1 #if !defined(_FX_JPEG_TURBO_)
2 /*
3 * jdmarker.c
4 *
5 * Copyright (C) 1991-1998, 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 routines to decode JPEG datastream markers.
10 * Most of the complexity arises from our desire to support input
11 * suspension: if not all of the data for a marker is available,
12 * we must exit back to the application. On resumption, we reprocess
13 * the marker.
14 */
15
16 #define JPEG_INTERNALS
17 #include "jinclude.h"
18 #include "jpeglib.h"
19
20
21 typedef enum { /* JPEG marker codes */
22 M_SOF0 = 0xc0,
23 M_SOF1 = 0xc1,
24 M_SOF2 = 0xc2,
25 M_SOF3 = 0xc3,
26
27 M_SOF5 = 0xc5,
28 M_SOF6 = 0xc6,
29 M_SOF7 = 0xc7,
30
31 M_JPG = 0xc8,
32 M_SOF9 = 0xc9,
33 M_SOF10 = 0xca,
34 M_SOF11 = 0xcb,
35
36 M_SOF13 = 0xcd,
37 M_SOF14 = 0xce,
38 M_SOF15 = 0xcf,
39
40 M_DHT = 0xc4,
41
42 M_DAC = 0xcc,
43
44 M_RST0 = 0xd0,
45 M_RST1 = 0xd1,
46 M_RST2 = 0xd2,
47 M_RST3 = 0xd3,
48 M_RST4 = 0xd4,
49 M_RST5 = 0xd5,
50 M_RST6 = 0xd6,
51 M_RST7 = 0xd7,
52
53 M_SOI = 0xd8,
54 M_EOI = 0xd9,
55 M_SOS = 0xda,
56 M_DQT = 0xdb,
57 M_DNL = 0xdc,
58 M_DRI = 0xdd,
59 M_DHP = 0xde,
60 M_EXP = 0xdf,
61
62 M_APP0 = 0xe0,
63 M_APP1 = 0xe1,
64 M_APP2 = 0xe2,
65 M_APP3 = 0xe3,
66 M_APP4 = 0xe4,
67 M_APP5 = 0xe5,
68 M_APP6 = 0xe6,
69 M_APP7 = 0xe7,
70 M_APP8 = 0xe8,
71 M_APP9 = 0xe9,
72 M_APP10 = 0xea,
73 M_APP11 = 0xeb,
74 M_APP12 = 0xec,
75 M_APP13 = 0xed,
76 M_APP14 = 0xee,
77 M_APP15 = 0xef,
78
79 M_JPG0 = 0xf0,
80 M_JPG13 = 0xfd,
81 M_COM = 0xfe,
82
83 M_TEM = 0x01,
84
85 M_ERROR = 0x100
86 } JPEG_MARKER;
87
88
89 /* Private state */
90
91 typedef struct {
92 struct jpeg_marker_reader pub; /* public fields */
93
94 /* Application-overridable marker processing methods */
95 jpeg_marker_parser_method process_COM;
96 jpeg_marker_parser_method process_APPn[16];
97
98 /* Limit on marker data length to save for each marker type */
99 unsigned int length_limit_COM;
100 unsigned int length_limit_APPn[16];
101
102 /* Status of COM/APPn marker saving */
103 jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
104 unsigned int bytes_read; /* data bytes read so far in marker */
105 /* Note: cur_marker is not linked into marker_list until it's all read. */
106 } my_marker_reader;
107
108 typedef my_marker_reader * my_marker_ptr;
109
110
111 /*
112 * Macros for fetching data from the data source module.
113 *
114 * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
115 * the current restart point; we update them only when we have reached a
116 * suitable place to restart if a suspension occurs.
117 */
118
119 /* Declare and initialize local copies of input pointer/count */
120 #define INPUT_VARS(cinfo) \
121 struct jpeg_source_mgr * datasrc = (cinfo)->src; \
122 const JOCTET * next_input_byte = datasrc->next_input_byte; \
123 size_t bytes_in_buffer = datasrc->bytes_in_buffer
124
125 /* Unload the local copies --- do this only at a restart boundary */
126 #define INPUT_SYNC(cinfo) \
127 ( datasrc->next_input_byte = next_input_byte, \
128 datasrc->bytes_in_buffer = bytes_in_buffer )
129
130 /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
131 #define INPUT_RELOAD(cinfo) \
132 ( next_input_byte = datasrc->next_input_byte, \
133 bytes_in_buffer = datasrc->bytes_in_buffer )
134
135 /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
136 * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
137 * but we must reload the local copies after a successful fill.
138 */
139 #define MAKE_BYTE_AVAIL(cinfo,action) \
140 if (bytes_in_buffer == 0) { \
141 if (! (*datasrc->fill_input_buffer) (cinfo)) \
142 { action; } \
143 INPUT_RELOAD(cinfo); \
144 }
145
146 /* Read a byte into variable V.
147 * If must suspend, take the specified action (typically "return FALSE").
148 */
149 #define INPUT_BYTE(cinfo,V,action) \
150 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
151 bytes_in_buffer--; \
152 V = GETJOCTET(*next_input_byte++); )
153
154 /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
155 * V should be declared unsigned int or perhaps INT32.
156 */
157 #define INPUT_2BYTES(cinfo,V,action) \
158 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
159 bytes_in_buffer--; \
160 V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
161 MAKE_BYTE_AVAIL(cinfo,action); \
162 bytes_in_buffer--; \
163 V += GETJOCTET(*next_input_byte++); )
164
165
166 /*
167 * Routines to process JPEG markers.
168 *
169 * Entry condition: JPEG marker itself has been read and its code saved
170 * in cinfo->unread_marker; input restart point is just after the marker.
171 *
172 * Exit: if return TRUE, have read and processed any parameters, and have
173 * updated the restart point to point after the parameters.
174 * If return FALSE, was forced to suspend before reaching end of
175 * marker parameters; restart point has not been moved. Same routine
176 * will be called again after application supplies more input data.
