ac3enc: Restructure DEBUG ifdefs to avoid unused function parameter warnings
[libav.git] / libavcodec / jrevdct.c
1 /*
2 * This file is part of the Independent JPEG Group's software.
3 *
4 * The authors make NO WARRANTY or representation, either express or implied,
5 * with respect to this software, its quality, accuracy, merchantability, or
6 * fitness for a particular purpose. This software is provided "AS IS", and
7 * you, its user, assume the entire risk as to its quality and accuracy.
8 *
9 * This software is copyright (C) 1991, 1992, Thomas G. Lane.
10 * All Rights Reserved except as specified below.
11 *
12 * Permission is hereby granted to use, copy, modify, and distribute this
13 * software (or portions thereof) for any purpose, without fee, subject to
14 * these conditions:
15 * (1) If any part of the source code for this software is distributed, then
16 * this README file must be included, with this copyright and no-warranty
17 * notice unaltered; and any additions, deletions, or changes to the original
18 * files must be clearly indicated in accompanying documentation.
19 * (2) If only executable code is distributed, then the accompanying
20 * documentation must state that "this software is based in part on the work
21 * of the Independent JPEG Group".
22 * (3) Permission for use of this software is granted only if the user accepts
23 * full responsibility for any undesirable consequences; the authors accept
24 * NO LIABILITY for damages of any kind.
25 *
26 * These conditions apply to any software derived from or based on the IJG
27 * code, not just to the unmodified library. If you use our work, you ought
28 * to acknowledge us.
29 *
30 * Permission is NOT granted for the use of any IJG author's name or company
31 * name in advertising or publicity relating to this software or products
32 * derived from it. This software may be referred to only as "the Independent
33 * JPEG Group's software".
34 *
35 * We specifically permit and encourage the use of this software as the basis
36 * of commercial products, provided that all warranty or liability claims are
37 * assumed by the product vendor.
38 *
39 * This file contains the basic inverse-DCT transformation subroutine.
40 *
41 * This implementation is based on an algorithm described in
42 * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
43 * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
44 * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
45 * The primary algorithm described there uses 11 multiplies and 29 adds.
46 * We use their alternate method with 12 multiplies and 32 adds.
47 * The advantage of this method is that no data path contains more than one
48 * multiplication; this allows a very simple and accurate implementation in
49 * scaled fixed-point arithmetic, with a minimal number of shifts.
50 *
51 * I've made lots of modifications to attempt to take advantage of the
52 * sparse nature of the DCT matrices we're getting. Although the logic
53 * is cumbersome, it's straightforward and the resulting code is much
54 * faster.
55 *
56 * A better way to do this would be to pass in the DCT block as a sparse
57 * matrix, perhaps with the difference cases encoded.
58 */
59
60 /**
61 * @file
62 * Independent JPEG Group's LLM idct.
63 */
64
65 #include "libavutil/common.h"
66
67 #include "dct.h"
68 #include "idctdsp.h"
69
70 #define EIGHT_BIT_SAMPLES
71
72 #define DCTSIZE 8
73 #define DCTSIZE2 64
74
75 #define GLOBAL
76
77 #define RIGHT_SHIFT(x, n) ((x) >> (n))
78
79 typedef int16_t DCTBLOCK[DCTSIZE2];
80
81 #define CONST_BITS 13
82
83 /*
84 * This routine is specialized to the case DCTSIZE = 8.
85 */
86
87 #if DCTSIZE != 8
88 Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
89 #endif
90
91
92 /*
93 * A 2-D IDCT can be done by 1-D IDCT on each row followed by 1-D IDCT
94 * on each column. Direct algorithms are also available, but they are
95 * much more complex and seem not to be any faster when reduced to code.
96 *
97 * The poop on this scaling stuff is as follows:
98 *
99 * Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
100 * larger than the true IDCT outputs. The final outputs are therefore
101 * a factor of N larger than desired; since N=8 this can be cured by
102 * a simple right shift at the end of the algorithm. The advantage of
103 * this arrangement is that we save two multiplications per 1-D IDCT,
104 * because the y0 and y4 inputs need not be divided by sqrt(N).
105 *
106 * We have to do addition and subtraction of the integer inputs, which
107 * is no problem, and multiplication by fractional constants, which is
108 * a problem to do in integer arithmetic. We multiply all the constants
109 * by CONST_SCALE and convert them to integer constants (thus retaining
110 * CONST_BITS bits of precision in the constants). After doing a
111 * multiplication we have to divide the product by CONST_SCALE, with proper
112 * rounding, to produce the correct output. This division can be done
113 * cheaply as a right shift of CONST_BITS bits. We postpone shifting
114 * as long as possible so that partial sums can be added together with
115 * full fractional precision.
