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/*
2
 * jrevdct.c
3
 *
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 * Copyright (C) 1991, 1992, Thomas G. Lane.
5
 * This file is part of the Independent JPEG Group's software.
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 * For conditions of distribution and use, see the accompanying README file.
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 *
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 * This file contains the basic inverse-DCT transformation subroutine.
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 *
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 * This implementation is based on an algorithm described in
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 *   C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
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 *   Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
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 *   Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
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 * The primary algorithm described there uses 11 multiplies and 29 adds.
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 * We use their alternate method with 12 multiplies and 32 adds.
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 * The advantage of this method is that no data path contains more than one
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 * multiplication; this allows a very simple and accurate implementation in
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 * scaled fixed-point arithmetic, with a minimal number of shifts.
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 * 
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 * I've made lots of modifications to attempt to take advantage of the
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 * sparse nature of the DCT matrices we're getting.  Although the logic
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 * is cumbersome, it's straightforward and the resulting code is much
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 * faster.
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 *
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 * A better way to do this would be to pass in the DCT block as a sparse
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 * matrix, perhaps with the difference cases encoded.
27
 */
28
 
29
/**
30
 * @file jrevdct.c
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 * Independent JPEG Group's LLM idct.
32
 */
33
 
34
#include "common.h"
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#include "dsputil.h"
36

    
37
#define EIGHT_BIT_SAMPLES
38

    
39
#define DCTSIZE 8
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#define DCTSIZE2 64
41

    
42
#define GLOBAL
43

    
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#define RIGHT_SHIFT(x, n) ((x) >> (n))
45

    
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typedef DCTELEM DCTBLOCK[DCTSIZE2];
47

    
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#define CONST_BITS 13
49

    
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/*
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 * This routine is specialized to the case DCTSIZE = 8.
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 */
53

    
54
#if DCTSIZE != 8
55
  Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
56
#endif
57

    
58

    
59
/*
60
 * A 2-D IDCT can be done by 1-D IDCT on each row followed by 1-D IDCT
61
 * on each column.  Direct algorithms are also available, but they are
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 * much more complex and seem not to be any faster when reduced to code.
63
 *
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 * The poop on this scaling stuff is as follows:
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 *
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 * Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
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 * larger than the true IDCT outputs.  The final outputs are therefore
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 * a factor of N larger than desired; since N=8 this can be cured by
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 * a simple right shift at the end of the algorithm.  The advantage of
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 * this arrangement is that we save two multiplications per 1-D IDCT,
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 * because the y0 and y4 inputs need not be divided by sqrt(N).
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 *
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 * We have to do addition and subtraction of the integer inputs, which
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 * is no problem, and multiplication by fractional constants, which is
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 * a problem to do in integer arithmetic.  We multiply all the constants
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 * by CONST_SCALE and convert them to integer constants (thus retaining
77
 * CONST_BITS bits of precision in the constants).  After doing a
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 * 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.  (To scale up 12-bit sample data further, an
88
 * intermediate int32 array would be needed.)
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
#ifdef EIGHT_BIT_SAMPLES
96
#define PASS1_BITS  2
97
#else
98
#define PASS1_BITS  1                /* lose a little precision to avoid overflow */
99
#endif
100

    
101
#define ONE        ((int32_t) 1)
102

    
103
#define CONST_SCALE (ONE << CONST_BITS)
104

    
105
/* Convert a positive real constant to an integer scaled by CONST_SCALE.
106
 * IMPORTANT: if your compiler doesn't do this arithmetic at compile time,
107
 * you will pay a significant penalty in run time.  In that case, figure
108
 * the correct integer constant values and insert them by hand.
109
 */
110

    
111
/* Actually FIX is no longer used, we precomputed them all */
112
#define FIX(x)        ((int32_t) ((x) * CONST_SCALE + 0.5)) 
113

    
114
/* Descale and correctly round an int32_t value that's scaled by N bits.
115
 * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
116
 * the fudge factor is correct for either sign of X.
117
 */
118

    
119
#define DESCALE(x,n)  RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
120

    
121
/* Multiply an int32_t variable by an int32_t constant to yield an int32_t result.
122
 * For 8-bit samples with the recommended scaling, all the variable
123
 * and constant values involved are no more than 16 bits wide, so a
124
 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply;
125
 * this provides a useful speedup on many machines.
126
 * There is no way to specify a 16x16->32 multiply in portable C, but
127
 * some C compilers will do the right thing if you provide the correct
128
 * combination of casts.
129
 * NB: for 12-bit samples, a full 32-bit multiplication will be needed.
130
 */
131

    
132
#ifdef EIGHT_BIT_SAMPLES
133
#ifdef SHORTxSHORT_32                /* may work if 'int' is 32 bits */
134
#define MULTIPLY(var,const)  (((int16_t) (var)) * ((int16_t) (const)))
135
#endif
136
#ifdef SHORTxLCONST_32                /* known to work with Microsoft C 6.0 */
137
#define MULTIPLY(var,const)  (((int16_t) (var)) * ((int32_t) (const)))
138
#endif
139
#endif
140