177 *
178 * This approach to suspension assumes that all of a marker's parameters
179 * can fit into a single input bufferload. This should hold for "normal"
180 * markers. Some COM/APPn markers might have large parameter segments
181 * that might not fit. If we are simply dropping such a marker, we use
182 * skip_input_data to get past it, and thereby put the problem on the
183 * source manager's shoulders. If we are saving the marker's contents
184 * into memory, we use a slightly different convention: when forced to
185 * suspend, the marker processor updates the restart point to the end of
186 * what it's consumed (ie, the end of the buffer) before returning FALSE.
187 * On resumption, cinfo->unread_marker still contains the marker code,
188 * but the data source will point to the next chunk of marker data.
189 * The marker processor must retain internal state to deal with this.
190 *
191 * Note that we don't bother to avoid duplicate trace messages if a
192 * suspension occurs within marker parameters. Other side effects
193 * require more care.
194 */
195
196
197 LOCAL(boolean)
get_soi(j_decompress_ptr cinfo)198 get_soi (j_decompress_ptr cinfo)
199 /* Process an SOI marker */
200 {
201 int i;
202
203 TRACEMS(cinfo, 1, JTRC_SOI);
204
205 if (cinfo->marker->saw_SOI)
206 ERREXIT(cinfo, JERR_SOI_DUPLICATE);
207
208 /* Reset all parameters that are defined to be reset by SOI */
209
210 for (i = 0; i < NUM_ARITH_TBLS; i++) {
211 cinfo->arith_dc_L[i] = 0;
212 cinfo->arith_dc_U[i] = 1;
213 cinfo->arith_ac_K[i] = 5;
214 }
215 cinfo->restart_interval = 0;
216
217 /* Set initial assumptions for colorspace etc */
218
219 cinfo->jpeg_color_space = JCS_UNKNOWN;
220 cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
221
222 cinfo->saw_JFIF_marker = FALSE;
223 cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
224 cinfo->JFIF_minor_version = 1;
225 cinfo->density_unit = 0;
226 cinfo->X_density = 1;
227 cinfo->Y_density = 1;
228 cinfo->saw_Adobe_marker = FALSE;
229 cinfo->Adobe_transform = 0;
230
231 cinfo->marker->saw_SOI = TRUE;
232
233 return TRUE;
234 }
235
236
237 LOCAL(boolean)
get_sof(j_decompress_ptr cinfo,boolean is_prog,boolean is_arith)238 get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
239 /* Process a SOFn marker */
240 {
241 INT32 length;
242 int c, ci;
243 jpeg_component_info * compptr;
244 /* LiuSunliang added 20111209 */
245 JDIMENSION image_width, image_height;
246 INPUT_VARS(cinfo);
247
248 cinfo->progressive_mode = is_prog;
249 cinfo->arith_code = is_arith;
250
251 INPUT_2BYTES(cinfo, length, return FALSE);
252
253 INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
254 INPUT_2BYTES(cinfo, image_height, return FALSE);
255 INPUT_2BYTES(cinfo, image_width, return FALSE);
256 INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
257
258 if (image_width <= JPEG_MAX_DIMENSION)
259 cinfo->image_width = image_width;
260
261 if (image_height <= JPEG_MAX_DIMENSION)
262 cinfo->image_height = image_height;
263
264 length -= 8;
265
266 TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
267 (int) cinfo->image_width, (int) cinfo->image_height,
268 cinfo->num_components);
269
270 if (cinfo->marker->saw_SOF)
271 ERREXIT(cinfo, JERR_SOF_DUPLICATE);
272
273 /* We don't support files in which the image height is initially specified */
274 /* as 0 and is later redefined by DNL. As long as we have to check that, */
275 /* might as well have a general sanity check. */
276 if (cinfo->image_height <= 0 || cinfo->image_width <= 0
277 || cinfo->num_components <= 0)
278 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
279
280 if (length != (cinfo->num_components * 3))
281 ERREXIT(cinfo, JERR_BAD_LENGTH);
282
283 if (cinfo->comp_info == NULL) /* do only once, even if suspend */
284 cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
285 ((j_common_ptr) cinfo, JPOOL_IMAGE,
286 cinfo->num_components * SIZEOF(jpeg_component_info));
287
288 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
289 ci++, compptr++) {
290 compptr->component_index = ci;
291 INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
292 /* XYQ 2008-03-25: Adobe CMYK JPEG has serious flaw: the K channel has same component id as C channel */
293 {
294 int i;
295 for (i = 0; i < ci; i ++)
296 if (compptr->component_id == cinfo->comp_info[i].component_id) break;
297 if (i < ci)
298 /* Found the error! We replace the id with something unlikely used elsewhere */
299 compptr->component_id += 0xf0;
300 }
301 /* end of modification */
302 INPUT_BYTE(cinfo, c, return FALSE);
303 compptr->h_samp_factor = (c >> 4) & 15;
304 compptr->v_samp_factor = (c ) & 15;
305 INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
306
307 TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
308 compptr->component_id, compptr->h_samp_factor,
