Coverage Report

Created: 2024-05-04 12:45

/proc/self/cwd/external/libjpeg_turbo/jdcoefct.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * jdcoefct.c
3
 *
4
 * This file was part of the Independent JPEG Group's software:
5
 * Copyright (C) 1994-1997, Thomas G. Lane.
6
 * libjpeg-turbo Modifications:
7
 * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
8
 * Copyright (C) 2010, 2015-2016, 2019-2020, 2022, D. R. Commander.
9
 * Copyright (C) 2015, 2020, Google, Inc.
10
 * For conditions of distribution and use, see the accompanying README.ijg
11
 * file.
12
 *
13
 * This file contains the coefficient buffer controller for decompression.
14
 * This controller is the top level of the JPEG decompressor proper.
15
 * The coefficient buffer lies between entropy decoding and inverse-DCT steps.
16
 *
17
 * In buffered-image mode, this controller is the interface between
18
 * input-oriented processing and output-oriented processing.
19
 * Also, the input side (only) is used when reading a file for transcoding.
20
 */
21
22
#include "jinclude.h"
23
#include "jdcoefct.h"
24
#include "jpegcomp.h"
25
26
27
/* Forward declarations */
28
METHODDEF(int) decompress_onepass(j_decompress_ptr cinfo,
29
                                  JSAMPIMAGE output_buf);
30
#ifdef D_MULTISCAN_FILES_SUPPORTED
31
METHODDEF(int) decompress_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf);
32
#endif
33
#ifdef BLOCK_SMOOTHING_SUPPORTED
34
LOCAL(boolean) smoothing_ok(j_decompress_ptr cinfo);
35
METHODDEF(int) decompress_smooth_data(j_decompress_ptr cinfo,
36
                                      JSAMPIMAGE output_buf);
37
#endif
38
39
40
/*
41
 * Initialize for an input processing pass.
42
 */
43
44
METHODDEF(void)
45
start_input_pass(j_decompress_ptr cinfo)
46
3.90k
{
47
3.90k
  cinfo->input_iMCU_row = 0;
48
3.90k
  start_iMCU_row(cinfo);
49
3.90k
}
50
51
52
/*
53
 * Initialize for an output processing pass.
54
 */
55
56
METHODDEF(void)
57
start_output_pass(j_decompress_ptr cinfo)
58
34
{
59
34
#ifdef BLOCK_SMOOTHING_SUPPORTED
60
34
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
61
62
  /* If multipass, check to see whether to use block smoothing on this pass */
63
34
  if (coef->pub.coef_arrays != NULL) {
64
1
    if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
65
0
      coef->pub.decompress_data = decompress_smooth_data;
66
1
    else
67
1
      coef->pub.decompress_data = decompress_data;
68
1
  }
69
34
#endif
70
34
  cinfo->output_iMCU_row = 0;
71
34
}
72
73
74
/*
75
 * Decompress and return some data in the single-pass case.
76
 * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
77
 * Input and output must run in lockstep since we have only a one-MCU buffer.
78
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
79
 *
80
 * NB: output_buf contains a plane for each component in image,
81
 * which we index according to the component's SOF position.
82
 */
83
84
METHODDEF(int)
85
decompress_onepass(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
86
9.46k
{
87
9.46k
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
88
9.46k
  JDIMENSION MCU_col_num;       /* index of current MCU within row */
89
9.46k
  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
90
9.46k
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
91
9.46k
  int blkn, ci, xindex, yindex, yoffset, useful_width;
92
9.46k
  JSAMPARRAY output_ptr;
93
9.46k
  JDIMENSION start_col, output_col;
94
9.46k
  jpeg_component_info *compptr;
95
9.46k
  inverse_DCT_method_ptr inverse_DCT;
96
97
  /* Loop to process as much as one whole iMCU row */
98
19.3k
  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
99
9.91k
       yoffset++) {
100
2.42M
    for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
101
2.41M
         MCU_col_num++) {
102
      /* Try to fetch an MCU.  Entropy decoder expects buffer to be zeroed. */
103
2.41M
      jzero_far((void *)coef->MCU_buffer[0],
104
2.41M
                (size_t)(cinfo->blocks_in_MCU * sizeof(JBLOCK)));
105
2.41M
      if (!cinfo->entropy->insufficient_data)
106
1.60M
        cinfo->master->last_good_iMCU_row = cinfo->input_iMCU_row;
107
2.41M
      if (!(*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
108
        /* Suspension forced; update state counters and exit */
109
11
        coef->MCU_vert_offset = yoffset;
110
11
        coef->MCU_ctr = MCU_col_num;
111
11
        return JPEG_SUSPENDED;
112
11
      }
113
114
      /* Only perform the IDCT on blocks that are contained within the desired
115
       * cropping region.
116
       */
117
2.41M
      if (MCU_col_num >= cinfo->master->first_iMCU_col &&
118
2.41M
          MCU_col_num <= cinfo->master->last_iMCU_col) {
119
        /* Determine where data should go in output_buf and do the IDCT thing.
120
         * We skip dummy blocks at the right and bottom edges (but blkn gets
121
         * incremented past them!).  Note the inner loop relies on having
122
         * allocated the MCU_buffer[] blocks sequentially.
123
         */
124
2.41M
        blkn = 0;               /* index of current DCT block within MCU */
125
6.84M
        for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
126
4.43M
          compptr = cinfo->cur_comp_info[ci];
127
          /* Don't bother to IDCT an uninteresting component. */
128
4.43M
          if (!compptr->component_needed) {
129
0
            blkn += compptr->MCU_blocks;
130
0
            continue;
131
0
          }
132
4.43M
          inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
133
4.43M
          useful_width = (MCU_col_num < last_MCU_col) ?
