1 #if !defined(_FX_JPEG_TURBO_)
2 /*
3 * jdphuff.c
4 *
5 * Copyright (C) 1995-1997, Thomas G. Lane.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains Huffman entropy decoding routines for progressive JPEG.
10 *
11 * Much of the complexity here has to do with supporting input suspension.
12 * If the data source module demands suspension, we want to be able to back
13 * up to the start of the current MCU. To do this, we copy state variables
14 * into local working storage, and update them back to the permanent
15 * storage only upon successful completion of an MCU.
16 */
17
18 #define JPEG_INTERNALS
19 #include "jinclude.h"
20 #include "jpeglib.h"
21 #include "jdhuff.h" /* Declarations shared with jdhuff.c */
22
23
24 #ifdef D_PROGRESSIVE_SUPPORTED
25
26 /*
27 * Expanded entropy decoder object for progressive Huffman decoding.
28 *
29 * The savable_state subrecord contains fields that change within an MCU,
30 * but must not be updated permanently until we complete the MCU.
31 */
32
33 typedef struct {
34 unsigned int EOBRUN; /* remaining EOBs in EOBRUN */
35 int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
36 } savable_state;
37
38 /* This macro is to work around compilers with missing or broken
39 * structure assignment. You'll need to fix this code if you have
40 * such a compiler and you change MAX_COMPS_IN_SCAN.
41 */
42
43 #ifndef NO_STRUCT_ASSIGN
44 #define ASSIGN_STATE(dest,src) ((dest) = (src))
45 #else
46 #if MAX_COMPS_IN_SCAN == 4
47 #define ASSIGN_STATE(dest,src) \
48 ((dest).EOBRUN = (src).EOBRUN, \
49 (dest).last_dc_val[0] = (src).last_dc_val[0], \
50 (dest).last_dc_val[1] = (src).last_dc_val[1], \
51 (dest).last_dc_val[2] = (src).last_dc_val[2], \
52 (dest).last_dc_val[3] = (src).last_dc_val[3])
53 #endif
54 #endif
55
56
57 typedef struct {
58 struct jpeg_entropy_decoder pub; /* public fields */
59
60 /* These fields are loaded into local variables at start of each MCU.
61 * In case of suspension, we exit WITHOUT updating them.
62 */
63 bitread_perm_state bitstate; /* Bit buffer at start of MCU */
64 savable_state saved; /* Other state at start of MCU */
65
66 /* These fields are NOT loaded into local working state. */
67 unsigned int restarts_to_go; /* MCUs left in this restart interval */
68
69 /* Pointers to derived tables (these workspaces have image lifespan) */
70 d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
71
72 d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */
73 } phuff_entropy_decoder;
74
75 typedef phuff_entropy_decoder * phuff_entropy_ptr;
76
77 /* Forward declarations */
78 METHODDEF(boolean) decode_mcu_DC_first JPP((j_decompress_ptr cinfo,
79 JBLOCKROW *MCU_data));
80 METHODDEF(boolean) decode_mcu_AC_first JPP((j_decompress_ptr cinfo,
81 JBLOCKROW *MCU_data));
82 METHODDEF(boolean) decode_mcu_DC_refine JPP((j_decompress_ptr cinfo,
83 JBLOCKROW *MCU_data));
84 METHODDEF(boolean) decode_mcu_AC_refine JPP((j_decompress_ptr cinfo,
85 JBLOCKROW *MCU_data));
86
87
88 /*
89 * Initialize for a Huffman-compressed scan.
90 */
91
92 METHODDEF(void)
start_pass_phuff_decoder(j_decompress_ptr cinfo)93 start_pass_phuff_decoder (j_decompress_ptr cinfo)
94 {
95 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
96 boolean is_DC_band, bad;
97 int ci, coefi, tbl;
98 int *coef_bit_ptr;
99 jpeg_component_info * compptr;
100
101 is_DC_band = (cinfo->Ss == 0);
102
103 /* Validate scan parameters */
104 bad = FALSE;
105 if (is_DC_band) {
106 if (cinfo->Se != 0)
107 bad = TRUE;
108 } else {
109 /* need not check Ss/Se < 0 since they came from unsigned bytes */
110 if (cinfo->Ss > cinfo->Se || cinfo->Se >= DCTSIZE2)
111 bad = TRUE;
112 /* AC scans may have only one component */
113 if (cinfo->comps_in_scan != 1)
114 bad = TRUE;
115 }
116 if (cinfo->Ah != 0) {
117 /* Successive approximation refinement scan: must have Al = Ah-1. */
118 if (cinfo->Al != cinfo->Ah-1)
119 bad = TRUE;
120 }
121 if (cinfo->Al > 13) /* need not check for < 0 */
122 bad = TRUE;
123 /* Arguably the maximum Al value should be less than 13 for 8-bit precision,
124 * but the spec doesn't say so, and we try to be liberal about what we
125 * accept. Note: large Al values could result in out-of-range DC
126 * coefficients during early scans, leading to bizarre displays due to
127 * overflows in the IDCT math. But we won't crash.