309 compptr->v_samp_factor, compptr->quant_tbl_no);
310 }
311
312 cinfo->marker->saw_SOF = TRUE;
313
314 INPUT_SYNC(cinfo);
315 return TRUE;
316 }
317
318
319 LOCAL(boolean)
get_sos(j_decompress_ptr cinfo)320 get_sos (j_decompress_ptr cinfo)
321 /* Process a SOS marker */
322 {
323 INT32 length;
324 int i, ci, n, c, cc;
325 jpeg_component_info * compptr;
326 INPUT_VARS(cinfo);
327
328 if (! cinfo->marker->saw_SOF)
329 ERREXIT(cinfo, JERR_SOS_NO_SOF);
330
331 INPUT_2BYTES(cinfo, length, return FALSE);
332
333 INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
334
335 TRACEMS1(cinfo, 1, JTRC_SOS, n);
336
337 if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
338 ERREXIT(cinfo, JERR_BAD_LENGTH);
339
340 cinfo->comps_in_scan = n;
341
342 /* Collect the component-spec parameters */
343
344 for (i = 0; i < n; i++) {
345 INPUT_BYTE(cinfo, cc, return FALSE);
346 INPUT_BYTE(cinfo, c, return FALSE);
347
348 /* XYQ 2008-03-25: Adobe CMYK JPEG has serious flaw: the K channel has same component id as C channel */
349 {
350 int j;
351 for (j = 0; j < i; j ++)
352 if (cc == cinfo->cur_comp_info[j]->component_id) break;
353 if (j < i)
354 /* found the error! */
355 cc += 0xf0;
356 }
357 /* end of modification */
358 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
359 ci++, compptr++) {
360 if (cc == compptr->component_id)
361 goto id_found;
362 }
363
364 ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
365
366 id_found:
367
368 cinfo->cur_comp_info[i] = compptr;
369 compptr->dc_tbl_no = (c >> 4) & 15;
370 compptr->ac_tbl_no = (c ) & 15;
371
372 TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
373 compptr->dc_tbl_no, compptr->ac_tbl_no);
374 /* This CSi (cc) should differ from the previous CSi */
375 for (ci = 0; ci < i; ci++) {
376 if (cinfo->cur_comp_info[ci] == compptr)
377 ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
378 }
379 }
380
381 /* Collect the additional scan parameters Ss, Se, Ah/Al. */
382 INPUT_BYTE(cinfo, c, return FALSE);
383 cinfo->Ss = c;
384 INPUT_BYTE(cinfo, c, return FALSE);
385 cinfo->Se = c;
386 INPUT_BYTE(cinfo, c, return FALSE);
387 cinfo->Ah = (c >> 4) & 15;
388 cinfo->Al = (c ) & 15;
389
390 TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
391 cinfo->Ah, cinfo->Al);
392
393 /* Prepare to scan data & restart markers */
394 cinfo->marker->next_restart_num = 0;
395
396 /* Count another SOS marker */
397 cinfo->input_scan_number++;
398
399 INPUT_SYNC(cinfo);
400 return TRUE;
401 }
402
403
404 #ifdef D_ARITH_CODING_SUPPORTED
405
406 LOCAL(boolean)
get_dac(j_decompress_ptr cinfo)407 get_dac (j_decompress_ptr cinfo)
408 /* Process a DAC marker */
409 {
410 INT32 length;
411 int index, val;
412 INPUT_VARS(cinfo);
413
414 INPUT_2BYTES(cinfo, length, return FALSE);
415 length -= 2;
416
417 while (length > 0) {
418 INPUT_BYTE(cinfo, index, return FALSE);
419 INPUT_BYTE(cinfo, val, return FALSE);
420
421 length -= 2;
422
423 TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
424
425 if (index < 0 || index >= (2*NUM_ARITH_TBLS))
426 ERREXIT1(cinfo, JERR_DAC_INDEX, index);
427
428 if (index >= NUM_ARITH_TBLS) { /* define AC table */
429 cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
430 } else { /* define DC table */
431 cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
432 cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
433 if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
434 ERREXIT1(cinfo, JERR_DAC_VALUE, val);
435 }
436 }
437
438 if (length != 0)
439 ERREXIT(cinfo, JERR_BAD_LENGTH);
440
441 INPUT_SYNC(cinfo);
442 return TRUE;
443 }
444
445 #else /* ! D_ARITH_CODING_SUPPORTED */
446
447 #define get_dac(cinfo) skip_variable(cinfo)
448
449 #endif /* D_ARITH_CODING_SUPPORTED */
450
451
452 LOCAL(boolean)
get_dht(j_decompress_ptr cinfo)453 get_dht (j_decompress_ptr cinfo)
454 /* Process a DHT marker */
455 {
456 INT32 length;
457 UINT8 bits[17];
458 UINT8 huffval[256];
459 int i, index, count;
460 JHUFF_TBL **htblptr;
461 INPUT_VARS(cinfo);
462
463 INPUT_2BYTES(cinfo, length, return FALSE);
464 length -= 2;
465
466 while (length > 16) {
467 INPUT_BYTE(cinfo, index, return FALSE);
468
469 TRACEMS1(cinfo, 1, JTRC_DHT, index);
470
471 bits[0] = 0;
472 count = 0;
473 for (i = 1; i <= 16; i++) {
474 INPUT_BYTE(cinfo, bits[i], return FALSE);
475 count += bits[i];
476 }
477
478 length -= 1 + 16;
479
480 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
481 bits[1], bits[2], bits[3], bits[4],
482 bits[5], bits[6], bits[7], bits[8]);
483 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
484 bits[9], bits[10], bits[11], bits[12],
485 bits[13], bits[14], bits[15], bits[16]);
486
487 /* Here we just do minimal validation of the counts to avoid walking
488 * off the end of our table space. jdhuff.c will check more carefully.
