Coverage Report

Created: 2024-06-18 06:05

/src/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, 2022-2023, 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 lossy 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 "jpegapicomp.h"
25
#include "jsamplecomp.h"
26
27
28
/* Forward declarations */
29
METHODDEF(int) decompress_onepass(j_decompress_ptr cinfo,
30
                                  _JSAMPIMAGE output_buf);
31
#ifdef D_MULTISCAN_FILES_SUPPORTED
32
METHODDEF(int) decompress_data(j_decompress_ptr cinfo, _JSAMPIMAGE output_buf);
33
#endif
34
#ifdef BLOCK_SMOOTHING_SUPPORTED
35
LOCAL(boolean) smoothing_ok(j_decompress_ptr cinfo);
36
METHODDEF(int) decompress_smooth_data(j_decompress_ptr cinfo,
37
                                      _JSAMPIMAGE output_buf);
38
#endif
39
40
41
/*
42
 * Initialize for an input processing pass.
43
 */
44
45
METHODDEF(void)
46
start_input_pass(j_decompress_ptr cinfo)
47
0
{
48
0
  cinfo->input_iMCU_row = 0;
49
0
  start_iMCU_row(cinfo);
50
0
}
51
52
53
/*
54
 * Initialize for an output processing pass.
55
 */
56
57
METHODDEF(void)
58
start_output_pass(j_decompress_ptr cinfo)
59
0
{
60
0
#ifdef BLOCK_SMOOTHING_SUPPORTED
61
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
62
63
  /* If multipass, check to see whether to use block smoothing on this pass */
64
0
  if (coef->pub.coef_arrays != NULL) {
65
0
    if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
66
0
      coef->pub._decompress_data = decompress_smooth_data;
67
0
    else
68
0
      coef->pub._decompress_data = decompress_data;
69
0
  }
70
0
#endif
71
0
  cinfo->output_iMCU_row = 0;
72
0
}
73
74
75
/*
76
 * Decompress and return some data in the single-pass case.
77
 * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
78
 * Input and output must run in lockstep since we have only a one-MCU buffer.
79
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
80
 *
81
 * NB: output_buf contains a plane for each component in image,
82
 * which we index according to the component's SOF position.
83
 */
84
85
METHODDEF(int)
86
decompress_onepass(j_decompress_ptr cinfo, _JSAMPIMAGE output_buf)
87
0
{
88
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
89
0
  JDIMENSION MCU_col_num;       /* index of current MCU within row */
90
0
  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
91
0
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
92
0
  int blkn, ci, xindex, yindex, yoffset, useful_width;
93
0
  _JSAMPARRAY output_ptr;
94
0
  JDIMENSION start_col, output_col;
95
0
  jpeg_component_info *compptr;
96
0
  _inverse_DCT_method_ptr inverse_DCT;
97
98
  /* Loop to process as much as one whole iMCU row */
99
0
  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
100
0
       yoffset++) {
101
0
    for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
102
0
         MCU_col_num++) {
103
      /* Try to fetch an MCU.  Entropy decoder expects buffer to be zeroed. */
104
0
      jzero_far((void *)coef->MCU_buffer[0],
105
0
                (size_t)(cinfo->blocks_in_MCU * sizeof(JBLOCK)));
106
0
      if (!cinfo->entropy->insufficient_data)
107
0
        cinfo->master->last_good_iMCU_row = cinfo->input_iMCU_row;
108
0
      if (!(*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
109
        /* Suspension forced; update state counters and exit */
110
0
        coef->MCU_vert_offset = yoffset;
111
0
        coef->MCU_ctr = MCU_col_num;
112
0
        return JPEG_SUSPENDED;
113
0
      }
114
115
      /* Only perform the IDCT on blocks that are contained within the desired
116
       * cropping region.
117
       */
118
0
      if (MCU_col_num >= cinfo->master->first_iMCU_col &&
119
0
          MCU_col_num <= cinfo->master->last_iMCU_col) {
120
        /* Determine where data should go in output_buf and do the IDCT thing.
121
         * We skip dummy blocks at the right and bottom edges (but blkn gets
122
         * incremented past them!).  Note the inner loop relies on having
123
         * allocated the MCU_buffer[] blocks sequentially.
124
         */
125
0
        blkn = 0;               /* index of current DCT block within MCU */
126
0
        for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
127
0
          compptr = cinfo->cur_comp_info[ci];
128
          /* Don't bother to IDCT an uninteresting component. */
129
0
          if (!compptr->component_needed) {
130
0
            blkn += compptr->MCU_blocks;
131
0
            continue;
132
0
          }
133
0
          inverse_DCT = cinfo->idct->_inverse_DCT[compptr->component_index];
134
0
          useful_width = (MCU_col_num < last_MCU_col) ?