128 */
129 if (bad)
130 ERREXIT4(cinfo, JERR_BAD_PROGRESSION,
131 cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);
132 /* Update progression status, and verify that scan order is legal.
133 * Note that inter-scan inconsistencies are treated as warnings
134 * not fatal errors ... not clear if this is right way to behave.
135 */
136 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
137 int cindex = cinfo->cur_comp_info[ci]->component_index;
138 coef_bit_ptr = & cinfo->coef_bits[cindex][0];
139 if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
140 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
141 for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
142 int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
143 if (cinfo->Ah != expected)
144 WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
145 coef_bit_ptr[coefi] = cinfo->Al;
146 }
147 }
148
149 /* Select MCU decoding routine */
150 if (cinfo->Ah == 0) {
151 if (is_DC_band)
152 entropy->pub.decode_mcu = decode_mcu_DC_first;
153 else
154 entropy->pub.decode_mcu = decode_mcu_AC_first;
155 } else {
156 if (is_DC_band)
157 entropy->pub.decode_mcu = decode_mcu_DC_refine;
158 else
159 entropy->pub.decode_mcu = decode_mcu_AC_refine;
160 }
161
162 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
163 compptr = cinfo->cur_comp_info[ci];
164 /* Make sure requested tables are present, and compute derived tables.
165 * We may build same derived table more than once, but it's not expensive.
166 */
167 if (is_DC_band) {
168 if (cinfo->Ah == 0) { /* DC refinement needs no table */
169 tbl = compptr->dc_tbl_no;
170 jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,
171 & entropy->derived_tbls[tbl]);
172 }
173 } else {
174 tbl = compptr->ac_tbl_no;
175 jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,
176 & entropy->derived_tbls[tbl]);
177 /* remember the single active table */
178 entropy->ac_derived_tbl = entropy->derived_tbls[tbl];
179 }
180 /* Initialize DC predictions to 0 */
181 entropy->saved.last_dc_val[ci] = 0;
182 }
183
184 /* Initialize bitread state variables */
185 entropy->bitstate.bits_left = 0;
186 entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
187 entropy->pub.insufficient_data = FALSE;
188
189 /* Initialize private state variables */
190 entropy->saved.EOBRUN = 0;
191
192 /* Initialize restart counter */
193 entropy->restarts_to_go = cinfo->restart_interval;
194 }
195
196
197 /*
198 * Figure F.12: extend sign bit.
199 * On some machines, a shift and add will be faster than a table lookup.
200 */
201
202 #ifdef AVOID_TABLES
203
204 #define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))
205
206 #else
207
208 #define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
209
210 static const int extend_test[16] = /* entry n is 2**(n-1) */
211 { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
212 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
213
214 static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
215 { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
216 ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
217 ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
218 ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };
219
220 #endif /* AVOID_TABLES */
221
222
223 /*
224 * Check for a restart marker & resynchronize decoder.
225 * Returns FALSE if must suspend.
226 */
227
228 LOCAL(boolean)
process_restart(j_decompress_ptr cinfo)229 process_restart (j_decompress_ptr cinfo)
230 {
231 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
232 int ci;
233
234 /* Throw away any unused bits remaining in bit buffer; */
235 /* include any full bytes in next_marker's count of discarded bytes */
236 cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
237 entropy->bitstate.bits_left = 0;
238
239 /* Advance past the RSTn marker */
240 if (! (*cinfo->marker->read_restart_marker) (cinfo))
241 return FALSE;
242
243 /* Re-initialize DC predictions to 0 */
244 for (ci = 0; ci < cinfo->comps_in_scan; ci++)
245 entropy->saved.last_dc_val[ci] = 0;
246 /* Re-init EOB run count, too */
247 entropy->saved.EOBRUN = 0;
248
249 /* Reset restart counter */
250 entropy->restarts_to_go = cinfo->restart_interval;
251
252 /* Reset out-of-data flag, unless read_restart_marker left us smack up
253 * against a marker. In that case we will end up treating the next data
254 * segment as empty, and we can avoid producing bogus output pixels by
255 * leaving the flag set.
