Line data Source code
1 : /*
2 : * jdmarker.c
3 : *
4 : * This file was part of the Independent JPEG Group's software:
5 : * Copyright (C) 1991-1998, Thomas G. Lane.
6 : * libjpeg-turbo Modifications:
7 : * Copyright (C) 2012, 2015, D. R. Commander.
8 : * For conditions of distribution and use, see the accompanying README.ijg
9 : * file.
10 : *
11 : * This file contains routines to decode JPEG datastream markers.
12 : * Most of the complexity arises from our desire to support input
13 : * suspension: if not all of the data for a marker is available,
14 : * we must exit back to the application. On resumption, we reprocess
15 : * the marker.
16 : */
17 :
18 : #define JPEG_INTERNALS
19 : #include "jinclude.h"
20 : #include "jpeglib.h"
21 :
22 :
23 : typedef enum { /* JPEG marker codes */
24 : M_SOF0 = 0xc0,
25 : M_SOF1 = 0xc1,
26 : M_SOF2 = 0xc2,
27 : M_SOF3 = 0xc3,
28 :
29 : M_SOF5 = 0xc5,
30 : M_SOF6 = 0xc6,
31 : M_SOF7 = 0xc7,
32 :
33 : M_JPG = 0xc8,
34 : M_SOF9 = 0xc9,
35 : M_SOF10 = 0xca,
36 : M_SOF11 = 0xcb,
37 :
38 : M_SOF13 = 0xcd,
39 : M_SOF14 = 0xce,
40 : M_SOF15 = 0xcf,
41 :
42 : M_DHT = 0xc4,
43 :
44 : M_DAC = 0xcc,
45 :
46 : M_RST0 = 0xd0,
47 : M_RST1 = 0xd1,
48 : M_RST2 = 0xd2,
49 : M_RST3 = 0xd3,
50 : M_RST4 = 0xd4,
51 : M_RST5 = 0xd5,
52 : M_RST6 = 0xd6,
53 : M_RST7 = 0xd7,
54 :
55 : M_SOI = 0xd8,
56 : M_EOI = 0xd9,
57 : M_SOS = 0xda,
58 : M_DQT = 0xdb,
59 : M_DNL = 0xdc,
60 : M_DRI = 0xdd,
61 : M_DHP = 0xde,
62 : M_EXP = 0xdf,
63 :
64 : M_APP0 = 0xe0,
65 : M_APP1 = 0xe1,
66 : M_APP2 = 0xe2,
67 : M_APP3 = 0xe3,
68 : M_APP4 = 0xe4,
69 : M_APP5 = 0xe5,
70 : M_APP6 = 0xe6,
71 : M_APP7 = 0xe7,
72 : M_APP8 = 0xe8,
73 : M_APP9 = 0xe9,
74 : M_APP10 = 0xea,
75 : M_APP11 = 0xeb,
76 : M_APP12 = 0xec,
77 : M_APP13 = 0xed,
78 : M_APP14 = 0xee,
79 : M_APP15 = 0xef,
80 :
81 : M_JPG0 = 0xf0,
82 : M_JPG13 = 0xfd,
83 : M_COM = 0xfe,
84 :
85 : M_TEM = 0x01,
86 :
87 : M_ERROR = 0x100
88 : } JPEG_MARKER;
89 :
90 :
91 : /* Private state */
92 :
93 : typedef struct {
94 : struct jpeg_marker_reader pub; /* public fields */
95 :
96 : /* Application-overridable marker processing methods */
97 : jpeg_marker_parser_method process_COM;
98 : jpeg_marker_parser_method process_APPn[16];
99 :
100 : /* Limit on marker data length to save for each marker type */
101 : unsigned int length_limit_COM;
102 : unsigned int length_limit_APPn[16];
103 :
104 : /* Status of COM/APPn marker saving */
105 : jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
106 : unsigned int bytes_read; /* data bytes read so far in marker */
107 : /* Note: cur_marker is not linked into marker_list until it's all read. */
108 : } my_marker_reader;
109 :
110 : typedef my_marker_reader *my_marker_ptr;
111 :
112 :
113 : /*
114 : * Macros for fetching data from the data source module.
115 : *
116 : * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
117 : * the current restart point; we update them only when we have reached a
118 : * suitable place to restart if a suspension occurs.
119 : */
120 :
121 : /* Declare and initialize local copies of input pointer/count */
122 : #define INPUT_VARS(cinfo) \
123 : struct jpeg_source_mgr *datasrc = (cinfo)->src; \
124 : const JOCTET *next_input_byte = datasrc->next_input_byte; \
125 : size_t bytes_in_buffer = datasrc->bytes_in_buffer
126 :
127 : /* Unload the local copies --- do this only at a restart boundary */
128 : #define INPUT_SYNC(cinfo) \
129 : ( datasrc->next_input_byte = next_input_byte, \
130 : datasrc->bytes_in_buffer = bytes_in_buffer )
131 :
132 : /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
133 : #define INPUT_RELOAD(cinfo) \
134 : ( next_input_byte = datasrc->next_input_byte, \
135 : bytes_in_buffer = datasrc->bytes_in_buffer )
136 :
137 : /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
138 : * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
139 : * but we must reload the local copies after a successful fill.
140 : */
141 : #define MAKE_BYTE_AVAIL(cinfo,action) \
142 : if (bytes_in_buffer == 0) { \
143 : if (! (*datasrc->fill_input_buffer) (cinfo)) \
144 : { action; } \
145 : INPUT_RELOAD(cinfo); \
146 : }
147 :
148 : /* Read a byte into variable V.
149 : * If must suspend, take the specified action (typically "return FALSE").
150 : */
151 : #define INPUT_BYTE(cinfo,V,action) \
152 : MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
153 : bytes_in_buffer--; \
154 : V = GETJOCTET(*next_input_byte++); )
155 :
156 : /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
157 : * V should be declared unsigned int or perhaps JLONG.
158 : */
159 : #define INPUT_2BYTES(cinfo,V,action) \
160 : MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
161 : bytes_in_buffer--; \
162 : V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
163 : MAKE_BYTE_AVAIL(cinfo,action); \
164 : bytes_in_buffer--; \
165 : V += GETJOCTET(*next_input_byte++); )
166 :
167 :
168 : /*
169 : * Routines to process JPEG markers.
170 : *
171 : * Entry condition: JPEG marker itself has been read and its code saved
172 : * in cinfo->unread_marker; input restart point is just after the marker.
173 : *
174 : * Exit: if return TRUE, have read and processed any parameters, and have
175 : * updated the restart point to point after the parameters.
176 : * If return FALSE, was forced to suspend before reaching end of
177 : * marker parameters; restart point has not been moved. Same routine
178 : * will be called again after application supplies more input data.