116 *
117 * The outputs of the first pass are scaled up by PASS1_BITS bits so that
118 * they are represented to better-than-integral precision. These outputs
119 * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
120 * with the recommended scaling. (To scale up 12-bit sample data further, an
121 * intermediate int32 array would be needed.)
122 *
123 * To avoid overflow of the 32-bit intermediate results in pass 2, we must
124 * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
125 * shows that the values given below are the most effective.
126 */
127
128 #ifdef EIGHT_BIT_SAMPLES
129 #define PASS1_BITS 2
130 #else
131 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */
132 #endif
133
134 #define ONE ((int32_t) 1)
135
136 #define CONST_SCALE (ONE << CONST_BITS)
137
138 /* Convert a positive real constant to an integer scaled by CONST_SCALE.
139 * IMPORTANT: if your compiler doesn't do this arithmetic at compile time,
140 * you will pay a significant penalty in run time. In that case, figure
141 * the correct integer constant values and insert them by hand.
142 */
143
144 /* Actually FIX is no longer used, we precomputed them all */
145 #define FIX(x) ((int32_t) ((x) * CONST_SCALE + 0.5))
146
147 /* Descale and correctly round an int32_t value that's scaled by N bits.
148 * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
149 * the fudge factor is correct for either sign of X.
150 */
151
152 #define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
153
154 /* Multiply an int32_t variable by an int32_t constant to yield an int32_t result.
155 * For 8-bit samples with the recommended scaling, all the variable
156 * and constant values involved are no more than 16 bits wide, so a
157 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply;
158 * this provides a useful speedup on many machines.
159 * There is no way to specify a 16x16->32 multiply in portable C, but
160 * some C compilers will do the right thing if you provide the correct
161 * combination of casts.
162 * NB: for 12-bit samples, a full 32-bit multiplication will be needed.
163 */
164
165 #ifdef EIGHT_BIT_SAMPLES
166 #ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
167 #define MULTIPLY(var,const) (((int16_t) (var)) * ((int16_t) (const)))
168 #endif
169 #ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
170 #define MULTIPLY(var,const) (((int16_t) (var)) * ((int32_t) (const)))
171 #endif
172 #endif
173
174 #ifndef MULTIPLY /* default definition */
175 #define MULTIPLY(var,const) ((var) * (const))
176 #endif
177
178
179 /*
180 Unlike our decoder where we approximate the FIXes, we need to use exact
181 ones here or successive P-frames will drift too much with Reference frame coding
182 */
183 #define FIX_0_211164243 1730
184 #define FIX_0_275899380 2260
185 #define FIX_0_298631336 2446
186 #define FIX_0_390180644 3196
187 #define FIX_0_509795579 4176
188 #define FIX_0_541196100 4433
189 #define FIX_0_601344887 4926
190 #define FIX_0_765366865 6270
191 #define FIX_0_785694958 6436
192 #define FIX_0_899976223 7373
193 #define FIX_1_061594337 8697
194 #define FIX_1_111140466 9102
195 #define FIX_1_175875602 9633
196 #define FIX_1_306562965 10703
197 #define FIX_1_387039845 11363
198 #define FIX_1_451774981 11893
199 #define FIX_1_501321110 12299
200 #define FIX_1_662939225 13623
201 #define FIX_1_847759065 15137
202 #define FIX_1_961570560 16069
203 #define FIX_2_053119869 16819
204 #define FIX_2_172734803 17799
205 #define FIX_2_562915447 20995
206 #define FIX_3_072711026 25172
207
208 /*
209 * Perform the inverse DCT on one block of coefficients.
210 */
211
212 void ff_j_rev_dct(DCTBLOCK data)
213 {
214 int32_t tmp0, tmp1, tmp2, tmp3;
215 int32_t tmp10, tmp11, tmp12, tmp13;
216 int32_t z1, z2, z3, z4, z5;
217 int32_t d0, d1, d2, d3, d4, d5, d6, d7;
218 register int16_t *dataptr;
219 int rowctr;
220
221 /* Pass 1: process rows. */
222 /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
223 /* furthermore, we scale the results by 2**PASS1_BITS. */
224
225 dataptr = data;
226
227 for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
228 /* Due to quantization, we will usually find that many of the input
229 * coefficients are zero, especially the AC terms. We can exploit this
230 * by short-circuiting the IDCT calculation for any row in which all
231 * the AC terms are zero. In that case each output is equal to the
232 * DC coefficient (with scale factor as needed).
233 * With typical images and quantization tables, half or more of the
234 * row DCT calculations can be simplified this way.