256 */
257 if (cinfo->unread_marker == 0)
258 entropy->pub.insufficient_data = FALSE;
259
260 return TRUE;
261 }
262
263
264 /*
265 * Huffman MCU decoding.
266 * Each of these routines decodes and returns one MCU's worth of
267 * Huffman-compressed coefficients.
268 * The coefficients are reordered from zigzag order into natural array order,
269 * but are not dequantized.
270 *
271 * The i'th block of the MCU is stored into the block pointed to by
272 * MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
273 *
274 * We return FALSE if data source requested suspension. In that case no
275 * changes have been made to permanent state. (Exception: some output
276 * coefficients may already have been assigned. This is harmless for
277 * spectral selection, since we'll just re-assign them on the next call.
278 * Successive approximation AC refinement has to be more careful, however.)
279 */
280
281 /*
282 * MCU decoding for DC initial scan (either spectral selection,
283 * or first pass of successive approximation).
284 */
285
286 METHODDEF(boolean)
decode_mcu_DC_first(j_decompress_ptr cinfo,JBLOCKROW * MCU_data)287 decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
288 {
289 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
290 int Al = cinfo->Al;
291 register int s, r;
292 int blkn, ci;
293 JBLOCKROW block;
294 BITREAD_STATE_VARS;
295 savable_state state;
296 d_derived_tbl * tbl;
297 jpeg_component_info * compptr;
298
299 /* Process restart marker if needed; may have to suspend */
300 if (cinfo->restart_interval) {
301 if (entropy->restarts_to_go == 0)
302 if (! process_restart(cinfo))
303 return FALSE;
304 }
305
306 /* If we've run out of data, just leave the MCU set to zeroes.
307 * This way, we return uniform gray for the remainder of the segment.
308 */
309 if (! entropy->pub.insufficient_data) {
310
311 /* Load up working state */
312 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
313 ASSIGN_STATE(state, entropy->saved);
314
315 /* Outer loop handles each block in the MCU */
316
317 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
318 block = MCU_data[blkn];
319 ci = cinfo->MCU_membership[blkn];
320 compptr = cinfo->cur_comp_info[ci];
321 tbl = entropy->derived_tbls[compptr->dc_tbl_no];
322
323 /* Decode a single block's worth of coefficients */
324
325 /* Section F.2.2.1: decode the DC coefficient difference */
326 HUFF_DECODE(s, br_state, tbl, return FALSE, label1);
327 if (s) {
328 CHECK_BIT_BUFFER(br_state, s, return FALSE);
329 r = GET_BITS(s);
330 s = HUFF_EXTEND(r, s);
331 }
332
333 /* Convert DC difference to actual value, update last_dc_val */
334 s += state.last_dc_val[ci];
335 state.last_dc_val[ci] = s;
336 /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */
337 (*block)[0] = (JCOEF) (s << Al);
338 }
339
340 /* Completed MCU, so update state */
341 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
342 ASSIGN_STATE(entropy->saved, state);
343 }
344
345 /* Account for restart interval (no-op if not using restarts) */
346 entropy->restarts_to_go--;
347
348 return TRUE;
349 }
350
351
352 /*
353 * MCU decoding for AC initial scan (either spectral selection,
354 * or first pass of successive approximation).
355 */
356
357 METHODDEF(boolean)
decode_mcu_AC_first(j_decompress_ptr cinfo,JBLOCKROW * MCU_data)358 decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
359 {
360 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
361 int Se = cinfo->Se;
362 int Al = cinfo->Al;
363 register int s, k, r;
364 unsigned int EOBRUN;
365 JBLOCKROW block;
366 BITREAD_STATE_VARS;
367 d_derived_tbl * tbl;
368
369 /* Process restart marker if needed; may have to suspend */
370 if (cinfo->restart_interval) {
371 if (entropy->restarts_to_go == 0)
372 if (! process_restart(cinfo))
373 return FALSE;
374 }
375
376 /* If we've run out of data, just leave the MCU set to zeroes.
377 * This way, we return uniform gray for the remainder of the segment.
378 */
379 if (! entropy->pub.insufficient_data) {
380
381 /* Load up working state.
382 * We can avoid loading/saving bitread state if in an EOB run.