    
141
#ifndef MULTIPLY                /* default definition */
142
#define MULTIPLY(var,const)  ((var) * (const))
143
#endif
144

    
145

    
146
/* 
147
  Unlike our decoder where we approximate the FIXes, we need to use exact
148
ones here or successive P-frames will drift too much with Reference frame coding 
149
*/
150
#define FIX_0_211164243 1730
151
#define FIX_0_275899380 2260
152
#define FIX_0_298631336 2446
153
#define FIX_0_390180644 3196
154
#define FIX_0_509795579 4176
155
#define FIX_0_541196100 4433
156
#define FIX_0_601344887 4926
157
#define FIX_0_765366865 6270
158
#define FIX_0_785694958 6436
159
#define FIX_0_899976223 7373
160
#define FIX_1_061594337 8697
161
#define FIX_1_111140466 9102
162
#define FIX_1_175875602 9633
163
#define FIX_1_306562965 10703
164
#define FIX_1_387039845 11363
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#define FIX_1_451774981 11893
166
#define FIX_1_501321110 12299
167
#define FIX_1_662939225 13623
168
#define FIX_1_847759065 15137
169
#define FIX_1_961570560 16069
170
#define FIX_2_053119869 16819
171
#define FIX_2_172734803 17799
172
#define FIX_2_562915447 20995
173
#define FIX_3_072711026 25172
174

    
175
/*
176
 * Perform the inverse DCT on one block of coefficients.
177
 */
178

    
179
void j_rev_dct(DCTBLOCK data)
180
{
181
  int32_t tmp0, tmp1, tmp2, tmp3;
182
  int32_t tmp10, tmp11, tmp12, tmp13;
183
  int32_t z1, z2, z3, z4, z5;
184
  int32_t d0, d1, d2, d3, d4, d5, d6, d7;
185
  register DCTELEM *dataptr;
186
  int rowctr;
187
   
188
  /* Pass 1: process rows. */
189
  /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
190
  /* furthermore, we scale the results by 2**PASS1_BITS. */
191

    
192
  dataptr = data;
193

    
194
  for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
195
    /* Due to quantization, we will usually find that many of the input
196
     * coefficients are zero, especially the AC terms.  We can exploit this
197
     * by short-circuiting the IDCT calculation for any row in which all
198
     * the AC terms are zero.  In that case each output is equal to the
199
     * DC coefficient (with scale factor as needed).
200
     * With typical images and quantization tables, half or more of the
201
     * row DCT calculations can be simplified this way.
202
     */
203

    
204
    register int *idataptr = (int*)dataptr;
205

    
206
    /* WARNING: we do the same permutation as MMX idct to simplify the
207
       video core */
208
    d0 = dataptr[0];
209
    d2 = dataptr[1];
210
    d4 = dataptr[2];
211
    d6 = dataptr[3];
212
    d1 = dataptr[4];
213
    d3 = dataptr[5];
214
    d5 = dataptr[6];
215
    d7 = dataptr[7];
216

    
217
    if ((d1 | d2 | d3 | d4 | d5 | d6 | d7) == 0) {
218
      /* AC terms all zero */
219
      if (d0) {
220
          /* Compute a 32 bit value to assign. */
221
          DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS);
222
          register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000);
223
          
224
          idataptr[0] = v;
225
          idataptr[1] = v;
226
          idataptr[2] = v;
227
          idataptr[3] = v;
228
      }
229
      
230
      dataptr += DCTSIZE;        /* advance pointer to next row */
231
      continue;
232
    }
233

    
234
    /* Even part: reverse the even part of the forward DCT. */
235
    /* The rotator is sqrt(2)*c(-6). */
236
{
237
    if (d6) {
238
        if (d4) {
239
            if (d2) {
240
                if (d0) {
241
                    /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
242
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
243
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
244
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
245

    
246
                    tmp0 = (d0 + d4) << CONST_BITS;
247
                    tmp1 = (d0 - d4) << CONST_BITS;
248

    
249
                    tmp10 = tmp0 + tmp3;
250
                    tmp13 = tmp0 - tmp3;
251
                    tmp11 = tmp1 + tmp2;
252
                    tmp12 = tmp1 - tmp2;
253
                } else {
254
                    /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */
255
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
256
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
257
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
258

    
259
                    tmp0 = d4 << CONST_BITS;
260

    
261
                    tmp10 = tmp0 + tmp3;
262
                    tmp13 = tmp0 - tmp3;
263
                    tmp11 = tmp2 - tmp0;
264
                    tmp12 = -(tmp0 + tmp2);
265
                }
266
            } else {
267
                if (d0) {
268
                    /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
269
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
270
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
271

    
272
                    tmp0 = (d0 + d4) << CONST_BITS;
273
                    tmp1 = (d0 - d4) << CONST_BITS;
274

    
275
                    tmp10 = tmp0 + tmp3;
276
                    tmp13 = tmp0 - tmp3;
277
                    tmp11 = tmp1 + tmp2;
278
                    tmp12 = tmp1 - tmp2;
279
                } else {
280
                    /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */
281
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
282
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
283