135
0
                         compptr->MCU_width : compptr->last_col_width;
136
0
          output_ptr = output_buf[compptr->component_index] +
137
0
                       yoffset * compptr->_DCT_scaled_size;
138
0
          start_col = (MCU_col_num - cinfo->master->first_iMCU_col) *
139
0
                      compptr->MCU_sample_width;
140
0
          for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
141
0
            if (cinfo->input_iMCU_row < last_iMCU_row ||
142
0
                yoffset + yindex < compptr->last_row_height) {
143
0
              output_col = start_col;
144
0
              for (xindex = 0; xindex < useful_width; xindex++) {
145
0
                (*inverse_DCT) (cinfo, compptr,
146
0
                                (JCOEFPTR)coef->MCU_buffer[blkn + xindex],
147
0
                                output_ptr, output_col);
148
0
                output_col += compptr->_DCT_scaled_size;
149
0
              }
150
0
            }
151
0
            blkn += compptr->MCU_width;
152
0
            output_ptr += compptr->_DCT_scaled_size;
153
0
          }
154
0
        }
155
0
      }
156
0
    }
157
    /* Completed an MCU row, but perhaps not an iMCU row */
158
0
    coef->MCU_ctr = 0;
159
0
  }
160
  /* Completed the iMCU row, advance counters for next one */
161
0
  cinfo->output_iMCU_row++;
162
0
  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
163
0
    start_iMCU_row(cinfo);
164
0
    return JPEG_ROW_COMPLETED;
165
0
  }
166
  /* Completed the scan */
167
0
  (*cinfo->inputctl->finish_input_pass) (cinfo);
168
0
  return JPEG_SCAN_COMPLETED;
169
0
}
170
171
172
/*
173
 * Dummy consume-input routine for single-pass operation.
174
 */
175
176
METHODDEF(int)
177
dummy_consume_data(j_decompress_ptr cinfo)
178
0
{
179
0
  return JPEG_SUSPENDED;        /* Always indicate nothing was done */
180
0
}
181
182
183
#ifdef D_MULTISCAN_FILES_SUPPORTED
184
185
/*
186
 * Consume input data and store it in the full-image coefficient buffer.
187
 * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
188
 * ie, v_samp_factor block rows for each component in the scan.
189
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
190
 */
191
192
METHODDEF(int)
193
consume_data(j_decompress_ptr cinfo)
194
0
{
195
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
196
0
  JDIMENSION MCU_col_num;       /* index of current MCU within row */
197
0
  int blkn, ci, xindex, yindex, yoffset;
198
0
  JDIMENSION start_col;
199
0
  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
200
0
  JBLOCKROW buffer_ptr;
201
0
  jpeg_component_info *compptr;
202
203
  /* Align the virtual buffers for the components used in this scan. */
204
0
  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
205
0
    compptr = cinfo->cur_comp_info[ci];
206
0
    buffer[ci] = (*cinfo->mem->access_virt_barray)
207
0
      ((j_common_ptr)cinfo, coef->whole_image[compptr->component_index],
208
0
       cinfo->input_iMCU_row * compptr->v_samp_factor,
209
0
       (JDIMENSION)compptr->v_samp_factor, TRUE);
210
    /* Note: entropy decoder expects buffer to be zeroed,
211
     * but this is handled automatically by the memory manager
212
     * because we requested a pre-zeroed array.
213
     */
214
0
  }
215
216
  /* Loop to process one whole iMCU row */
217
0
  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
218
0
       yoffset++) {
219
0
    for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
220
0
         MCU_col_num++) {
221
      /* Construct list of pointers to DCT blocks belonging to this MCU */
222
0
      blkn = 0;                 /* index of current DCT block within MCU */
223
0
      for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
224
0
        compptr = cinfo->cur_comp_info[ci];
225
0
        start_col = MCU_col_num * compptr->MCU_width;
226
0
        for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
227
0
          buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
228
0
          for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
229
0
            coef->MCU_buffer[blkn++] = buffer_ptr++;
230
0
          }
231
0
        }
232
0
      }
233
0
      if (!cinfo->entropy->insufficient_data)
234
0
        cinfo->master->last_good_iMCU_row = cinfo->input_iMCU_row;
235
      /* Try to fetch the MCU. */
236
0
      if (!(*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
237
        /* Suspension forced; update state counters and exit */
238
0
        coef->MCU_vert_offset = yoffset;
239
0
        coef->MCU_ctr = MCU_col_num;
240
0
        return JPEG_SUSPENDED;
241
0
      }
242
0
    }
243
    /* Completed an MCU row, but perhaps not an iMCU row */
244
0
    coef->MCU_ctr = 0;
245
0
  }
246
  /* Completed the iMCU row, advance counters for next one */
247
0
  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
248
0
    start_iMCU_row(cinfo);
249
0
    return JPEG_ROW_COMPLETED;
250
0
  }
251
  /* Completed the scan */
252
0
  (*cinfo->inputctl->finish_input_pass) (cinfo);
253
0
  return JPEG_SCAN_COMPLETED;
254
0
}
255
256
257
/*
258
 * Decompress and return some data in the multi-pass case.
259
 * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
260
 * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
261
 *
262
 * NB: output_buf contains a plane for each component in image.