235 */
236
237 register int *idataptr = (int*)dataptr;
238
239 /* WARNING: we do the same permutation as MMX idct to simplify the
240 video core */
241 d0 = dataptr[0];
242 d2 = dataptr[1];
243 d4 = dataptr[2];
244 d6 = dataptr[3];
245 d1 = dataptr[4];
246 d3 = dataptr[5];
247 d5 = dataptr[6];
248 d7 = dataptr[7];
249
250 if ((d1 | d2 | d3 | d4 | d5 | d6 | d7) == 0) {
251 /* AC terms all zero */
252 if (d0) {
253 /* Compute a 32 bit value to assign. */
254 int16_t dcval = (int16_t) (d0 * (1 << PASS1_BITS));
255 register int v = (dcval & 0xffff) | ((dcval * (1 << 16)) & 0xffff0000);
256
257 idataptr[0] = v;
258 idataptr[1] = v;
259 idataptr[2] = v;
260 idataptr[3] = v;
261 }
262
263 dataptr += DCTSIZE; /* advance pointer to next row */
264 continue;
265 }
266
267 /* Even part: reverse the even part of the forward DCT. */
268 /* The rotator is sqrt(2)*c(-6). */
269 {
270 if (d6) {
271 if (d2) {
272 /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
273 z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
274 tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
275 tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
276
277 tmp0 = (d0 + d4) * CONST_SCALE;
278 tmp1 = (d0 - d4) * CONST_SCALE;
279
280 tmp10 = tmp0 + tmp3;
281 tmp13 = tmp0 - tmp3;
282 tmp11 = tmp1 + tmp2;
283 tmp12 = tmp1 - tmp2;
284 } else {
285 /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
286 tmp2 = MULTIPLY(-d6, FIX_1_306562965);
287 tmp3 = MULTIPLY(d6, FIX_0_541196100);
288
289 tmp0 = (d0 + d4) * CONST_SCALE;
290 tmp1 = (d0 - d4) * CONST_SCALE;
291
292 tmp10 = tmp0 + tmp3;
293 tmp13 = tmp0 - tmp3;
294 tmp11 = tmp1 + tmp2;
295 tmp12 = tmp1 - tmp2;
296 }
297 } else {
298 if (d2) {
299 /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
300 tmp2 = MULTIPLY(d2, FIX_0_541196100);
301 tmp3 = MULTIPLY(d2, FIX_1_306562965);
302
303 tmp0 = (d0 + d4) * CONST_SCALE;
304 tmp1 = (d0 - d4) * CONST_SCALE;
305
306 tmp10 = tmp0 + tmp3;
307 tmp13 = tmp0 - tmp3;
308 tmp11 = tmp1 + tmp2;
309 tmp12 = tmp1 - tmp2;
310 } else {
311 /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
312 tmp10 = tmp13 = (d0 + d4) * CONST_SCALE;
313 tmp11 = tmp12 = (d0 - d4) * CONST_SCALE;
314 }
315 }
316
317 /* Odd part per figure 8; the matrix is unitary and hence its
318 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
319 */
320
321 if (d7) {
322 if (d5) {
323 if (d3) {
324 if (d1) {
325 /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
326 z1 = d7 + d1;
327 z2 = d5 + d3;
328 z3 = d7 + d3;
329 z4 = d5 + d1;
330 z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
331
332 tmp0 = MULTIPLY(d7, FIX_0_298631336);
333 tmp1 = MULTIPLY(d5, FIX_2_053119869);
334 tmp2 = MULTIPLY(d3, FIX_3_072711026);
335 tmp3 = MULTIPLY(d1, FIX_1_501321110);
336 z1 = MULTIPLY(-z1, FIX_0_899976223);
337 z2 = MULTIPLY(-z2, FIX_2_562915447);
338 z3 = MULTIPLY(-z3, FIX_1_961570560);
339 z4 = MULTIPLY(-z4, FIX_0_390180644);
340
341 z3 += z5;
342 z4 += z5;
343
344 tmp0 += z1 + z3;
345 tmp1 += z2 + z4;
346 tmp2 += z2 + z3;
347 tmp3 += z1 + z4;
348 } else {
349 /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
350 z2 = d5 + d3;
351 z3 = d7 + d3;
352 z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
353
354 tmp0 = MULTIPLY(d7, FIX_0_298631336);
355 tmp1 = MULTIPLY(d5, FIX_2_053119869);
356 tmp2 = MULTIPLY(d3, FIX_3_072711026);
357 z1 = MULTIPLY(-d7, FIX_0_899976223);
358 z2 = MULTIPLY(-z2, FIX_2_562915447);
359 z3 = MULTIPLY(-z3, FIX_1_961570560);
360 z4 = MULTIPLY(-d5, FIX_0_390180644);
361
362 z3 += z5;
363 z4 += z5;
364
365 tmp0 += z1 + z3;
