIZE*7] + wsptr[DCTSIZE*0];
3449
3450 tmp10 = tmp0 + tmp7;
3451 tmp14 = tmp0 - tmp7;
3452 tmp11 = tmp1 + tmp6;
3453 tmp15 = tmp1 - tmp6;
3454 tmp12 = tmp2 + tmp5;
3455 tmp16 = tmp2 - tmp5;
3456 tmp13 = tmp3 + tmp4;
3457 tmp17 = tmp3 - tmp4;
3458
3459 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*7];
3460 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*6];
3461 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*5];
3462 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*4];
3463 tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*3];
3464 tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*2];
3465 tmp6 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*1];
3466 tmp7 = dataptr[DCTSIZE*7] - wsptr[DCTSIZE*0];
3467
3468 dataptr[DCTSIZE*0] = (DCTELEM)
3469 DESCALE(tmp10 + tmp11 + tmp12 + tmp13, PASS1_BITS+1);
3470 dataptr[DCTSIZE*4] = (DCTELEM)
3471 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
3472 MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
3473 CONST_BITS+PASS1_BITS+1);
3474
3475 tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
3476 MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
3477
3478 dataptr[DCTSIZE*2] = (DCTELEM)
3479 DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
3480 + MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
3481 CONST_BITS+PASS1_BITS+1);
3482 dataptr[DCTSIZE*6] = (DCTELEM)
3483 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
3484 - MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
3485 CONST_BITS+PASS1_BITS+1);
3486
3487 /* Odd part */
3488
3489 tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
3490 MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
3491 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
3492 MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
3493 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
3494 MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
3495 tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
3496 MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
3497 tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
3498 MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
3499 tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
3500 MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
3501 tmp10 = tmp11 + tmp12 + tmp13 -
3502 MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
3503 MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
3504 tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
3505 - MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
3506 tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
3507 + MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
3508 tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
3509 + MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
3510
3511 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS+1);
3512 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS+1);
3513 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS+1);
3514 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS+1);
3515
3516 dataptr++; /* advance pointer to next column */
3517 wsptr++; /* advance pointer to next column */
3518 }
3519 }
3520
3521
3522 /*
3523 * Perform the forward DCT on a 7x14 sample block.
3524 *
3525 * 7-point FDCT in pass 1 (rows), 14-point in pass 2 (columns).
3526 */
3527
3528 GLOBAL(void)
3529 jpeg_fdct_7x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3530 {
3531 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
3532 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
3533 INT32 z1, z2, z3;
3534 DCTELEM workspace[8*6];
3535 DCTELEM *dataptr;
3536 DCTELEM *wsptr;
3537 JSAMPROW elemptr;
3538 int ctr;
3539 SHIFT_TEMPS
3540
3541 /* Pre-zero output coefficient block. */
3542 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3543
3544 /* Pass 1: process rows. */
3545 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3546 /* furthermore, we scale the results by 2**PASS1_BITS. */
3547 /* 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14). */
3548
3549 dataptr = data;
3550 ctr = 0;
3551 for (;;) {
3552 elemptr = sample_data[ctr] + start_col;
3553
3554 /* Even part */
3555