263
 */
264
265
METHODDEF(int)
266
decompress_data(j_decompress_ptr cinfo, _JSAMPIMAGE output_buf)
267
0
{
268
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
269
0
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
270
0
  JDIMENSION block_num;
271
0
  int ci, block_row, block_rows;
272
0
  JBLOCKARRAY buffer;
273
0
  JBLOCKROW buffer_ptr;
274
0
  _JSAMPARRAY output_ptr;
275
0
  JDIMENSION output_col;
276
0
  jpeg_component_info *compptr;
277
0
  _inverse_DCT_method_ptr inverse_DCT;
278
279
  /* Force some input to be done if we are getting ahead of the input. */
280
0
  while (cinfo->input_scan_number < cinfo->output_scan_number ||
281
0
         (cinfo->input_scan_number == cinfo->output_scan_number &&
282
0
          cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
283
0
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
284
0
      return JPEG_SUSPENDED;
285
0
  }
286
287
  /* OK, output from the virtual arrays. */
288
0
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
289
0
       ci++, compptr++) {
290
    /* Don't bother to IDCT an uninteresting component. */
291
0
    if (!compptr->component_needed)
292
0
      continue;
293
    /* Align the virtual buffer for this component. */
294
0
    buffer = (*cinfo->mem->access_virt_barray)
295
0
      ((j_common_ptr)cinfo, coef->whole_image[ci],
296
0
       cinfo->output_iMCU_row * compptr->v_samp_factor,
297
0
       (JDIMENSION)compptr->v_samp_factor, FALSE);
298
    /* Count non-dummy DCT block rows in this iMCU row. */
299
0
    if (cinfo->output_iMCU_row < last_iMCU_row)
300
0
      block_rows = compptr->v_samp_factor;
301
0
    else {
302
      /* NB: can't use last_row_height here; it is input-side-dependent! */
303
0
      block_rows = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
304
0
      if (block_rows == 0) block_rows = compptr->v_samp_factor;
305
0
    }
306
0
    inverse_DCT = cinfo->idct->_inverse_DCT[ci];
307
0
    output_ptr = output_buf[ci];
308
    /* Loop over all DCT blocks to be processed. */
309
0
    for (block_row = 0; block_row < block_rows; block_row++) {
310
0
      buffer_ptr = buffer[block_row] + cinfo->master->first_MCU_col[ci];
311
0
      output_col = 0;
312
0
      for (block_num = cinfo->master->first_MCU_col[ci];
313
0
           block_num <= cinfo->master->last_MCU_col[ci]; block_num++) {
314
0
        (*inverse_DCT) (cinfo, compptr, (JCOEFPTR)buffer_ptr, output_ptr,
315
0
                        output_col);
316
0
        buffer_ptr++;
317
0
        output_col += compptr->_DCT_scaled_size;
318
0
      }
319
0
      output_ptr += compptr->_DCT_scaled_size;
320
0
    }
321
0
  }
322
323
0
  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
324
0
    return JPEG_ROW_COMPLETED;
325
0
  return JPEG_SCAN_COMPLETED;
326
0
}
327
328
#endif /* D_MULTISCAN_FILES_SUPPORTED */
329
330
331
#ifdef BLOCK_SMOOTHING_SUPPORTED
332
333
/*
334
 * This code applies interblock smoothing; the first 9 AC coefficients are
335
 * estimated from the DC values of a DCT block and its 24 neighboring blocks.
336
 * We apply smoothing only for progressive JPEG decoding, and only if
337
 * the coefficients it can estimate are not yet known to full precision.
338
 */
339
340
/* Natural-order array positions of the first 9 zigzag-order coefficients */
341
0
#define Q01_POS  1
342
0
#define Q10_POS  8
343
0
#define Q20_POS  16
344
0
#define Q11_POS  9
345
0
#define Q02_POS  2
346
0
#define Q03_POS  3
347
0
#define Q12_POS  10
348
0
#define Q21_POS  17
349
0
#define Q30_POS  24
350
351
/*
352
 * Determine whether block smoothing is applicable and safe.
353
 * We also latch the current states of the coef_bits[] entries for the
354
 * AC coefficients; otherwise, if the input side of the decompressor
355
 * advances into a new scan, we might think the coefficients are known
356
 * more accurately than they really are.
