jdcoefct.c
Go to the documentation of this file.
1 /*
2  * jdcoefct.c
3  *
4  * Copyright (C) 1994-1997, Thomas G. Lane.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This file contains the coefficient buffer controller for decompression.
9  * This controller is the top level of the JPEG decompressor proper.
10  * The coefficient buffer lies between entropy decoding and inverse-DCT steps.
11  *
12  * In buffered-image mode, this controller is the interface between
13  * input-oriented processing and output-oriented processing.
14  * Also, the input side (only) is used when reading a file for transcoding.
15  */
16 
17 #define JPEG_INTERNALS
18 #include "jinclude.h"
19 #include "jpeglib.h"
20 
21 /* Block smoothing is only applicable for progressive JPEG, so: */
22 #ifndef D_PROGRESSIVE_SUPPORTED
23 #undef BLOCK_SMOOTHING_SUPPORTED
24 #endif
25 
26 /* Private buffer controller object */
27 
28 typedef struct {
29  struct jpeg_d_coef_controller pub; /* public fields */
30 
31  /* These variables keep track of the current location of the input side. */
32  /* cinfo->input_iMCU_row is also used for this. */
33  JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
34  int MCU_vert_offset; /* counts MCU rows within iMCU row */
35  int MCU_rows_per_iMCU_row; /* number of such rows needed */
36 
37  /* The output side's location is represented by cinfo->output_iMCU_row. */
38 
39  /* In single-pass modes, it's sufficient to buffer just one MCU.
40  * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
41  * and let the entropy decoder write into that workspace each time.
42  * (On 80x86, the workspace is FAR even though it's not really very big;
43  * this is to keep the module interfaces unchanged when a large coefficient
44  * buffer is necessary.)
45  * In multi-pass modes, this array points to the current MCU's blocks
46  * within the virtual arrays; it is used only by the input side.
47  */
48  JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
49 
50 #ifdef D_MULTISCAN_FILES_SUPPORTED
51  /* In multi-pass modes, we need a virtual block array for each component. */
52  jvirt_barray_ptr whole_image[MAX_COMPONENTS];
53 #endif
54 
55 #ifdef BLOCK_SMOOTHING_SUPPORTED
56  /* When doing block smoothing, we latch coefficient Al values here */
58 #define SAVED_COEFS 6 /* we save coef_bits[0..5] */
59 #endif
61 
63 
64 /* Forward declarations */
67 #ifdef D_MULTISCAN_FILES_SUPPORTED
70 #endif
71 #ifdef BLOCK_SMOOTHING_SUPPORTED
72 LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo));
75 #endif
76 
77 
78 LOCAL(void)
80 /* Reset within-iMCU-row counters for a new row (input side) */
81 {
82  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
83 
84  /* In an interleaved scan, an MCU row is the same as an iMCU row.
85  * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
86  * But at the bottom of the image, process only what's left.
87  */
88  if (cinfo->comps_in_scan > 1) {
89  coef->MCU_rows_per_iMCU_row = 1;
90  } else {
91  if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
93  else
95  }
96 
97  coef->MCU_ctr = 0;
98  coef->MCU_vert_offset = 0;
99 }
100 
101 
102 /*
103  * Initialize for an input processing pass.
104  */
105 
106 METHODDEF(void)
108 {
109  cinfo->input_iMCU_row = 0;
110  start_iMCU_row(cinfo);
111 }
112 
113 
114 /*
115  * Initialize for an output processing pass.
116  */
117 
118 METHODDEF(void)
120 {
121 #ifdef BLOCK_SMOOTHING_SUPPORTED
122  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
123 
124  /* If multipass, check to see whether to use block smoothing on this pass */
125  if (coef->pub.coef_arrays != NULL) {
126  if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
127  coef->pub.decompress_data = decompress_smooth_data;
128  else
129  coef->pub.decompress_data = decompress_data;
130  }
131 #endif
132  cinfo->output_iMCU_row = 0;
133 }
134 
135 
136 /*
137  * Decompress and return some data in the single-pass case.
138  * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
139  * Input and output must run in lockstep since we have only a one-MCU buffer.