    
284
                    tmp0 = d4 << CONST_BITS;
285

    
286
                    tmp10 = tmp0 + tmp3;
287
                    tmp13 = tmp0 - tmp3;
288
                    tmp11 = tmp2 - tmp0;
289
                    tmp12 = -(tmp0 + tmp2);
290
                }
291
            }
292
        } else {
293
            if (d2) {
294
                if (d0) {
295
                    /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */
296
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
297
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
298
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
299

    
300
                    tmp0 = d0 << CONST_BITS;
301

    
302
                    tmp10 = tmp0 + tmp3;
303
                    tmp13 = tmp0 - tmp3;
304
                    tmp11 = tmp0 + tmp2;
305
                    tmp12 = tmp0 - tmp2;
306
                } else {
307
                    /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */
308
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
309
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
310
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
311

    
312
                    tmp10 = tmp3;
313
                    tmp13 = -tmp3;
314
                    tmp11 = tmp2;
315
                    tmp12 = -tmp2;
316
                }
317
            } else {
318
                if (d0) {
319
                    /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */
320
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
321
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
322

    
323
                    tmp0 = d0 << CONST_BITS;
324

    
325
                    tmp10 = tmp0 + tmp3;
326
                    tmp13 = tmp0 - tmp3;
327
                    tmp11 = tmp0 + tmp2;
328
                    tmp12 = tmp0 - tmp2;
329
                } else {
330
                    /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */
331
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
332
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
333

    
334
                    tmp10 = tmp3;
335
                    tmp13 = -tmp3;
336
                    tmp11 = tmp2;
337
                    tmp12 = -tmp2;
338
                }
339
            }
340
        }
341
    } else {
342
        if (d4) {
343
            if (d2) {
344
                if (d0) {
345
                    /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
346
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
347
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
348

    
349
                    tmp0 = (d0 + d4) << CONST_BITS;
350
                    tmp1 = (d0 - d4) << CONST_BITS;
351

    
352
                    tmp10 = tmp0 + tmp3;
353
                    tmp13 = tmp0 - tmp3;
354
                    tmp11 = tmp1 + tmp2;
355
                    tmp12 = tmp1 - tmp2;
356
                } else {
357
                    /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */
358
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
359
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
360

    
361
                    tmp0 = d4 << CONST_BITS;
362

    
363
                    tmp10 = tmp0 + tmp3;
364
                    tmp13 = tmp0 - tmp3;
365
                    tmp11 = tmp2 - tmp0;
366
                    tmp12 = -(tmp0 + tmp2);
367
                }
368
            } else {
369
                if (d0) {
370
                    /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
371
                    tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
372
                    tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
373
                } else {
374
                    /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */
375
                    tmp10 = tmp13 = d4 << CONST_BITS;
376
                    tmp11 = tmp12 = -tmp10;
377
                }
378
            }
379
        } else {
380
            if (d2) {
381
                if (d0) {
382
                    /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */
383
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
384
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
385

    
386
                    tmp0 = d0 << CONST_BITS;
387

    
388
                    tmp10 = tmp0 + tmp3;
389
                    tmp13 = tmp0 - tmp3;
390
                    tmp11 = tmp0 + tmp2;
391
                    tmp12 = tmp0 - tmp2;
392
                } else {
393
                    /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */
394
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
395
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
396

    
397
                    tmp10 = tmp3;
398
                    tmp13 = -tmp3;
399
                    tmp11 = tmp2;
400
                    tmp12 = -tmp2;
401
                }
402
            } else {
403
                if (d0) {
404
                    /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */
405
                    tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS;
406
                } else {
407
                    /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */
408
                    tmp10 = tmp13 = tmp11 = tmp12 = 0;
409
                }
410
            }
411
        }
412
      }
413

    
414
    /* Odd part per figure 8; the matrix is unitary and hence its
415
     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
416
     */
417

    
418
    if (d7) {
419
        if (d5) {
420
            if (d3) {
421
                if (d1) {
422
                    /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
423
                    z1 = d7 + d1;
424
                    z2 = d5 + d3;
425
                    z3 = d7 + d3;
426
                    z4 = d5 + d1;
427
                    z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
428
                    
429
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
430
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
431
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
432
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
433
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
434
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
435
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
436
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
437
                    
438
                    z3 += z5;
439
                    z4 += z5;
440
                    
441
                    tmp0 += z1 + z3;
442
                    tmp1 += z2 + z4;
443
                    tmp2 += z2 + z3;
444
                    tmp3 += z1 + z4;
445
                } else {
446
                    /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
447
                    z2 = d5 + d3;
448
                    z3 = d7 + d3;
449
                    z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
450
                    
451
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
452
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
453
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
454
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
455
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
456
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
457
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
458
                    
459
                    z3 += z5;
460
                    z4 += z5;
461
                    
462
                    tmp0 += z1 + z3;
463
                    tmp1 += z2 + z4;
464
                    tmp2 += z2 + z3;
465
                    tmp3 = z1 + z4;
466
                }
467
            } else {
468
                if (d1) {
469
                    /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
470
                    z1 = d7 + d1;
471
                    z4 = d5 + d1;
472
                    z5 = MULTIPLY(d7 + z4, FIX_1_175875602);
473
                    