3556 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[6]);
3557 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[5]);
3558 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[4]);
3559 tmp3 = GETJSAMPLE(elemptr[3]);
3560
3561 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[6]);
3562 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[5]);
3563 tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[4]);
3564
3565 z1 = tmp0 + tmp2;
3566 /* Apply unsigned->signed conversion */
3567 dataptr[0] = (DCTELEM)
3568 ((z1 + tmp1 + tmp3 - 7 * CENTERJSAMPLE) << PASS1_BITS);
3569 tmp3 += tmp3;
3570 z1 -= tmp3;
3571 z1 -= tmp3;
3572 z1 = MULTIPLY(z1, FIX(0.353553391)); /* (c2+c6-c4)/2 */
3573 z2 = MULTIPLY(tmp0 - tmp2, FIX(0.920609002)); /* (c2+c4-c6)/2 */
3574 z3 = MULTIPLY(tmp1 - tmp2, FIX(0.314692123)); /* c6 */
3575 dataptr[2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS-PASS1_BITS);
3576 z1 -= z2;
3577 z2 = MULTIPLY(tmp0 - tmp1, FIX(0.881747734)); /* c4 */
3578 dataptr[4] = (DCTELEM)
3579 DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.707106781)), /* c2+c6-c4 */
3580 CONST_BITS-PASS1_BITS);
3581 dataptr[6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS-PASS1_BITS);
3582
3583 /* Odd part */
3584
3585 tmp1 = MULTIPLY(tmp10 + tmp11, FIX(0.935414347)); /* (c3+c1-c5)/2 */
3586 tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.170262339)); /* (c3+c5-c1)/2 */
3587 tmp0 = tmp1 - tmp2;
3588 tmp1 += tmp2;
3589 tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.378756276)); /* -c1 */
3590 tmp1 += tmp2;
3591 tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.613604268)); /* c5 */
3592 tmp0 += tmp3;
3593 tmp2 += tmp3 + MULTIPLY(tmp12, FIX(1.870828693)); /* c3+c1-c5 */
3594
3595 dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-PASS1_BITS);
3596 dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-PASS1_BITS);
3597 dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-PASS1_BITS);
3598
3599 ctr++;
3600
3601 if (ctr != DCTSIZE) {
3602 if (ctr == 14)
3603 break; /* Done. */
3604 dataptr += DCTSIZE; /* advance pointer to next row */
3605 } else
3606 dataptr = workspace; /* switch pointer to extended workspace */
3607 }
3608
3609 /* Pass 2: process columns.
3610 * We remove the PASS1_BITS scaling, but leave the results scaled up
3611 * by an overall factor of 8.
3612 * We must also scale the output by (8/7)*(8/14) = 32/49, which we
3613 * fold into the constant multipliers:
3614 * 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28) * 32/49.
3615 */
3616
3617 dataptr = data;
3618 wsptr = workspace;
3619 for (ctr = 0; ctr < 7; ctr++) {
3620 /* Even part */
3621
3622 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*5];
3623 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*4];
3624 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*3];
3625 tmp13 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*2];
3626 tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*1];
3627 tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*0];
3628 tmp6 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
3629
3630 tmp10 = tmp0 + tmp6;
3631 tmp14 = tmp0 - tmp6;
3632 tmp11 = tmp1 + tmp5;
3633 tmp15 = tmp1 - tmp5;
3634 tmp12 = tmp2 + tmp4;
3635 tmp16 = tmp2 - tmp4;
3636
3637 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*5];
3638 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*4];
3639 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*3];
3640 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*2];
3641 tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*1];
3642 tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*0];
3643 tmp6 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
3644
3645 dataptr[DCTSIZE*0] = (DCTELEM)
3646 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12 + tmp13,
3647 FIX(0.653061224)), /* 32/49 */
3648 CONST_BITS+PASS1_BITS);
3649 tmp13 += tmp13;
3650 dataptr[DCTSIZE*4] = (DCTELEM)
3651 DESCALE(MULTIPLY(tmp10 - tmp13, FIX(0.832106052)) + /* c4 */
3652 MULTIPLY(tmp11 - tmp13, FIX(0.205513223)) - /* c12 */
3653 MULTIPLY(tmp12 - tmp13, FIX(0.575835255)), /* c8 */
3654 CONST_BITS+PASS1_BITS);
3655
3656 tmp10 = MULTIPLY(tmp14 + tmp15, FIX(0.722074570)); /* c6 */
3657
3658 dataptr[DCTSIZE*2] = (DCTELEM)