140  * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
141  *
142  * NB: output_buf contains a plane for each component in image,
143  * which we index according to the component's SOF position.
144  */
145 
146 METHODDEF(int)
148 {
149  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
150  JDIMENSION MCU_col_num; /* index of current MCU within row */
151  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
152  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
153  int blkn, ci, xindex, yindex, yoffset, useful_width;
154  JSAMPARRAY output_ptr;
155  JDIMENSION start_col, output_col;
157  inverse_DCT_method_ptr inverse_DCT;
158 
159  /* Loop to process as much as one whole iMCU row */
160  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
161  yoffset++) {
162  for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
163  MCU_col_num++) {
164  /* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */
165  jzero_far((void FAR *) coef->MCU_buffer[0],
166  (size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK)));
167  if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
168  /* Suspension forced; update state counters and exit */
169  coef->MCU_vert_offset = yoffset;
170  coef->MCU_ctr = MCU_col_num;
171  return JPEG_SUSPENDED;
172  }
173  /* Determine where data should go in output_buf and do the IDCT thing.
174  * We skip dummy blocks at the right and bottom edges (but blkn gets
175  * incremented past them!). Note the inner loop relies on having
176  * allocated the MCU_buffer[] blocks sequentially.
177  */
178  blkn = 0; /* index of current DCT block within MCU */
179  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
180  compptr = cinfo->cur_comp_info[ci];
181  /* Don't bother to IDCT an uninteresting component. */
182  if (! compptr->component_needed) {
183  blkn += compptr->MCU_blocks;
184  continue;
185  }
186  inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
187  useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
189  output_ptr = output_buf[compptr->component_index] +
190  yoffset * compptr->DCT_scaled_size;
191  start_col = MCU_col_num * compptr->MCU_sample_width;
192  for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
193  if (cinfo->input_iMCU_row < last_iMCU_row ||
194  yoffset+yindex < compptr->last_row_height) {
195  output_col = start_col;
196  for (xindex = 0; xindex < useful_width; xindex++) {
197  (*inverse_DCT) (cinfo, compptr,
198  (JCOEFPTR) coef->MCU_buffer[blkn+xindex],
199  output_ptr, output_col);
201  }
202  }
203  blkn += compptr->MCU_width;
204  output_ptr += compptr->DCT_scaled_size;
205  }
206  }
207  }
208  /* Completed an MCU row, but perhaps not an iMCU row */
209  coef->MCU_ctr = 0;
210  }
211  /* Completed the iMCU row, advance counters for next one */
212  cinfo->output_iMCU_row++;
213  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
214  start_iMCU_row(cinfo);
215  return JPEG_ROW_COMPLETED;
216  }
217  /* Completed the scan */
218  (*cinfo->inputctl->finish_input_pass) (cinfo);
219  return JPEG_SCAN_COMPLETED;
220 }
221 
222 
223 /*
224  * Dummy consume-input routine for single-pass operation.
225  */
226 
227 METHODDEF(int)
229 {
230  return JPEG_SUSPENDED; /* Always indicate nothing was done */
231 }
232 
233 
234 #ifdef D_MULTISCAN_FILES_SUPPORTED
235 
236 /*
237  * Consume input data and store it in the full-image coefficient buffer.
238  * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
239  * ie, v_samp_factor block rows for each component in the scan.
240  * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
241  */
242 
243 METHODDEF(int)
245 {
246  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
247  JDIMENSION MCU_col_num; /* index of current MCU within row */
248  int blkn, ci, xindex, yindex, yoffset;
249  JDIMENSION start_col;
251  JBLOCKROW buffer_ptr;
253 
254  /* Align the virtual buffers for the components used in this scan. */
255  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
256  compptr = cinfo->cur_comp_info[ci];
257  buffer[ci] = (*cinfo->mem->access_virt_barray)
259  cinfo->input_iMCU_row * compptr->v_samp_factor,
261  /* Note: entropy decoder expects buffer to be zeroed,
262  * but this is handled automatically by the memory manager
263  * because we requested a pre-zeroed array.