179 : *
180 : * This approach to suspension assumes that all of a marker's parameters
181 : * can fit into a single input bufferload. This should hold for "normal"
182 : * markers. Some COM/APPn markers might have large parameter segments
183 : * that might not fit. If we are simply dropping such a marker, we use
184 : * skip_input_data to get past it, and thereby put the problem on the
185 : * source manager's shoulders. If we are saving the marker's contents
186 : * into memory, we use a slightly different convention: when forced to
187 : * suspend, the marker processor updates the restart point to the end of
188 : * what it's consumed (ie, the end of the buffer) before returning FALSE.
189 : * On resumption, cinfo->unread_marker still contains the marker code,
190 : * but the data source will point to the next chunk of marker data.
191 : * The marker processor must retain internal state to deal with this.
192 : *
193 : * Note that we don't bother to avoid duplicate trace messages if a
194 : * suspension occurs within marker parameters. Other side effects
195 : * require more care.
196 : */
197 :
198 :
199 : LOCAL(boolean)
200 0 : get_soi (j_decompress_ptr cinfo)
201 : /* Process an SOI marker */
202 : {
203 : int i;
204 :
205 0 : TRACEMS(cinfo, 1, JTRC_SOI);
206 :
207 0 : if (cinfo->marker->saw_SOI)
208 0 : ERREXIT(cinfo, JERR_SOI_DUPLICATE);
209 :
210 : /* Reset all parameters that are defined to be reset by SOI */
211 :
212 0 : for (i = 0; i < NUM_ARITH_TBLS; i++) {
213 0 : cinfo->arith_dc_L[i] = 0;
214 0 : cinfo->arith_dc_U[i] = 1;
215 0 : cinfo->arith_ac_K[i] = 5;
216 : }
217 0 : cinfo->restart_interval = 0;
218 :
219 : /* Set initial assumptions for colorspace etc */
220 :
221 0 : cinfo->jpeg_color_space = JCS_UNKNOWN;
222 0 : cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
223 :
224 0 : cinfo->saw_JFIF_marker = FALSE;
225 0 : cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
226 0 : cinfo->JFIF_minor_version = 1;
227 0 : cinfo->density_unit = 0;
228 0 : cinfo->X_density = 1;
229 0 : cinfo->Y_density = 1;
230 0 : cinfo->saw_Adobe_marker = FALSE;
231 0 : cinfo->Adobe_transform = 0;
232 :
233 0 : cinfo->marker->saw_SOI = TRUE;
234 :
235 0 : return TRUE;
236 : }
237 :
238 :
239 : LOCAL(boolean)
240 0 : get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
241 : /* Process a SOFn marker */
242 : {
243 : JLONG length;
244 : int c, ci;
245 : jpeg_component_info *compptr;
246 0 : INPUT_VARS(cinfo);
247 :
248 0 : cinfo->progressive_mode = is_prog;
249 0 : cinfo->arith_code = is_arith;
250 :
251 0 : INPUT_2BYTES(cinfo, length, return FALSE);
252 :
253 0 : INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
254 0 : INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
255 0 : INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
256 0 : INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
257 :
258 0 : length -= 8;
259 :
260 0 : TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
261 : (int) cinfo->image_width, (int) cinfo->image_height,
262 : cinfo->num_components);
263 :
264 0 : if (cinfo->marker->saw_SOF)
265 0 : ERREXIT(cinfo, JERR_SOF_DUPLICATE);
266 :
267 : /* We don't support files in which the image height is initially specified */
268 : /* as 0 and is later redefined by DNL. As long as we have to check that, */
269 : /* might as well have a general sanity check. */
270 0 : if (cinfo->image_height <= 0 || cinfo->image_width <= 0
271 0 : || cinfo->num_components <= 0)
272 0 : ERREXIT(cinfo, JERR_EMPTY_IMAGE);
273 :
274 0 : if (length != (cinfo->num_components * 3))
275 0 : ERREXIT(cinfo, JERR_BAD_LENGTH);
276 :
277 0 : if (cinfo->comp_info == NULL) /* do only once, even if suspend */
278 0 : cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
279 : ((j_common_ptr) cinfo, JPOOL_IMAGE,
280 0 : cinfo->num_components * sizeof(jpeg_component_info));
281 :
282 0 : for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
283 0 : ci++, compptr++) {
284 0 : compptr->component_index = ci;
285 0 : INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
286 0 : INPUT_BYTE(cinfo, c, return FALSE);
287 0 : compptr->h_samp_factor = (c >> 4) & 15;
288 0 : compptr->v_samp_factor = (c ) & 15;
289 0 : INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
290 :
291 0 : TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
292 : compptr->component_id, compptr->h_samp_factor,
293 : compptr->v_samp_factor, compptr->quant_tbl_no);
294 : }
295 :
296 0 : cinfo->marker->saw_SOF = TRUE;
297 :
298 0 : INPUT_SYNC(cinfo);
299 0 : return TRUE;
300 : }
301 :
302 :
303 : LOCAL(boolean)
304 0 : get_sos (j_decompress_ptr cinfo)
305 : /* Process a SOS marker */
306 : {
307 : JLONG length;
308 : int i, ci, n, c, cc, pi;
309 : jpeg_component_info *compptr;
310 0 : INPUT_VARS(cinfo);
311 :
312 0 : if (! cinfo->marker->saw_SOF)
313 0 : ERREXIT(cinfo, JERR_SOS_NO_SOF);
314 :
315 0 : INPUT_2BYTES(cinfo, length, return FALSE);
316 :
317 0 : INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
318 :
319 0 : TRACEMS1(cinfo, 1, JTRC_SOS, n);
320 :
321 0 : if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
322 0 : ERREXIT(cinfo, JERR_BAD_LENGTH);
323 :
324 0 : cinfo->comps_in_scan = n;
325 :
326 : /* Collect the component-spec parameters */
327 :
328 0 : for (i = 0; i < MAX_COMPS_IN_SCAN; i++)
329 0 : cinfo->cur_comp_info[i] = NULL;
330 :
331 0 : for (i = 0; i < n; i++) {
332 0 : INPUT_BYTE(cinfo, cc, return FALSE);
333 0 : INPUT_BYTE(cinfo, c, return FALSE);
334 :
335 0 : for (ci = 0, compptr = cinfo->comp_info;
336 0 : ci < cinfo->num_components && ci < MAX_COMPS_IN_SCAN;