3659 DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.178337691)) /* c2-c6 */
3660 + MULTIPLY(tmp16, FIX(0.400721155)), /* c10 */
3661 CONST_BITS+PASS1_BITS);
3662 dataptr[DCTSIZE*6] = (DCTELEM)
3663 DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.122795725)) /* c6+c10 */
3664 - MULTIPLY(tmp16, FIX(0.900412262)), /* c2 */
3665 CONST_BITS+PASS1_BITS);
3666
3667 /* Odd part */
3668
3669 tmp10 = tmp1 + tmp2;
3670 tmp11 = tmp5 - tmp4;
3671 dataptr[DCTSIZE*7] = (DCTELEM)
3672 DESCALE(MULTIPLY(tmp0 - tmp10 + tmp3 - tmp11 - tmp6,
3673 FIX(0.653061224)), /* 32/49 */
3674 CONST_BITS+PASS1_BITS);
3675 tmp3 = MULTIPLY(tmp3 , FIX(0.653061224)); /* 32/49 */
3676 tmp10 = MULTIPLY(tmp10, - FIX(0.103406812)); /* -c13 */
3677 tmp11 = MULTIPLY(tmp11, FIX(0.917760839)); /* c1 */
3678 tmp10 += tmp11 - tmp3;
3679 tmp11 = MULTIPLY(tmp0 + tmp2, FIX(0.782007410)) + /* c5 */
3680 MULTIPLY(tmp4 + tmp6, FIX(0.491367823)); /* c9 */
3681 dataptr[DCTSIZE*5] = (DCTELEM)
3682 DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(1.550341076)) /* c3+c5-c13 */
3683 + MULTIPLY(tmp4, FIX(0.731428202)), /* c1+c11-c9 */
3684 CONST_BITS+PASS1_BITS);
3685 tmp12 = MULTIPLY(tmp0 + tmp1, FIX(0.871740478)) + /* c3 */
3686 MULTIPLY(tmp5 - tmp6, FIX(0.305035186)); /* c11 */
3687 dataptr[DCTSIZE*3] = (DCTELEM)
3688 DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.276965844)) /* c3-c9-c13 */
3689 - MULTIPLY(tmp5, FIX(2.004803435)), /* c1+c5+c11 */
3690 CONST_BITS+PASS1_BITS);
3691 dataptr[DCTSIZE*1] = (DCTELEM)
3692 DESCALE(tmp11 + tmp12 + tmp3
3693 - MULTIPLY(tmp0, FIX(0.735987049)) /* c3+c5-c1 */
3694 - MULTIPLY(tmp6, FIX(0.082925825)), /* c9-c11-c13 */
3695 CONST_BITS+PASS1_BITS);
3696
3697 dataptr++; /* advance pointer to next column */
3698 wsptr++; /* advance pointer to next column */
3699 }
3700 }
3701
3702
3703 /*
3704 * Perform the forward DCT on a 6x12 sample block.
3705 *
3706 * 6-point FDCT in pass 1 (rows), 12-point in pass 2 (columns).
3707 */
3708
3709 GLOBAL(void)
3710 jpeg_fdct_6x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3711 {
3712 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
3713 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
3714 DCTELEM workspace[8*4];
3715 DCTELEM *dataptr;
3716 DCTELEM *wsptr;
3717 JSAMPROW elemptr;
3718 int ctr;
3719 SHIFT_TEMPS
3720
3721 /* Pre-zero output coefficient block. */
3722 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3723
3724 /* Pass 1: process rows. */
3725 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3726 /* furthermore, we scale the results by 2**PASS1_BITS. */
3727 /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
3728
3729 dataptr = data;
3730 ctr = 0;
3731 for (;;) {
3732 elemptr = sample_data[ctr] + start_col;
3733
3734 /* Even part */
3735
3736 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
3737 tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
3738 tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
3739
3740 tmp10 = tmp0 + tmp2;
3741 tmp12 = tmp0 - tmp2;
3742
3743 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
3744 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
3745 tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
3746
3747 /* Apply unsigned->signed conversion */
3748 dataptr[0] = (DCTELEM)
3749 ((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << PASS1_BITS);
3750 dataptr[2] = (DCTELEM)
3751 DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
3752 CONST_BITS-PASS1_BITS);
3753 dataptr[4] = (DCTELEM)
3754 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
3755 CONST_BITS-PASS1_BITS);
3756
3757 /* Odd part */
3758
3759 tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
3760 CONST_BITS-PASS1_BITS);
3761
3762 dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << PASS1_BITS));
3763 dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << PASS1_BITS);
3764 dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << PASS1_BITS));
3765
3766 ctr++;
3767
3768 if (ctr != DCTSIZE) {
3769 if (ctr == 12)
3770 break; /* Done. */
3771 dataptr += DCTSIZE; /* advance pointer to next row */
3772 } else
3773 dataptr = workspace; /* switch pointer to extended workspace */
3774 }
3775
3776 /* Pass 2: process columns.