264  */
265  }
266 
267  /* Loop to process one whole iMCU row */
268  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
269  yoffset++) {
270  for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
271  MCU_col_num++) {
272  /* Construct list of pointers to DCT blocks belonging to this MCU */
273  blkn = 0; /* index of current DCT block within MCU */
274  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
275  compptr = cinfo->cur_comp_info[ci];
276  start_col = MCU_col_num * compptr->MCU_width;
277  for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
278  buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
279  for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
280  coef->MCU_buffer[blkn++] = buffer_ptr++;
281  }
282  }
283  }
284  /* Try to fetch the MCU. */
285  if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
286  /* Suspension forced; update state counters and exit */
287  coef->MCU_vert_offset = yoffset;
288  coef->MCU_ctr = MCU_col_num;
289  return JPEG_SUSPENDED;
290  }
291  }
292  /* Completed an MCU row, but perhaps not an iMCU row */
293  coef->MCU_ctr = 0;
294  }
295  /* Completed the iMCU row, advance counters for next one */
296  if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
297  start_iMCU_row(cinfo);
298  return JPEG_ROW_COMPLETED;
299  }
300  /* Completed the scan */
301  (*cinfo->inputctl->finish_input_pass) (cinfo);
302  return JPEG_SCAN_COMPLETED;
303 }
304 
305 
306 /*
307  * Decompress and return some data in the multi-pass case.
308  * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
309  * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
310  *
311  * NB: output_buf contains a plane for each component in image.
312  */
313 
314 METHODDEF(int)
316 {
317  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
318  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
319  JDIMENSION block_num;
320  int ci, block_row, block_rows;
322  JBLOCKROW buffer_ptr;
323  JSAMPARRAY output_ptr;
326  inverse_DCT_method_ptr inverse_DCT;
327 
328  /* Force some input to be done if we are getting ahead of the input. */
329  while (cinfo->input_scan_number < cinfo->output_scan_number ||
330  (cinfo->input_scan_number == cinfo->output_scan_number &&
331  cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
332  if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
333  return JPEG_SUSPENDED;
334  }
335 
336  /* OK, output from the virtual arrays. */
337  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
338  ci++, compptr++) {
339  /* Don't bother to IDCT an uninteresting component. */
340  if (! compptr->component_needed)
341  continue;
342  /* Align the virtual buffer for this component. */
343  buffer = (*cinfo->mem->access_virt_barray)
344  ((j_common_ptr) cinfo, coef->whole_image[ci],
345  cinfo->output_iMCU_row * compptr->v_samp_factor,
347  /* Count non-dummy DCT block rows in this iMCU row. */
348  if (cinfo->output_iMCU_row < last_iMCU_row)
349  block_rows = compptr->v_samp_factor;
350  else {
351  /* NB: can't use last_row_height here; it is input-side-dependent! */
352  block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
353  if (block_rows == 0) block_rows = compptr->v_samp_factor;
354  }
355  inverse_DCT = cinfo->idct->inverse_DCT[ci];
356  output_ptr = output_buf[ci];
357  /* Loop over all DCT blocks to be processed. */
358  for (block_row = 0; block_row < block_rows; block_row++) {
359  buffer_ptr = buffer[block_row];
360  output_col = 0;
361  for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) {
362  (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr,
363  output_ptr, output_col);
364  buffer_ptr++;
366  }
367  output_ptr += compptr->DCT_scaled_size;
368  }
369  }
370 
371  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
372  return JPEG_ROW_COMPLETED;
373  return JPEG_SCAN_COMPLETED;
374 }
375 
376 #endif /* D_MULTISCAN_FILES_SUPPORTED */
377 
378 
379 #ifdef BLOCK_SMOOTHING_SUPPORTED
380 
381 /*
382  * This code applies interblock smoothing as described by section K.8
383  * of the JPEG standard: the first 5 AC coefficients are estimated from
384  * the DC values of a DCT block and its 8 neighboring blocks.
385  * We apply smoothing only for progressive JPEG decoding, and only if
386  * the coefficients it can estimate are not yet known to full precision.
387  */
388 
389 /* Natural-order array positions of the first 5 zigzag-order coefficients */
390 #define Q01_POS 1
391 #define Q10_POS 8
392 #define Q20_POS 16
393 #define Q11_POS 9
394 #define Q02_POS 2
395 
396 /*
397  * Determine whether block smoothing is applicable and safe.