366 tmp1 += z2 + z4;
367 tmp2 += z2 + z3;
368 tmp3 = z1 + z4;
369 }
370 } else {
371 if (d1) {
372 /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
373 z1 = d7 + d1;
374 z4 = d5 + d1;
375 z5 = MULTIPLY(d7 + z4, FIX_1_175875602);
376
377 tmp0 = MULTIPLY(d7, FIX_0_298631336);
378 tmp1 = MULTIPLY(d5, FIX_2_053119869);
379 tmp3 = MULTIPLY(d1, FIX_1_501321110);
380 z1 = MULTIPLY(-z1, FIX_0_899976223);
381 z2 = MULTIPLY(-d5, FIX_2_562915447);
382 z3 = MULTIPLY(-d7, FIX_1_961570560);
383 z4 = MULTIPLY(-z4, FIX_0_390180644);
384
385 z3 += z5;
386 z4 += z5;
387
388 tmp0 += z1 + z3;
389 tmp1 += z2 + z4;
390 tmp2 = z2 + z3;
391 tmp3 += z1 + z4;
392 } else {
393 /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
394 tmp0 = MULTIPLY(-d7, FIX_0_601344887);
395 z1 = MULTIPLY(-d7, FIX_0_899976223);
396 z3 = MULTIPLY(-d7, FIX_1_961570560);
397 tmp1 = MULTIPLY(-d5, FIX_0_509795579);
398 z2 = MULTIPLY(-d5, FIX_2_562915447);
399 z4 = MULTIPLY(-d5, FIX_0_390180644);
400 z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
401
402 z3 += z5;
403 z4 += z5;
404
405 tmp0 += z3;
406 tmp1 += z4;
407 tmp2 = z2 + z3;
408 tmp3 = z1 + z4;
409 }
410 }
411 } else {
412 if (d3) {
413 if (d1) {
414 /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
415 z1 = d7 + d1;
416 z3 = d7 + d3;
417 z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
418
419 tmp0 = MULTIPLY(d7, FIX_0_298631336);
420 tmp2 = MULTIPLY(d3, FIX_3_072711026);
421 tmp3 = MULTIPLY(d1, FIX_1_501321110);
422 z1 = MULTIPLY(-z1, FIX_0_899976223);
423 z2 = MULTIPLY(-d3, FIX_2_562915447);
424 z3 = MULTIPLY(-z3, FIX_1_961570560);
425 z4 = MULTIPLY(-d1, FIX_0_390180644);
426
427 z3 += z5;
428 z4 += z5;
429
430 tmp0 += z1 + z3;
431 tmp1 = z2 + z4;
432 tmp2 += z2 + z3;
433 tmp3 += z1 + z4;
434 } else {
435 /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
436 z3 = d7 + d3;
437
438 tmp0 = MULTIPLY(-d7, FIX_0_601344887);
439 z1 = MULTIPLY(-d7, FIX_0_899976223);
440 tmp2 = MULTIPLY(d3, FIX_0_509795579);
441 z2 = MULTIPLY(-d3, FIX_2_562915447);
442 z5 = MULTIPLY(z3, FIX_1_175875602);
443 z3 = MULTIPLY(-z3, FIX_0_785694958);
444
445 tmp0 += z3;
446 tmp1 = z2 + z5;
447 tmp2 += z3;
448 tmp3 = z1 + z5;
449 }
450 } else {
451 if (d1) {
452 /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
453 z1 = d7 + d1;
454 z5 = MULTIPLY(z1, FIX_1_175875602);
455
456 z1 = MULTIPLY(z1, FIX_0_275899380);
457 z3 = MULTIPLY(-d7, FIX_1_961570560);
458 tmp0 = MULTIPLY(-d7, FIX_1_662939225);
459 z4 = MULTIPLY(-d1, FIX_0_390180644);
460 tmp3 = MULTIPLY(d1, FIX_1_111140466);
461
462 tmp0 += z1;
463 tmp1 = z4 + z5;
464 tmp2 = z3 + z5;
465 tmp3 += z1;
466 } else {
467 /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
468 tmp0 = MULTIPLY(-d7, FIX_1_387039845);
469 tmp1 = MULTIPLY(d7, FIX_1_175875602);
470 tmp2 = MULTIPLY(-d7, FIX_0_785694958);
471 tmp3 = MULTIPLY(d7, FIX_0_275899380);
472 }
473 }
474 }
475 } else {
476 if (d5) {
477 if (d3) {
478 if (d1) {
479 /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
480 z2 = d5 + d3;
481 z4 = d5 + d1;
482 z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
483
484 tmp1 = MULTIPLY(d5, FIX_2_053119869);
485 tmp2 = MULTIPLY(d3, FIX_3_072711026);
486 tmp3 = MULTIPLY(d1, FIX_1_501321110);
487 z1 = MULTIPLY(-d1, FIX_0_899976223);
488 z2 = MULTIPLY(-z2, FIX_2_562915447);
489 z3 = MULTIPLY(-d3, FIX_1_961570560);
490 z4 = MULTIPLY(-z4, FIX_0_390180644);
491
492 z3 += z5;
493 z4 += z5;
494
495 tmp0 = z1 + z3;
496 tmp1 += z2 + z4;
497 tmp2 += z2 + z3;
498 tmp3 += z1 + z4;
499 } else {
500 /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