474
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
475
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
476
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
477
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
478
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
479
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
480
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
481
                    
482
                    z3 += z5;
483
                    z4 += z5;
484
                    
485
                    tmp0 += z1 + z3;
486
                    tmp1 += z2 + z4;
487
                    tmp2 = z2 + z3;
488
                    tmp3 += z1 + z4;
489
                } else {
490
                    /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
491
                    tmp0 = MULTIPLY(-d7, FIX_0_601344887); 
492
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
493
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
494
                    tmp1 = MULTIPLY(-d5, FIX_0_509795579);
495
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
496
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
497
                    z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
498
                    
499
                    z3 += z5;
500
                    z4 += z5;
501
                    
502
                    tmp0 += z3;
503
                    tmp1 += z4;
504
                    tmp2 = z2 + z3;
505
                    tmp3 = z1 + z4;
506
                }
507
            }
508
        } else {
509
            if (d3) {
510
                if (d1) {
511
                    /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
512
                    z1 = d7 + d1;
513
                    z3 = d7 + d3;
514
                    z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
515
                    
516
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
517
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
518
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
519
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
520
                    z2 = MULTIPLY(-d3, FIX_2_562915447);
521
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
522
                    z4 = MULTIPLY(-d1, FIX_0_390180644);
523
                    
524
                    z3 += z5;
525
                    z4 += z5;
526
                    
527
                    tmp0 += z1 + z3;
528
                    tmp1 = z2 + z4;
529
                    tmp2 += z2 + z3;
530
                    tmp3 += z1 + z4;
531
                } else {
532
                    /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
533
                    z3 = d7 + d3;
534
                    
535
                    tmp0 = MULTIPLY(-d7, FIX_0_601344887); 
536
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
537
                    tmp2 = MULTIPLY(d3, FIX_0_509795579);
538
                    z2 = MULTIPLY(-d3, FIX_2_562915447);
539
                    z5 = MULTIPLY(z3, FIX_1_175875602);
540
                    z3 = MULTIPLY(-z3, FIX_0_785694958);
541
                    
542
                    tmp0 += z3;
543
                    tmp1 = z2 + z5;
544
                    tmp2 += z3;
545
                    tmp3 = z1 + z5;
546
                }
547
            } else {
548
                if (d1) {
549
                    /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
550
                    z1 = d7 + d1;
551
                    z5 = MULTIPLY(z1, FIX_1_175875602);
552

    
553
                    z1 = MULTIPLY(z1, FIX_0_275899380);
554
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
555
                    tmp0 = MULTIPLY(-d7, FIX_1_662939225); 
556
                    z4 = MULTIPLY(-d1, FIX_0_390180644);
557
                    tmp3 = MULTIPLY(d1, FIX_1_111140466);
558

    
559
                    tmp0 += z1;
560
                    tmp1 = z4 + z5;
561
                    tmp2 = z3 + z5;
562
                    tmp3 += z1;
563
                } else {
564
                    /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
565
                    tmp0 = MULTIPLY(-d7, FIX_1_387039845);
566
                    tmp1 = MULTIPLY(d7, FIX_1_175875602);
567
                    tmp2 = MULTIPLY(-d7, FIX_0_785694958);
568
                    tmp3 = MULTIPLY(d7, FIX_0_275899380);
569
                }
570
            }
571
        }
572
    } else {
573
        if (d5) {
574
            if (d3) {
575
                if (d1) {
576
                    /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
577
                    z2 = d5 + d3;
578
                    z4 = d5 + d1;
579
                    z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
580
                    
581
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
582
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
583
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
584
                    z1 = MULTIPLY(-d1, FIX_0_899976223);
585
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
586
                    z3 = MULTIPLY(-d3, FIX_1_961570560);
587
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
588
                    
589
                    z3 += z5;
590
                    z4 += z5;
591
                    
592
                    tmp0 = z1 + z3;
593
                    tmp1 += z2 + z4;
594
                    tmp2 += z2 + z3;
595
                    tmp3 += z1 + z4;
596
                } else {
597
                    /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
598
                    z2 = d5 + d3;
599
                    
600
                    z5 = MULTIPLY(z2, FIX_1_175875602);
601
                    tmp1 = MULTIPLY(d5, FIX_1_662939225);
602
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
603
                    z2 = MULTIPLY(-z2, FIX_1_387039845);
604
                    tmp2 = MULTIPLY(d3, FIX_1_111140466);
605
                    z3 = MULTIPLY(-d3, FIX_1_961570560);
606
                    
607
                    tmp0 = z3 + z5;
608
                    tmp1 += z2;
609
                    tmp2 += z2;
610
                    tmp3 = z4 + z5;
611
                }
612
            } else {
613
                if (d1) {
614
                    /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
615
                    z4 = d5 + d1;
616
                    
617
                    z5 = MULTIPLY(z4, FIX_1_175875602);
618
                    z1 = MULTIPLY(-d1, FIX_0_899976223);
619
                    tmp3 = MULTIPLY(d1, FIX_0_601344887);
620
                    tmp1 = MULTIPLY(-d5, FIX_0_509795579);
621
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
622
                    z4 = MULTIPLY(z4, FIX_0_785694958);
623
                    