337 0 : ci++, compptr++) {
338 0 : if (cc == compptr->component_id && !cinfo->cur_comp_info[ci])
339 0 : goto id_found;
340 : }
341 :
342 0 : ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
343 :
344 : id_found:
345 :
346 0 : cinfo->cur_comp_info[i] = compptr;
347 0 : compptr->dc_tbl_no = (c >> 4) & 15;
348 0 : compptr->ac_tbl_no = (c ) & 15;
349 :
350 0 : TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
351 : compptr->dc_tbl_no, compptr->ac_tbl_no);
352 :
353 : /* This CSi (cc) should differ from the previous CSi */
354 0 : for (pi = 0; pi < i; pi++) {
355 0 : if (cinfo->cur_comp_info[pi] == compptr) {
356 0 : ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
357 : }
358 : }
359 : }
360 :
361 : /* Collect the additional scan parameters Ss, Se, Ah/Al. */
362 0 : INPUT_BYTE(cinfo, c, return FALSE);
363 0 : cinfo->Ss = c;
364 0 : INPUT_BYTE(cinfo, c, return FALSE);
365 0 : cinfo->Se = c;
366 0 : INPUT_BYTE(cinfo, c, return FALSE);
367 0 : cinfo->Ah = (c >> 4) & 15;
368 0 : cinfo->Al = (c ) & 15;
369 :
370 0 : TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
371 : cinfo->Ah, cinfo->Al);
372 :
373 : /* Prepare to scan data & restart markers */
374 0 : cinfo->marker->next_restart_num = 0;
375 :
376 : /* Count another SOS marker */
377 0 : cinfo->input_scan_number++;
378 :
379 0 : INPUT_SYNC(cinfo);
380 0 : return TRUE;
381 : }
382 :
383 :
384 : #ifdef D_ARITH_CODING_SUPPORTED
385 :
386 : LOCAL(boolean)
387 : get_dac (j_decompress_ptr cinfo)
388 : /* Process a DAC marker */
389 : {
390 : JLONG length;
391 : int index, val;
392 : INPUT_VARS(cinfo);
393 :
394 : INPUT_2BYTES(cinfo, length, return FALSE);
395 : length -= 2;
396 :
397 : while (length > 0) {
398 : INPUT_BYTE(cinfo, index, return FALSE);
399 : INPUT_BYTE(cinfo, val, return FALSE);
400 :
401 : length -= 2;
402 :
403 : TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
404 :
405 : if (index < 0 || index >= (2*NUM_ARITH_TBLS))
406 : ERREXIT1(cinfo, JERR_DAC_INDEX, index);
407 :
408 : if (index >= NUM_ARITH_TBLS) { /* define AC table */
409 : cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
410 : } else { /* define DC table */
411 : cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
412 : cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
413 : if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
414 : ERREXIT1(cinfo, JERR_DAC_VALUE, val);
415 : }
416 : }
417 :
418 : if (length != 0)
419 : ERREXIT(cinfo, JERR_BAD_LENGTH);
420 :
421 : INPUT_SYNC(cinfo);
422 : return TRUE;
423 : }
424 :
425 : #else /* ! D_ARITH_CODING_SUPPORTED */
426 :
427 : #define get_dac(cinfo) skip_variable(cinfo)
428 :
429 : #endif /* D_ARITH_CODING_SUPPORTED */
430 :
431 :
432 : LOCAL(boolean)
433 0 : get_dht (j_decompress_ptr cinfo)
434 : /* Process a DHT marker */
435 : {
436 : JLONG length;
437 : UINT8 bits[17];
438 : UINT8 huffval[256];
439 : int i, index, count;
440 : JHUFF_TBL **htblptr;
441 0 : INPUT_VARS(cinfo);
442 :
443 0 : INPUT_2BYTES(cinfo, length, return FALSE);
444 0 : length -= 2;
445 :
446 0 : while (length > 16) {
447 0 : INPUT_BYTE(cinfo, index, return FALSE);
448 :
449 0 : TRACEMS1(cinfo, 1, JTRC_DHT, index);
450 :
451 0 : bits[0] = 0;
452 0 : count = 0;
453 0 : for (i = 1; i <= 16; i++) {
454 0 : INPUT_BYTE(cinfo, bits[i], return FALSE);
455 0 : count += bits[i];
456 : }
457 :
458 0 : length -= 1 + 16;
459 :
460 0 : TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
461 : bits[1], bits[2], bits[3], bits[4],
462 : bits[5], bits[6], bits[7], bits[8]);
463 0 : TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
464 : bits[9], bits[10], bits[11], bits[12],
465 : bits[13], bits[14], bits[15], bits[16]);
466 :
467 : /* Here we just do minimal validation of the counts to avoid walking
468 : * off the end of our table space. jdhuff.c will check more carefully.
469 : */
470 0 : if (count > 256 || ((JLONG) count) > length)
471 0 : ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
472 :
473 0 : for (i = 0; i < count; i++)
474 0 : INPUT_BYTE(cinfo, huffval[i], return FALSE);
475 :
476 0 : MEMZERO(&huffval[count], (256 - count) * sizeof(UINT8));
477 :
478 0 : length -= count;
479 :
480 0 : if (index & 0x10) { /* AC table definition */
481 0 : index -= 0x10;
482 0 : if (index < 0 || index >= NUM_HUFF_TBLS)
483 0 : ERREXIT1(cinfo, JERR_DHT_INDEX, index);
484 0 : htblptr = &cinfo->ac_huff_tbl_ptrs[index];
485 : } else { /* DC table definition */
486 0 : if (index < 0 || index >= NUM_HUFF_TBLS)
487 0 : ERREXIT1(cinfo, JERR_DHT_INDEX, index);
488 0 : htblptr = &cinfo->dc_huff_tbl_ptrs[index];
489 : }
490 :
491 0 : if (*htblptr == NULL)
492 0 : *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
493 :
494 0 : MEMCOPY((*htblptr)->bits, bits, sizeof((*htblptr)->bits));
495 0 : MEMCOPY((*htblptr)->huffval, huffval, sizeof((*htblptr)->huffval));
496 : }
497 :
498 0 : if (length != 0)
499 0 : ERREXIT(cinfo, JERR_BAD_LENGTH);
500 :
501 0 : INPUT_SYNC(cinfo);
502 0 : return TRUE;
503 : }
504 :
505 :
506 : LOCAL(boolean)
507 0 : get_dqt (j_decompress_ptr cinfo)
508 : /* Process a DQT marker */
509 : {
510 : JLONG length;
511 : int n, i, prec;
512 : unsigned int tmp;
513 : JQUANT_TBL *quant_ptr;
514 0 : INPUT_VARS(cinfo);
515 :
516 0 : INPUT_2BYTES(cinfo, length, return FALSE);
517 0 : length -= 2;
518 :
519 0 : while (length > 0) {
520 0 : INPUT_BYTE(cinfo, n, return FALSE);
521 0 : prec = n >> 4;
522 0 : n &= 0x0F;
523 :
524 0 : TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
525 :
526 0 : if (n >= NUM_QUANT_TBLS)
527 0 : ERREXIT1(cinfo, JERR_DQT_INDEX, n);
528 :