357
 */
358
359
LOCAL(boolean)
360
smoothing_ok(j_decompress_ptr cinfo)
361
0
{
362
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
363
0
  boolean smoothing_useful = FALSE;
364
0
  int ci, coefi;
365
0
  jpeg_component_info *compptr;
366
0
  JQUANT_TBL *qtable;
367
0
  int *coef_bits, *prev_coef_bits;
368
0
  int *coef_bits_latch, *prev_coef_bits_latch;
369
370
0
  if (!cinfo->progressive_mode || cinfo->coef_bits == NULL)
371
0
    return FALSE;
372
373
  /* Allocate latch area if not already done */
374
0
  if (coef->coef_bits_latch == NULL)
375
0
    coef->coef_bits_latch = (int *)
376
0
      (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
377
0
                                  cinfo->num_components * 2 *
378
0
                                  (SAVED_COEFS * sizeof(int)));
379
0
  coef_bits_latch = coef->coef_bits_latch;
380
0
  prev_coef_bits_latch =
381
0
    &coef->coef_bits_latch[cinfo->num_components * SAVED_COEFS];
382
383
0
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
384
0
       ci++, compptr++) {
385
    /* All components' quantization values must already be latched. */
386
0
    if ((qtable = compptr->quant_table) == NULL)
387
0
      return FALSE;
388
    /* Verify DC & first 9 AC quantizers are nonzero to avoid zero-divide. */
389
0
    if (qtable->quantval[0] == 0 ||
390
0
        qtable->quantval[Q01_POS] == 0 ||
391
0
        qtable->quantval[Q10_POS] == 0 ||
392
0
        qtable->quantval[Q20_POS] == 0 ||
393
0
        qtable->quantval[Q11_POS] == 0 ||
394
0
        qtable->quantval[Q02_POS] == 0 ||
395
0
        qtable->quantval[Q03_POS] == 0 ||
396
0
        qtable->quantval[Q12_POS] == 0 ||
397
0
        qtable->quantval[Q21_POS] == 0 ||
398
0
        qtable->quantval[Q30_POS] == 0)
399
0
      return FALSE;
400
    /* DC values must be at least partly known for all components. */
401
0
    coef_bits = cinfo->coef_bits[ci];
402
0
    prev_coef_bits = cinfo->coef_bits[ci + cinfo->num_components];
403
0
    if (coef_bits[0] < 0)
404
0
      return FALSE;
405
0
    coef_bits_latch[0] = coef_bits[0];
406
    /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
407
0
    for (coefi = 1; coefi < SAVED_COEFS; coefi++) {
408
0
      if (cinfo->input_scan_number > 1)
409
0
        prev_coef_bits_latch[coefi] = prev_coef_bits[coefi];
410
0
      else
411
0
        prev_coef_bits_latch[coefi] = -1;
412
0
      coef_bits_latch[coefi] = coef_bits[coefi];
413
0
      if (coef_bits[coefi] != 0)
414
0
        smoothing_useful = TRUE;
415
0
    }
416
0
    coef_bits_latch += SAVED_COEFS;
417
0
    prev_coef_bits_latch += SAVED_COEFS;
418
0
  }
419
420
0
  return smoothing_useful;
421
0
}
422
423
424
/*
425
 * Variant of decompress_data for use when doing block smoothing.
426
 */
427
428
METHODDEF(int)
429
decompress_smooth_data(j_decompress_ptr cinfo, _JSAMPIMAGE output_buf)
430
0
{
431
0
  my_coef_ptr coef = (my_coef_ptr)cinfo->coef;
432
0
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
433
0
  JDIMENSION block_num, last_block_column;
434
0
  int ci, block_row, block_rows, access_rows, image_block_row,
435
0
    image_block_rows;
436
0
  JBLOCKARRAY buffer;
437
0
  JBLOCKROW buffer_ptr, prev_prev_block_row, prev_block_row;
438
0
  JBLOCKROW next_block_row, next_next_block_row;
439
0
  _JSAMPARRAY output_ptr;
440
0
  JDIMENSION output_col;
441
0
  jpeg_component_info *compptr;
442
0
  _inverse_DCT_method_ptr inverse_DCT;
443
0
  boolean change_dc;
444
0
  JCOEF *workspace;
445
0
  int *coef_bits;
446
0
  JQUANT_TBL *quanttbl;
447
0
  JLONG Q00, Q01, Q02, Q03 = 0, Q10, Q11, Q12 = 0, Q20, Q21 = 0, Q30 = 0, num;
448
0
  int DC01, DC02, DC03, DC04, DC05, DC06, DC07, DC08, DC09, DC10, DC11, DC12,
449
0
      DC13, DC14, DC15, DC16, DC17, DC18, DC19, DC20, DC21, DC22, DC23, DC24,
450
0
      DC25;
451
0
  int Al, pred;
452
453
  /* Keep a local variable to avoid looking it up more than once */
454
0
  workspace = coef->workspace;
455
456
  /* Force some input to be done if we are getting ahead of the input. */
457
0
  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
458
0
         !cinfo->inputctl->eoi_reached) {
459
0
    if (cinfo->input_scan_number == cinfo->output_scan_number) {
460
      /* If input is working on current scan, we ordinarily want it to
461
       * have completed the current row.  But if input scan is DC,
462
       * we want it to keep two rows ahead so that next two block rows' DC
463
       * values are up to date.