134
4.41M
                         compptr->MCU_width : compptr->last_col_width;
135
4.43M
          output_ptr = output_buf[compptr->component_index] +
136
4.43M
                       yoffset * compptr->_DCT_scaled_size;
137
4.43M
          start_col = (MCU_col_num - cinfo->master->first_iMCU_col) *
138
4.43M
                      compptr->MCU_sample_width;
139
9.06M
          for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
140
4.63M
            if (cinfo->input_iMCU_row < last_iMCU_row ||
141
4.63M
                yoffset + yindex < compptr->last_row_height) {
142
4.63M
              output_col = start_col;
143
10.4M
              for (xindex = 0; xindex < useful_width; xindex++) {
144
5.81M
                (*inverse_DCT) (cinfo, compptr,
145
5.81M
                                (JCOEFPTR)coef->MCU_buffer[blkn + xindex],
146
5.81M
                                output_ptr, output_col);
147
5.81M
                output_col += compptr->_DCT_scaled_size;
148
5.81M
              }
149
4.63M
            }
150
4.63M
            blkn += compptr->MCU_width;
151
4.63M
            output_ptr += compptr->_DCT_scaled_size;
152
4.63M
          }
153
4.43M
        }
154
2.41M
      }
155
2.41M
    }
156
    /* Completed an MCU row, but perhaps not an iMCU row */
157
9.90k
    coef->MCU_ctr = 0;
158
9.90k
  }
159
  /* Completed the iMCU row, advance counters for next one */
160
9.45k
  cinfo->output_iMCU_row++;
161
9.45k
  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
162
9.43k
    start_iMCU_row(cinfo);
163
9.43k
    return JPEG_ROW_COMPLETED;
164
9.43k
  }
165
  /* Completed the scan */
166
22
  (*cinfo->inputctl->finish_input_pass) (cinfo);
167
22
  return JPEG_SCAN_COMPLETED;
168
9.45k
}
169
170
171
/*
172
 * Dummy consume-input routine for single-pass operation.
173
 */
174
175
METHODDEF(int)
176
dummy_consume_data(j_decompress_ptr cinfo)
177
0
{
178
0
  return JPEG_SUSPENDED;        /* Always indicate nothing was done */
179
0
}
180
181
182
#ifdef D_MULTISCAN_FILES_SUPPORTED
183
184
/*
185
 * Consume input data and store it in the full-image coefficient buffer.
186
 * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
187
 * ie, v_samp_factor block rows for each component in the scan.
188
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
189
 */
190
191
METHODDEF(int)
192
consume_data(j_decompress_ptr cinfo)
193
623k
{
194
623k
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
195
623k
  JDIMENSION MCU_col_num;       /* index of current MCU within row */
196
623k
  int blkn, ci, xindex, yindex, yoffset;
197
623k
  JDIMENSION start_col;
198
623k
  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
199
623k
  JBLOCKROW buffer_ptr;
200
623k
  jpeg_component_info *compptr;
201
202
  /* Align the virtual buffers for the components used in this scan. */
203
1.26M
  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
204
638k
    compptr = cinfo->cur_comp_info[ci];
205
638k
    buffer[ci] = (*cinfo->mem->access_virt_barray)
206
638k
      ((j_common_ptr)cinfo, coef->whole_image[compptr->component_index],
207
638k
       cinfo->input_iMCU_row * compptr->v_samp_factor,
208
638k
       (JDIMENSION)compptr->v_samp_factor, TRUE);
209
    /* Note: entropy decoder expects buffer to be zeroed,
210
     * but this is handled automatically by the memory manager
211
     * because we requested a pre-zeroed array.
212
     */
213
638k
  }
214
215
  /* Loop to process one whole iMCU row */
216
1.24M
  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
217
624k
       yoffset++) {
218
41.3M
    for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
219
40.6M
         MCU_col_num++) {
220
      /* Construct list of pointers to DCT blocks belonging to this MCU */
221
40.6M
      blkn = 0;                 /* index of current DCT block within MCU */
222
87.0M
      for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
223
46.3M
        compptr = cinfo->cur_comp_info[ci];
224
46.3M
        start_col = MCU_col_num * compptr->MCU_width;
225
96.5M
        for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
226
50.1M
          buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
227
115M
          for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
228
65.7M
            coef->MCU_buffer[blkn++] = buffer_ptr++;
229
65.7M
          }
230
50.1M
        }
231
46.3M
      }
232
40.6M
      if (!cinfo->entropy->insufficient_data)
233
9.64M
        cinfo->master->last_good_iMCU_row = cinfo->input_iMCU_row;
234
      /* Try to fetch the MCU. */
235
40.6M
      if (!(*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
236
        /* Suspension forced; update state counters and exit */
237
0
        coef->MCU_vert_offset = yoffset;
238
0
        coef->MCU_ctr = MCU_col_num;
239
0
        return JPEG_SUSPENDED;
240
0
      }
241
40.6M
    }
242
    /* Completed an MCU row, but perhaps not an iMCU row */
243
624k
    coef->MCU_ctr = 0;
244
624k
  }
245
  /* Completed the iMCU row, advance counters for next one */
246
623k
  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
247
619k
    start_iMCU_row(cinfo);
248
619k
    return JPEG_ROW_COMPLETED;
249
619k
  }
250
  /* Completed the scan */
251
3.87k
  (*cinfo->inputctl->finish_input_pass) (cinfo);
252
3.87k
  return JPEG_SCAN_COMPLETED;
253
623k
}
254
255
256
/*
257
 * Decompress and return some data in the multi-pass case.