501 z2 = d5 + d3;
502
503 z5 = MULTIPLY(z2, FIX_1_175875602);
504 tmp1 = MULTIPLY(d5, FIX_1_662939225);
505 z4 = MULTIPLY(-d5, FIX_0_390180644);
506 z2 = MULTIPLY(-z2, FIX_1_387039845);
507 tmp2 = MULTIPLY(d3, FIX_1_111140466);
508 z3 = MULTIPLY(-d3, FIX_1_961570560);
509
510 tmp0 = z3 + z5;
511 tmp1 += z2;
512 tmp2 += z2;
513 tmp3 = z4 + z5;
514 }
515 } else {
516 if (d1) {
517 /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
518 z4 = d5 + d1;
519
520 z5 = MULTIPLY(z4, FIX_1_175875602);
521 z1 = MULTIPLY(-d1, FIX_0_899976223);
522 tmp3 = MULTIPLY(d1, FIX_0_601344887);
523 tmp1 = MULTIPLY(-d5, FIX_0_509795579);
524 z2 = MULTIPLY(-d5, FIX_2_562915447);
525 z4 = MULTIPLY(z4, FIX_0_785694958);
526
527 tmp0 = z1 + z5;
528 tmp1 += z4;
529 tmp2 = z2 + z5;
530 tmp3 += z4;
531 } else {
532 /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
533 tmp0 = MULTIPLY(d5, FIX_1_175875602);
534 tmp1 = MULTIPLY(d5, FIX_0_275899380);
535 tmp2 = MULTIPLY(-d5, FIX_1_387039845);
536 tmp3 = MULTIPLY(d5, FIX_0_785694958);
537 }
538 }
539 } else {
540 if (d3) {
541 if (d1) {
542 /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
543 z5 = d1 + d3;
544 tmp3 = MULTIPLY(d1, FIX_0_211164243);
545 tmp2 = MULTIPLY(-d3, FIX_1_451774981);
546 z1 = MULTIPLY(d1, FIX_1_061594337);
547 z2 = MULTIPLY(-d3, FIX_2_172734803);
548 z4 = MULTIPLY(z5, FIX_0_785694958);
549 z5 = MULTIPLY(z5, FIX_1_175875602);
550
551 tmp0 = z1 - z4;
552 tmp1 = z2 + z4;
553 tmp2 += z5;
554 tmp3 += z5;
555 } else {
556 /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
557 tmp0 = MULTIPLY(-d3, FIX_0_785694958);
558 tmp1 = MULTIPLY(-d3, FIX_1_387039845);
559 tmp2 = MULTIPLY(-d3, FIX_0_275899380);
560 tmp3 = MULTIPLY(d3, FIX_1_175875602);
561 }
562 } else {
563 if (d1) {
564 /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
565 tmp0 = MULTIPLY(d1, FIX_0_275899380);
566 tmp1 = MULTIPLY(d1, FIX_0_785694958);
567 tmp2 = MULTIPLY(d1, FIX_1_175875602);
568 tmp3 = MULTIPLY(d1, FIX_1_387039845);
569 } else {
570 /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
571 tmp0 = tmp1 = tmp2 = tmp3 = 0;
572 }
573 }
574 }
575 }
576 }
577 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
578
579 dataptr[0] = (int16_t) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
580 dataptr[7] = (int16_t) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
581 dataptr[1] = (int16_t) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
582 dataptr[6] = (int16_t) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
583 dataptr[2] = (int16_t) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
584 dataptr[5] = (int16_t) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
585 dataptr[3] = (int16_t) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
586 dataptr[4] = (int16_t) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
587
588 dataptr += DCTSIZE; /* advance pointer to next row */
589 }
590
591 /* Pass 2: process columns. */
592 /* Note that we must descale the results by a factor of 8 == 2**3, */
593 /* and also undo the PASS1_BITS scaling. */
594
595 dataptr = data;
596 for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
597 /* Columns of zeroes can be exploited in the same way as we did with rows.
598 * However, the row calculation has created many nonzero AC terms, so the
599 * simplification applies less often (typically 5% to 10% of the time).
600 * On machines with very fast multiplication, it's possible that the
601 * test takes more time than it's worth. In that case this section
602 * may be commented out.