464
       */
465
0
      JDIMENSION delta = (cinfo->Ss == 0) ? 2 : 0;
466
0
      if (cinfo->input_iMCU_row > cinfo->output_iMCU_row + delta)
467
0
        break;
468
0
    }
469
0
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
470
0
      return JPEG_SUSPENDED;
471
0
  }
472
473
  /* OK, output from the virtual arrays. */
474
0
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
475
0
       ci++, compptr++) {
476
    /* Don't bother to IDCT an uninteresting component. */
477
0
    if (!compptr->component_needed)
478
0
      continue;
479
    /* Count non-dummy DCT block rows in this iMCU row. */
480
0
    if (cinfo->output_iMCU_row + 1 < last_iMCU_row) {
481
0
      block_rows = compptr->v_samp_factor;
482
0
      access_rows = block_rows * 3; /* this and next two iMCU rows */
483
0
    } else if (cinfo->output_iMCU_row < last_iMCU_row) {
484
0
      block_rows = compptr->v_samp_factor;
485
0
      access_rows = block_rows * 2; /* this and next iMCU row */
486
0
    } else {
487
      /* NB: can't use last_row_height here; it is input-side-dependent! */
488
0
      block_rows = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
489
0
      if (block_rows == 0) block_rows = compptr->v_samp_factor;
490
0
      access_rows = block_rows; /* this iMCU row only */
491
0
    }
492
    /* Align the virtual buffer for this component. */
493
0
    if (cinfo->output_iMCU_row > 1) {
494
0
      access_rows += 2 * compptr->v_samp_factor; /* prior two iMCU rows too */
495
0
      buffer = (*cinfo->mem->access_virt_barray)
496
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
497
0
         (cinfo->output_iMCU_row - 2) * compptr->v_samp_factor,
498
0
         (JDIMENSION)access_rows, FALSE);
499
0
      buffer += 2 * compptr->v_samp_factor; /* point to current iMCU row */
500
0
    } else if (cinfo->output_iMCU_row > 0) {
501
0
      access_rows += compptr->v_samp_factor; /* prior iMCU row too */
502
0
      buffer = (*cinfo->mem->access_virt_barray)
503
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
504
0
         (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
505
0
         (JDIMENSION)access_rows, FALSE);
506
0
      buffer += compptr->v_samp_factor; /* point to current iMCU row */
507
0
    } else {
508
0
      buffer = (*cinfo->mem->access_virt_barray)
509
0
        ((j_common_ptr)cinfo, coef->whole_image[ci],
510
0
         (JDIMENSION)0, (JDIMENSION)access_rows, FALSE);
511
0
    }
512
    /* Fetch component-dependent info.
513
     * If the current scan is incomplete, then we use the component-dependent
514
     * info from the previous scan.
515
     */
516
0
    if (cinfo->output_iMCU_row > cinfo->master->last_good_iMCU_row)
517
0
      coef_bits =
518
0
        coef->coef_bits_latch + ((ci + cinfo->num_components) * SAVED_COEFS);
519
0
    else
520
0
      coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
521
522
    /* We only do DC interpolation if no AC coefficient data is available. */
523
0
    change_dc =
524
0
      coef_bits[1] == -1 && coef_bits[2] == -1 && coef_bits[3] == -1 &&
525
0
      coef_bits[4] == -1 && coef_bits[5] == -1 && coef_bits[6] == -1 &&
526
0
      coef_bits[7] == -1 && coef_bits[8] == -1 && coef_bits[9] == -1;
527
528
0
    quanttbl = compptr->quant_table;
529
0
    Q00 = quanttbl->quantval[0];
530
0
    Q01 = quanttbl->quantval[Q01_POS];
531
0
    Q10 = quanttbl->quantval[Q10_POS];
532
0
    Q20 = quanttbl->quantval[Q20_POS];
533
0
    Q11 = quanttbl->quantval[Q11_POS];
534
0
    Q02 = quanttbl->quantval[Q02_POS];
535
0
    if (change_dc) {
536
0
      Q03 = quanttbl->quantval[Q03_POS];
537
0
      Q12 = quanttbl->quantval[Q12_POS];
538
0
      Q21 = quanttbl->quantval[Q21_POS];
539
0
      Q30 = quanttbl->quantval[Q30_POS];
540
0
    }
541
0
    inverse_DCT = cinfo->idct->_inverse_DCT[ci];
542
0
    output_ptr = output_buf[ci];
543
    /* Loop over all DCT blocks to be processed. */
544
0
    image_block_rows = block_rows * cinfo->total_iMCU_rows;
545
0
    for (block_row = 0; block_row < block_rows; block_row++) {
546
0
      image_block_row = cinfo->output_iMCU_row * block_rows + block_row;
547
0
      buffer_ptr = buffer[block_row] + cinfo->master->first_MCU_col[ci];
548
549
0
      if (image_block_row > 0)
550
0
        prev_block_row =
551
0
          buffer[block_row - 1] + cinfo->master->first_MCU_col[ci];
552
0
      else
553
0
        prev_block_row = buffer_ptr;
554
555
0
      if (image_block_row > 1)
556
0
        prev_prev_block_row =
557
0
          buffer[block_row - 2] + cinfo->master->first_MCU_col[ci];
558
0
      else
559
0
        prev_prev_block_row = prev_block_row;
560
561
0
      if (image_block_row < image_block_rows - 1)
562
0
        next_block_row =
563
0
          buffer[block_row + 1] + cinfo->master->first_MCU_col[ci];
564
0
      else
565
0
        next_block_row = buffer_ptr;
566
567
0
      if (image_block_row < image_block_rows - 2)
568
0
        next_next_block_row =
569
0
          buffer[block_row + 2] + cinfo->master->first_MCU_col[ci];
570
0
      else
571
0
        next_next_block_row = next_block_row;
572
573
      /* We fetch the surrounding DC values using a sliding-register approach.
574
       * Initialize all 25 here so as to do the right thing on narrow pics.