624
                    tmp0 = z1 + z5;
625
                    tmp1 += z4;
626
                    tmp2 = z2 + z5;
627
                    tmp3 += z4;
628
                } else {
629
                    /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
630
                    tmp0 = MULTIPLY(d5, FIX_1_175875602);
631
                    tmp1 = MULTIPLY(d5, FIX_0_275899380);
632
                    tmp2 = MULTIPLY(-d5, FIX_1_387039845);
633
                    tmp3 = MULTIPLY(d5, FIX_0_785694958);
634
                }
635
            }
636
        } else {
637
            if (d3) {
638
                if (d1) {
639
                    /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
640
                    z5 = d1 + d3;
641
                    tmp3 = MULTIPLY(d1, FIX_0_211164243);
642
                    tmp2 = MULTIPLY(-d3, FIX_1_451774981);
643
                    z1 = MULTIPLY(d1, FIX_1_061594337);
644
                    z2 = MULTIPLY(-d3, FIX_2_172734803);
645
                    z4 = MULTIPLY(z5, FIX_0_785694958);
646
                    z5 = MULTIPLY(z5, FIX_1_175875602);
647
                    
648
                    tmp0 = z1 - z4;
649
                    tmp1 = z2 + z4;
650
                    tmp2 += z5;
651
                    tmp3 += z5;
652
                } else {
653
                    /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
654
                    tmp0 = MULTIPLY(-d3, FIX_0_785694958);
655
                    tmp1 = MULTIPLY(-d3, FIX_1_387039845);
656
                    tmp2 = MULTIPLY(-d3, FIX_0_275899380);
657
                    tmp3 = MULTIPLY(d3, FIX_1_175875602);
658
                }
659
            } else {
660
                if (d1) {
661
                    /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
662
                    tmp0 = MULTIPLY(d1, FIX_0_275899380);
663
                    tmp1 = MULTIPLY(d1, FIX_0_785694958);
664
                    tmp2 = MULTIPLY(d1, FIX_1_175875602);
665
                    tmp3 = MULTIPLY(d1, FIX_1_387039845);
666
                } else {
667
                    /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
668
                    tmp0 = tmp1 = tmp2 = tmp3 = 0;
669
                }
670
            }
671
        }
672
    }
673
}
674
    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
675

    
676
    dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
677
    dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
678
    dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
679
    dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
680
    dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
681
    dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
682
    dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
683
    dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
684

    
685
    dataptr += DCTSIZE;                /* advance pointer to next row */
686
  }
687

    
688
  /* Pass 2: process columns. */
689
  /* Note that we must descale the results by a factor of 8 == 2**3, */
690
  /* and also undo the PASS1_BITS scaling. */
691

    
692
  dataptr = data;
693
  for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
694
    /* Columns of zeroes can be exploited in the same way as we did with rows.
695
     * However, the row calculation has created many nonzero AC terms, so the
696
     * simplification applies less often (typically 5% to 10% of the time).
697
     * On machines with very fast multiplication, it's possible that the
698
     * test takes more time than it's worth.  In that case this section
699
     * may be commented out.
700
     */
701

    
702
    d0 = dataptr[DCTSIZE*0];
703
    d1 = dataptr[DCTSIZE*1];
704
    d2 = dataptr[DCTSIZE*2];
705
    d3 = dataptr[DCTSIZE*3];
706
    d4 = dataptr[DCTSIZE*4];
707
    d5 = dataptr[DCTSIZE*5];
708
    d6 = dataptr[DCTSIZE*6];
709
    d7 = dataptr[DCTSIZE*7];
710

    
711
    /* Even part: reverse the even part of the forward DCT. */
712
    /* The rotator is sqrt(2)*c(-6). */
713
    if (d6) {
714
        if (d4) {
715
            if (d2) {
716
                if (d0) {
717
                    /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
718
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
719
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
720
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
721

    
722
                    tmp0 = (d0 + d4) << CONST_BITS;
723
                    tmp1 = (d0 - d4) << CONST_BITS;
724

    
725
                    tmp10 = tmp0 + tmp3;
726
                    tmp13 = tmp0 - tmp3;
727
                    tmp11 = tmp1 + tmp2;
728
                    tmp12 = tmp1 - tmp2;
729
                } else {
730
                    /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */
731
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
732
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
733
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
734

    
735
                    tmp0 = d4 << CONST_BITS;
736

    
737
                    tmp10 = tmp0 + tmp3;
738
                    tmp13 = tmp0 - tmp3;
739
                    tmp11 = tmp2 - tmp0;
740
                    tmp12 = -(tmp0 + tmp2);
741
                }
742
            } else {
743
                if (d0) {
744
                    /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
745
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
746
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
747

    
748
                    tmp0 = (d0 + d4) << CONST_BITS;
749
                    tmp1 = (d0 - d4) << CONST_BITS;
750