258
 * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
259
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
260
 *
261
 * NB: output_buf contains a plane for each component in image.
262
 */
263
264
METHODDEF(int)
265
decompress_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
266
4
{
267
4
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
268
4
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
269
4
  JDIMENSION block_num;
270
4
  int ci, block_row, block_rows;
271
4
  JBLOCKARRAY buffer;
272
4
  JBLOCKROW buffer_ptr;
273
4
  JSAMPARRAY output_ptr;
274
4
  JDIMENSION output_col;
275
4
  jpeg_component_info *compptr;
276
4
  inverse_DCT_method_ptr inverse_DCT;
277
278
  /* Force some input to be done if we are getting ahead of the input. */
279
4
  while (cinfo->input_scan_number < cinfo->output_scan_number ||
280
4
         (cinfo->input_scan_number == cinfo->output_scan_number &&
281
4
          cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
282
0
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
283
0
      return JPEG_SUSPENDED;
284
0
  }
285
286
  /* OK, output from the virtual arrays. */
287
16
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
288
12
       ci++, compptr++) {
289
    /* Don't bother to IDCT an uninteresting component. */
290
12
    if (!compptr->component_needed)
291
0
      continue;
292
    /* Align the virtual buffer for this component. */
293
12
    buffer = (*cinfo->mem->access_virt_barray)
294
12
      ((j_common_ptr)cinfo, coef->whole_image[ci],
295
12
       cinfo->output_iMCU_row * compptr->v_samp_factor,
296
12
       (JDIMENSION)compptr->v_samp_factor, FALSE);
297
    /* Count non-dummy DCT block rows in this iMCU row. */
298
12
    if (cinfo->output_iMCU_row < last_iMCU_row)
299
9
      block_rows = compptr->v_samp_factor;
300
3
    else {
301
      /* NB: can't use last_row_height here; it is input-side-dependent! */
302
3
      block_rows = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
303
3
      if (block_rows == 0) block_rows = compptr->v_samp_factor;
304
3
    }
305
12
    inverse_DCT = cinfo->idct->inverse_DCT[ci];
306
12
    output_ptr = output_buf[ci];
307
    /* Loop over all DCT blocks to be processed. */
308
24
    for (block_row = 0; block_row < block_rows; block_row++) {
309
12
      buffer_ptr = buffer[block_row] + cinfo->master->first_MCU_col[ci];
310
12
      output_col = 0;
311
12
      for (block_num = cinfo->master->first_MCU_col[ci];
312
89.9k
           block_num <= cinfo->master->last_MCU_col[ci]; block_num++) {
313
89.9k
        (*inverse_DCT) (cinfo, compptr, (JCOEFPTR)buffer_ptr, output_ptr,
314
89.9k
                        output_col);
315
89.9k
        buffer_ptr++;
316
89.9k
        output_col += compptr->_DCT_scaled_size;
317
89.9k
      }
318
12
      output_ptr += compptr->_DCT_scaled_size;
319
12
    }
320
12
  }
321
322
4
  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
323
3
    return JPEG_ROW_COMPLETED;
324
1
  return JPEG_SCAN_COMPLETED;
325
4
}
326
327
#endif /* D_MULTISCAN_FILES_SUPPORTED */
328
329
330
#ifdef BLOCK_SMOOTHING_SUPPORTED
331
332
/*
333
 * This code applies interblock smoothing; the first 9 AC coefficients are
334
 * estimated from the DC values of a DCT block and its 24 neighboring blocks.
335
 * We apply smoothing only for progressive JPEG decoding, and only if
336
 * the coefficients it can estimate are not yet known to full precision.
337
 */
338
339
/* Natural-order array positions of the first 9 zigzag-order coefficients */
340
0
#define Q01_POS  1
341
0
#define Q10_POS  8
342
0
#define Q20_POS  16
343
0
#define Q11_POS  9
344
0
#define Q02_POS  2
345
0
#define Q03_POS  3
346
0
#define Q12_POS  10
347
0
#define Q21_POS  17
348
0
#define Q30_POS  24
349
350
/*
351
 * Determine whether block smoothing is applicable and safe.
352
 * We also latch the current states of the coef_bits[] entries for the
353
 * AC coefficients; otherwise, if the input side of the decompressor
354
 * advances into a new scan, we might think the coefficients are known
355
 * more accurately than they really are.