575
       */
576
0
      DC01 = DC02 = DC03 = DC04 = DC05 = (int)prev_prev_block_row[0][0];
577
0
      DC06 = DC07 = DC08 = DC09 = DC10 = (int)prev_block_row[0][0];
578
0
      DC11 = DC12 = DC13 = DC14 = DC15 = (int)buffer_ptr[0][0];
579
0
      DC16 = DC17 = DC18 = DC19 = DC20 = (int)next_block_row[0][0];
580
0
      DC21 = DC22 = DC23 = DC24 = DC25 = (int)next_next_block_row[0][0];
581
0
      output_col = 0;
582
0
      last_block_column = compptr->width_in_blocks - 1;
583
0
      for (block_num = cinfo->master->first_MCU_col[ci];
584
0
           block_num <= cinfo->master->last_MCU_col[ci]; block_num++) {
585
        /* Fetch current DCT block into workspace so we can modify it. */
586
0
        jcopy_block_row(buffer_ptr, (JBLOCKROW)workspace, (JDIMENSION)1);
587
        /* Update DC values */
588
0
        if (block_num == cinfo->master->first_MCU_col[ci] &&
589
0
            block_num < last_block_column) {
590
0
          DC04 = DC05 = (int)prev_prev_block_row[1][0];
591
0
          DC09 = DC10 = (int)prev_block_row[1][0];
592
0
          DC14 = DC15 = (int)buffer_ptr[1][0];
593
0
          DC19 = DC20 = (int)next_block_row[1][0];
594
0
          DC24 = DC25 = (int)next_next_block_row[1][0];
595
0
        }
596
0
        if (block_num + 1 < last_block_column) {
597
0
          DC05 = (int)prev_prev_block_row[2][0];
598
0
          DC10 = (int)prev_block_row[2][0];
599
0
          DC15 = (int)buffer_ptr[2][0];
600
0
          DC20 = (int)next_block_row[2][0];
601
0
          DC25 = (int)next_next_block_row[2][0];
602
0
        }
603
        /* If DC interpolation is enabled, compute coefficient estimates using
604
         * a Gaussian-like kernel, keeping the averages of the DC values.
605
         *
606
         * If DC interpolation is disabled, compute coefficient estimates using
607
         * an algorithm similar to the one described in Section K.8 of the JPEG
608
         * standard, except applied to a 5x5 window rather than a 3x3 window.
609
         *
610
         * An estimate is applied only if the coefficient is still zero and is
611
         * not known to be fully accurate.
612
         */
613
        /* AC01 */
614
0
        if ((Al = coef_bits[1]) != 0 && workspace[1] == 0) {
615
0
          num = Q00 * (change_dc ?
616
0
                (-DC01 - DC02 + DC04 + DC05 - 3 * DC06 + 13 * DC07 -
617
0
                 13 * DC09 + 3 * DC10 - 3 * DC11 + 38 * DC12 - 38 * DC14 +
618
0
                 3 * DC15 - 3 * DC16 + 13 * DC17 - 13 * DC19 + 3 * DC20 -
619
0
                 DC21 - DC22 + DC24 + DC25) :
620
0
                (-7 * DC11 + 50 * DC12 - 50 * DC14 + 7 * DC15));
621
0
          if (num >= 0) {
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
          } else {
626
0
            pred = (int)(((Q01 << 7) - num) / (Q01 << 8));
627
0
            if (Al > 0 && pred >= (1 << Al))
628
0
              pred = (1 << Al) - 1;
629
0
            pred = -pred;
630
0
          }
631
0
          workspace[1] = (JCOEF)pred;
632
0
        }
633
        /* AC10 */
634
0
        if ((Al = coef_bits[2]) != 0 && workspace[8] == 0) {
635
0
          num = Q00 * (change_dc ?
636
0
                (-DC01 - 3 * DC02 - 3 * DC03 - 3 * DC04 - DC05 - DC06 +
637
0
                 13 * DC07 + 38 * DC08 + 13 * DC09 - DC10 + DC16 -
638
0
                 13 * DC17 - 38 * DC18 - 13 * DC19 + DC20 + DC21 +
639
0
                 3 * DC22 + 3 * DC23 + 3 * DC24 + DC25) :
640
0
                (-7 * DC03 + 50 * DC08 - 50 * DC18 + 7 * DC23));
641
0
          if (num >= 0) {
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
          } else {
646
0
            pred = (int)(((Q10 << 7) - num) / (Q10 << 8));
647
0
            if (Al > 0 && pred >= (1 << Al))
648
0
              pred = (1 << Al) - 1;
649
0
            pred = -pred;
650
0
          }
651
0
          workspace[8] = (JCOEF)pred;
652
0
        }
653
        /* AC20 */
654
0
        if ((Al = coef_bits[3]) != 0 && workspace[16] == 0) {
655
0
          num = Q00 * (change_dc ?
656
0
                (DC03 + 2 * DC07 + 7 * DC08 + 2 * DC09 - 5 * DC12 - 14 * DC13 -
657
0
                 5 * DC14 + 2 * DC17 + 7 * DC18 + 2 * DC19 + DC23) :
658
0
                (-DC03 + 13 * DC08 - 24 * DC13 + 13 * DC18 - DC23));
659
0
          if (num >= 0) {
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
          } else {
664
0
            pred = (int)(((Q20 << 7) - num) / (Q20 << 8));
665
0
            if (Al > 0 && pred >= (1 << Al))
666
0
              pred = (1 << Al) - 1;
667
0
            pred = -pred;
668
0
          }
669
0
          workspace[16] = (JCOEF)pred;
670
0
        }
671
        /* AC11 */
672
0
        if ((Al = coef_bits[4]) != 0 && workspace[9] == 0) {
673
0
          num = Q00 * (change_dc ?