398  * We also latch the current states of the coef_bits[] entries for the
399  * AC coefficients; otherwise, if the input side of the decompressor
400  * advances into a new scan, we might think the coefficients are known
401  * more accurately than they really are.
402  */
403 
404 LOCAL(boolean)
406 {
407  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
408  boolean smoothing_useful = FALSE;
409  int ci, coefi;
411  JQUANT_TBL * qtable;
412  int * coef_bits;
413  int * coef_bits_latch;
414 
415  if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)
416  return FALSE;
417 
418  /* Allocate latch area if not already done */
419  if (coef->coef_bits_latch == NULL)
420  coef->coef_bits_latch = (int *)
421  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
422  cinfo->num_components *
423  (SAVED_COEFS * SIZEOF(int)));
424  coef_bits_latch = coef->coef_bits_latch;
425 
426  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
427  ci++, compptr++) {
428  /* All components' quantization values must already be latched. */
429  if ((qtable = compptr->quant_table) == NULL)
430  return FALSE;
431  /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
432  if (qtable->quantval[0] == 0 ||
433  qtable->quantval[Q01_POS] == 0 ||
434  qtable->quantval[Q10_POS] == 0 ||
435  qtable->quantval[Q20_POS] == 0 ||
436  qtable->quantval[Q11_POS] == 0 ||
437  qtable->quantval[Q02_POS] == 0)
438  return FALSE;
439  /* DC values must be at least partly known for all components. */
440  coef_bits = cinfo->coef_bits[ci];
441  if (coef_bits[0] < 0)
442  return FALSE;
443  /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
444  for (coefi = 1; coefi <= 5; coefi++) {
445  coef_bits_latch[coefi] = coef_bits[coefi];
446  if (coef_bits[coefi] != 0)
447  smoothing_useful = TRUE;
448  }
449  coef_bits_latch += SAVED_COEFS;
450  }
451 
452  return smoothing_useful;
453 }
454 
455 
456 /*
457  * Variant of decompress_data for use when doing block smoothing.
458  */
459 
460 METHODDEF(int)
462 {
463  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
464  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
465  JDIMENSION block_num, last_block_column;
466  int ci, block_row, block_rows, access_rows;
468  JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
469  JSAMPARRAY output_ptr;
472  inverse_DCT_method_ptr inverse_DCT;
473  boolean first_row, last_row;
474  JBLOCK workspace;
475  int *coef_bits;
476  JQUANT_TBL *quanttbl;
477  INT32 Q00,Q01,Q02,Q10,Q11,Q20, num;
478  int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9;
479  int Al, pred;
480 
481  /* Force some input to be done if we are getting ahead of the input. */
482  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
483  ! cinfo->inputctl->eoi_reached) {
484  if (cinfo->input_scan_number == cinfo->output_scan_number) {
485  /* If input is working on current scan, we ordinarily want it to
486  * have completed the current row. But if input scan is DC,
487  * we want it to keep one row ahead so that next block row's DC
488  * values are up to date.