356
 */
357
358
LOCAL(boolean)
359
smoothing_ok(j_decompress_ptr cinfo)
360
1
{
361
1
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
362
1
  boolean smoothing_useful = FALSE;
363
1
  int ci, coefi;
364
1
  jpeg_component_info *compptr;
365
1
  JQUANT_TBL *qtable;
366
1
  int *coef_bits, *prev_coef_bits;
367
1
  int *coef_bits_latch, *prev_coef_bits_latch;
368
369
1
  if (!cinfo->progressive_mode || cinfo->coef_bits == NULL)
370
1
    return FALSE;
371
372
  /* Allocate latch area if not already done */
373
0
  if (coef->coef_bits_latch == NULL)
374
0
    coef->coef_bits_latch = (int *)
375
0
      (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
376
0
                                  cinfo->num_components * 2 *
377
0
                                  (SAVED_COEFS * sizeof(int)));
378
0
  coef_bits_latch = coef->coef_bits_latch;
379
0
  prev_coef_bits_latch =
380
0
    &coef->coef_bits_latch[cinfo->num_components * SAVED_COEFS];
381
382
0
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
383
0
       ci++, compptr++) {
384
    /* All components' quantization values must already be latched. */
385
0
    if ((qtable = compptr->quant_table) == NULL)
386
0
      return FALSE;
387
    /* Verify DC & first 9 AC quantizers are nonzero to avoid zero-divide. */
388
0
    if (qtable->quantval[0] == 0 ||
389
0
        qtable->quantval[Q01_POS] == 0 ||
390
0
        qtable->quantval[Q10_POS] == 0 ||
391
0
        qtable->quantval[Q20_POS] == 0 ||
392
0
        qtable->quantval[Q11_POS] == 0 ||
393
0
        qtable->quantval[Q02_POS] == 0 ||
394
0
        qtable->quantval[Q03_POS] == 0 ||
395
0
        qtable->quantval[Q12_POS] == 0 ||
396
0
        qtable->quantval[Q21_POS] == 0 ||
397
0
        qtable->quantval[Q30_POS] == 0)
398
0
      return FALSE;
399
    /* DC values must be at least partly known for all components. */
400
0
    coef_bits = cinfo->coef_bits[ci];
401
0
    prev_coef_bits = cinfo->coef_bits[ci + cinfo->num_components];
402
0
    if (coef_bits[0] < 0)
403
0
      return FALSE;
404
0
    coef_bits_latch[0] = coef_bits[0];
405
    /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
406
0
    for (coefi = 1; coefi < SAVED_COEFS; coefi++) {
407
0
      if (cinfo->input_scan_number > 1)
408
0
        prev_coef_bits_latch[coefi] = prev_coef_bits[coefi];
409
0
      else
410
0
        prev_coef_bits_latch[coefi] = -1;
411
0
      coef_bits_latch[coefi] = coef_bits[coefi];
412
0
      if (coef_bits[coefi] != 0)
413
0
        smoothing_useful = TRUE;
414
0
    }
415
0
    coef_bits_latch += SAVED_COEFS;
416
0
    prev_coef_bits_latch += SAVED_COEFS;
417
0
  }
418
419
0
  return smoothing_useful;
420
0
}
421
422
423
/*
424
 * Variant of decompress_data for use when doing block smoothing.
425
 */
426
427
METHODDEF(int)
428
decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
429
0
{
430
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
431
0
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
432
0
  JDIMENSION block_num, last_block_column;
433
0
  int ci, block_row, block_rows, access_rows;
434
0
  JBLOCKARRAY buffer;
435
0
  JBLOCKROW buffer_ptr, prev_prev_block_row, prev_block_row;
436
0
  JBLOCKROW next_block_row, next_next_block_row;
437
0
  JSAMPARRAY output_ptr;
438
0
  JDIMENSION output_col;
439
0
  jpeg_component_info *compptr;
440
0
  inverse_DCT_method_ptr inverse_DCT;
441
0
  boolean change_dc;
442
0
  JCOEF *workspace;
443
0
  int *coef_bits;
444
0
  JQUANT_TBL *quanttbl;
445
0
  JLONG Q00, Q01, Q02, Q03 = 0, Q10, Q11, Q12 = 0, Q20, Q21 = 0, Q30 = 0, num;
446
0
  int DC01, DC02, DC03, DC04, DC05, DC06, DC07, DC08, DC09, DC10, DC11, DC12,
447
0
      DC13, DC14, DC15, DC16, DC17, DC18, DC19, DC20, DC21, DC22, DC23, DC24,
448
0
      DC25;
449
0
  int Al, pred;
450
451
  /* Keep a local variable to avoid looking it up more than once */
452
0
  workspace = coef->workspace;
453
454
  /* Force some input to be done if we are getting ahead of the input. */
455
0
  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
456
0
         !cinfo->inputctl->eoi_reached) {
457
0
    if (cinfo->input_scan_number == cinfo->output_scan_number) {
458
      /* If input is working on current scan, we ordinarily want it to
459
       * have completed the current row.  But if input scan is DC,
460
       * we want it to keep two rows ahead so that next two block rows' DC
461
       * values are up to date.