603 */
604
605 d0 = dataptr[DCTSIZE*0];
606 d1 = dataptr[DCTSIZE*1];
607 d2 = dataptr[DCTSIZE*2];
608 d3 = dataptr[DCTSIZE*3];
609 d4 = dataptr[DCTSIZE*4];
610 d5 = dataptr[DCTSIZE*5];
611 d6 = dataptr[DCTSIZE*6];
612 d7 = dataptr[DCTSIZE*7];
613
614 /* Even part: reverse the even part of the forward DCT. */
615 /* The rotator is sqrt(2)*c(-6). */
616 if (d6) {
617 if (d2) {
618 /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
619 z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
620 tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
621 tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
622
623 tmp0 = (d0 + d4) * CONST_SCALE;
624 tmp1 = (d0 - d4) * CONST_SCALE;
625
626 tmp10 = tmp0 + tmp3;
627 tmp13 = tmp0 - tmp3;
628 tmp11 = tmp1 + tmp2;
629 tmp12 = tmp1 - tmp2;
630 } else {
631 /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
632 tmp2 = MULTIPLY(-d6, FIX_1_306562965);
633 tmp3 = MULTIPLY(d6, FIX_0_541196100);
634
635 tmp0 = (d0 + d4) * CONST_SCALE;
636 tmp1 = (d0 - d4) * CONST_SCALE;
637
638 tmp10 = tmp0 + tmp3;
639 tmp13 = tmp0 - tmp3;
640 tmp11 = tmp1 + tmp2;
641 tmp12 = tmp1 - tmp2;
642 }
643 } else {
644 if (d2) {
645 /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
646 tmp2 = MULTIPLY(d2, FIX_0_541196100);
647 tmp3 = MULTIPLY(d2, FIX_1_306562965);
648
649 tmp0 = (d0 + d4) * CONST_SCALE;
650 tmp1 = (d0 - d4) * CONST_SCALE;
651
652 tmp10 = tmp0 + tmp3;
653 tmp13 = tmp0 - tmp3;
654 tmp11 = tmp1 + tmp2;
655 tmp12 = tmp1 - tmp2;
656 } else {
657 /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
658 tmp10 = tmp13 = (d0 + d4) * CONST_SCALE;
659 tmp11 = tmp12 = (d0 - d4) * CONST_SCALE;
660 }
661 }
662
663 /* Odd part per figure 8; the matrix is unitary and hence its
664 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
665 */
666 if (d7) {
667 if (d5) {
668 if (d3) {
669 if (d1) {
670 /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
671 z1 = d7 + d1;
672 z2 = d5 + d3;
673 z3 = d7 + d3;
674 z4 = d5 + d1;
675 z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
676
677 tmp0 = MULTIPLY(d7, FIX_0_298631336);
678 tmp1 = MULTIPLY(d5, FIX_2_053119869);
679 tmp2 = MULTIPLY(d3, FIX_3_072711026);
680 tmp3 = MULTIPLY(d1, FIX_1_501321110);
681 z1 = MULTIPLY(-z1, FIX_0_899976223);
682 z2 = MULTIPLY(-z2, FIX_2_562915447);
683 z3 = MULTIPLY(-z3, FIX_1_961570560);
684 z4 = MULTIPLY(-z4, FIX_0_390180644);
685
686 z3 += z5;
687 z4 += z5;
688
689 tmp0 += z1 + z3;
690 tmp1 += z2 + z4;
691 tmp2 += z2 + z3;
692 tmp3 += z1 + z4;
693 } else {
694 /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
695 z2 = d5 + d3;
696 z3 = d7 + d3;
697 z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
698
699 tmp0 = MULTIPLY(d7, FIX_0_298631336);
700 tmp1 = MULTIPLY(d5, FIX_2_053119869);
701 tmp2 = MULTIPLY(d3, FIX_3_072711026);
702 z1 = MULTIPLY(-d7, FIX_0_899976223);
703 z2 = MULTIPLY(-z2, FIX_2_562915447);
704 z3 = MULTIPLY(-z3, FIX_1_961570560);
705 z4 = MULTIPLY(-d5, FIX_0_390180644);
706
707 z3 += z5;
708 z4 += z5;
709
710 tmp0 += z1 + z3;
711 tmp1 += z2 + z4;
712 tmp2 += z2 + z3;
713 tmp3 = z1 + z4;
714 }
715 } else {
716 if (d1) {
717 /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
718 z1 = d7 + d1;
719 z3 = d7;
720 z4 = d5 + d1;
721 z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
722