3777 * We remove the PASS1_BITS scaling, but leave the results scaled up
3778 * by an overall factor of 8.
3779 * We must also scale the output by (8/6)*(8/12) = 8/9, which we
3780 * fold into the constant multipliers:
3781 * 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24) * 8/9.
3782 */
3783
3784 dataptr = data;
3785 wsptr = workspace;
3786 for (ctr = 0; ctr < 6; ctr++) {
3787 /* Even part */
3788
3789 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*3];
3790 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*2];
3791 tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*1];
3792 tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*0];
3793 tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*7];
3794 tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*6];
3795
3796 tmp10 = tmp0 + tmp5;
3797 tmp13 = tmp0 - tmp5;
3798 tmp11 = tmp1 + tmp4;
3799 tmp14 = tmp1 - tmp4;
3800 tmp12 = tmp2 + tmp3;
3801 tmp15 = tmp2 - tmp3;
3802
3803 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*3];
3804 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*2];
3805 tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*1];
3806 tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*0];
3807 tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*7];
3808 tmp5 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*6];
3809
3810 dataptr[DCTSIZE*0] = (DCTELEM)
3811 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(0.888888889)), /* 8/9 */
3812 CONST_BITS+PASS1_BITS);
3813 dataptr[DCTSIZE*6] = (DCTELEM)
3814 DESCALE(MULTIPLY(tmp13 - tmp14 - tmp15, FIX(0.888888889)), /* 8/9 */
3815 CONST_BITS+PASS1_BITS);
3816 dataptr[DCTSIZE*4] = (DCTELEM)
3817 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.088662108)), /* c4 */
3818 CONST_BITS+PASS1_BITS);
3819 dataptr[DCTSIZE*2] = (DCTELEM)
3820 DESCALE(MULTIPLY(tmp14 - tmp15, FIX(0.888888889)) + /* 8/9 */
3821 MULTIPLY(tmp13 + tmp15, FIX(1.214244803)), /* c2 */
3822 CONST_BITS+PASS1_BITS);
3823
3824 /* Odd part */
3825
3826 tmp10 = MULTIPLY(tmp1 + tmp4, FIX(0.481063200)); /* c9 */
3827 tmp14 = tmp10 + MULTIPLY(tmp1, FIX(0.680326102)); /* c3-c9 */
3828 tmp15 = tmp10 - MULTIPLY(tmp4, FIX(1.642452502)); /* c3+c9 */
3829 tmp12 = MULTIPLY(tmp0 + tmp2, FIX(0.997307603)); /* c5 */
3830 tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.765261039)); /* c7 */
3831 tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.516244403)) /* c5+c7-c1 */
3832 + MULTIPLY(tmp5, FIX(0.164081699)); /* c11 */
3833 tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.164081699)); /* -c11 */
3834 tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.079550144)) /* c1+c5-c11 */
3835 + MULTIPLY(tmp5, FIX(0.765261039)); /* c7 */
3836 tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.645144899)) /* c1+c11-c7 */
3837 - MULTIPLY(tmp5, FIX(0.997307603)); /* c5 */
3838 tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.161389302)) /* c3 */
3839 - MULTIPLY(tmp2 + tmp5, FIX(0.481063200)); /* c9 */
3840
3841 dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS);
3842 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS);
3843 dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS);
3844 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS);
3845
3846 dataptr++; /* advance pointer to next column */
3847 wsptr++; /* advance pointer to next column */
3848 }
3849 }
3850
3851
3852 /*
3853 * Perform the forward DCT on a 5x10 sample block.
3854 *
3855 * 5-point FDCT in pass 1 (rows), 10-point in pass 2 (columns).