529 0 : if (cinfo->quant_tbl_ptrs[n] == NULL)
530 0 : cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
531 0 : quant_ptr = cinfo->quant_tbl_ptrs[n];
532 :
533 0 : for (i = 0; i < DCTSIZE2; i++) {
534 0 : if (prec)
535 0 : INPUT_2BYTES(cinfo, tmp, return FALSE);
536 : else
537 0 : INPUT_BYTE(cinfo, tmp, return FALSE);
538 : /* We convert the zigzag-order table to natural array order. */
539 0 : quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
540 : }
541 :
542 0 : if (cinfo->err->trace_level >= 2) {
543 0 : for (i = 0; i < DCTSIZE2; i += 8) {
544 0 : TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
545 : quant_ptr->quantval[i], quant_ptr->quantval[i+1],
546 : quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
547 : quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
548 : quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
549 : }
550 : }
551 :
552 0 : length -= DCTSIZE2+1;
553 0 : if (prec) length -= DCTSIZE2;
554 : }
555 :
556 0 : if (length != 0)
557 0 : ERREXIT(cinfo, JERR_BAD_LENGTH);
558 :
559 0 : INPUT_SYNC(cinfo);
560 0 : return TRUE;
561 : }
562 :
563 :
564 : LOCAL(boolean)
565 0 : get_dri (j_decompress_ptr cinfo)
566 : /* Process a DRI marker */
567 : {
568 : JLONG length;
569 : unsigned int tmp;
570 0 : INPUT_VARS(cinfo);
571 :
572 0 : INPUT_2BYTES(cinfo, length, return FALSE);
573 :
574 0 : if (length != 4)
575 0 : ERREXIT(cinfo, JERR_BAD_LENGTH);
576 :
577 0 : INPUT_2BYTES(cinfo, tmp, return FALSE);
578 :
579 0 : TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
580 :
581 0 : cinfo->restart_interval = tmp;
582 :
583 0 : INPUT_SYNC(cinfo);
584 0 : return TRUE;
585 : }
586 :
587 :
588 : /*
589 : * Routines for processing APPn and COM markers.
590 : * These are either saved in memory or discarded, per application request.
591 : * APP0 and APP14 are specially checked to see if they are
592 : * JFIF and Adobe markers, respectively.
593 : */
594 :
595 : #define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
596 : #define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
597 : #define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
598 :
599 :
600 : LOCAL(void)
601 0 : examine_app0 (j_decompress_ptr cinfo, JOCTET *data,
602 : unsigned int datalen, JLONG remaining)
603 : /* Examine first few bytes from an APP0.
604 : * Take appropriate action if it is a JFIF marker.
605 : * datalen is # of bytes at data[], remaining is length of rest of marker data.
606 : */
607 : {
608 0 : JLONG totallen = (JLONG) datalen + remaining;
609 :
610 0 : if (datalen >= APP0_DATA_LEN &&
611 0 : GETJOCTET(data[0]) == 0x4A &&
612 0 : GETJOCTET(data[1]) == 0x46 &&
613 0 : GETJOCTET(data[2]) == 0x49 &&
614 0 : GETJOCTET(data[3]) == 0x46 &&
615 0 : GETJOCTET(data[4]) == 0) {
616 : /* Found JFIF APP0 marker: save info */
617 0 : cinfo->saw_JFIF_marker = TRUE;
618 0 : cinfo->JFIF_major_version = GETJOCTET(data[5]);
619 0 : cinfo->JFIF_minor_version = GETJOCTET(data[6]);
620 0 : cinfo->density_unit = GETJOCTET(data[7]);
621 0 : cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
622 0 : cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
623 : /* Check version.
624 : * Major version must be 1, anything else signals an incompatible change.
625 : * (We used to treat this as an error, but now it's a nonfatal warning,
626 : * because some bozo at Hijaak couldn't read the spec.)
627 : * Minor version should be 0..2, but process anyway if newer.
628 : */
629 0 : if (cinfo->JFIF_major_version != 1)
630 0 : WARNMS2(cinfo, JWRN_JFIF_MAJOR,
631 : cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
632 : /* Generate trace messages */
633 0 : TRACEMS5(cinfo, 1, JTRC_JFIF,
634 : cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
635 : cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
636 : /* Validate thumbnail dimensions and issue appropriate messages */
637 0 : if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
638 0 : TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
639 : GETJOCTET(data[12]), GETJOCTET(data[13]));
640 0 : totallen -= APP0_DATA_LEN;
641 0 : if (totallen !=
642 0 : ((JLONG)GETJOCTET(data[12]) * (JLONG)GETJOCTET(data[13]) * (JLONG) 3))
643 0 : TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
644 0 : } else if (datalen >= 6 &&
645 0 : GETJOCTET(data[0]) == 0x4A &&
646 0 : GETJOCTET(data[1]) == 0x46 &&
647 0 : GETJOCTET(data[2]) == 0x58 &&
648 0 : GETJOCTET(data[3]) == 0x58 &&
649 0 : GETJOCTET(data[4]) == 0) {
650 : /* Found JFIF "JFXX" extension APP0 marker */
651 : /* The library doesn't actually do anything with these,
652 : * but we try to produce a helpful trace message.
653 : */
654 0 : switch (GETJOCTET(data[5])) {
655 : case 0x10:
656 0 : TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
657 0 : break;
658 : case 0x11:
659 0 : TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
660 0 : break;
661 : case 0x13:
662 0 : TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
663 0 : break;
664 : default:
665 0 : TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
666 : GETJOCTET(data[5]), (int) totallen);
667 0 : break;
668 : }
669 0 : } else {
670 : /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
671 0 : TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
672 : }
673 0 : }
674 :
675 :
676 : LOCAL(void)
677 0 : examine_app14 (j_decompress_ptr cinfo, JOCTET *data,
678 : unsigned int datalen, JLONG remaining)
679 : /* Examine first few bytes from an APP14.
680 : * Take appropriate action if it is an Adobe marker.
681 : * datalen is # of bytes at data[], remaining is length of rest of marker data.