723 tmp0 = MULTIPLY(d7, FIX_0_298631336);
724 tmp1 = MULTIPLY(d5, FIX_2_053119869);
725 tmp3 = MULTIPLY(d1, FIX_1_501321110);
726 z1 = MULTIPLY(-z1, FIX_0_899976223);
727 z2 = MULTIPLY(-d5, FIX_2_562915447);
728 z3 = MULTIPLY(-d7, FIX_1_961570560);
729 z4 = MULTIPLY(-z4, FIX_0_390180644);
730
731 z3 += z5;
732 z4 += z5;
733
734 tmp0 += z1 + z3;
735 tmp1 += z2 + z4;
736 tmp2 = z2 + z3;
737 tmp3 += z1 + z4;
738 } else {
739 /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
740 tmp0 = MULTIPLY(-d7, FIX_0_601344887);
741 z1 = MULTIPLY(-d7, FIX_0_899976223);
742 z3 = MULTIPLY(-d7, FIX_1_961570560);
743 tmp1 = MULTIPLY(-d5, FIX_0_509795579);
744 z2 = MULTIPLY(-d5, FIX_2_562915447);
745 z4 = MULTIPLY(-d5, FIX_0_390180644);
746 z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
747
748 z3 += z5;
749 z4 += z5;
750
751 tmp0 += z3;
752 tmp1 += z4;
753 tmp2 = z2 + z3;
754 tmp3 = z1 + z4;
755 }
756 }
757 } else {
758 if (d3) {
759 if (d1) {
760 /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
761 z1 = d7 + d1;
762 z3 = d7 + d3;
763 z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
764
765 tmp0 = MULTIPLY(d7, FIX_0_298631336);
766 tmp2 = MULTIPLY(d3, FIX_3_072711026);
767 tmp3 = MULTIPLY(d1, FIX_1_501321110);
768 z1 = MULTIPLY(-z1, FIX_0_899976223);
769 z2 = MULTIPLY(-d3, FIX_2_562915447);
770 z3 = MULTIPLY(-z3, FIX_1_961570560);
771 z4 = MULTIPLY(-d1, FIX_0_390180644);
772
773 z3 += z5;
774 z4 += z5;
775
776 tmp0 += z1 + z3;
777 tmp1 = z2 + z4;
778 tmp2 += z2 + z3;
779 tmp3 += z1 + z4;
780 } else {
781 /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
782 z3 = d7 + d3;
783
784 tmp0 = MULTIPLY(-d7, FIX_0_601344887);
785 z1 = MULTIPLY(-d7, FIX_0_899976223);
786 tmp2 = MULTIPLY(d3, FIX_0_509795579);
787 z2 = MULTIPLY(-d3, FIX_2_562915447);
788 z5 = MULTIPLY(z3, FIX_1_175875602);
789 z3 = MULTIPLY(-z3, FIX_0_785694958);
790
791 tmp0 += z3;
792 tmp1 = z2 + z5;
793 tmp2 += z3;
794 tmp3 = z1 + z5;
795 }
796 } else {
797 if (d1) {
798 /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
799 z1 = d7 + d1;
800 z5 = MULTIPLY(z1, FIX_1_175875602);
801
802 z1 = MULTIPLY(z1, FIX_0_275899380);
803 z3 = MULTIPLY(-d7, FIX_1_961570560);
804 tmp0 = MULTIPLY(-d7, FIX_1_662939225);
805 z4 = MULTIPLY(-d1, FIX_0_390180644);
806 tmp3 = MULTIPLY(d1, FIX_1_111140466);
807
808 tmp0 += z1;
809 tmp1 = z4 + z5;
810 tmp2 = z3 + z5;
811 tmp3 += z1;
812 } else {
813 /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
814 tmp0 = MULTIPLY(-d7, FIX_1_387039845);
815 tmp1 = MULTIPLY(d7, FIX_1_175875602);
816 tmp2 = MULTIPLY(-d7, FIX_0_785694958);
817 tmp3 = MULTIPLY(d7, FIX_0_275899380);
818 }
819 }
820 }
821 } else {
822 if (d5) {
823 if (d3) {
824 if (d1) {
825 /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
826 z2 = d5 + d3;
827 z4 = d5 + d1;
828 z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
829
830 tmp1 = MULTIPLY(d5, FIX_2_053119869);
831 tmp2 = MULTIPLY(d3, FIX_3_072711026);
832 tmp3 = MULTIPLY(d1, FIX_1_501321110);
833 z1 = MULTIPLY(-d1, FIX_0_899976223);
834 z2 = MULTIPLY(-z2, FIX_2_562915447);
835 z3 = MULTIPLY(-d3, FIX_1_961570560);
836 z4 = MULTIPLY(-z4, FIX_0_390180644);
837
838 z3 += z5;
839 z4 += z5;
840
841 tmp0 = z1 + z3;
842 tmp1 += z2 + z4;
843 tmp2 += z2 + z3;
844 tmp3 += z1 + z4;
845 } else {
846 /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