462
       */
463
0
      JDIMENSION delta = (cinfo->Ss == 0) ? 2 : 0;
464
0
      if (cinfo->input_iMCU_row > cinfo->output_iMCU_row + delta)
465
0
        break;
466
0
    }
467
0
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
468
0
      return JPEG_SUSPENDED;
469
0
  }
470
471
  /* OK, output from the virtual arrays. */
472
0
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
473
0
       ci++, compptr++) {
474
    /* Don't bother to IDCT an uninteresting component. */
475
0
    if (!compptr->component_needed)
476
0
      continue;
477
    /* Count non-dummy DCT block rows in this iMCU row. */
478
0
    if (cinfo->output_iMCU_row + 1 < last_iMCU_row) {
479
0
      block_rows = compptr->v_samp_factor;
480
0
      access_rows = block_rows * 3; /* this and next two iMCU rows */
481
0
    } else if (cinfo->output_iMCU_row < last_iMCU_row) {
482
0
      block_rows = compptr->v_samp_factor;
483
0
      access_rows = block_rows * 2; /* this and next iMCU row */
484
0
    } else {
485
      /* NB: can't use last_row_height here; it is input-side-dependent! */
486
0
      block_rows = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
487
0
      if (block_rows == 0) block_rows = compptr->v_samp_factor;
488
0
      access_rows = block_rows; /* this iMCU row only */
489
0
    }
490
    /* Align the virtual buffer for this component. */
491
0
    if (cinfo->output_iMCU_row > 1) {
492
0
      access_rows += 2 * compptr->v_samp_factor; /* prior two iMCU rows too */
493
0
      buffer = (*cinfo->mem->access_virt_barray)
494
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
495
0
         (cinfo->output_iMCU_row - 2) * compptr->v_samp_factor,
496
0
         (JDIMENSION)access_rows, FALSE);
497
0
      buffer += 2 * compptr->v_samp_factor; /* point to current iMCU row */
498
0
    } else if (cinfo->output_iMCU_row > 0) {
499
0
      buffer = (*cinfo->mem->access_virt_barray)
500
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
501
0
         (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
502
0
         (JDIMENSION)access_rows, FALSE);
503
0
      buffer += compptr->v_samp_factor; /* point to current iMCU row */
504
0
    } else {
505
0
      buffer = (*cinfo->mem->access_virt_barray)
506
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
507
0
         (JDIMENSION)0, (JDIMENSION)access_rows, FALSE);
508
0
    }
509
    /* Fetch component-dependent info.
510
     * If the current scan is incomplete, then we use the component-dependent
511
     * info from the previous scan.
512
     */
513
0
    if (cinfo->output_iMCU_row > cinfo->master->last_good_iMCU_row)
514
0
      coef_bits =
515
0
        coef->coef_bits_latch + ((ci + cinfo->num_components) * SAVED_COEFS);
516
0
    else
517
0
      coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
518
519
    /* We only do DC interpolation if no AC coefficient data is available. */
520
0
    change_dc =
521
0
      coef_bits[1] == -1 && coef_bits[2] == -1 && coef_bits[3] == -1 &&
522
0
      coef_bits[4] == -1 && coef_bits[5] == -1 && coef_bits[6] == -1 &&
523
0
      coef_bits[7] == -1 && coef_bits[8] == -1 && coef_bits[9] == -1;
524
525
0
    quanttbl = compptr->quant_table;
526
0
    Q00 = quanttbl->quantval[0];
527
0
    Q01 = quanttbl->quantval[Q01_POS];
528
0
    Q10 = quanttbl->quantval[Q10_POS];
529
0
    Q20 = quanttbl->quantval[Q20_POS];
530
0
    Q11 = quanttbl->quantval[Q11_POS];
531
0
    Q02 = quanttbl->quantval[Q02_POS];
532
0
    if (change_dc) {
533
0
      Q03 = quanttbl->quantval[Q03_POS];
534
0
      Q12 = quanttbl->quantval[Q12_POS];
535
0
      Q21 = quanttbl->quantval[Q21_POS];
536
0
      Q30 = quanttbl->quantval[Q30_POS];
537
0
    }
538
0
    inverse_DCT = cinfo->idct->inverse_DCT[ci];
539
0
    output_ptr = output_buf[ci];
540
    /* Loop over all DCT blocks to be processed. */
541
0
    for (block_row = 0; block_row < block_rows; block_row++) {
542
0
      buffer_ptr = buffer[block_row] + cinfo->master->first_MCU_col[ci];
543
544
0
      if (block_row > 0 || cinfo->output_iMCU_row > 0)
545
0
        prev_block_row =
546
0
          buffer[block_row - 1] + cinfo->master->first_MCU_col[ci];
547
0
      else
548
0
        prev_block_row = buffer_ptr;
549
550
0
      if (block_row > 1 || cinfo->output_iMCU_row > 1)
551
0
        prev_prev_block_row =
552
0
          buffer[block_row - 2] + cinfo->master->first_MCU_col[ci];
553
0
      else
554
0
        prev_prev_block_row = prev_block_row;
555
556
0
      if (block_row < block_rows - 1 || cinfo->output_iMCU_row < last_iMCU_row)
557
0
        next_block_row =
558
0
          buffer[block_row + 1] + cinfo->master->first_MCU_col[ci];
559
0
      else
560
0
        next_block_row = buffer_ptr;
561
562
0
      if (block_row < block_rows - 2 ||
563
0
          cinfo->output_iMCU_row + 1 < last_iMCU_row)
564
0
        next_next_block_row =
565
0
          buffer[block_row + 2] + cinfo->master->first_MCU_col[ci];
566
0
      else
567
0
        next_next_block_row = next_block_row;
568
569
      /* We fetch the surrounding DC values using a sliding-register approach.
570
       * Initialize all 25 here so as to do the right thing on narrow pics.