383 */
384 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
385
386 /* There is always only one block per MCU */
387
388 if (EOBRUN > 0) /* if it's a band of zeroes... */
389 EOBRUN--; /* ...process it now (we do nothing) */
390 else {
391 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
392 block = MCU_data[0];
393 tbl = entropy->ac_derived_tbl;
394
395 for (k = cinfo->Ss; k <= Se; k++) {
396 HUFF_DECODE(s, br_state, tbl, return FALSE, label2);
397 r = s >> 4;
398 s &= 15;
399 if (s) {
400 k += r;
401 CHECK_BIT_BUFFER(br_state, s, return FALSE);
402 r = GET_BITS(s);
403 s = HUFF_EXTEND(r, s);
404 /* Scale and output coefficient in natural (dezigzagged) order */
405 (*block)[jpeg_natural_order[k]] = (JCOEF) (s << Al);
406 } else {
407 if (r == 15) { /* ZRL */
408 k += 15; /* skip 15 zeroes in band */
409 } else { /* EOBr, run length is 2^r + appended bits */
410 EOBRUN = 1 << r;
411 if (r) { /* EOBr, r > 0 */
412 CHECK_BIT_BUFFER(br_state, r, return FALSE);
413 r = GET_BITS(r);
414 EOBRUN += r;
415 }
416 EOBRUN--; /* this band is processed at this moment */
417 break; /* force end-of-band */
418 }
419 }
420 }
421
422 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
423 }
424
425 /* Completed MCU, so update state */
426 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
427 }
428
429 /* Account for restart interval (no-op if not using restarts) */
430 entropy->restarts_to_go--;
431
432 return TRUE;
433 }
434
435
436 /*
437 * MCU decoding for DC successive approximation refinement scan.
438 * Note: we assume such scans can be multi-component, although the spec
439 * is not very clear on the point.
440 */
441
442 METHODDEF(boolean)
decode_mcu_DC_refine(j_decompress_ptr cinfo,JBLOCKROW * MCU_data)443 decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
444 {
445 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
446 int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
447 int blkn;
448 JBLOCKROW block;
449 BITREAD_STATE_VARS;
450
451 /* Process restart marker if needed; may have to suspend */
452 if (cinfo->restart_interval) {
453 if (entropy->restarts_to_go == 0)
454 if (! process_restart(cinfo))
455 return FALSE;
456 }
457
458 /* Not worth the cycles to check insufficient_data here,
459 * since we will not change the data anyway if we read zeroes.
460 */
461
462 /* Load up working state */
463 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
464
465 /* Outer loop handles each block in the MCU */
466
467 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
468 block = MCU_data[blkn];
469
470 /* Encoded data is simply the next bit of the two's-complement DC value */
471 CHECK_BIT_BUFFER(br_state, 1, return FALSE);
472 if (GET_BITS(1))
473 (*block)[0] |= p1;
474 /* Note: since we use |=, repeating the assignment later is safe */
475 }
476
477 /* Completed MCU, so update state */
478 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
479
480 /* Account for restart interval (no-op if not using restarts) */
481 entropy->restarts_to_go--;
482
483 return TRUE;
484 }
485
486
487 /*
488 * MCU decoding for AC successive approximation refinement scan.
489 */
490
491 METHODDEF(boolean)
decode_mcu_AC_refine(j_decompress_ptr cinfo,JBLOCKROW * MCU_data)492 decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
493 {
494 phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
495 int Se = cinfo->Se;
496 int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
497 int m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */
498 register int s, k, r;
499 unsigned int EOBRUN;
500 JBLOCKROW block;
501 JCOEFPTR thiscoef;
502 BITREAD_STATE_VARS;
503 d_derived_tbl * tbl;
504 int num_newnz;
505 int newnz_pos[DCTSIZE2];
506
507 /* Process restart marker if needed; may have to suspend */
508 if (cinfo->restart_interval) {
509 if (entropy->restarts_to_go == 0)
510 if (! process_restart(cinfo))
511 return FALSE;
512 }
513
514 /* If we've run out of data, don't modify the MCU.
515 */
516 if (! entropy->pub.insufficient_data) {
517
518 /* Load up working state */
519 BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
520 EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
521
522 /* There is always only one block per MCU */
523 block = MCU_data[0];
524 tbl = entropy->ac_derived_tbl;
525
526 /* If we are forced to suspend, we must undo the assignments to any newly
527 * nonzero coefficients in the block, because otherwise we'd get confused
528 * next time about which coefficients were already nonzero.
529 * But we need not undo addition of bits to already-nonzero coefficients;
530 * instead, we can test the current bit to see if we already did it.