3856 */
3857
3858 GLOBAL(void)
3859 jpeg_fdct_5x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
3860 {
3861 INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
3862 INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
3863 DCTELEM workspace[8*2];
3864 DCTELEM *dataptr;
3865 DCTELEM *wsptr;
3866 JSAMPROW elemptr;
3867 int ctr;
3868 SHIFT_TEMPS
3869
3870 /* Pre-zero output coefficient block. */
3871 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
3872
3873 /* Pass 1: process rows. */
3874 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3875 /* furthermore, we scale the results by 2**PASS1_BITS. */
3876 /* 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10). */
3877
3878 dataptr = data;
3879 ctr = 0;
3880 for (;;) {
3881 elemptr = sample_data[ctr] + start_col;
3882
3883 /* Even part */
3884
3885 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[4]);
3886 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[3]);
3887 tmp2 = GETJSAMPLE(elemptr[2]);
3888
3889 tmp10 = tmp0 + tmp1;
3890 tmp11 = tmp0 - tmp1;
3891
3892 tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[4]);
3893 tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[3]);
3894
3895 /* Apply unsigned->signed conversion */
3896 dataptr[0] = (DCTELEM)
3897 ((tmp10 + tmp2 - 5 * CENTERJSAMPLE) << PASS1_BITS);
3898 tmp11 = MULTIPLY(tmp11, FIX(0.790569415)); /* (c2+c4)/2 */
3899 tmp10 -= tmp2 << 2;
3900 tmp10 = MULTIPLY(tmp10, FIX(0.353553391)); /* (c2-c4)/2 */
3901 dataptr[2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS-PASS1_BITS);
3902 dataptr[4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS-PASS1_BITS);
3903
3904 /* Odd part */
3905
3906 tmp10 = MULTIPLY(tmp0 + tmp1, FIX(0.831253876)); /* c3 */
3907
3908 dataptr[1] = (DCTELEM)
3909 DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.513743148)), /* c1-c3 */
3910 CONST_BITS-PASS1_BITS);
3911 dataptr[3] = (DCTELEM)
3912 DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.176250899)), /* c1+c3 */
3913 CONST_BITS-PASS1_BITS);
3914
3915 ctr++;
3916
3917 if (ctr != DCTSIZE) {
3918 if (ctr == 10)
3919 break; /* Done. */
3920 dataptr += DCTSIZE; /* advance pointer to next row */
3921 } else
3922 dataptr = workspace; /* switch pointer to extended workspace */
3923 }
3924
3925 /* Pass 2: process columns.
3926 * We remove the PASS1_BITS scaling, but leave the results scaled up
3927 * by an overall factor of 8.
3928 * We must also scale the output by (8/5)*(8/10) = 32/25, which we
3929 * fold into the constant multipliers:
3930 * 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20) * 32/25.
3931 */
3932
3933 dataptr = data;
3934 wsptr = workspace;
3935 for (ctr = 0; ctr < 5; ctr++) {
3936 /* Even part */
3937
3938 tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*1];
3939 tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*0];
3940 tmp12 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*7];
3941 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*6];
3942 tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
3943
3944 tmp10 = tmp0 + tmp4;
3945 tmp13 = tmp0 - tmp4;
3946 tmp11 = tmp1 + tmp3;
3947 tmp14 = tmp1 - tmp3;
3948
3949 tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*1];
3950 tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*0];
3951 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*7];
3952 tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*6];
3953 tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
3954
3955 dataptr[DCTSIZE*0] = (DCTELEM)
3956 DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(1.28)), /* 32/25 */
3957 CONST_BITS+PASS1_BITS);
3958 tmp12 += tmp12;
3959 dataptr[DCTSIZE*4] = (DCTELEM)
3960 DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.464477191)) - /* c4 */
3961 MULTIPLY(tmp11 - tmp12, FIX(0.559380511)), /* c8 */
3962 CONST_BITS+PASS1_BITS);
3963 tmp10 = MULTIPLY(tmp13 + tmp14, FIX(1.064004961)); /* c6 */
3964 dataptr[DCTSIZE*2] = (DCTELEM)
3965 DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.657591230)), /* c2-c6 */
3966 CONST_BITS+PASS1_BITS);
3967 dataptr[DCTSIZE*6] = (DCTELEM)
3968 DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.785601151)), /* c2+c6 */
3969 CONST_BITS+PASS1_BITS);
3970
3971 /* Odd part */
3972
3973 tmp10 = tmp0 + tmp4;
3974 tmp11 = tmp1 - tmp3;
3975 dataptr[DCTSIZE*5] = (DCTELEM)
3976 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp2, FIX(1.28)), /* 32/25 */
3977 CONST_BITS+PASS1_BITS);