682 : */
683 : {
684 : unsigned int version, flags0, flags1, transform;
685 :
686 0 : if (datalen >= APP14_DATA_LEN &&
687 0 : GETJOCTET(data[0]) == 0x41 &&
688 0 : GETJOCTET(data[1]) == 0x64 &&
689 0 : GETJOCTET(data[2]) == 0x6F &&
690 0 : GETJOCTET(data[3]) == 0x62 &&
691 0 : GETJOCTET(data[4]) == 0x65) {
692 : /* Found Adobe APP14 marker */
693 0 : version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
694 0 : flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
695 0 : flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
696 0 : transform = GETJOCTET(data[11]);
697 0 : TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
698 0 : cinfo->saw_Adobe_marker = TRUE;
699 0 : cinfo->Adobe_transform = (UINT8) transform;
700 : } else {
701 : /* Start of APP14 does not match "Adobe", or too short */
702 0 : TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
703 : }
704 0 : }
705 :
706 :
707 : METHODDEF(boolean)
708 0 : get_interesting_appn (j_decompress_ptr cinfo)
709 : /* Process an APP0 or APP14 marker without saving it */
710 : {
711 : JLONG length;
712 : JOCTET b[APPN_DATA_LEN];
713 : unsigned int i, numtoread;
714 0 : INPUT_VARS(cinfo);
715 :
716 0 : INPUT_2BYTES(cinfo, length, return FALSE);
717 0 : length -= 2;
718 :
719 : /* get the interesting part of the marker data */
720 0 : if (length >= APPN_DATA_LEN)
721 0 : numtoread = APPN_DATA_LEN;
722 0 : else if (length > 0)
723 0 : numtoread = (unsigned int) length;
724 : else
725 0 : numtoread = 0;
726 0 : for (i = 0; i < numtoread; i++)
727 0 : INPUT_BYTE(cinfo, b[i], return FALSE);
728 0 : length -= numtoread;
729 :
730 : /* process it */
731 0 : switch (cinfo->unread_marker) {
732 : case M_APP0:
733 0 : examine_app0(cinfo, (JOCTET *) b, numtoread, length);
734 0 : break;
735 : case M_APP14:
736 0 : examine_app14(cinfo, (JOCTET *) b, numtoread, length);
737 0 : break;
738 : default:
739 : /* can't get here unless jpeg_save_markers chooses wrong processor */
740 0 : ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
741 0 : break;
742 : }
743 :
744 : /* skip any remaining data -- could be lots */
745 0 : INPUT_SYNC(cinfo);
746 0 : if (length > 0)
747 0 : (*cinfo->src->skip_input_data) (cinfo, (long) length);
748 :
749 0 : return TRUE;
750 : }
751 :
752 :
753 : #ifdef SAVE_MARKERS_SUPPORTED
754 :
755 : METHODDEF(boolean)
756 0 : save_marker (j_decompress_ptr cinfo)
757 : /* Save an APPn or COM marker into the marker list */
758 : {
759 0 : my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
760 0 : jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
761 : unsigned int bytes_read, data_length;
762 : JOCTET *data;
763 0 : JLONG length = 0;
764 0 : INPUT_VARS(cinfo);
765 :
766 0 : if (cur_marker == NULL) {
767 : /* begin reading a marker */
768 0 : INPUT_2BYTES(cinfo, length, return FALSE);
769 0 : length -= 2;
770 0 : if (length >= 0) { /* watch out for bogus length word */
771 : /* figure out how much we want to save */
772 : unsigned int limit;
773 0 : if (cinfo->unread_marker == (int) M_COM)
774 0 : limit = marker->length_limit_COM;
775 : else
776 0 : limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
777 0 : if ((unsigned int) length < limit)
778 0 : limit = (unsigned int) length;
779 : /* allocate and initialize the marker item */
780 0 : cur_marker = (jpeg_saved_marker_ptr)
781 0 : (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
782 : sizeof(struct jpeg_marker_struct) + limit);
783 0 : cur_marker->next = NULL;
784 0 : cur_marker->marker = (UINT8) cinfo->unread_marker;
785 0 : cur_marker->original_length = (unsigned int) length;
786 0 : cur_marker->data_length = limit;
787 : /* data area is just beyond the jpeg_marker_struct */
788 0 : data = cur_marker->data = (JOCTET *) (cur_marker + 1);
789 0 : marker->cur_marker = cur_marker;
790 0 : marker->bytes_read = 0;
791 0 : bytes_read = 0;
792 0 : data_length = limit;
793 : } else {
794 : /* deal with bogus length word */
795 0 : bytes_read = data_length = 0;
796 0 : data = NULL;
797 : }
798 : } else {
799 : /* resume reading a marker */
800 0 : bytes_read = marker->bytes_read;
801 0 : data_length = cur_marker->data_length;
802 0 : data = cur_marker->data + bytes_read;
803 : }
804 :
805 0 : while (bytes_read < data_length) {
806 0 : INPUT_SYNC(cinfo); /* move the restart point to here */
807 0 : marker->bytes_read = bytes_read;
808 : /* If there's not at least one byte in buffer, suspend */
809 0 : MAKE_BYTE_AVAIL(cinfo, return FALSE);
810 : /* Copy bytes with reasonable rapidity */
811 0 : while (bytes_read < data_length && bytes_in_buffer > 0) {
812 0 : *data++ = *next_input_byte++;
813 0 : bytes_in_buffer--;
814 0 : bytes_read++;
815 : }
816 : }
817 :
818 : /* Done reading what we want to read */
819 0 : if (cur_marker != NULL) { /* will be NULL if bogus length word */
820 : /* Add new marker to end of list */
821 0 : if (cinfo->marker_list == NULL) {
822 0 : cinfo->marker_list = cur_marker;
823 : } else {
824 0 : jpeg_saved_marker_ptr prev = cinfo->marker_list;
825 0 : while (prev->next != NULL)
826 0 : prev = prev->next;
827 0 : prev->next = cur_marker;
828 : }
829 : /* Reset pointer & calc remaining data length */
830 0 : data = cur_marker->data;
831 0 : length = cur_marker->original_length - data_length;
832 : }
833 : /* Reset to initial state for next marker */
834 0 : marker->cur_marker = NULL;
835 :
836 : /* Process the marker if interesting; else just make a generic trace msg */
837 0 : switch (cinfo->unread_marker) {
838 : case M_APP0:
839 0 : examine_app0(cinfo, data, data_length, length);
840 0 : break;
841 : case M_APP14:
842 0 : examine_app14(cinfo, data, data_length, length);
843 0 : break;
844 : default:
845 0 : TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
846 : (int) (data_length + length));
847 0 : break;
848 : }
849 :
850 : /* skip any remaining data -- could be lots */
851 0 : INPUT_SYNC(cinfo); /* do before skip_input_data */
852 0 : if (length > 0)
853 0 : (*cinfo->src->skip_input_data) (cinfo, (long) length);
854 :
855 0 : return TRUE;
856 : }
857 :
858 : #endif /* SAVE_MARKERS_SUPPORTED */
859 :
860 :
861 : METHODDEF(boolean)
862 0 : skip_variable (j_decompress_ptr cinfo)
863 : /* Skip over an unknown or uninteresting variable-length marker */
864 : {
865 : JLONG length;
866 0 : INPUT_VARS(cinfo);
867 :
868 0 : INPUT_2BYTES(cinfo, length, return FALSE);
869 0 : length -= 2;
870 :
871 0 : TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
872 :
873 0 : INPUT_SYNC(cinfo); /* do before skip_input_data */
874 0 : if (length > 0)
875 0 : (*cinfo->src->skip_input_data) (cinfo, (long) length);
876 :
877 0 : return TRUE;
878 : }
879 :
880 :
881 : /*
882 : * Find the next JPEG marker, save it in cinfo->unread_marker.