489  */
490  JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;
491  if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta)
492  break;
493  }
494  if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
495  return JPEG_SUSPENDED;
496  }
497 
498  /* OK, output from the virtual arrays. */
499  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
500  ci++, compptr++) {
501  /* Don't bother to IDCT an uninteresting component. */
502  if (! compptr->component_needed)
503  continue;
504  /* Count non-dummy DCT block rows in this iMCU row. */
505  if (cinfo->output_iMCU_row < last_iMCU_row) {
506  block_rows = compptr->v_samp_factor;
507  access_rows = block_rows * 2; /* this and next iMCU row */
508  last_row = FALSE;
509  } else {
510  /* NB: can't use last_row_height here; it is input-side-dependent! */
511  block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
512  if (block_rows == 0) block_rows = compptr->v_samp_factor;
513  access_rows = block_rows; /* this iMCU row only */
514  last_row = TRUE;
515  }
516  /* Align the virtual buffer for this component. */
517  if (cinfo->output_iMCU_row > 0) {
518  access_rows += compptr->v_samp_factor; /* prior iMCU row too */
519  buffer = (*cinfo->mem->access_virt_barray)
520  ((j_common_ptr) cinfo, coef->whole_image[ci],
521  (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
522  (JDIMENSION) access_rows, FALSE);
523  buffer += compptr->v_samp_factor; /* point to current iMCU row */
524  first_row = FALSE;
525  } else {
526  buffer = (*cinfo->mem->access_virt_barray)
527  ((j_common_ptr) cinfo, coef->whole_image[ci],
528  (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE);
529  first_row = TRUE;
530  }
531  /* Fetch component-dependent info */
532  coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
533  quanttbl = compptr->quant_table;
534  Q00 = quanttbl->quantval[0];
535  Q01 = quanttbl->quantval[Q01_POS];
536  Q10 = quanttbl->quantval[Q10_POS];
537  Q20 = quanttbl->quantval[Q20_POS];
538  Q11 = quanttbl->quantval[Q11_POS];
539  Q02 = quanttbl->quantval[Q02_POS];
540  inverse_DCT = cinfo->idct->inverse_DCT[ci];
541  output_ptr = output_buf[ci];
542  /* Loop over all DCT blocks to be processed. */
543  for (block_row = 0; block_row < block_rows; block_row++) {
544  buffer_ptr = buffer[block_row];
545  if (first_row && block_row == 0)
546  prev_block_row = buffer_ptr;
547  else
548  prev_block_row = buffer[block_row-1];
549  if (last_row && block_row == block_rows-1)
550  next_block_row = buffer_ptr;
551  else
552  next_block_row = buffer[block_row+1];
553  /* We fetch the surrounding DC values using a sliding-register approach.
554  * Initialize all nine here so as to do the right thing on narrow pics.
555  */
556  DC1 = DC2 = DC3 = (int) prev_block_row[0][0];
557  DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];
558  DC7 = DC8 = DC9 = (int) next_block_row[0][0];
559  output_col = 0;
560  last_block_column = compptr->width_in_blocks - 1;
561  for (block_num = 0; block_num <= last_block_column; block_num++) {
562  /* Fetch current DCT block into workspace so we can modify it. */
563  jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1);
564  /* Update DC values */
565  if (block_num < last_block_column) {
566  DC3 = (int) prev_block_row[1][0];
567  DC6 = (int) buffer_ptr[1][0];
568  DC9 = (int) next_block_row[1][0];
569  }
570  /* Compute coefficient estimates per K.8.
571  * An estimate is applied only if coefficient is still zero,
572  * and is not known to be fully accurate.
573  */
574  /* AC01 */
575  if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) {
576  num = 36 * Q00 * (DC4 - DC6);
577  if (num >= 0) {