489 */
490 if (count > 256 || ((INT32) count) > length)
491 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
492
493 for (i = 0; i < count; i++)
494 INPUT_BYTE(cinfo, huffval[i], return FALSE);
495
496 length -= count;
497
498 if (index & 0x10) { /* AC table definition */
499 index -= 0x10;
500 htblptr = &cinfo->ac_huff_tbl_ptrs[index];
501 } else { /* DC table definition */
502 htblptr = &cinfo->dc_huff_tbl_ptrs[index];
503 }
504
505 if (index < 0 || index >= NUM_HUFF_TBLS)
506 ERREXIT1(cinfo, JERR_DHT_INDEX, index);
507
508 if (*htblptr == NULL)
509 *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
510
511 MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
512 MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
513 }
514
515 if (length != 0)
516 ERREXIT(cinfo, JERR_BAD_LENGTH);
517
518 INPUT_SYNC(cinfo);
519 return TRUE;
520 }
521
522
523 LOCAL(boolean)
get_dqt(j_decompress_ptr cinfo)524 get_dqt (j_decompress_ptr cinfo)
525 /* Process a DQT marker */
526 {
527 INT32 length;
528 int n, i, prec;
529 unsigned int tmp;
530 JQUANT_TBL *quant_ptr;
531 INPUT_VARS(cinfo);
532
533 INPUT_2BYTES(cinfo, length, return FALSE);
534 length -= 2;
535
536 while (length > 0) {
537 INPUT_BYTE(cinfo, n, return FALSE);
538 prec = n >> 4;
539 n &= 0x0F;
540
541 TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
542
543 if (n >= NUM_QUANT_TBLS)
544 ERREXIT1(cinfo, JERR_DQT_INDEX, n);
545
546 if (cinfo->quant_tbl_ptrs[n] == NULL)
547 cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
548 quant_ptr = cinfo->quant_tbl_ptrs[n];
549
550 for (i = 0; i < DCTSIZE2; i++) {
551 if (prec)
552 INPUT_2BYTES(cinfo, tmp, return FALSE);
553 else
554 INPUT_BYTE(cinfo, tmp, return FALSE);
555 /* We convert the zigzag-order table to natural array order. */
556 quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
557 }
558
559 if (cinfo->err->trace_level >= 2) {
560 for (i = 0; i < DCTSIZE2; i += 8) {
561 TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
562 quant_ptr->quantval[i], quant_ptr->quantval[i+1],
563 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
564 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
565 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
566 }
567 }
568
569 length -= DCTSIZE2+1;
570 if (prec) length -= DCTSIZE2;
571 }
572
573 if (length != 0)
574 ERREXIT(cinfo, JERR_BAD_LENGTH);
575
576 INPUT_SYNC(cinfo);
577 return TRUE;
578 }
579
580
581 LOCAL(boolean)
get_dri(j_decompress_ptr cinfo)582 get_dri (j_decompress_ptr cinfo)
583 /* Process a DRI marker */
584 {
585 INT32 length;
586 unsigned int tmp;
587 INPUT_VARS(cinfo);
588
589 INPUT_2BYTES(cinfo, length, return FALSE);
590
591 if (length != 4)
592 ERREXIT(cinfo, JERR_BAD_LENGTH);
593
594 INPUT_2BYTES(cinfo, tmp, return FALSE);
595
596 TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
597
598 cinfo->restart_interval = tmp;
599
600 INPUT_SYNC(cinfo);
601 return TRUE;
602 }
603
604
605 /*
606 * Routines for processing APPn and COM markers.
607 * These are either saved in memory or discarded, per application request.
608 * APP0 and APP14 are specially checked to see if they are
609 * JFIF and Adobe markers, respectively.
610 */
611
612 #define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
613 #define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
614 #define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
615
616
617 LOCAL(void)
examine_app0(j_decompress_ptr cinfo,JOCTET FAR * data,unsigned int datalen,INT32 remaining)618 examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
619 unsigned int datalen, INT32 remaining)
620 /* Examine first few bytes from an APP0.
621 * Take appropriate action if it is a JFIF marker.
622 * datalen is # of bytes at data[], remaining is length of rest of marker data.
623 */
624 {
625 INT32 totallen = (INT32) datalen + remaining;
626
627 if (datalen >= APP0_DATA_LEN &&
628 GETJOCTET(data[0]) == 0x4A &&
629 GETJOCTET(data[1]) == 0x46 &&
630 GETJOCTET(data[2]) == 0x49 &&
631 GETJOCTET(data[3]) == 0x46 &&
632 GETJOCTET(data[4]) == 0) {
633 /* Found JFIF APP0 marker: save info */
634 cinfo->saw_JFIF_marker = TRUE;
635 cinfo->JFIF_major_version = GETJOCTET(data[5]);
636 cinfo->JFIF_minor_version = GETJOCTET(data[6]);
637 cinfo->density_unit = GETJOCTET(data[7]);
638 cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
639 cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
640 /* Check version.
641 * Major version must be 1, anything else signals an incompatible change.
642 * (We used to treat this as an error, but now it's a nonfatal warning,
643 * because some bozo at Hijaak couldn't read the spec.)
644 * Minor version should be 0..2, but process anyway if newer.
645 */
646 if (cinfo->JFIF_major_version != 1)
647 WARNMS2(cinfo, JWRN_JFIF_MAJOR,
648 cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
649 /* Generate trace messages */
650 TRACEMS5(cinfo, 1, JTRC_JFIF,
651 cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
652 cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
653 /* Validate thumbnail dimensions and issue appropriate messages */
654 if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
655 TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
656 GETJOCTET(data[12]), GETJOCTET(data[13]));
657 totallen -= APP0_DATA_LEN;
658 if (totallen !=
659 ((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
660 TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
661 } else if (datalen >= 6 &&
662 GETJOCTET(data[0]) == 0x4A &&
663 GETJOCTET(data[1]) == 0x46 &&
664 GETJOCTET(data[2]) == 0x58 &&
665 GETJOCTET(data[3]) == 0x58 &&
666 GETJOCTET(data[4]) == 0) {
667 /* Found JFIF "JFXX" extension APP0 marker */
668 /* The library doesn't actually do anything with these,
669 * but we try to produce a helpful trace message.
670 */
671 switch (GETJOCTET(data[5])) {
672 case 0x10:
673 TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
674 break;
675 case 0x11:
676 TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
677 break;
678 case 0x13:
679 TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
680 break;
681 default:
682 TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
683 GETJOCTET(data[5]), (int) totallen);
684 break;
685 }
686 } else {
687 /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
688 TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
689 }
690 }
691
692
693 LOCAL(void)
examine_app14(j_decompress_ptr cinfo,JOCTET FAR * data,unsigned int datalen,INT32 remaining)694 examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
695 unsigned int datalen, INT32 remaining)
696 /* Examine first few bytes from an APP14.
697 * Take appropriate action if it is an Adobe marker.
698 * datalen is # of bytes at data[], remaining is length of rest of marker data.