571
       */
572
0
      DC01 = DC02 = DC03 = DC04 = DC05 = (int)prev_prev_block_row[0][0];
573
0
      DC06 = DC07 = DC08 = DC09 = DC10 = (int)prev_block_row[0][0];
574
0
      DC11 = DC12 = DC13 = DC14 = DC15 = (int)buffer_ptr[0][0];
575
0
      DC16 = DC17 = DC18 = DC19 = DC20 = (int)next_block_row[0][0];
576
0
      DC21 = DC22 = DC23 = DC24 = DC25 = (int)next_next_block_row[0][0];
577
0
      output_col = 0;
578
0
      last_block_column = compptr->width_in_blocks - 1;
579
0
      for (block_num = cinfo->master->first_MCU_col[ci];
580
0
           block_num <= cinfo->master->last_MCU_col[ci]; block_num++) {
581
        /* Fetch current DCT block into workspace so we can modify it. */
582
0
        jcopy_block_row(buffer_ptr, (JBLOCKROW)workspace, (JDIMENSION)1);
583
        /* Update DC values */
584
0
        if (block_num == cinfo->master->first_MCU_col[ci] &&
585
0
            block_num < last_block_column) {
586
0
          DC04 = (int)prev_prev_block_row[1][0];
587
0
          DC09 = (int)prev_block_row[1][0];
588
0
          DC14 = (int)buffer_ptr[1][0];
589
0
          DC19 = (int)next_block_row[1][0];
590
0
          DC24 = (int)next_next_block_row[1][0];
591
0
        }
592
0
        if (block_num + 1 < last_block_column) {
593
0
          DC05 = (int)prev_prev_block_row[2][0];
594
0
          DC10 = (int)prev_block_row[2][0];
595
0
          DC15 = (int)buffer_ptr[2][0];
596
0
          DC20 = (int)next_block_row[2][0];
597
0
          DC25 = (int)next_next_block_row[2][0];
598
0
        }
599
        /* If DC interpolation is enabled, compute coefficient estimates using
600
         * a Gaussian-like kernel, keeping the averages of the DC values.
601
         *
602
         * If DC interpolation is disabled, compute coefficient estimates using
603
         * an algorithm similar to the one described in Section K.8 of the JPEG
604
         * standard, except applied to a 5x5 window rather than a 3x3 window.
605
         *
606
         * An estimate is applied only if the coefficient is still zero and is
607
         * not known to be fully accurate.
608
         */
609
        /* AC01 */
610
0
        if ((Al = coef_bits[1]) != 0 && workspace[1] == 0) {
611
0
          num = Q00 * (change_dc ?
612
0
                (-DC01 - DC02 + DC04 + DC05 - 3 * DC06 + 13 * DC07 -
613
0
                 13 * DC09 + 3 * DC10 - 3 * DC11 + 38 * DC12 - 38 * DC14 +
614
0
                 3 * DC15 - 3 * DC16 + 13 * DC17 - 13 * DC19 + 3 * DC20 -
615
0
                 DC21 - DC22 + DC24 + DC25) :
616
0
                (-7 * DC11 + 50 * DC12 - 50 * DC14 + 7 * DC15));
617
0
          if (num >= 0) {
618
0
            pred = (int)(((Q01 << 7) + num) / (Q01 << 8));
619
0
            if (Al > 0 && pred >= (1 << Al))
620
0
              pred = (1 << Al) - 1;
621
0
          } else {
622
0
            pred = (int)(((Q01 << 7) - num) / (Q01 << 8));
623
0
            if (Al > 0 && pred >= (1 << Al))
624
0
              pred = (1 << Al) - 1;
625
0
            pred = -pred;
626
0
          }
627
0
          workspace[1] = (JCOEF)pred;
628
0
        }
629
        /* AC10 */
630
0
        if ((Al = coef_bits[2]) != 0 && workspace[8] == 0) {
631
0
          num = Q00 * (change_dc ?
632
0
                (-DC01 - 3 * DC02 - 3 * DC03 - 3 * DC04 - DC05 - DC06 +
633
0
                 13 * DC07 + 38 * DC08 + 13 * DC09 - DC10 + DC16 -
634
0
                 13 * DC17 - 38 * DC18 - 13 * DC19 + DC20 + DC21 +
635
0
                 3 * DC22 + 3 * DC23 + 3 * DC24 + DC25) :
636
0
                (-7 * DC03 + 50 * DC08 - 50 * DC18 + 7 * DC23));
637
0
          if (num >= 0) {
638
0
            pred = (int)(((Q10 << 7) + num) / (Q10 << 8));
639
0
            if (Al > 0 && pred >= (1 << Al))
640
0
              pred = (1 << Al) - 1;
641
0
          } else {
642
0
            pred = (int)(((Q10 << 7) - num) / (Q10 << 8));
643
0
            if (Al > 0 && pred >= (1 << Al))
644
0
              pred = (1 << Al) - 1;
645
0
            pred = -pred;
646
0
          }
647
0
          workspace[8] = (JCOEF)pred;
648
0
        }
649
        /* AC20 */
650
0
        if ((Al = coef_bits[3]) != 0 && workspace[16] == 0) {
651
0
          num = Q00 * (change_dc ?
652
0
                (DC03 + 2 * DC07 + 7 * DC08 + 2 * DC09 - 5 * DC12 - 14 * DC13 -
653
0
                 5 * DC14 + 2 * DC17 + 7 * DC18 + 2 * DC19 + DC23) :
654
0
                (-DC03 + 13 * DC08 - 24 * DC13 + 13 * DC18 - DC23));
655
0
          if (num >= 0) {
656
0
            pred = (int)(((Q20 << 7) + num) / (Q20 << 8));
657
0
            if (Al > 0 && pred >= (1 << Al))
658
0
              pred = (1 << Al) - 1;
659
0
          } else {
660
0
            pred = (int)(((Q20 << 7) - num) / (Q20 << 8));
661
0
            if (Al > 0 && pred >= (1 << Al))
662
0
              pred = (1 << Al) - 1;
663
0
            pred = -pred;
664
0
          }
665
0
          workspace[16] = (JCOEF)pred;
666
0
        }
667
        /* AC11 */
668
0
        if ((Al = coef_bits[4]) != 0 && workspace[9] == 0) {
669
0
          num = Q00 * (change_dc ?