578  pred = (int) (((Q01<<7) + num) / (Q01<<8));
579  if (Al > 0 && pred >= (1<<Al))
580  pred = (1<<Al)-1;
581  } else {
582  pred = (int) (((Q01<<7) - num) / (Q01<<8));
583  if (Al > 0 && pred >= (1<<Al))
584  pred = (1<<Al)-1;
585  pred = -pred;
586  }
587  workspace[1] = (JCOEF) pred;
588  }
589  /* AC10 */
590  if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) {
591  num = 36 * Q00 * (DC2 - DC8);
592  if (num >= 0) {
593  pred = (int) (((Q10<<7) + num) / (Q10<<8));
594  if (Al > 0 && pred >= (1<<Al))
595  pred = (1<<Al)-1;
596  } else {
597  pred = (int) (((Q10<<7) - num) / (Q10<<8));
598  if (Al > 0 && pred >= (1<<Al))
599  pred = (1<<Al)-1;
600  pred = -pred;
601  }
602  workspace[8] = (JCOEF) pred;
603  }
604  /* AC20 */
605  if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) {
606  num = 9 * Q00 * (DC2 + DC8 - 2*DC5);
607  if (num >= 0) {
608  pred = (int) (((Q20<<7) + num) / (Q20<<8));
609  if (Al > 0 && pred >= (1<<Al))
610  pred = (1<<Al)-1;
611  } else {
612  pred = (int) (((Q20<<7) - num) / (Q20<<8));
613  if (Al > 0 && pred >= (1<<Al))
614  pred = (1<<Al)-1;
615  pred = -pred;
616  }
617  workspace[16] = (JCOEF) pred;
618  }
619  /* AC11 */
620  if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) {
621  num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
622  if (num >= 0) {
623  pred = (int) (((Q11<<7) + num) / (Q11<<8));
624  if (Al > 0 && pred >= (1<<Al))
625  pred = (1<<Al)-1;
626  } else {
627  pred = (int) (((Q11<<7) - num) / (Q11<<8));
628  if (Al > 0 && pred >= (1<<Al))
629  pred = (1<<Al)-1;
630  pred = -pred;
631  }
632  workspace[9] = (JCOEF) pred;
633  }
634  /* AC02 */
635  if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) {
636  num = 9 * Q00 * (DC4 + DC6 - 2*DC5);
637  if (num >= 0) {
638  pred = (int) (((Q02<<7) + num) / (Q02<<8));
639  if (Al > 0 && pred >= (1<<Al))
640  pred = (1<<Al)-1;
641  } else {
642  pred = (int) (((Q02<<7) - num) / (Q02<<8));
643  if (Al > 0 && pred >= (1<<Al))
644  pred = (1<<Al)-1;
645  pred = -pred;
646  }
647  workspace[2] = (JCOEF) pred;
648  }
649  /* OK, do the IDCT */
650  (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace,
651  output_ptr, output_col);
652  /* Advance for next column */
653  DC1 = DC2; DC2 = DC3;
654  DC4 = DC5; DC5 = DC6;
655  DC7 = DC8; DC8 = DC9;
656  buffer_ptr++, prev_block_row++, next_block_row++;
658  }
659  output_ptr += compptr->DCT_scaled_size;
660  }
661  }
662 
663  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
664  return JPEG_ROW_COMPLETED;
665  return JPEG_SCAN_COMPLETED;
666 }
667 
668 #endif /* BLOCK_SMOOTHING_SUPPORTED */
669 
670 
671 /*
672  * Initialize coefficient buffer controller.
673  */
674 
675 GLOBAL(void)
677 {
678  my_coef_ptr coef;
679 
680  coef = (my_coef_ptr)
681  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
683  cinfo->coef = (struct jpeg_d_coef_controller *) coef;
684  coef->pub.start_input_pass = start_input_pass;
685  coef->pub.start_output_pass = start_output_pass;
686 #ifdef BLOCK_SMOOTHING_SUPPORTED
687  coef->coef_bits_latch = NULL;
688 #endif
689 
690  /* Create the coefficient buffer. */
691  if (need_full_buffer) {
692 #ifdef D_MULTISCAN_FILES_SUPPORTED
693  /* Allocate a full-image virtual array for each component, */
694  /* padded to a multiple of samp_factor DCT blocks in each direction. */
695  /* Note we ask for a pre-zeroed array. */
696  int ci, access_rows;
698 
699  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
700  ci++, compptr++) {
701  access_rows = compptr->v_samp_factor;
702 #ifdef BLOCK_SMOOTHING_SUPPORTED
703  /* If block smoothing could be used, need a bigger window */
704  if (cinfo->progressive_mode)