699 */
700 {
701 unsigned int version, flags0, flags1, transform;
702
703 if (datalen >= APP14_DATA_LEN &&
704 GETJOCTET(data[0]) == 0x41 &&
705 GETJOCTET(data[1]) == 0x64 &&
706 GETJOCTET(data[2]) == 0x6F &&
707 GETJOCTET(data[3]) == 0x62 &&
708 GETJOCTET(data[4]) == 0x65) {
709 /* Found Adobe APP14 marker */
710 version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
711 flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
712 flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
713 transform = GETJOCTET(data[11]);
714 TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
715 cinfo->saw_Adobe_marker = TRUE;
716 cinfo->Adobe_transform = (UINT8) transform;
717 } else {
718 /* Start of APP14 does not match "Adobe", or too short */
719 TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
720 }
721 }
722
723
724 METHODDEF(boolean)
get_interesting_appn(j_decompress_ptr cinfo)725 get_interesting_appn (j_decompress_ptr cinfo)
726 /* Process an APP0 or APP14 marker without saving it */
727 {
728 INT32 length;
729 JOCTET b[APPN_DATA_LEN];
730 unsigned int i, numtoread;
731 INPUT_VARS(cinfo);
732
733 INPUT_2BYTES(cinfo, length, return FALSE);
734 length -= 2;
735
736 /* get the interesting part of the marker data */
737 if (length >= APPN_DATA_LEN)
738 numtoread = APPN_DATA_LEN;
739 else if (length > 0)
740 numtoread = (unsigned int) length;
741 else
742 numtoread = 0;
743 for (i = 0; i < numtoread; i++)
744 INPUT_BYTE(cinfo, b[i], return FALSE);
745 length -= numtoread;
746
747 /* process it */
748 switch (cinfo->unread_marker) {
749 case M_APP0:
750 examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
751 break;
752 case M_APP14:
753 examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
754 break;
755 default:
756 /* can't get here unless jpeg_save_markers chooses wrong processor */
757 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
758 break;
759 }
760
761 /* skip any remaining data -- could be lots */
762 INPUT_SYNC(cinfo);
763 if (length > 0)
764 (*cinfo->src->skip_input_data) (cinfo, (long) length);
765
766 return TRUE;
767 }
768
769
770 #ifdef SAVE_MARKERS_SUPPORTED
771
772 METHODDEF(boolean)
save_marker(j_decompress_ptr cinfo)773 save_marker (j_decompress_ptr cinfo)
774 /* Save an APPn or COM marker into the marker list */
775 {
776 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
777 jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
778 unsigned int bytes_read, data_length;
779 JOCTET FAR * data;
780 INT32 length = 0;
781 INPUT_VARS(cinfo);
782
783 if (cur_marker == NULL) {
784 /* begin reading a marker */
785 INPUT_2BYTES(cinfo, length, return FALSE);
786 length -= 2;
787 if (length >= 0) { /* watch out for bogus length word */
788 /* figure out how much we want to save */
789 unsigned int limit;
790 if (cinfo->unread_marker == (int) M_COM)
791 limit = marker->length_limit_COM;
792 else
793 limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
794 if ((unsigned int) length < limit)
795 limit = (unsigned int) length;
796 /* allocate and initialize the marker item */
797 cur_marker = (jpeg_saved_marker_ptr)
798 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
799 SIZEOF(struct jpeg_marker_struct) + limit);
800 cur_marker->next = NULL;
801 cur_marker->marker = (UINT8) cinfo->unread_marker;
802 cur_marker->original_length = (unsigned int) length;
803 cur_marker->data_length = limit;
804 /* data area is just beyond the jpeg_marker_struct */
805 data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
806 marker->cur_marker = cur_marker;
807 marker->bytes_read = 0;
808 bytes_read = 0;
809 data_length = limit;
810 } else {
811 /* deal with bogus length word */
812 bytes_read = data_length = 0;
813 data = NULL;
814 }
815 } else {
816 /* resume reading a marker */
817 bytes_read = marker->bytes_read;
818 data_length = cur_marker->data_length;
819 data = cur_marker->data + bytes_read;
820 }
821
822 while (bytes_read < data_length) {
823 INPUT_SYNC(cinfo); /* move the restart point to here */
824 marker->bytes_read = bytes_read;
825 /* If there's not at least one byte in buffer, suspend */
826 MAKE_BYTE_AVAIL(cinfo, return FALSE);
827 /* Copy bytes with reasonable rapidity */
828 while (bytes_read < data_length && bytes_in_buffer > 0) {
829 *data++ = *next_input_byte++;
830 bytes_in_buffer--;
831 bytes_read++;
832 }
833 }
834
835 /* Done reading what we want to read */
836 if (cur_marker != NULL) { /* will be NULL if bogus length word */
837 /* Add new marker to end of list */
838 if (cinfo->marker_list == NULL) {
839 cinfo->marker_list = cur_marker;
840 } else {
841 jpeg_saved_marker_ptr prev = cinfo->marker_list;
842 while (prev->next != NULL)
843 prev = prev->next;
844 prev->next = cur_marker;
845 }
846 /* Reset pointer & calc remaining data length */
847 data = cur_marker->data;
848 length = cur_marker->original_length - data_length;
849 }
850 /* Reset to initial state for next marker */
851 marker->cur_marker = NULL;
852
853 /* Process the marker if interesting; else just make a generic trace msg */
854 switch (cinfo->unread_marker) {
855 case M_APP0:
856 examine_app0(cinfo, data, data_length, length);
857 break;
858 case M_APP14:
859 examine_app14(cinfo, data, data_length, length);
860 break;
861 default:
862 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
863 (int) (data_length + length));
864 break;
865 }
866
867 /* skip any remaining data -- could be lots */
868 INPUT_SYNC(cinfo); /* do before skip_input_data */
869 if (length > 0)
870 (*cinfo->src->skip_input_data) (cinfo, (long) length);
871
872 return TRUE;
873 }
874
875 #endif /* SAVE_MARKERS_SUPPORTED */
876
877
878 METHODDEF(boolean)
skip_variable(j_decompress_ptr cinfo)879 skip_variable (j_decompress_ptr cinfo)
880 /* Skip over an unknown or uninteresting variable-length marker */
881 {
882 INT32 length;
883 INPUT_VARS(cinfo);
884
885 INPUT_2BYTES(cinfo, length, return FALSE);
886 length -= 2;
887
888 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
889
890 INPUT_SYNC(cinfo); /* do before skip_input_data */
891 if (length > 0)
892 (*cinfo->src->skip_input_data) (cinfo, (long) length);
893
894 return TRUE;
895 }
896
897
898 /*
899 * Find the next JPEG marker, save it in cinfo->unread_marker.