670
0
                (-DC01 + DC05 + 9 * DC07 - 9 * DC09 - 9 * DC17 +
671
0
                 9 * DC19 + DC21 - DC25) :
672
0
                (DC10 + DC16 - 10 * DC17 + 10 * DC19 - DC02 - DC20 + DC22 -
673
0
                 DC24 + DC04 - DC06 + 10 * DC07 - 10 * DC09));
674
0
          if (num >= 0) {
675
0
            pred = (int)(((Q11 << 7) + num) / (Q11 << 8));
676
0
            if (Al > 0 && pred >= (1 << Al))
677
0
              pred = (1 << Al) - 1;
678
0
          } else {
679
0
            pred = (int)(((Q11 << 7) - num) / (Q11 << 8));
680
0
            if (Al > 0 && pred >= (1 << Al))
681
0
              pred = (1 << Al) - 1;
682
0
            pred = -pred;
683
0
          }
684
0
          workspace[9] = (JCOEF)pred;
685
0
        }
686
        /* AC02 */
687
0
        if ((Al = coef_bits[5]) != 0 && workspace[2] == 0) {
688
0
          num = Q00 * (change_dc ?
689
0
                (2 * DC07 - 5 * DC08 + 2 * DC09 + DC11 + 7 * DC12 - 14 * DC13 +
690
0
                 7 * DC14 + DC15 + 2 * DC17 - 5 * DC18 + 2 * DC19) :
691
0
                (-DC11 + 13 * DC12 - 24 * DC13 + 13 * DC14 - DC15));
692
0
          if (num >= 0) {
693
0
            pred = (int)(((Q02 << 7) + num) / (Q02 << 8));
694
0
            if (Al > 0 && pred >= (1 << Al))
695
0
              pred = (1 << Al) - 1;
696
0
          } else {
697
0
            pred = (int)(((Q02 << 7) - num) / (Q02 << 8));
698
0
            if (Al > 0 && pred >= (1 << Al))
699
0
              pred = (1 << Al) - 1;
700
0
            pred = -pred;
701
0
          }
702
0
          workspace[2] = (JCOEF)pred;
703
0
        }
704
0
        if (change_dc) {
705
          /* AC03 */
706
0
          if ((Al = coef_bits[6]) != 0 && workspace[3] == 0) {
707
0
            num = Q00 * (DC07 - DC09 + 2 * DC12 - 2 * DC14 + DC17 - DC19);
708
0
            if (num >= 0) {
709
0
              pred = (int)(((Q03 << 7) + num) / (Q03 << 8));
710
0
              if (Al > 0 && pred >= (1 << Al))
711
0
                pred = (1 << Al) - 1;
712
0
            } else {
713
0
              pred = (int)(((Q03 << 7) - num) / (Q03 << 8));
714
0
              if (Al > 0 && pred >= (1 << Al))
715
0
                pred = (1 << Al) - 1;
716
0
              pred = -pred;
717
0
            }
718
0
            workspace[3] = (JCOEF)pred;
719
0
          }
720
          /* AC12 */
721
0
          if ((Al = coef_bits[7]) != 0 && workspace[10] == 0) {
722
0
            num = Q00 * (DC07 - 3 * DC08 + DC09 - DC17 + 3 * DC18 - DC19);
723
0
            if (num >= 0) {
724
0
              pred = (int)(((Q12 << 7) + num) / (Q12 << 8));
725
0
              if (Al > 0 && pred >= (1 << Al))
726
0
                pred = (1 << Al) - 1;
727
0
            } else {
728
0
              pred = (int)(((Q12 << 7) - num) / (Q12 << 8));
729
0
              if (Al > 0 && pred >= (1 << Al))
730
0
                pred = (1 << Al) - 1;
731
0
              pred = -pred;
732
0
            }
733
0
            workspace[10] = (JCOEF)pred;
734
0
          }
735
          /* AC21 */
736
0
          if ((Al = coef_bits[8]) != 0 && workspace[17] == 0) {
737
0
            num = Q00 * (DC07 - DC09 - 3 * DC12 + 3 * DC14 + DC17 - DC19);
738
0
            if (num >= 0) {
739
0
              pred = (int)(((Q21 << 7) + num) / (Q21 << 8));
740
0
              if (Al > 0 && pred >= (1 << Al))
741
0
                pred = (1 << Al) - 1;
742
0
            } else {
743
0
              pred = (int)(((Q21 << 7) - num) / (Q21 << 8));
744
0
              if (Al > 0 && pred >= (1 << Al))
745
0
                pred = (1 << Al) - 1;
746
0
              pred = -pred;
747
0
            }
748
0
            workspace[17] = (JCOEF)pred;
749
0
          }
750
          /* AC30 */
751
0
          if ((Al = coef_bits[9]) != 0 && workspace[24] == 0) {
752
0
            num = Q00 * (DC07 + 2 * DC08 + DC09 - DC17 - 2 * DC18 - DC19);
753
0
            if (num >= 0) {
754
0
              pred = (int)(((Q30 << 7) + num) / (Q30 << 8));
755
0
              if (Al > 0 && pred >= (1 << Al))
756
0
                pred = (1 << Al) - 1;
757
0
            } else {
758
0
              pred = (int)(((Q30 << 7) - num) / (Q30 << 8));
759
0
              if (Al > 0 && pred >= (1 << Al))
760
0
                pred = (1 << Al) - 1;
761
0
              pred = -pred;
762
0
            }
763
0
            workspace[24] = (JCOEF)pred;
764
0
          }
765
          /* coef_bits[0] is non-negative.  Otherwise this function would not
766
           * be called.