705  access_rows *= 3;
706 #endif
707  coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
708  ((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,
710  (long) compptr->h_samp_factor),
712  (long) compptr->v_samp_factor),
713  (JDIMENSION) access_rows);
714  }
715  coef->pub.consume_data = consume_data;
716  coef->pub.decompress_data = decompress_data;
717  coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
718 #else
719  ERREXIT(cinfo, JERR_NOT_COMPILED);
720 #endif
721  } else {
722  /* We only need a single-MCU buffer. */
724  int i;
725 
726  buffer = (JBLOCKROW)
727  (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
729  for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
730  coef->MCU_buffer[i] = buffer + i;
731  }
732  coef->pub.consume_data = dummy_consume_data;
733  coef->pub.decompress_data = decompress_onepass;
734  coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
735  }
736 }
MAX_COMPS_IN_SCAN
#define MAX_COMPS_IN_SCAN
Definition: jpeglib.h:46
jpeg_component_info::MCU_height
int MCU_height
Definition: jpeglib.h:165
jround_up
jround_up(long a, long b)
Definition: jutils.c:81
jzero_far
jzero_far(void FAR *target, size_t bytestozero)
Definition: jutils.c:165
my_coef_controller::coef_bits_latch
int * coef_bits_latch
Definition: jdcoefct.c:57
i
png_uint_32 i
Definition: png.h:2732
jpeg_decompress_struct::comps_in_scan
int comps_in_scan
Definition: jpeglib.h:596
jpeglib.h
jpeg_d_coef_controller
Definition: jpegint.h:166
JPEG_ROW_COMPLETED
#define JPEG_ROW_COMPLETED
Definition: jpeglib.h:998
SAVED_COEFS
#define SAVED_COEFS
Definition: jdcoefct.c:58
my_coef_controller::MCU_buffer
JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU]
Definition: jccoefct.c:51
j_common_ptr
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:261
decompress_data
decompress_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
Definition: jdcoefct.c:315
JBLOCK
JCOEF JBLOCK[DCTSIZE2]
Definition: jpeglib.h:70
jpeg_component_info::MCU_width
int MCU_width
Definition: jpeglib.h:164
need_full_buffer
boolean need_full_buffer
Definition: jpegint.h:338
LOCAL
#define LOCAL(type)
Definition: jmorecfg.h:186
jinclude.h
JBLOCKARRAY
JBLOCKROW * JBLOCKARRAY
Definition: jpeglib.h:72
jpeg_component_info::width_in_blocks
JDIMENSION width_in_blocks
Definition: jpeglib.h:139
buffer
png_infop png_bytep buffer
Definition: png.h:2039
for
#define for
Definition: IcePreprocessor.h:129
JQUANT_TBL::quantval
UINT16 quantval[DCTSIZE2]
Definition: jpeglib.h:88
jpeg_component_info::DCT_scaled_size
int DCT_scaled_size
Definition: jpeglib.h:147
JPOOL_IMAGE
#define JPOOL_IMAGE
Definition: jpeglib.h:749
jinit_d_coef_controller
jinit_d_coef_controller(j_decompress_ptr cinfo, boolean need_full_buffer)
Definition: jdcoefct.c:676
GLOBAL
#define GLOBAL(type)
Definition: jmorecfg.h:188
jpeg_component_info::MCU_blocks
int MCU_blocks
Definition: jpeglib.h:166
jpeg_component_info::component_needed
boolean component_needed
Definition: jpeglib.h:160
jcopy_block_row
jcopy_block_row(JBLOCKROW input_row, JBLOCKROW output_row, JDIMENSION num_blocks)
Definition: jutils.c:145
ERREXIT
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
JBLOCKROW
JBLOCK FAR * JBLOCKROW
Definition: jpeglib.h:71
consume_data
consume_data(j_decompress_ptr cinfo)
Definition: jdcoefct.c:244
jpeg_decompress_struct::total_iMCU_rows
JDIMENSION total_iMCU_rows
Definition: jpeglib.h:580
my_coef_controller::MCU_ctr
JDIMENSION MCU_ctr
Definition: jdcoefct.c:33
jpeg_common_struct
Definition: jpeglib.h:253
Q11_POS
#define Q11_POS
Definition: jdcoefct.c:393
JCOEFPTR
JCOEF FAR * JCOEFPTR
Definition: jpeglib.h:75
JPP
#define JPP(arglist)
Definition: jpeglib.h:818
compptr