3978 tmp2 = MULTIPLY(tmp2, FIX(1.28)); /* 32/25 */
3979 dataptr[DCTSIZE*1] = (DCTELEM)
3980 DESCALE(MULTIPLY(tmp0, FIX(1.787906876)) + /* c1 */
3981 MULTIPLY(tmp1, FIX(1.612894094)) + tmp2 + /* c3 */
3982 MULTIPLY(tmp3, FIX(0.821810588)) + /* c7 */
3983 MULTIPLY(tmp4, FIX(0.283176630)), /* c9 */
3984 CONST_BITS+PASS1_BITS);
3985 tmp12 = MULTIPLY(tmp0 - tmp4, FIX(1.217352341)) - /* (c3+c7)/2 */
3986 MULTIPLY(tmp1 + tmp3, FIX(0.752365123)); /* (c1-c9)/2 */
3987 tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.395541753)) + /* (c3-c7)/2 */
3988 MULTIPLY(tmp11, FIX(0.64)) - tmp2; /* 16/25 */
3989 dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS+PASS1_BITS);
3990 dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS+PASS1_BITS);
3991
3992 dataptr++; /* advance pointer to next column */
3993 wsptr++; /* advance pointer to next column */
3994 }
3995 }
3996
3997
3998 /*
3999 * Perform the forward DCT on a 4x8 sample block.
4000 *
4001 * 4-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
4002 */
4003
4004 GLOBAL(void)
4005 jpeg_fdct_4x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
4006 {
4007 INT32 tmp0, tmp1, tmp2, tmp3;
4008 INT32 tmp10, tmp11, tmp12, tmp13;
4009 INT32 z1;
4010 DCTELEM *dataptr;
4011 JSAMPROW elemptr;
4012 int ctr;
4013 SHIFT_TEMPS
4014
4015 /* Pre-zero output coefficient block. */
4016 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
4017
4018 /* Pass 1: process rows. */
4019 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
4020 /* furthermore, we scale the results by 2**PASS1_BITS. */
4021 /* We must also scale the output by 8/4 = 2, which we add here. */
4022 /* 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16). */
4023
4024 dataptr = data;
4025 for (ctr = 0; ctr < DCTSIZE; ctr++) {
4026 elemptr = sample_data[ctr] + start_col;
4027
4028 /* Even part */
4029
4030 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
4031 tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
4032
4033 tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
4034 tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
4035
4036 /* Apply unsigned->signed conversion */
4037 dataptr[0] = (DCTELEM)
4038 ((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+1));
4039 dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+1));
4040
4041 /* Odd part */
4042
4043 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
4044 /* Add fudge factor here for final descale. */
4045 tmp0 += ONE << (CONST_BITS-PASS1_BITS-2);
4046
4047 dataptr[1] = (DCTELEM)
4048 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
4049 CONST_BITS-PASS1_BITS-1);
4050 dataptr[3] = (DCTELEM)
4051 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
4052 CONST_BITS-PASS1_BITS-1);
4053
4054 dataptr += DCTSIZE; /* advance pointer to next row */
4055 }
4056
4057 /* Pass 2: process columns.
4058 * We remove the PASS1_BITS scaling, but leave the results scaled up
4059 * by an overall factor of 8.
4060 */
4061
4062 dataptr = data;
4063 for (ctr = 0; ctr < 4; ctr++) {
4064 /* Even part per LL&M figure 1 --- note that published figure is faulty;
4065 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
4066 */
4067
4068 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
4069 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
4070 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
4071 tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
4072
4073 /* Add fudge factor here for final descale. */
4074 tmp10 = tmp0 + tmp3 + (ONE << (PASS1_BITS-1));
4075 tmp12 = tmp0 - tmp3;
4076 tmp11 = tmp1 + tmp2;
4077 tmp13 = tmp1 - tmp2;
4078
4079 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
4080 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
4081 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
4082 tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
4083
4084 dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
4085 dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
4086
4087 z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
4088 /* Add fudge factor here for final descale. */
4089 z1 += ONE << (CONST_BITS+PASS1_BITS-1);
4090 dataptr[DCTSIZE*2] = (DCTELEM)
4091 RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
4092 dataptr[DCTSIZE*6] = (DCTELEM)
4093 RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
4094
4095 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
4096 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
4097 * i0..i3 in the paper are tmp0..tmp3 here.