900 * Returns FALSE if had to suspend before reaching a marker;
901 * in that case cinfo->unread_marker is unchanged.
902 *
903 * Note that the result might not be a valid marker code,
904 * but it will never be 0 or FF.
905 */
906
907 LOCAL(boolean)
next_marker(j_decompress_ptr cinfo)908 next_marker (j_decompress_ptr cinfo)
909 {
910 int c;
911 INPUT_VARS(cinfo);
912
913 for (;;) {
914 INPUT_BYTE(cinfo, c, return FALSE);
915 /* Skip any non-FF bytes.
916 * This may look a bit inefficient, but it will not occur in a valid file.
917 * We sync after each discarded byte so that a suspending data source
918 * can discard the byte from its buffer.
919 */
920 while (c != 0xFF) {
921 cinfo->marker->discarded_bytes++;
922 INPUT_SYNC(cinfo);
923 INPUT_BYTE(cinfo, c, return FALSE);
924 }
925 /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
926 * pad bytes, so don't count them in discarded_bytes. We assume there
927 * will not be so many consecutive FF bytes as to overflow a suspending
928 * data source's input buffer.
929 */
930 do {
931 INPUT_BYTE(cinfo, c, return FALSE);
932 } while (c == 0xFF);
933 if (c != 0)
934 break; /* found a valid marker, exit loop */
935 /* Reach here if we found a stuffed-zero data sequence (FF/00).
936 * Discard it and loop back to try again.
937 */
938 cinfo->marker->discarded_bytes += 2;
939 INPUT_SYNC(cinfo);
940 }
941
942 if (cinfo->marker->discarded_bytes != 0) {
943 WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
944 cinfo->marker->discarded_bytes = 0;
945 }
946
947 cinfo->unread_marker = c;
948
949 INPUT_SYNC(cinfo);
950 return TRUE;
951 }
952
953
954 LOCAL(boolean)
first_marker(j_decompress_ptr cinfo)955 first_marker (j_decompress_ptr cinfo)
956 /* Like next_marker, but used to obtain the initial SOI marker. */
957 /* For this marker, we do not allow preceding garbage or fill; otherwise,
958 * we might well scan an entire input file before realizing it ain't JPEG.
959 * If an application wants to process non-JFIF files, it must seek to the
960 * SOI before calling the JPEG library.
961 */
962 {
963 int c, c2;
964 INPUT_VARS(cinfo);
965
966 INPUT_BYTE(cinfo, c, return FALSE);
967 INPUT_BYTE(cinfo, c2, return FALSE);
968 if (c != 0xFF || c2 != (int) M_SOI)
969 ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
970
971 cinfo->unread_marker = c2;
972
973 INPUT_SYNC(cinfo);
974 return TRUE;
975 }
976
977
978 /*
979 * Read markers until SOS or EOI.
980 *
981 * Returns same codes as are defined for jpeg_consume_input:
982 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
983 */
984
985 METHODDEF(int)
read_markers(j_decompress_ptr cinfo)986 read_markers (j_decompress_ptr cinfo)
987 {
988 /* Outer loop repeats once for each marker. */
989 for (;;) {
990 /* Collect the marker proper, unless we already did. */
991 /* NB: first_marker() enforces the requirement that SOI appear first. */
992 if (cinfo->unread_marker == 0) {
993 if (! cinfo->marker->saw_SOI) {
994 if (! first_marker(cinfo))
995 return JPEG_SUSPENDED;
996 } else {
997 if (! next_marker(cinfo))
998 return JPEG_SUSPENDED;
999 }
1000 }
1001 /* At this point cinfo->unread_marker contains the marker code and the
1002 * input point is just past the marker proper, but before any parameters.
1003 * A suspension will cause us to return with this state still true.
1004 */
1005 switch (cinfo->unread_marker) {
1006 case M_SOI:
1007 if (! get_soi(cinfo))
1008 return JPEG_SUSPENDED;
1009 break;
1010
1011 case M_SOF0: /* Baseline */
1012 case M_SOF1: /* Extended sequential, Huffman */
1013 if (! get_sof(cinfo, FALSE, FALSE))
1014 return JPEG_SUSPENDED;
1015 break;
1016
1017 case M_SOF2: /* Progressive, Huffman */
1018 if (! get_sof(cinfo, TRUE, FALSE))
1019 return JPEG_SUSPENDED;
1020 break;
1021
1022 case M_SOF9: /* Extended sequential, arithmetic */
1023 if (! get_sof(cinfo, FALSE, TRUE))
1024 return JPEG_SUSPENDED;
1025 break;
1026
1027 case M_SOF10: /* Progressive, arithmetic */
1028 if (! get_sof(cinfo, TRUE, TRUE))
1029 return JPEG_SUSPENDED;
1030 break;
1031
1032 /* Currently unsupported SOFn types */
1033 case M_SOF3: /* Lossless, Huffman */
1034 case M_SOF5: /* Differential sequential, Huffman */
1035 case M_SOF6: /* Differential progressive, Huffman */
1036 case M_SOF7: /* Differential lossless, Huffman */
1037 case M_JPG: /* Reserved for JPEG extensions */
1038 case M_SOF11: /* Lossless, arithmetic */
1039 case M_SOF13: /* Differential sequential, arithmetic */
1040 case M_SOF14: /* Differential progressive, arithmetic */
1041 case M_SOF15: /* Differential lossless, arithmetic */
1042 ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
1043 break;
1044
1045 case M_SOS:
1046 if (! get_sos(cinfo))
1047 return JPEG_SUSPENDED;
1048 cinfo->unread_marker = 0; /* processed the marker */
1049 return JPEG_REACHED_SOS;
1050
1051 case M_EOI:
1052 TRACEMS(cinfo, 1, JTRC_EOI);
1053 cinfo->unread_marker = 0; /* processed the marker */
1054 return JPEG_REACHED_EOI;
1055
1056 case M_DAC:
1057 if (! get_dac(cinfo))
1058 return JPEG_SUSPENDED;
1059 break;
1060
1061 case M_DHT:
1062 if (! get_dht(cinfo))
1063 return JPEG_SUSPENDED;
1064 break;
1065
1066 case M_DQT:
1067 if (! get_dqt(cinfo))
1068 return JPEG_SUSPENDED;
1069 break;
1070
1071 case M_DRI:
1072 if (! get_dri(cinfo))
1073 return JPEG_SUSPENDED;
1074 break;
1075
1076 case M_APP0:
1077 case M_APP1:
1078 case M_APP2:
1079 case M_APP3:
1080 case M_APP4:
1081 case M_APP5:
1082 case M_APP6:
1083 case M_APP7:
1084 case M_APP8:
1085 case M_APP9:
1086 case M_APP10:
1087 case M_APP11:
1088 case M_APP12:
1089 case M_APP13:
1090 case M_APP14:
1091 case M_APP15:
1092 if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
1093 cinfo->unread_marker - (int) M_APP0]) (cinfo))
1094 return JPEG_SUSPENDED;
1095 break;
1096
1097 case M_COM:
1098 if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
1099 return JPEG_SUSPENDED;
1100 break;
1101
1102 case M_RST0: /* these are all parameterless */
1103 case M_RST1:
1104 case M_RST2:
1105 case M_RST3:
1106 case M_RST4:
1107 case M_RST5:
1108 case M_RST6:
1109 case M_RST7:
1110 case M_TEM:
1111 TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
1112 break;
1113
1114 case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
1115 if (! skip_variable(cinfo))
1116 return JPEG_SUSPENDED;
1117 break;
1118
1119 default: /* must be DHP, EXP, JPGn, or RESn */
1120 /* For now, we treat the reserved markers as fatal errors since they are
1121 * likely to be used to signal incompatible JPEG Part 3 extensions.