883 : * Returns FALSE if had to suspend before reaching a marker;
884 : * in that case cinfo->unread_marker is unchanged.
885 : *
886 : * Note that the result might not be a valid marker code,
887 : * but it will never be 0 or FF.
888 : */
889 :
890 : LOCAL(boolean)
891 0 : next_marker (j_decompress_ptr cinfo)
892 : {
893 : int c;
894 0 : INPUT_VARS(cinfo);
895 :
896 : for (;;) {
897 0 : INPUT_BYTE(cinfo, c, return FALSE);
898 : /* Skip any non-FF bytes.
899 : * This may look a bit inefficient, but it will not occur in a valid file.
900 : * We sync after each discarded byte so that a suspending data source
901 : * can discard the byte from its buffer.
902 : */
903 0 : while (c != 0xFF) {
904 0 : cinfo->marker->discarded_bytes++;
905 0 : INPUT_SYNC(cinfo);
906 0 : INPUT_BYTE(cinfo, c, return FALSE);
907 : }
908 : /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
909 : * pad bytes, so don't count them in discarded_bytes. We assume there
910 : * will not be so many consecutive FF bytes as to overflow a suspending
911 : * data source's input buffer.
912 : */
913 : do {
914 0 : INPUT_BYTE(cinfo, c, return FALSE);
915 0 : } while (c == 0xFF);
916 0 : if (c != 0)
917 0 : break; /* found a valid marker, exit loop */
918 : /* Reach here if we found a stuffed-zero data sequence (FF/00).
919 : * Discard it and loop back to try again.
920 : */
921 0 : cinfo->marker->discarded_bytes += 2;
922 0 : INPUT_SYNC(cinfo);
923 : }
924 :
925 0 : if (cinfo->marker->discarded_bytes != 0) {
926 0 : WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
927 0 : cinfo->marker->discarded_bytes = 0;
928 : }
929 :
930 0 : cinfo->unread_marker = c;
931 :
932 0 : INPUT_SYNC(cinfo);
933 0 : return TRUE;
934 : }
935 :
936 :
937 : LOCAL(boolean)
938 0 : first_marker (j_decompress_ptr cinfo)
939 : /* Like next_marker, but used to obtain the initial SOI marker. */
940 : /* For this marker, we do not allow preceding garbage or fill; otherwise,
941 : * we might well scan an entire input file before realizing it ain't JPEG.
942 : * If an application wants to process non-JFIF files, it must seek to the
943 : * SOI before calling the JPEG library.
944 : */
945 : {
946 : int c, c2;
947 0 : INPUT_VARS(cinfo);
948 :
949 0 : INPUT_BYTE(cinfo, c, return FALSE);
950 0 : INPUT_BYTE(cinfo, c2, return FALSE);
951 0 : if (c != 0xFF || c2 != (int) M_SOI)
952 0 : ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
953 :
954 0 : cinfo->unread_marker = c2;
955 :
956 0 : INPUT_SYNC(cinfo);
957 0 : return TRUE;
958 : }
959 :
960 :
961 : /*
962 : * Read markers until SOS or EOI.
963 : *
964 : * Returns same codes as are defined for jpeg_consume_input:
965 : * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
966 : */
967 :
968 : METHODDEF(int)
969 0 : read_markers (j_decompress_ptr cinfo)
970 : {
971 : /* Outer loop repeats once for each marker. */
972 : for (;;) {
973 : /* Collect the marker proper, unless we already did. */
974 : /* NB: first_marker() enforces the requirement that SOI appear first. */
975 0 : if (cinfo->unread_marker == 0) {
976 0 : if (! cinfo->marker->saw_SOI) {
977 0 : if (! first_marker(cinfo))
978 0 : return JPEG_SUSPENDED;
979 : } else {
980 0 : if (! next_marker(cinfo))
981 0 : return JPEG_SUSPENDED;
982 : }
983 : }
984 : /* At this point cinfo->unread_marker contains the marker code and the
985 : * input point is just past the marker proper, but before any parameters.
986 : * A suspension will cause us to return with this state still true.
987 : */
988 0 : switch (cinfo->unread_marker) {
989 : case M_SOI:
990 0 : if (! get_soi(cinfo))
991 0 : return JPEG_SUSPENDED;
992 0 : break;
993 :
994 : case M_SOF0: /* Baseline */
995 : case M_SOF1: /* Extended sequential, Huffman */
996 0 : if (! get_sof(cinfo, FALSE, FALSE))
997 0 : return JPEG_SUSPENDED;
998 0 : break;
999 :
1000 : case M_SOF2: /* Progressive, Huffman */
1001 0 : if (! get_sof(cinfo, TRUE, FALSE))
1002 0 : return JPEG_SUSPENDED;
1003 0 : break;
1004 :
1005 : case M_SOF9: /* Extended sequential, arithmetic */
1006 0 : if (! get_sof(cinfo, FALSE, TRUE))
1007 0 : return JPEG_SUSPENDED;
1008 0 : break;
1009 :
1010 : case M_SOF10: /* Progressive, arithmetic */
1011 0 : if (! get_sof(cinfo, TRUE, TRUE))
1012 0 : return JPEG_SUSPENDED;
1013 0 : break;
1014 :
1015 : /* Currently unsupported SOFn types */
1016 : case M_SOF3: /* Lossless, Huffman */
1017 : case M_SOF5: /* Differential sequential, Huffman */
1018 : case M_SOF6: /* Differential progressive, Huffman */
1019 : case M_SOF7: /* Differential lossless, Huffman */
1020 : case M_JPG: /* Reserved for JPEG extensions */
1021 : case M_SOF11: /* Lossless, arithmetic */
1022 : case M_SOF13: /* Differential sequential, arithmetic */
1023 : case M_SOF14: /* Differential progressive, arithmetic */
1024 : case M_SOF15: /* Differential lossless, arithmetic */
1025 0 : ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
1026 0 : break;
1027 :
1028 : case M_SOS:
1029 0 : if (! get_sos(cinfo))
1030 0 : return JPEG_SUSPENDED;
1031 0 : cinfo->unread_marker = 0; /* processed the marker */
1032 0 : return JPEG_REACHED_SOS;
1033 :
1034 : case M_EOI:
1035 0 : TRACEMS(cinfo, 1, JTRC_EOI);
1036 0 : cinfo->unread_marker = 0; /* processed the marker */
1037 0 : return JPEG_REACHED_EOI;
1038 :
1039 : case M_DAC:
1040 0 : if (! get_dac(cinfo))
1041 0 : return JPEG_SUSPENDED;
1042 0 : break;
1043 :
1044 : case M_DHT:
1045 0 : if (! get_dht(cinfo))
1046 0 : return JPEG_SUSPENDED;
1047 0 : break;
1048 :
1049 : case M_DQT:
1050 0 : if (! get_dqt(cinfo))
1051 0 : return JPEG_SUSPENDED;
1052 0 : break;
1053 :
1054 : case M_DRI:
1055 0 : if (! get_dri(cinfo))
1056 0 : return JPEG_SUSPENDED;
1057 0 : break;
1058 :
1059 : case M_APP0:
1060 : case M_APP1:
1061 : case M_APP2:
1062 : case M_APP3:
1063 : case M_APP4:
1064 : case M_APP5:
1065 : case M_APP6:
1066 : case M_APP7:
1067 : case M_APP8:
1068 : case M_APP9:
1069 : case M_APP10:
1070 : case M_APP11:
1071 : case M_APP12:
1072 : case M_APP13:
1073 : case M_APP14:
1074 : case M_APP15:
1075 0 : if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
1076 0 : cinfo->unread_marker - (int) M_APP0]) (cinfo))
1077 0 : return JPEG_SUSPENDED;
1078 0 : break;
1079 :
1080 : case M_COM:
1081 0 : if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
1082 0 : return JPEG_SUSPENDED;
1083 0 : break;
1084 :
1085 : case M_RST0: /* these are all parameterless */
1086 : case M_RST1:
1087 : case M_RST2:
1088 : case M_RST3:
1089 : case M_RST4:
1090 : case M_RST5:
1091 : case M_RST6:
1092 : case M_RST7:
1093 : case M_TEM:
1094 0 : TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
1095 0 : break;
1096 :
1097 : case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
1098 0 : if (! skip_variable(cinfo))
1099 0 : return JPEG_SUSPENDED;
1100 0 : break;
1101 :
1102 : default: /* must be DHP, EXP, JPGn, or RESn */
1103 : /* For now, we treat the reserved markers as fatal errors since they are
1104 : * likely to be used to signal incompatible JPEG Part 3 extensions.
1105 : * Once the JPEG 3 version-number marker is well defined, this code
1106 : * ought to change!
1107 : */
1108 0 : ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
1109 0 : break;
1110 : }
1111 : /* Successfully processed marker, so reset state variable */
1112 0 : cinfo->unread_marker = 0;
1113 : } /* end loop */
1114 : }
1115 :
1116 :
1117 : /*
1118 : * Read a restart marker, which is expected to appear next in the datastream;
1119 : * if the marker is not there, take appropriate recovery action.
1120 : * Returns FALSE if suspension is required.
1121 : *
1122 : * This is called by the entropy decoder after it has read an appropriate
1123 : * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
1124 : * has already read a marker from the data source. Under normal conditions
1125 : * cinfo->unread_marker will be reset to 0 before returning; if not reset,
1126 : * it holds a marker which the decoder will be unable to read past.
1127 : */
1128 :
1129 : METHODDEF(boolean)
1130 0 : read_restart_marker (j_decompress_ptr cinfo)
1131 : {
1132 : /* Obtain a marker unless we already did. */
1133 : /* Note that next_marker will complain if it skips any data. */
1134 0 : if (cinfo->unread_marker == 0) {
1135 0 : if (! next_marker(cinfo))
1136 0 : return FALSE;
1137 : }
1138 :
1139 0 : if (cinfo->unread_marker ==
1140 0 : ((int) M_RST0 + cinfo->marker->next_restart_num)) {
1141 : /* Normal case --- swallow the marker and let entropy decoder continue */
1142 0 : TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
1143 0 : cinfo->unread_marker = 0;
1144 : } else {
1145 : /* Uh-oh, the restart markers have been messed up. */
1146 : /* Let the data source manager determine how to resync. */
1147 0 : if (! (*cinfo->src->resync_to_restart) (cinfo,
1148 0 : cinfo->marker->next_restart_num))
1149 0 : return FALSE;
1150 : }
1151 :
1152 : /* Update next-restart state */
1153 0 : cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
1154 :
1155 0 : return TRUE;
1156 : }
1157 :
1158 :
1159 : /*
1160 : * This is the default resync_to_restart method for data source managers
1161 : * to use if they don't have any better approach. Some data source managers
1162 : * may be able to back up, or may have additional knowledge about the data
1163 : * which permits a more intelligent recovery strategy; such managers would
1164 : * presumably supply their own resync method.
1165 : *
1166 : * read_restart_marker calls resync_to_restart if it finds a marker other than
1167 : * the restart marker it was expecting. (This code is *not* used unless
1168 : * a nonzero restart interval has been declared.) cinfo->unread_marker is
1169 : * the marker code actually found (might be anything, except 0 or FF).
1170 : * The desired restart marker number (0..7) is passed as a parameter.
1171 : * This routine is supposed to apply whatever error recovery strategy seems
1172 : * appropriate in order to position the input stream to the next data segment.
1173 : * Note that cinfo->unread_marker is treated as a marker appearing before
1174 : * the current data-source input point; usually it should be reset to zero
1175 : * before returning.
1176 : * Returns FALSE if suspension is required.
1177 : *
1178 : * This implementation is substantially constrained by wanting to treat the
1179 : * input as a data stream; this means we can't back up. Therefore, we have
1180 : * only the following actions to work with:
1181 : * 1. Simply discard the marker and let the entropy decoder resume at next
1182 : * byte of file.
1183 : * 2. Read forward until we find another marker, discarding intervening
1184 : * data. (In theory we could look ahead within the current bufferload,
1185 : * without having to discard data if we don't find the desired marker.
1186 : * This idea is not implemented here, in part because it makes behavior
1187 : * dependent on buffer size and chance buffer-boundary positions.)
1188 : * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
1189 : * This will cause the entropy decoder to process an empty data segment,
1190 : * inserting dummy zeroes, and then we will reprocess the marker.
1191 : *
1192 : * #2 is appropriate if we think the desired marker lies ahead, while #3 is
1193 : * appropriate if the found marker is a future restart marker (indicating
1194 : * that we have missed the desired restart marker, probably because it got
1195 : * corrupted).
1196 : * We apply #2 or #3 if the found marker is a restart marker no more than
1197 : * two counts behind or ahead of the expected one. We also apply #2 if the
1198 : * found marker is not a legal JPEG marker code (it's certainly bogus data).
1199 : * If the found marker is a restart marker more than 2 counts away, we do #1
1200 : * (too much risk that the marker is erroneous; with luck we will be able to
1201 : * resync at some future point).