    
751
                    tmp10 = tmp0 + tmp3;
752
                    tmp13 = tmp0 - tmp3;
753
                    tmp11 = tmp1 + tmp2;
754
                    tmp12 = tmp1 - tmp2;
755
                } else {
756
                    /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */
757
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
758
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
759

    
760
                    tmp0 = d4 << CONST_BITS;
761

    
762
                    tmp10 = tmp0 + tmp3;
763
                    tmp13 = tmp0 - tmp3;
764
                    tmp11 = tmp2 - tmp0;
765
                    tmp12 = -(tmp0 + tmp2);
766
                }
767
            }
768
        } else {
769
            if (d2) {
770
                if (d0) {
771
                    /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */
772
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
773
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
774
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
775

    
776
                    tmp0 = d0 << CONST_BITS;
777

    
778
                    tmp10 = tmp0 + tmp3;
779
                    tmp13 = tmp0 - tmp3;
780
                    tmp11 = tmp0 + tmp2;
781
                    tmp12 = tmp0 - tmp2;
782
                } else {
783
                    /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */
784
                    z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
785
                    tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
786
                    tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
787

    
788
                    tmp10 = tmp3;
789
                    tmp13 = -tmp3;
790
                    tmp11 = tmp2;
791
                    tmp12 = -tmp2;
792
                }
793
            } else {
794
                if (d0) {
795
                    /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */
796
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
797
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
798

    
799
                    tmp0 = d0 << CONST_BITS;
800

    
801
                    tmp10 = tmp0 + tmp3;
802
                    tmp13 = tmp0 - tmp3;
803
                    tmp11 = tmp0 + tmp2;
804
                    tmp12 = tmp0 - tmp2;
805
                } else {
806
                    /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */
807
                    tmp2 = MULTIPLY(-d6, FIX_1_306562965);
808
                    tmp3 = MULTIPLY(d6, FIX_0_541196100);
809

    
810
                    tmp10 = tmp3;
811
                    tmp13 = -tmp3;
812
                    tmp11 = tmp2;
813
                    tmp12 = -tmp2;
814
                }
815
            }
816
        }
817
    } else {
818
        if (d4) {
819
            if (d2) {
820
                if (d0) {
821
                    /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
822
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
823
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
824

    
825
                    tmp0 = (d0 + d4) << CONST_BITS;
826
                    tmp1 = (d0 - d4) << CONST_BITS;
827

    
828
                    tmp10 = tmp0 + tmp3;
829
                    tmp13 = tmp0 - tmp3;
830
                    tmp11 = tmp1 + tmp2;
831
                    tmp12 = tmp1 - tmp2;
832
                } else {
833
                    /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */
834
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
835
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
836

    
837
                    tmp0 = d4 << CONST_BITS;
838

    
839
                    tmp10 = tmp0 + tmp3;
840
                    tmp13 = tmp0 - tmp3;
841
                    tmp11 = tmp2 - tmp0;
842
                    tmp12 = -(tmp0 + tmp2);
843
                }
844
            } else {
845
                if (d0) {
846
                    /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
847
                    tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
848
                    tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
849
                } else {
850
                    /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */
851
                    tmp10 = tmp13 = d4 << CONST_BITS;
852
                    tmp11 = tmp12 = -tmp10;
853
                }
854
            }
855
        } else {
856
            if (d2) {
857
                if (d0) {
858
                    /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */
859
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
860
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
861

    
862
                    tmp0 = d0 << CONST_BITS;
863

    
864
                    tmp10 = tmp0 + tmp3;
865
                    tmp13 = tmp0 - tmp3;
866
                    tmp11 = tmp0 + tmp2;
867
                    tmp12 = tmp0 - tmp2;
868
                } else {
869
                    /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */
870
                    tmp2 = MULTIPLY(d2, FIX_0_541196100);
871
                    tmp3 = MULTIPLY(d2, FIX_1_306562965);
872

    
873
                    tmp10 = tmp3;
874
                    tmp13 = -tmp3;
875
                    tmp11 = tmp2;
876
                    tmp12 = -tmp2;
877
                }
878
            } else {
879
                if (d0) {
880
                    /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */
881
                    tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS;
882
                } else {
883
                    /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */
884
                    tmp10 = tmp13 = tmp11 = tmp12 = 0;
885
                }
886
            }
887
        }
888
    }
889

    
890
    /* Odd part per figure 8; the matrix is unitary and hence its
891
     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
892
     */
893
    if (d7) {
894
        if (d5) {
895
            if (d3) {
896
                if (d1) {
897
                    /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
898
                    z1 = d7 + d1;
899
                    z2 = d5 + d3;
900
                    z3 = d7 + d3;
901
                    z4 = d5 + d1;
902
                    z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
903
                    
904
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
905
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
906
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
907
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
908
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
909
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
910
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
911
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
912
                    
913
                    z3 += z5;
914
                    z4 += z5;
915
                    
916
                    tmp0 += z1 + z3;
917
                    tmp1 += z2 + z4;
918
                    tmp2 += z2 + z3;
919
                    tmp3 += z1 + z4;
920
                } else {
921
                    /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
922
                    z1 = d7;
923
                    z2 = d5 + d3;
924
                    z3 = d7 + d3;
925
                    z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
926
                    