1122 * Once the JPEG 3 version-number marker is well defined, this code
1123 * ought to change!
1124 */
1125 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
1126 break;
1127 }
1128 /* Successfully processed marker, so reset state variable */
1129 cinfo->unread_marker = 0;
1130 } /* end loop */
1131 }
1132
1133
1134 /*
1135 * Read a restart marker, which is expected to appear next in the datastream;
1136 * if the marker is not there, take appropriate recovery action.
1137 * Returns FALSE if suspension is required.
1138 *
1139 * This is called by the entropy decoder after it has read an appropriate
1140 * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
1141 * has already read a marker from the data source. Under normal conditions
1142 * cinfo->unread_marker will be reset to 0 before returning; if not reset,
1143 * it holds a marker which the decoder will be unable to read past.
1144 */
1145
1146 METHODDEF(boolean)
read_restart_marker(j_decompress_ptr cinfo)1147 read_restart_marker (j_decompress_ptr cinfo)
1148 {
1149 /* Obtain a marker unless we already did. */
1150 /* Note that next_marker will complain if it skips any data. */
1151 if (cinfo->unread_marker == 0) {
1152 if (! next_marker(cinfo))
1153 return FALSE;
1154 }
1155
1156 if (cinfo->unread_marker ==
1157 ((int) M_RST0 + cinfo->marker->next_restart_num)) {
1158 /* Normal case --- swallow the marker and let entropy decoder continue */
1159 TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
1160 cinfo->unread_marker = 0;
1161 } else {
1162 /* Uh-oh, the restart markers have been messed up. */
1163 /* Let the data source manager determine how to resync. */
1164 if (! (*cinfo->src->resync_to_restart) (cinfo,
1165 cinfo->marker->next_restart_num))
1166 return FALSE;
1167 }
1168
1169 /* Update next-restart state */
1170 cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
1171
1172 return TRUE;
1173 }
1174
1175
1176 /*
1177 * This is the default resync_to_restart method for data source managers
1178 * to use if they don't have any better approach. Some data source managers
1179 * may be able to back up, or may have additional knowledge about the data
1180 * which permits a more intelligent recovery strategy; such managers would
1181 * presumably supply their own resync method.
1182 *
1183 * read_restart_marker calls resync_to_restart if it finds a marker other than
1184 * the restart marker it was expecting. (This code is *not* used unless
1185 * a nonzero restart interval has been declared.) cinfo->unread_marker is
1186 * the marker code actually found (might be anything, except 0 or FF).
1187 * The desired restart marker number (0..7) is passed as a parameter.
1188 * This routine is supposed to apply whatever error recovery strategy seems
1189 * appropriate in order to position the input stream to the next data segment.
1190 * Note that cinfo->unread_marker is treated as a marker appearing before
1191 * the current data-source input point; usually it should be reset to zero
1192 * before returning.
1193 * Returns FALSE if suspension is required.
1194 *
1195 * This implementation is substantially constrained by wanting to treat the
1196 * input as a data stream; this means we can't back up. Therefore, we have
1197 * only the following actions to work with:
1198 * 1. Simply discard the marker and let the entropy decoder resume at next
1199 * byte of file.
1200 * 2. Read forward until we find another marker, discarding intervening
1201 * data. (In theory we could look ahead within the current bufferload,
1202 * without having to discard data if we don't find the desired marker.
1203 * This idea is not implemented here, in part because it makes behavior
1204 * dependent on buffer size and chance buffer-boundary positions.)
1205 * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
1206 * This will cause the entropy decoder to process an empty data segment,
1207 * inserting dummy zeroes, and then we will reprocess the marker.
1208 *
1209 * #2 is appropriate if we think the desired marker lies ahead, while #3 is
1210 * appropriate if the found marker is a future restart marker (indicating
1211 * that we have missed the desired restart marker, probably because it got
1212 * corrupted).
1213 * We apply #2 or #3 if the found marker is a restart marker no more than
1214 * two counts behind or ahead of the expected one. We also apply #2 if the
1215 * found marker is not a legal JPEG marker code (it's certainly bogus data).
1216 * If the found marker is a restart marker more than 2 counts away, we do #1
1217 * (too much risk that the marker is erroneous; with luck we will be able to
1218 * resync at some future point).
1219 * For any valid non-restart JPEG marker, we apply #3. This keeps us from
1220 * overrunning the end of a scan. An implementation limited to single-scan
1221 * files might find it better to apply #2 for markers other than EOI, since
1222 * any other marker would have to be bogus data in that case.