1202 : * For any valid non-restart JPEG marker, we apply #3. This keeps us from
1203 : * overrunning the end of a scan. An implementation limited to single-scan
1204 : * files might find it better to apply #2 for markers other than EOI, since
1205 : * any other marker would have to be bogus data in that case.
1206 : */
1207 :
1208 : GLOBAL(boolean)
1209 0 : jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
1210 : {
1211 0 : int marker = cinfo->unread_marker;
1212 0 : int action = 1;
1213 :
1214 : /* Always put up a warning. */
1215 0 : WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
1216 :
1217 : /* Outer loop handles repeated decision after scanning forward. */
1218 : for (;;) {
1219 0 : if (marker < (int) M_SOF0)
1220 0 : action = 2; /* invalid marker */
1221 0 : else if (marker < (int) M_RST0 || marker > (int) M_RST7)
1222 0 : action = 3; /* valid non-restart marker */
1223 : else {
1224 0 : if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
1225 0 : marker == ((int) M_RST0 + ((desired+2) & 7)))
1226 0 : action = 3; /* one of the next two expected restarts */
1227 0 : else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
1228 0 : marker == ((int) M_RST0 + ((desired-2) & 7)))
1229 0 : action = 2; /* a prior restart, so advance */
1230 : else
1231 0 : action = 1; /* desired restart or too far away */
1232 : }
1233 0 : TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
1234 0 : switch (action) {
1235 : case 1:
1236 : /* Discard marker and let entropy decoder resume processing. */
1237 0 : cinfo->unread_marker = 0;
1238 0 : return TRUE;
1239 : case 2:
1240 : /* Scan to the next marker, and repeat the decision loop. */
1241 0 : if (! next_marker(cinfo))
1242 0 : return FALSE;
1243 0 : marker = cinfo->unread_marker;
1244 0 : break;
1245 : case 3:
1246 : /* Return without advancing past this marker. */
1247 : /* Entropy decoder will be forced to process an empty segment. */
1248 0 : return TRUE;
1249 : }
1250 : } /* end loop */
1251 : }
1252 :
1253 :
1254 : /*
1255 : * Reset marker processing state to begin a fresh datastream.
1256 : */
1257 :
1258 : METHODDEF(void)
1259 0 : reset_marker_reader (j_decompress_ptr cinfo)
1260 : {
1261 0 : my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1262 :
1263 0 : cinfo->comp_info = NULL; /* until allocated by get_sof */
1264 0 : cinfo->input_scan_number = 0; /* no SOS seen yet */
1265 0 : cinfo->unread_marker = 0; /* no pending marker */
1266 0 : marker->pub.saw_SOI = FALSE; /* set internal state too */
1267 0 : marker->pub.saw_SOF = FALSE;
1268 0 : marker->pub.discarded_bytes = 0;
1269 0 : marker->cur_marker = NULL;
1270 0 : }
1271 :
1272 :
1273 : /*
1274 : * Initialize the marker reader module.
1275 : * This is called only once, when the decompression object is created.
1276 : */
1277 :
1278 : GLOBAL(void)
1279 0 : jinit_marker_reader (j_decompress_ptr cinfo)
1280 : {
1281 : my_marker_ptr marker;
1282 : int i;
1283 :
1284 : /* Create subobject in permanent pool */
1285 0 : marker = (my_marker_ptr)
1286 0 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
1287 : sizeof(my_marker_reader));
1288 0 : cinfo->marker = (struct jpeg_marker_reader *) marker;
1289 : /* Initialize public method pointers */
1290 0 : marker->pub.reset_marker_reader = reset_marker_reader;
1291 0 : marker->pub.read_markers = read_markers;
1292 0 : marker->pub.read_restart_marker = read_restart_marker;
1293 : /* Initialize COM/APPn processing.
1294 : * By default, we examine and then discard APP0 and APP14,
1295 : * but simply discard COM and all other APPn.
1296 : */
1297 0 : marker->process_COM = skip_variable;
1298 0 : marker->length_limit_COM = 0;
1299 0 : for (i = 0; i < 16; i++) {
1300 0 : marker->process_APPn[i] = skip_variable;
1301 0 : marker->length_limit_APPn[i] = 0;
1302 : }
1303 0 : marker->process_APPn[0] = get_interesting_appn;
1304 0 : marker->process_APPn[14] = get_interesting_appn;
1305 : /* Reset marker processing state */
1306 0 : reset_marker_reader(cinfo);
1307 0 : }
1308 :
1309 :
1310 : /*
1311 : * Control saving of COM and APPn markers into marker_list.
1312 : */
1313 :
1314 : #ifdef SAVE_MARKERS_SUPPORTED
1315 :
1316 : GLOBAL(void)
1317 0 : jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
1318 : unsigned int length_limit)
1319 : {
1320 0 : my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1321 : long maxlength;
1322 : jpeg_marker_parser_method processor;
1323 :
1324 : /* Length limit mustn't be larger than what we can allocate
1325 : * (should only be a concern in a 16-bit environment).
1326 : */
1327 0 : maxlength = cinfo->mem->max_alloc_chunk - sizeof(struct jpeg_marker_struct);
1328 0 : if (((long) length_limit) > maxlength)
1329 0 : length_limit = (unsigned int) maxlength;
1330 :
1331 : /* Choose processor routine to use.
1332 : * APP0/APP14 have special requirements.
1333 : */
1334 0 : if (length_limit) {
1335 0 : processor = save_marker;
1336 : /* If saving APP0/APP14, save at least enough for our internal use. */
1337 0 : if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
1338 0 : length_limit = APP0_DATA_LEN;
1339 0 : else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
1340 0 : length_limit = APP14_DATA_LEN;
1341 : } else {
1342 0 : processor = skip_variable;
1343 : /* If discarding APP0/APP14, use our regular on-the-fly processor. */
1344 0 : if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
1345 0 : processor = get_interesting_appn;
1346 : }
1347 :
1348 0 : if (marker_code == (int) M_COM) {
1349 0 : marker->process_COM = processor;
1350 0 : marker->length_limit_COM = length_limit;
1351 0 : } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
1352 0 : marker->process_APPn[marker_code - (int) M_APP0] = processor;
1353 0 : marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
1354 : } else
1355 0 : ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
1356 0 : }
1357 :
1358 : #endif /* SAVE_MARKERS_SUPPORTED */
1359 :
1360 :
1361 : /*
1362 : * Install a special processing method for COM or APPn markers.
1363 : */
1364 :
1365 : GLOBAL(void)
1366 0 : jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
1367 : jpeg_marker_parser_method routine)
1368 : {
1369 0 : my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1370 :
1371 0 : if (marker_code == (int) M_COM)
1372 0 : marker->process_COM = routine;
1373 0 : else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
1374 0 : marker->process_APPn[marker_code - (int) M_APP0] = routine;
1375 : else
1376 0 : ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
1377 0 : }
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