4098 */
4099
4100 tmp10 = tmp0 + tmp3;
4101 tmp11 = tmp1 + tmp2;
4102 tmp12 = tmp0 + tmp2;
4103 tmp13 = tmp1 + tmp3;
4104 z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
4105 /* Add fudge factor here for final descale. */
4106 z1 += ONE << (CONST_BITS+PASS1_BITS-1);
4107
4108 tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
4109 tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
4110 tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
4111 tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
4112 tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
4113 tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
4114 tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
4115 tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
4116
4117 tmp12 += z1;
4118 tmp13 += z1;
4119
4120 dataptr[DCTSIZE*1] = (DCTELEM)
4121 RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
4122 dataptr[DCTSIZE*3] = (DCTELEM)
4123 RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
4124 dataptr[DCTSIZE*5] = (DCTELEM)
4125 RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
4126 dataptr[DCTSIZE*7] = (DCTELEM)
4127 RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
4128
4129 dataptr++; /* advance pointer to next column */
4130 }
4131 }
4132
4133
4134 /*
4135 * Perform the forward DCT on a 3x6 sample block.
4136 *
4137 * 3-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
4138 */
4139
4140 GLOBAL(void)
4141 jpeg_fdct_3x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
4142 {
4143 INT32 tmp0, tmp1, tmp2;
4144 INT32 tmp10, tmp11, tmp12;
4145 DCTELEM *dataptr;
4146 JSAMPROW elemptr;
4147 int ctr;
4148 SHIFT_TEMPS
4149
4150 /* Pre-zero output coefficient block. */
4151 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
4152
4153 /* Pass 1: process rows. */
4154 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
4155 /* furthermore, we scale the results by 2**PASS1_BITS. */
4156 /* We scale the results further by 2 as part of output adaption */
4157 /* scaling for different DCT size. */
4158 /* 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6). */
4159
4160 dataptr = data;
4161 for (ctr = 0; ctr < 6; ctr++) {
4162 elemptr = sample_data[ctr] + start_col;
4163
4164 /* Even part */
4165
4166 tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[2]);
4167 tmp1 = GETJSAMPLE(elemptr[1]);
4168
4169 tmp2 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[2]);
4170
4171 /* Apply unsigned->signed conversion */
4172 dataptr[0] = (DCTELEM)
4173 ((tmp0 + tmp1 - 3 * CENTERJSAMPLE) << (PASS1_BITS+1));
4174 dataptr[2] = (DCTELEM)
4175 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(0.707106781)), /* c2 */
4176 CONST_BITS-PASS1_BITS-1);
4177
4178 /* Odd part */
4179
4180 dataptr[1] = (DCTELEM)
4181 DESCALE(MULTIPLY(tmp2, FIX(1.224744871)), /* c1 */
4182 CONST_BITS-PASS1_BITS-1);
4183
4184 dataptr += DCTSIZE; /* advance pointer to next row */
4185 }
4186
4187 /* Pass 2: process columns.
4188 * We remove the PASS1_BITS scaling, but leave the results scaled up
4189 * by an overall factor of 8.
4190 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
4191 * fold into the constant multipliers (other part was done in pass 1):
4192 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
4193 */
4194
4195 dataptr = data;
4196 for (ctr = 0; ctr < 3; ctr++) {
4197 /* Even part */
4198
4199 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
4200 tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
4201 tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
4202
4203 tmp10 = tmp0 + tmp2;
4204 tmp12 = tmp0 - tmp2;
4205
4206 tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
4207 tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
4208 tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
4209
4210 dataptr[DCTSIZE*0] = (DCTELEM)
4211 DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
4212 CONST_BITS+PASS1_BITS);
4213 dataptr[DCTSIZE*2] = (DCTELEM)
4214 DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
4215 CONST_BITS+PASS1_BITS);
4216 dataptr[DCTSIZE*4] = (DCTELEM)
4217 DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
4218 CONST_BITS+PASS1_BITS);
4219
4220 /* Odd part */
4221
4222 tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
4223
4224 dataptr[DCTSIZE*1] = (DCTELEM)
4225 DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
4226 CONST_BITS+PASS1_BITS);
4227 dataptr[DCTSIZE*3] = (DCTELEM)
4228 DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
4229 CONST_BITS+PASS1_BITS);
4230 dataptr[DCTSIZE*5] = (DCTELEM)
4231 DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
4232 CONST_BITS+PASS1_BITS);
4233
4234 dataptr++; /* advance pointer to next column */
4235 }
4236 }
4237
4238
4239 /*
4240 * Perform the forward DCT on a 2x4 sample block.