927
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
928
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
929
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
930
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
931
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
932
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
933
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
934
                    
935
                    z3 += z5;
936
                    z4 += z5;
937
                    
938
                    tmp0 += z1 + z3;
939
                    tmp1 += z2 + z4;
940
                    tmp2 += z2 + z3;
941
                    tmp3 = z1 + z4;
942
                }
943
            } else {
944
                if (d1) {
945
                    /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
946
                    z1 = d7 + d1;
947
                    z2 = d5;
948
                    z3 = d7;
949
                    z4 = d5 + d1;
950
                    z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
951
                    
952
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
953
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
954
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
955
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
956
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
957
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
958
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
959
                    
960
                    z3 += z5;
961
                    z4 += z5;
962
                    
963
                    tmp0 += z1 + z3;
964
                    tmp1 += z2 + z4;
965
                    tmp2 = z2 + z3;
966
                    tmp3 += z1 + z4;
967
                } else {
968
                    /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
969
                    tmp0 = MULTIPLY(-d7, FIX_0_601344887); 
970
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
971
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
972
                    tmp1 = MULTIPLY(-d5, FIX_0_509795579);
973
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
974
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
975
                    z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
976
                    
977
                    z3 += z5;
978
                    z4 += z5;
979
                    
980
                    tmp0 += z3;
981
                    tmp1 += z4;
982
                    tmp2 = z2 + z3;
983
                    tmp3 = z1 + z4;
984
                }
985
            }
986
        } else {
987
            if (d3) {
988
                if (d1) {
989
                    /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
990
                    z1 = d7 + d1;
991
                    z3 = d7 + d3;
992
                    z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
993
                    
994
                    tmp0 = MULTIPLY(d7, FIX_0_298631336); 
995
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
996
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
997
                    z1 = MULTIPLY(-z1, FIX_0_899976223);
998
                    z2 = MULTIPLY(-d3, FIX_2_562915447);
999
                    z3 = MULTIPLY(-z3, FIX_1_961570560);
1000
                    z4 = MULTIPLY(-d1, FIX_0_390180644);
1001
                    
1002
                    z3 += z5;
1003
                    z4 += z5;
1004
                    
1005
                    tmp0 += z1 + z3;
1006
                    tmp1 = z2 + z4;
1007
                    tmp2 += z2 + z3;
1008
                    tmp3 += z1 + z4;
1009
                } else {
1010
                    /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
1011
                    z3 = d7 + d3;
1012
                    
1013
                    tmp0 = MULTIPLY(-d7, FIX_0_601344887); 
1014
                    z1 = MULTIPLY(-d7, FIX_0_899976223);
1015
                    tmp2 = MULTIPLY(d3, FIX_0_509795579);
1016
                    z2 = MULTIPLY(-d3, FIX_2_562915447);
1017
                    z5 = MULTIPLY(z3, FIX_1_175875602);
1018
                    z3 = MULTIPLY(-z3, FIX_0_785694958);
1019
                    
1020
                    tmp0 += z3;
1021
                    tmp1 = z2 + z5;
1022
                    tmp2 += z3;
1023
                    tmp3 = z1 + z5;
1024
                }
1025
            } else {
1026
                if (d1) {
1027
                    /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
1028
                    z1 = d7 + d1;
1029
                    z5 = MULTIPLY(z1, FIX_1_175875602);
1030

    
1031
                    z1 = MULTIPLY(z1, FIX_0_275899380);
1032
                    z3 = MULTIPLY(-d7, FIX_1_961570560);
1033
                    tmp0 = MULTIPLY(-d7, FIX_1_662939225); 
1034
                    z4 = MULTIPLY(-d1, FIX_0_390180644);
1035
                    tmp3 = MULTIPLY(d1, FIX_1_111140466);
1036

    
1037
                    tmp0 += z1;
1038
                    tmp1 = z4 + z5;
1039
                    tmp2 = z3 + z5;
1040
                    tmp3 += z1;
1041
                } else {
1042
                    /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
1043
                    tmp0 = MULTIPLY(-d7, FIX_1_387039845);
1044
                    tmp1 = MULTIPLY(d7, FIX_1_175875602);
1045
                    tmp2 = MULTIPLY(-d7, FIX_0_785694958);
1046
                    tmp3 = MULTIPLY(d7, FIX_0_275899380);
1047
                }
1048
            }
1049
        }
1050
    } else {
1051
        if (d5) {
1052
            if (d3) {
1053
                if (d1) {
1054
                    /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
1055
                    z2 = d5 + d3;
1056
                    z4 = d5 + d1;
1057
                    z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
1058
                    
1059
                    tmp1 = MULTIPLY(d5, FIX_2_053119869);
1060
                    tmp2 = MULTIPLY(d3, FIX_3_072711026);
1061
                    tmp3 = MULTIPLY(d1, FIX_1_501321110);
1062
                    z1 = MULTIPLY(-d1, FIX_0_899976223);
1063
                    z2 = MULTIPLY(-z2, FIX_2_562915447);
1064
                    z3 = MULTIPLY(-d3, FIX_1_961570560);
1065
                    z4 = MULTIPLY(-z4, FIX_0_390180644);
1066
                    