674
0
                (-DC01 + DC05 + 9 * DC07 - 9 * DC09 - 9 * DC17 +
675
0
                 9 * DC19 + DC21 - DC25) :
676
0
                (DC10 + DC16 - 10 * DC17 + 10 * DC19 - DC02 - DC20 + DC22 -
677
0
                 DC24 + DC04 - DC06 + 10 * DC07 - 10 * DC09));
678
0
          if (num >= 0) {
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
          } else {
683
0
            pred = (int)(((Q11 << 7) - num) / (Q11 << 8));
684
0
            if (Al > 0 && pred >= (1 << Al))
685
0
              pred = (1 << Al) - 1;
686
0
            pred = -pred;
687
0
          }
688
0
          workspace[9] = (JCOEF)pred;
689
0
        }
690
        /* AC02 */
691
0
        if ((Al = coef_bits[5]) != 0 && workspace[2] == 0) {
692
0
          num = Q00 * (change_dc ?
693
0
                (2 * DC07 - 5 * DC08 + 2 * DC09 + DC11 + 7 * DC12 - 14 * DC13 +
694
0
                 7 * DC14 + DC15 + 2 * DC17 - 5 * DC18 + 2 * DC19) :
695
0
                (-DC11 + 13 * DC12 - 24 * DC13 + 13 * DC14 - DC15));
696
0
          if (num >= 0) {
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
          } else {
701
0
            pred = (int)(((Q02 << 7) - num) / (Q02 << 8));
702
0
            if (Al > 0 && pred >= (1 << Al))
703
0
              pred = (1 << Al) - 1;
704
0
            pred = -pred;
705
0
          }
706
0
          workspace[2] = (JCOEF)pred;
707
0
        }
708
0
        if (change_dc) {
709
          /* AC03 */
710
0
          if ((Al = coef_bits[6]) != 0 && workspace[3] == 0) {
711
0
            num = Q00 * (DC07 - DC09 + 2 * DC12 - 2 * DC14 + DC17 - DC19);
712
0
            if (num >= 0) {
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
            } else {
717
0
              pred = (int)(((Q03 << 7) - num) / (Q03 << 8));
718
0
              if (Al > 0 && pred >= (1 << Al))
719
0
                pred = (1 << Al) - 1;
720
0
              pred = -pred;
721
0
            }
722
0
            workspace[3] = (JCOEF)pred;
723
0
          }
724
          /* AC12 */
725
0
          if ((Al = coef_bits[7]) != 0 && workspace[10] == 0) {
726
0
            num = Q00 * (DC07 - 3 * DC08 + DC09 - DC17 + 3 * DC18 - DC19);
727
0
            if (num >= 0) {
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
            } else {
732
0
              pred = (int)(((Q12 << 7) - num) / (Q12 << 8));
733
0
              if (Al > 0 && pred >= (1 << Al))
734
0
                pred = (1 << Al) - 1;
735
0
              pred = -pred;
736
0
            }
737
0
            workspace[10] = (JCOEF)pred;
738
0
          }
739
          /* AC21 */
740
0
          if ((Al = coef_bits[8]) != 0 && workspace[17] == 0) {
741
0
            num = Q00 * (DC07 - DC09 - 3 * DC12 + 3 * DC14 + DC17 - DC19);
742
0
            if (num >= 0) {
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
            } else {
747
0
              pred = (int)(((Q21 << 7) - num) / (Q21 << 8));
748
0
              if (Al > 0 && pred >= (1 << Al))
749
0
                pred = (1 << Al) - 1;
750
0
              pred = -pred;
751
0
            }
752
0
            workspace[17] = (JCOEF)pred;
753
0
          }
754
          /* AC30 */
755
0
          if ((Al = coef_bits[9]) != 0 && workspace[24] == 0) {
756
0
            num = Q00 * (DC07 + 2 * DC08 + DC09 - DC17 - 2 * DC18 - DC19);
757
0
            if (num >= 0) {
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
            } else {
762
0
              pred = (int)(((Q30 << 7) - num) / (Q30 << 8));
763
0
              if (Al > 0 && pred >= (1 << Al))
764
0
                pred = (1 << Al) - 1;
765
0
              pred = -pred;
766
0
            }
767
0
            workspace[24] = (JCOEF)pred;
768
0
          }
769
          /* coef_bits[0] is non-negative.  Otherwise this function would not
770
           * be called.