4241 *
4242 * 2-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
4243 */
4244
4245 GLOBAL(void)
4246 jpeg_fdct_2x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
4247 {
4248 INT32 tmp0, tmp1;
4249 INT32 tmp10, tmp11;
4250 DCTELEM *dataptr;
4251 JSAMPROW elemptr;
4252 int ctr;
4253 SHIFT_TEMPS
4254
4255 /* Pre-zero output coefficient block. */
4256 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
4257
4258 /* Pass 1: process rows. */
4259 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
4260 /* We must also scale the output by (8/2)*(8/4) = 2**3, which we add here. */
4261
4262 dataptr = data;
4263 for (ctr = 0; ctr < 4; ctr++) {
4264 elemptr = sample_data[ctr] + start_col;
4265
4266 /* Even part */
4267
4268 tmp0 = GETJSAMPLE(elemptr[0]);
4269 tmp1 = GETJSAMPLE(elemptr[1]);
4270
4271 /* Apply unsigned->signed conversion */
4272 dataptr[0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 3);
4273
4274 /* Odd part */
4275
4276 dataptr[1] = (DCTELEM) ((tmp0 - tmp1) << 3);
4277
4278 dataptr += DCTSIZE; /* advance pointer to next row */
4279 }
4280
4281 /* Pass 2: process columns.
4282 * We leave the results scaled up by an overall factor of 8.
4283 * 4-point FDCT kernel,
4284 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
4285 */
4286
4287 dataptr = data;
4288 for (ctr = 0; ctr < 2; ctr++) {
4289 /* Even part */
4290
4291 tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3];
4292 tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
4293
4294 tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
4295 tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
4296
4297 dataptr[DCTSIZE*0] = (DCTELEM) (tmp0 + tmp1);
4298 dataptr[DCTSIZE*2] = (DCTELEM) (tmp0 - tmp1);
4299
4300 /* Odd part */
4301
4302 tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
4303 /* Add fudge factor here for final descale. */
4304 tmp0 += ONE << (CONST_BITS-1);
4305
4306 dataptr[DCTSIZE*1] = (DCTELEM)
4307 RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
4308 CONST_BITS);
4309 dataptr[DCTSIZE*3] = (DCTELEM)
4310 RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
4311 CONST_BITS);
4312
4313 dataptr++; /* advance pointer to next column */
4314 }
4315 }
4316
4317
4318 /*
4319 * Perform the forward DCT on a 1x2 sample block.
4320 *
4321 * 1-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
4322 */
4323
4324 GLOBAL(void)
4325 jpeg_fdct_1x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
4326 {
4327 INT32 tmp0, tmp1;
4328
4329 /* Pre-zero output coefficient block. */
4330 MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
4331
4332 tmp0 = GETJSAMPLE(sample_data[0][start_col]);
4333 tmp1 = GETJSAMPLE(sample_data[1][start_col]);
4334
4335 /* We leave the results scaled up by an overall factor of 8.
4336 * We must also scale the output by (8/1)*(8/2) = 2**5.
4337 */
4338
4339 /* Even part */
4340 /* Apply unsigned->signed conversion */
4341 data[DCTSIZE*0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
4342
4343 /* Odd part */
4344 data[DCTSIZE*1] = (DCTELEM) ((tmp0 - tmp1) << 5);
4345 }
4346
4347 #endif /* DCT_SCALING_SUPPORTED */
4348 #endif /* DCT_ISLOW_SUPPORTED */