531 */
532 num_newnz = 0;
533
534 /* initialize coefficient loop counter to start of band */
535 k = cinfo->Ss;
536
537 if (EOBRUN == 0) {
538 for (; k <= Se; k++) {
539 HUFF_DECODE(s, br_state, tbl, goto undoit, label3);
540 r = s >> 4;
541 s &= 15;
542 if (s) {
543 if (s != 1) /* size of new coef should always be 1 */
544 WARNMS(cinfo, JWRN_HUFF_BAD_CODE);
545 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
546 if (GET_BITS(1))
547 s = p1; /* newly nonzero coef is positive */
548 else
549 s = m1; /* newly nonzero coef is negative */
550 } else {
551 if (r != 15) {
552 EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */
553 if (r) {
554 CHECK_BIT_BUFFER(br_state, r, goto undoit);
555 r = GET_BITS(r);
556 EOBRUN += r;
557 }
558 break; /* rest of block is handled by EOB logic */
559 }
560 /* note s = 0 for processing ZRL */
561 }
562 /* Advance over already-nonzero coefs and r still-zero coefs,
563 * appending correction bits to the nonzeroes. A correction bit is 1
564 * if the absolute value of the coefficient must be increased.
565 */
566 do {
567 thiscoef = *block + jpeg_natural_order[k];
568 if (*thiscoef != 0) {
569 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
570 if (GET_BITS(1)) {
571 if ((*thiscoef & p1) == 0) { /* do nothing if already set it */
572 if (*thiscoef >= 0)
573 *thiscoef += p1;
574 else
575 *thiscoef += m1;
576 }
577 }
578 } else {
579 if (--r < 0)
580 break; /* reached target zero coefficient */
581 }
582 k++;
583 } while (k <= Se);
584 if (s) {
585 int pos = jpeg_natural_order[k];
586 /* Output newly nonzero coefficient */
587 (*block)[pos] = (JCOEF) s;
588 /* Remember its position in case we have to suspend */
589 newnz_pos[num_newnz++] = pos;
590 }
591 }
592 }
593
594 if (EOBRUN > 0) {
595 /* Scan any remaining coefficient positions after the end-of-band
596 * (the last newly nonzero coefficient, if any). Append a correction
597 * bit to each already-nonzero coefficient. A correction bit is 1
598 * if the absolute value of the coefficient must be increased.
599 */
600 for (; k <= Se; k++) {
601 thiscoef = *block + jpeg_natural_order[k];
602 if (*thiscoef != 0) {
603 CHECK_BIT_BUFFER(br_state, 1, goto undoit);
604 if (GET_BITS(1)) {
605 if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */
606 if (*thiscoef >= 0)
607 *thiscoef += p1;
608 else
609 *thiscoef += m1;
610 }
611 }
612 }
613 }
614 /* Count one block completed in EOB run */
615 EOBRUN--;
616 }
617
618 /* Completed MCU, so update state */
619 BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
620 entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
621 }
622
623 /* Account for restart interval (no-op if not using restarts) */
624 entropy->restarts_to_go--;
625
626 return TRUE;
627
628 undoit:
629 /* Re-zero any output coefficients that we made newly nonzero */
630 while (num_newnz > 0)
631 (*block)[newnz_pos[--num_newnz]] = 0;
632
633 return FALSE;
634 }
635
636
637 /*
638 * Module initialization routine for progressive Huffman entropy decoding.
639 */
640
641 GLOBAL(void)
jinit_phuff_decoder(j_decompress_ptr cinfo)642 jinit_phuff_decoder (j_decompress_ptr cinfo)
643 {
644 phuff_entropy_ptr entropy;
645 int *coef_bit_ptr;
646 int ci, i;
647
648 entropy = (phuff_entropy_ptr)
649 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
650 SIZEOF(phuff_entropy_decoder));
651 cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
652 entropy->pub.start_pass = start_pass_phuff_decoder;
653
654 /* Mark derived tables unallocated */
655 for (i = 0; i < NUM_HUFF_TBLS; i++) {
656 entropy->derived_tbls[i] = NULL;
657 }
658
659 /* Create progression status table */
660 cinfo->coef_bits = (int (*)[DCTSIZE2])
661 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
662 cinfo->num_components*DCTSIZE2*SIZEOF(int));
663 coef_bit_ptr = & cinfo->coef_bits[0][0];
664 for (ci = 0; ci < cinfo->num_components; ci++)
665 for (i = 0; i < DCTSIZE2; i++)
666 *coef_bit_ptr++ = -1;
667 }
668
669 #endif /* D_PROGRESSIVE_SUPPORTED */
670
671 #endif //_FX_JPEG_TURBO_
672