771
           */
772
0
          num = Q00 *
773
0
                (-2 * DC01 - 6 * DC02 - 8 * DC03 - 6 * DC04 - 2 * DC05 -
774
0
                 6 * DC06 + 6 * DC07 + 42 * DC08 + 6 * DC09 - 6 * DC10 -
775
0
                 8 * DC11 + 42 * DC12 + 152 * DC13 + 42 * DC14 - 8 * DC15 -
776
0
                 6 * DC16 + 6 * DC17 + 42 * DC18 + 6 * DC19 - 6 * DC20 -
777
0
                 2 * DC21 - 6 * DC22 - 8 * DC23 - 6 * DC24 - 2 * DC25);
778
0
          if (num >= 0) {
779
0
            pred = (int)(((Q00 << 7) + num) / (Q00 << 8));
780
0
          } else {
781
0
            pred = (int)(((Q00 << 7) - num) / (Q00 << 8));
782
0
            pred = -pred;
783
0
          }
784
0
          workspace[0] = (JCOEF)pred;
785
0
        }  /* change_dc */
786
787
        /* OK, do the IDCT */
788
0
        (*inverse_DCT) (cinfo, compptr, (JCOEFPTR)workspace, output_ptr,
789
0
                        output_col);
790
        /* Advance for next column */
791
0
        DC01 = DC02;  DC02 = DC03;  DC03 = DC04;  DC04 = DC05;
792
0
        DC06 = DC07;  DC07 = DC08;  DC08 = DC09;  DC09 = DC10;
793
0
        DC11 = DC12;  DC12 = DC13;  DC13 = DC14;  DC14 = DC15;
794
0
        DC16 = DC17;  DC17 = DC18;  DC18 = DC19;  DC19 = DC20;
795
0
        DC21 = DC22;  DC22 = DC23;  DC23 = DC24;  DC24 = DC25;
796
0
        buffer_ptr++, prev_block_row++, next_block_row++,
797
0
          prev_prev_block_row++, next_next_block_row++;
798
0
        output_col += compptr->_DCT_scaled_size;
799
0
      }
800
0
      output_ptr += compptr->_DCT_scaled_size;
801
0
    }
802
0
  }
803
804
0
  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
805
0
    return JPEG_ROW_COMPLETED;
806
0
  return JPEG_SCAN_COMPLETED;
807
0
}
808
809
#endif /* BLOCK_SMOOTHING_SUPPORTED */
810
811
812
/*
813
 * Initialize coefficient buffer controller.
814
 */
815
816
GLOBAL(void)
817
_jinit_d_coef_controller(j_decompress_ptr cinfo, boolean need_full_buffer)
818
0
{
819
0
  my_coef_ptr coef;
820
821
0
  if (cinfo->data_precision != BITS_IN_JSAMPLE)
822
0
    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
823
824
0
  coef = (my_coef_ptr)
825
0
    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
826
0
                                sizeof(my_coef_controller));
827
0
  cinfo->coef = (struct jpeg_d_coef_controller *)coef;
828
0
  coef->pub.start_input_pass = start_input_pass;
829
0
  coef->pub.start_output_pass = start_output_pass;
830
0
#ifdef BLOCK_SMOOTHING_SUPPORTED
831
0
  coef->coef_bits_latch = NULL;
832
0
#endif
833
834
  /* Create the coefficient buffer. */
835
0
  if (need_full_buffer) {
836
0
#ifdef D_MULTISCAN_FILES_SUPPORTED
837
    /* Allocate a full-image virtual array for each component, */
838
    /* padded to a multiple of samp_factor DCT blocks in each direction. */
839
    /* Note we ask for a pre-zeroed array. */
840
0
    int ci, access_rows;
841
0
    jpeg_component_info *compptr;
842
843
0
    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
844
0
         ci++, compptr++) {
845
0
      access_rows = compptr->v_samp_factor;
846
0
#ifdef BLOCK_SMOOTHING_SUPPORTED
847
      /* If block smoothing could be used, need a bigger window */
848
0
      if (cinfo->progressive_mode)
849
0
        access_rows *= 5;
850
0
#endif
851
0
      coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
852
0
        ((j_common_ptr)cinfo, JPOOL_IMAGE, TRUE,
853
0
         (JDIMENSION)jround_up((long)compptr->width_in_blocks,
854
0
                               (long)compptr->h_samp_factor),
855
0
         (JDIMENSION)jround_up((long)compptr->height_in_blocks,
856
0
                               (long)compptr->v_samp_factor),
857
0
         (JDIMENSION)access_rows);
858
0
    }
859
0
    coef->pub.consume_data = consume_data;
860
0
    coef->pub._decompress_data = decompress_data;
861
0
    coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
862
#else
863
    ERREXIT(cinfo, JERR_NOT_COMPILED);
864
#endif
865
0
  } else {
866
    /* We only need a single-MCU buffer. */
867
0
    JBLOCKROW buffer;
868
0
    int i;
869
870
0
    buffer = (JBLOCKROW)
871
0
      (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE,
872
0
                                  D_MAX_BLOCKS_IN_MCU * sizeof(JBLOCK));
873
0
    for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
874
0
      coef->MCU_buffer[i] = buffer + i;
875
0
    }
876
0
    coef->pub.consume_data = dummy_consume_data;
877
0
    coef->pub._decompress_data = decompress_onepass;
878
0
    coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
879
0
  }
880
881
  /* Allocate the workspace buffer */
882
0
  coef->workspace = (JCOEF *)
883
0
    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
884
0
                                sizeof(JCOEF) * DCTSIZE2);
885
0
}
Unexecuted instantiation: j12init_d_coef_controller
Unexecuted instantiation: jinit_d_coef_controller