1067
                    z3 += z5;
1068
                    z4 += z5;
1069
                    
1070
                    tmp0 = z1 + z3;
1071
                    tmp1 += z2 + z4;
1072
                    tmp2 += z2 + z3;
1073
                    tmp3 += z1 + z4;
1074
                } else {
1075
                    /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
1076
                    z2 = d5 + d3;
1077
                    
1078
                    z5 = MULTIPLY(z2, FIX_1_175875602);
1079
                    tmp1 = MULTIPLY(d5, FIX_1_662939225);
1080
                    z4 = MULTIPLY(-d5, FIX_0_390180644);
1081
                    z2 = MULTIPLY(-z2, FIX_1_387039845);
1082
                    tmp2 = MULTIPLY(d3, FIX_1_111140466);
1083
                    z3 = MULTIPLY(-d3, FIX_1_961570560);
1084
                    
1085
                    tmp0 = z3 + z5;
1086
                    tmp1 += z2;
1087
                    tmp2 += z2;
1088
                    tmp3 = z4 + z5;
1089
                }
1090
            } else {
1091
                if (d1) {
1092
                    /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
1093
                    z4 = d5 + d1;
1094
                    
1095
                    z5 = MULTIPLY(z4, FIX_1_175875602);
1096
                    z1 = MULTIPLY(-d1, FIX_0_899976223);
1097
                    tmp3 = MULTIPLY(d1, FIX_0_601344887);
1098
                    tmp1 = MULTIPLY(-d5, FIX_0_509795579);
1099
                    z2 = MULTIPLY(-d5, FIX_2_562915447);
1100
                    z4 = MULTIPLY(z4, FIX_0_785694958);
1101
                    
1102
                    tmp0 = z1 + z5;
1103
                    tmp1 += z4;
1104
                    tmp2 = z2 + z5;
1105
                    tmp3 += z4;
1106
                } else {
1107
                    /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
1108
                    tmp0 = MULTIPLY(d5, FIX_1_175875602);
1109
                    tmp1 = MULTIPLY(d5, FIX_0_275899380);
1110
                    tmp2 = MULTIPLY(-d5, FIX_1_387039845);
1111
                    tmp3 = MULTIPLY(d5, FIX_0_785694958);
1112
                }
1113
            }
1114
        } else {
1115
            if (d3) {
1116
                if (d1) {
1117
                    /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
1118
                    z5 = d1 + d3;
1119
                    tmp3 = MULTIPLY(d1, FIX_0_211164243);
1120
                    tmp2 = MULTIPLY(-d3, FIX_1_451774981);
1121
                    z1 = MULTIPLY(d1, FIX_1_061594337);
1122
                    z2 = MULTIPLY(-d3, FIX_2_172734803);
1123
                    z4 = MULTIPLY(z5, FIX_0_785694958);
1124
                    z5 = MULTIPLY(z5, FIX_1_175875602);
1125
                    
1126
                    tmp0 = z1 - z4;
1127
                    tmp1 = z2 + z4;
1128
                    tmp2 += z5;
1129
                    tmp3 += z5;
1130
                } else {
1131
                    /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
1132
                    tmp0 = MULTIPLY(-d3, FIX_0_785694958);
1133
                    tmp1 = MULTIPLY(-d3, FIX_1_387039845);
1134
                    tmp2 = MULTIPLY(-d3, FIX_0_275899380);
1135
                    tmp3 = MULTIPLY(d3, FIX_1_175875602);
1136
                }
1137
            } else {
1138
                if (d1) {
1139
                    /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
1140
                    tmp0 = MULTIPLY(d1, FIX_0_275899380);
1141
                    tmp1 = MULTIPLY(d1, FIX_0_785694958);
1142
                    tmp2 = MULTIPLY(d1, FIX_1_175875602);
1143
                    tmp3 = MULTIPLY(d1, FIX_1_387039845);
1144
                } else {
1145
                    /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
1146
                    tmp0 = tmp1 = tmp2 = tmp3 = 0;
1147
                }
1148
            }
1149
        }
1150
    }
1151

    
1152
    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
1153

    
1154
    dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3,
1155
                                           CONST_BITS+PASS1_BITS+3);
1156
    dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3,
1157
                                           CONST_BITS+PASS1_BITS+3);
1158
    dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2,
1159
                                           CONST_BITS+PASS1_BITS+3);
1160
    dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2,
1161
                                           CONST_BITS+PASS1_BITS+3);
1162
    dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1,
1163
                                           CONST_BITS+PASS1_BITS+3);
1164
    dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1,
1165
                                           CONST_BITS+PASS1_BITS+3);
1166
    dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0,
1167
                                           CONST_BITS+PASS1_BITS+3);
1168
    dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0,
1169
                                           CONST_BITS+PASS1_BITS+3);
1170
    
1171
    dataptr++;                        /* advance pointer to next column */
1172
  }
1173
}
1174

    
1175
#undef FIX
1176
#undef CONST_BITS