767
           */
768
0
          num = Q00 *
769
0
                (-2 * DC01 - 6 * DC02 - 8 * DC03 - 6 * DC04 - 2 * DC05 -
770
0
                 6 * DC06 + 6 * DC07 + 42 * DC08 + 6 * DC09 - 6 * DC10 -
771
0
                 8 * DC11 + 42 * DC12 + 152 * DC13 + 42 * DC14 - 8 * DC15 -
772
0
                 6 * DC16 + 6 * DC17 + 42 * DC18 + 6 * DC19 - 6 * DC20 -
773
0
                 2 * DC21 - 6 * DC22 - 8 * DC23 - 6 * DC24 - 2 * DC25);
774
0
          if (num >= 0) {
775
0
            pred = (int)(((Q00 << 7) + num) / (Q00 << 8));
776
0
          } else {
777
0
            pred = (int)(((Q00 << 7) - num) / (Q00 << 8));
778
0
            pred = -pred;
779
0
          }
780
0
          workspace[0] = (JCOEF)pred;
781
0
        }  /* change_dc */
782
783
        /* OK, do the IDCT */
784
0
        (*inverse_DCT) (cinfo, compptr, (JCOEFPTR)workspace, output_ptr,
785
0
                        output_col);
786
        /* Advance for next column */
787
0
        DC01 = DC02;  DC02 = DC03;  DC03 = DC04;  DC04 = DC05;
788
0
        DC06 = DC07;  DC07 = DC08;  DC08 = DC09;  DC09 = DC10;
789
0
        DC11 = DC12;  DC12 = DC13;  DC13 = DC14;  DC14 = DC15;
790
0
        DC16 = DC17;  DC17 = DC18;  DC18 = DC19;  DC19 = DC20;
791
0
        DC21 = DC22;  DC22 = DC23;  DC23 = DC24;  DC24 = DC25;
792
0
        buffer_ptr++, prev_block_row++, next_block_row++,
793
0
          prev_prev_block_row++, next_next_block_row++;
794
0
        output_col += compptr->_DCT_scaled_size;
795
0
      }
796
0
      output_ptr += compptr->_DCT_scaled_size;
797
0
    }
798
0
  }
799
800
0
  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
801
0
    return JPEG_ROW_COMPLETED;
802
0
  return JPEG_SCAN_COMPLETED;
803
0
}
804
805
#endif /* BLOCK_SMOOTHING_SUPPORTED */
806
807
808
/*
809
 * Initialize coefficient buffer controller.
810
 */
811
812
GLOBAL(void)
813
jinit_d_coef_controller(j_decompress_ptr cinfo, boolean need_full_buffer)
814
124
{
815
124
  my_coef_ptr coef;
816
817
124
  coef = (my_coef_ptr)
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    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
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                                sizeof(my_coef_controller));
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  cinfo->coef = (struct jpeg_d_coef_controller *)coef;
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  coef->pub.start_input_pass = start_input_pass;
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  coef->pub.start_output_pass = start_output_pass;
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#ifdef BLOCK_SMOOTHING_SUPPORTED
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  coef->coef_bits_latch = NULL;
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#endif
826
827
  /* Create the coefficient buffer. */
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  if (need_full_buffer) {
829
91
#ifdef D_MULTISCAN_FILES_SUPPORTED
830
    /* Allocate a full-image virtual array for each component, */
831
    /* padded to a multiple of samp_factor DCT blocks in each direction. */
832
    /* Note we ask for a pre-zeroed array. */
833
91
    int ci, access_rows;
834
91
    jpeg_component_info *compptr;
835
836
351
    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
837
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         ci++, compptr++) {
838
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      access_rows = compptr->v_samp_factor;
839
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#ifdef BLOCK_SMOOTHING_SUPPORTED
840
      /* If block smoothing could be used, need a bigger window */
841
260
      if (cinfo->progressive_mode)
842
18
        access_rows *= 5;
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260
#endif
844
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      coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
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        ((j_common_ptr)cinfo, JPOOL_IMAGE, TRUE,
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         (JDIMENSION)jround_up((long)compptr->width_in_blocks,
847
260
                               (long)compptr->h_samp_factor),
848
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         (JDIMENSION)jround_up((long)compptr->height_in_blocks,
849
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                               (long)compptr->v_samp_factor),
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260
         (JDIMENSION)access_rows);
851
260
    }
852
91
    coef->pub.consume_data = consume_data;
853
91
    coef->pub.decompress_data = decompress_data;
854
91
    coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
855
#else
856
    ERREXIT(cinfo, JERR_NOT_COMPILED);
857
#endif
858
91
  } else {
859
    /* We only need a single-MCU buffer. */
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33
    JBLOCKROW buffer;
861
33
    int i;
862
863
33
    buffer = (JBLOCKROW)
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33
      (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE,
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33
                                  D_MAX_BLOCKS_IN_MCU * sizeof(JBLOCK));
866
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    for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
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      coef->MCU_buffer[i] = buffer + i;
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    }
869
33
    coef->pub.consume_data = dummy_consume_data;
870
33
    coef->pub.decompress_data = decompress_onepass;
871
33
    coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
872
33
  }
873
874
  /* Allocate the workspace buffer */
875
124
  coef->workspace = (JCOEF *)
876
124
    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
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124
                                sizeof(JCOEF) * DCTSIZE2);
878
124
}