jpeg_component_info * compptr
Definition: jdct.h:102
JDIMENSION
unsigned int JDIMENSION
Definition: jmorecfg.h:171
int
typedef int
Definition: png.h:1111
jpeg_component_info::component_index
int component_index
Definition: jpeglib.h:121
Q01_POS
#define Q01_POS
Definition: jdcoefct.c:390
SIZEOF
#define SIZEOF(object)
Definition: jinclude.h:80
start_input_pass
start_input_pass(j_decompress_ptr cinfo)
Definition: jdcoefct.c:107
jvirt_barray_control
Definition: jmemmgr.c:166
jpeg_decompress_struct::cur_comp_info
jpeg_component_info * cur_comp_info[MAX_COMPS_IN_SCAN]
Definition: jpeglib.h:597
jpeg_component_info::last_row_height
int last_row_height
Definition: jpeglib.h:169
output_buf
jpeg_component_info JCOEFPTR JSAMPARRAY output_buf
Definition: jdct.h:103
jpeg_component_info::height_in_blocks
JDIMENSION height_in_blocks
Definition: jpeglib.h:140
start_output_pass
start_output_pass(j_decompress_ptr cinfo)
Definition: jdcoefct.c:119
my_coef_controller::MCU_rows_per_iMCU_row
int MCU_rows_per_iMCU_row
Definition: jccoefct.c:40
Q10_POS
#define Q10_POS
Definition: jdcoefct.c:391
jpeg_decompress_struct::input_iMCU_row
JDIMENSION input_iMCU_row
Definition: jpeglib.h:495
TRUE
#define TRUE
Definition: OPC_IceHook.h:13
output_col
jpeg_component_info JCOEFPTR JSAMPARRAY JDIMENSION output_col
Definition: jdct.h:103
JSAMPIMAGE
JSAMPARRAY * JSAMPIMAGE
Definition: jpeglib.h:68
Q02_POS
#define Q02_POS
Definition: jdcoefct.c:394
dummy_consume_data
dummy_consume_data(j_decompress_ptr cinfo)
Definition: jdcoefct.c:228
JPEG_SUSPENDED
#define JPEG_SUSPENDED
Definition: jpeglib.h:965
FALSE
#define FALSE
Definition: OPC_IceHook.h:9
jpeg_component_info::quant_table
JQUANT_TBL * quant_table
Definition: jpeglib.h:175
D_MAX_BLOCKS_IN_MCU
#define D_MAX_BLOCKS_IN_MCU
Definition: jpeglib.h:57
MAX_COMPONENTS
#define MAX_COMPONENTS
Definition: jmorecfg.h:35
my_coef_controller
Definition: jccoefct.c:34
jpeg_component_info::MCU_sample_width
int MCU_sample_width
Definition: jpeglib.h:167
my_coef_ptr
my_coef_controller * my_coef_ptr
Definition: jdcoefct.c:62
METHODDEF
METHODDEF(int)
Definition: jdcoefct.c:65
JPEG_SCAN_COMPLETED
#define JPEG_SCAN_COMPLETED
Definition: jpeglib.h:999
smoothing_ok
smoothing_ok(j_decompress_ptr cinfo)
Definition: jdcoefct.c:405
my_coef_controller::whole_image
jvirt_barray_ptr whole_image[MAX_COMPONENTS]
Definition: jccoefct.c:54
JSAMPARRAY
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:67
FAR
#define FAR
Definition: jmorecfg.h:215
jpeg_component_info::h_samp_factor
int h_samp_factor
Definition: jpeglib.h:122
jpeg_component_info::last_col_width
int last_col_width
Definition: jpeglib.h:168
jpeg_decompress_struct::coef
struct jpeg_d_coef_controller * coef
Definition: jpeglib.h:621
decompress_onepass
decompress_onepass(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
Definition: jdcoefct.c:147
decompress_smooth_data
decompress_smooth_data(j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
Definition: jdcoefct.c:461
INT32
long INT32
Definition: jmorecfg.h:161
JQUANT_TBL
Definition: jpeglib.h:83
my_coef_controller::MCU_vert_offset
int MCU_vert_offset
Definition: jccoefct.c:39
start_iMCU_row
start_iMCU_row(j_compress_ptr cinfo)
Definition: jctrans.c:227
Q20_POS
#define Q20_POS
Definition: jdcoefct.c:392
num
int num
Definition: png.h:1499
jpeg_component_info::v_samp_factor
int v_samp_factor
Definition: jpeglib.h:123
jpeg_decompress_struct
Definition: jpeglib.h:411
jpeg_component_info
Definition: jpeglib.h:116
my_coef_controller::pub
struct jpeg_c_coef_controller pub
Definition: jccoefct.c:35
JCOEF
short JCOEF
Definition: jmorecfg.h:99


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Wed Sep 7 2022 02:51:03