1223 */
1224
1225 GLOBAL(boolean)
jpeg_resync_to_restart(j_decompress_ptr cinfo,int desired)1226 jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
1227 {
1228 int marker = cinfo->unread_marker;
1229 int action = 1;
1230
1231 /* Always put up a warning. */
1232 WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
1233
1234 /* Outer loop handles repeated decision after scanning forward. */
1235 for (;;) {
1236 if (marker < (int) M_SOF0)
1237 action = 2; /* invalid marker */
1238 else if (marker < (int) M_RST0 || marker > (int) M_RST7)
1239 action = 3; /* valid non-restart marker */
1240 else {
1241 if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
1242 marker == ((int) M_RST0 + ((desired+2) & 7)))
1243 action = 3; /* one of the next two expected restarts */
1244 else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
1245 marker == ((int) M_RST0 + ((desired-2) & 7)))
1246 action = 2; /* a prior restart, so advance */
1247 else
1248 action = 1; /* desired restart or too far away */
1249 }
1250 TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
1251 switch (action) {
1252 case 1:
1253 /* Discard marker and let entropy decoder resume processing. */
1254 cinfo->unread_marker = 0;
1255 return TRUE;
1256 case 2:
1257 /* Scan to the next marker, and repeat the decision loop. */
1258 if (! next_marker(cinfo))
1259 return FALSE;
1260 marker = cinfo->unread_marker;
1261 break;
1262 case 3:
1263 /* Return without advancing past this marker. */
1264 /* Entropy decoder will be forced to process an empty segment. */
1265 return TRUE;
1266 }
1267 } /* end loop */
1268 }
1269
1270
1271 /*
1272 * Reset marker processing state to begin a fresh datastream.
1273 */
1274
1275 METHODDEF(void)
reset_marker_reader(j_decompress_ptr cinfo)1276 reset_marker_reader (j_decompress_ptr cinfo)
1277 {
1278 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1279
1280 cinfo->comp_info = NULL; /* until allocated by get_sof */
1281 cinfo->input_scan_number = 0; /* no SOS seen yet */
1282 cinfo->unread_marker = 0; /* no pending marker */
1283 marker->pub.saw_SOI = FALSE; /* set internal state too */
1284 marker->pub.saw_SOF = FALSE;
1285 marker->pub.discarded_bytes = 0;
1286 marker->cur_marker = NULL;
1287 }
1288
1289
1290 /*
1291 * Initialize the marker reader module.
1292 * This is called only once, when the decompression object is created.
1293 */
1294
1295 GLOBAL(void)
jinit_marker_reader(j_decompress_ptr cinfo)1296 jinit_marker_reader (j_decompress_ptr cinfo)
1297 {
1298 my_marker_ptr marker;
1299 int i;
1300
1301 /* Create subobject in permanent pool */
1302 marker = (my_marker_ptr)
1303 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
1304 SIZEOF(my_marker_reader));
1305 cinfo->marker = (struct jpeg_marker_reader *) marker;
1306 /* Initialize public method pointers */
1307 marker->pub.reset_marker_reader = reset_marker_reader;
1308 marker->pub.read_markers = read_markers;
1309 marker->pub.read_restart_marker = read_restart_marker;
1310 /* Initialize COM/APPn processing.
1311 * By default, we examine and then discard APP0 and APP14,
1312 * but simply discard COM and all other APPn.
1313 */
1314 marker->process_COM = skip_variable;
1315 marker->length_limit_COM = 0;
1316 for (i = 0; i < 16; i++) {
1317 marker->process_APPn[i] = skip_variable;
1318 marker->length_limit_APPn[i] = 0;
1319 }
1320 marker->process_APPn[0] = get_interesting_appn;
1321 marker->process_APPn[14] = get_interesting_appn;
1322 /* Reset marker processing state */
1323 reset_marker_reader(cinfo);
1324 }
1325
1326
1327 /*
1328 * Control saving of COM and APPn markers into marker_list.
1329 */
1330
1331 #ifdef SAVE_MARKERS_SUPPORTED
1332
1333 GLOBAL(void)
jpeg_save_markers(j_decompress_ptr cinfo,int marker_code,unsigned int length_limit)1334 jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
1335 unsigned int length_limit)
1336 {
1337 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1338 long maxlength;
1339 jpeg_marker_parser_method processor;
1340
1341 /* Length limit mustn't be larger than what we can allocate
1342 * (should only be a concern in a 16-bit environment).
1343 */
1344 maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
1345 if (((long) length_limit) > maxlength)
1346 length_limit = (unsigned int) maxlength;
1347
1348 /* Choose processor routine to use.
1349 * APP0/APP14 have special requirements.
1350 */
1351 if (length_limit) {
1352 processor = save_marker;
1353 /* If saving APP0/APP14, save at least enough for our internal use. */
1354 if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
1355 length_limit = APP0_DATA_LEN;
1356 else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
1357 length_limit = APP14_DATA_LEN;
1358 } else {
1359 processor = skip_variable;
1360 /* If discarding APP0/APP14, use our regular on-the-fly processor. */
1361 if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
1362 processor = get_interesting_appn;
1363 }
1364
1365 if (marker_code == (int) M_COM) {
1366 marker->process_COM = processor;
1367 marker->length_limit_COM = length_limit;
1368 } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
1369 marker->process_APPn[marker_code - (int) M_APP0] = processor;
1370 marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
1371 } else
1372 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
1373 }
1374
1375 #endif /* SAVE_MARKERS_SUPPORTED */
1376
1377
1378 /*
1379 * Install a special processing method for COM or APPn markers.
1380 */
1381
1382 GLOBAL(void)
jpeg_set_marker_processor(j_decompress_ptr cinfo,int marker_code,jpeg_marker_parser_method routine)1383 jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
1384 jpeg_marker_parser_method routine)
1385 {
1386 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1387
1388 if (marker_code == (int) M_COM)
1389 marker->process_COM = routine;
1390 else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
1391 marker->process_APPn[marker_code - (int) M_APP0] = routine;
1392 else
1393 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
1394 }
1395
1396 #endif //_FX_JPEG_TURBO_
1397