847 z2 = d5 + d3;
848
849 z5 = MULTIPLY(z2, FIX_1_175875602);
850 tmp1 = MULTIPLY(d5, FIX_1_662939225);
851 z4 = MULTIPLY(-d5, FIX_0_390180644);
852 z2 = MULTIPLY(-z2, FIX_1_387039845);
853 tmp2 = MULTIPLY(d3, FIX_1_111140466);
854 z3 = MULTIPLY(-d3, FIX_1_961570560);
855
856 tmp0 = z3 + z5;
857 tmp1 += z2;
858 tmp2 += z2;
859 tmp3 = z4 + z5;
860 }
861 } else {
862 if (d1) {
863 /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
864 z4 = d5 + d1;
865
866 z5 = MULTIPLY(z4, FIX_1_175875602);
867 z1 = MULTIPLY(-d1, FIX_0_899976223);
868 tmp3 = MULTIPLY(d1, FIX_0_601344887);
869 tmp1 = MULTIPLY(-d5, FIX_0_509795579);
870 z2 = MULTIPLY(-d5, FIX_2_562915447);
871 z4 = MULTIPLY(z4, FIX_0_785694958);
872
873 tmp0 = z1 + z5;
874 tmp1 += z4;
875 tmp2 = z2 + z5;
876 tmp3 += z4;
877 } else {
878 /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
879 tmp0 = MULTIPLY(d5, FIX_1_175875602);
880 tmp1 = MULTIPLY(d5, FIX_0_275899380);
881 tmp2 = MULTIPLY(-d5, FIX_1_387039845);
882 tmp3 = MULTIPLY(d5, FIX_0_785694958);
883 }
884 }
885 } else {
886 if (d3) {
887 if (d1) {
888 /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
889 z5 = d1 + d3;
890 tmp3 = MULTIPLY(d1, FIX_0_211164243);
891 tmp2 = MULTIPLY(-d3, FIX_1_451774981);
892 z1 = MULTIPLY(d1, FIX_1_061594337);
893 z2 = MULTIPLY(-d3, FIX_2_172734803);
894 z4 = MULTIPLY(z5, FIX_0_785694958);
895 z5 = MULTIPLY(z5, FIX_1_175875602);
896
897 tmp0 = z1 - z4;
898 tmp1 = z2 + z4;
899 tmp2 += z5;
900 tmp3 += z5;
901 } else {
902 /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
903 tmp0 = MULTIPLY(-d3, FIX_0_785694958);
904 tmp1 = MULTIPLY(-d3, FIX_1_387039845);
905 tmp2 = MULTIPLY(-d3, FIX_0_275899380);
906 tmp3 = MULTIPLY(d3, FIX_1_175875602);
907 }
908 } else {
909 if (d1) {
910 /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
911 tmp0 = MULTIPLY(d1, FIX_0_275899380);
912 tmp1 = MULTIPLY(d1, FIX_0_785694958);
913 tmp2 = MULTIPLY(d1, FIX_1_175875602);
914 tmp3 = MULTIPLY(d1, FIX_1_387039845);
915 } else {
916 /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
917 tmp0 = tmp1 = tmp2 = tmp3 = 0;
918 }
919 }
920 }
921 }
922
923 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
924
925 dataptr[DCTSIZE*0] = (int16_t) DESCALE(tmp10 + tmp3,
926 CONST_BITS+PASS1_BITS+3);
927 dataptr[DCTSIZE*7] = (int16_t) DESCALE(tmp10 - tmp3,
928 CONST_BITS+PASS1_BITS+3);
929 dataptr[DCTSIZE*1] = (int16_t) DESCALE(tmp11 + tmp2,
930 CONST_BITS+PASS1_BITS+3);
931 dataptr[DCTSIZE*6] = (int16_t) DESCALE(tmp11 - tmp2,
932 CONST_BITS+PASS1_BITS+3);
933 dataptr[DCTSIZE*2] = (int16_t) DESCALE(tmp12 + tmp1,
934 CONST_BITS+PASS1_BITS+3);
935 dataptr[DCTSIZE*5] = (int16_t) DESCALE(tmp12 - tmp1,
936 CONST_BITS+PASS1_BITS+3);
937 dataptr[DCTSIZE*3] = (int16_t) DESCALE(tmp13 + tmp0,
938 CONST_BITS+PASS1_BITS+3);
939 dataptr[DCTSIZE*4] = (int16_t) DESCALE(tmp13 - tmp0,
940 CONST_BITS+PASS1_BITS+3);
941
942 dataptr++; /* advance pointer to next column */
943 }
944 }
945
946 void ff_jref_idct_put(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
947 {
948 ff_j_rev_dct(block);
949 ff_put_pixels_clamped(block, dest, line_size);
950 }
951
952 void ff_jref_idct_add(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
953 {
954 ff_j_rev_dct(block);
955 ff_add_pixels_clamped(block, dest, line_size);
956 }