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 = *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)(*next_input_byte++)) << 8; \ |
163 | MAKE_BYTE_AVAIL(cinfo, action); \ |
164 | bytes_in_buffer--; \ |
165 | V += *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 | get_soi(j_decompress_ptr cinfo) |
201 | /* Process an SOI marker */ |
202 | { |
203 | int i; |
204 | |
205 | TRACEMS(cinfo, 1, JTRC_SOI); |
206 | |
207 | if (cinfo->marker->saw_SOI) |
208 | ERREXIT(cinfo, JERR_SOI_DUPLICATE); |
209 | |
210 | /* Reset all parameters that are defined to be reset by SOI */ |
211 | |
212 | for (i = 0; i < NUM_ARITH_TBLS; i++) { |
213 | cinfo->arith_dc_L[i] = 0; |
214 | cinfo->arith_dc_U[i] = 1; |
215 | cinfo->arith_ac_K[i] = 5; |
216 | } |
217 | cinfo->restart_interval = 0; |
218 | |
219 | /* Set initial assumptions for colorspace etc */ |
220 | |
221 | cinfo->jpeg_color_space = JCS_UNKNOWN; |
222 | cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */ |
223 | |
224 | cinfo->saw_JFIF_marker = FALSE; |
225 | cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */ |
226 | cinfo->JFIF_minor_version = 1; |
227 | cinfo->density_unit = 0; |
228 | cinfo->X_density = 1; |
229 | cinfo->Y_density = 1; |
230 | cinfo->saw_Adobe_marker = FALSE; |
231 | cinfo->Adobe_transform = 0; |
232 | |
233 | cinfo->marker->saw_SOI = TRUE; |
234 | |
235 | return TRUE; |
236 | } |
237 | |
238 | |
239 | LOCAL(boolean) |
240 | 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 | 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, cinfo->image_height, return FALSE); |
255 | INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE); |
256 | INPUT_BYTE(cinfo, cinfo->num_components, return FALSE); |
257 | |
258 | length -= 8; |
259 | |
260 | TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker, |
261 | (int)cinfo->image_width, (int)cinfo->image_height, |
262 | cinfo->num_components); |
263 | |
264 | if (cinfo->marker->saw_SOF) |
265 | 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 | if (cinfo->image_height <= 0 || cinfo->image_width <= 0 || |
271 | cinfo->num_components <= 0) |
272 | ERREXIT(cinfo, JERR_EMPTY_IMAGE); |
273 | |
274 | if (length != (cinfo->num_components * 3)) |
275 | ERREXIT(cinfo, JERR_BAD_LENGTH); |
276 | |
277 | if (cinfo->comp_info == NULL) /* do only once, even if suspend */ |
278 | cinfo->comp_info = (jpeg_component_info *)(*cinfo->mem->alloc_small) |
279 | ((j_common_ptr)cinfo, JPOOL_IMAGE, |
280 | cinfo->num_components * sizeof(jpeg_component_info)); |
281 | |
282 | for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
283 | ci++, compptr++) { |
284 | compptr->component_index = ci; |
285 | INPUT_BYTE(cinfo, compptr->component_id, return FALSE); |
286 | INPUT_BYTE(cinfo, c, return FALSE); |
287 | compptr->h_samp_factor = (c >> 4) & 15; |
288 | compptr->v_samp_factor = (c ) & 15; |
289 | INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE); |
290 | |
291 | 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 | cinfo->marker->saw_SOF = TRUE; |
297 | |
298 | INPUT_SYNC(cinfo); |
299 | return TRUE; |
300 | } |
301 | |
302 | |
303 | LOCAL(boolean) |
304 | 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 | INPUT_VARS(cinfo); |
311 | |
312 | if (!cinfo->marker->saw_SOF) |
313 | ERREXIT(cinfo, JERR_SOS_NO_SOF); |
314 | |
315 | INPUT_2BYTES(cinfo, length, return FALSE); |
316 | |
317 | INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */ |
318 | |
319 | TRACEMS1(cinfo, 1, JTRC_SOS, n); |
320 | |
321 | if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN) |
322 | ERREXIT(cinfo, JERR_BAD_LENGTH); |
323 | |
324 | cinfo->comps_in_scan = n; |
325 | |
326 | /* Collect the component-spec parameters */ |
327 | |
328 | for (i = 0; i < MAX_COMPS_IN_SCAN; i++) |
329 | cinfo->cur_comp_info[i] = NULL; |
330 | |
331 | for (i = 0; i < n; i++) { |
332 | INPUT_BYTE(cinfo, cc, return FALSE); |
333 | INPUT_BYTE(cinfo, c, return FALSE); |
334 | |
335 | for (ci = 0, compptr = cinfo->comp_info; |
336 | ci < cinfo->num_components && ci < MAX_COMPS_IN_SCAN; |
337 | ci++, compptr++) { |
338 | if (cc == compptr->component_id && !cinfo->cur_comp_info[ci]) |
339 | goto id_found; |
340 | } |
341 | |
342 | ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc); |
343 | |
344 | id_found: |
345 | |
346 | cinfo->cur_comp_info[i] = compptr; |
347 | compptr->dc_tbl_no = (c >> 4) & 15; |
348 | compptr->ac_tbl_no = (c ) & 15; |
349 | |
350 | 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 | for (pi = 0; pi < i; pi++) { |
355 | if (cinfo->cur_comp_info[pi] == compptr) { |
356 | ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc); |
357 | } |
358 | } |
359 | } |
360 | |
361 | /* Collect the additional scan parameters Ss, Se, Ah/Al. */ |
362 | INPUT_BYTE(cinfo, c, return FALSE); |
363 | cinfo->Ss = c; |
364 | INPUT_BYTE(cinfo, c, return FALSE); |
365 | cinfo->Se = c; |
366 | INPUT_BYTE(cinfo, c, return FALSE); |
367 | cinfo->Ah = (c >> 4) & 15; |
368 | cinfo->Al = (c ) & 15; |
369 | |
370 | TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se, |
371 | cinfo->Ah, cinfo->Al); |
372 | |
373 | /* Prepare to scan data & restart markers */ |
374 | cinfo->marker->next_restart_num = 0; |
375 | |
376 | /* Count another SOS marker */ |
377 | cinfo->input_scan_number++; |
378 | |
379 | INPUT_SYNC(cinfo); |
380 | 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 | 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 | INPUT_VARS(cinfo); |
442 | |
443 | INPUT_2BYTES(cinfo, length, return FALSE); |
444 | length -= 2; |
445 | |
446 | while (length > 16) { |
447 | INPUT_BYTE(cinfo, index, return FALSE); |
448 | |
449 | TRACEMS1(cinfo, 1, JTRC_DHT, index); |
450 | |
451 | bits[0] = 0; |
452 | count = 0; |
453 | for (i = 1; i <= 16; i++) { |
454 | INPUT_BYTE(cinfo, bits[i], return FALSE); |
455 | count += bits[i]; |
456 | } |
457 | |
458 | length -= 1 + 16; |
459 | |
460 | TRACEMS8(cinfo, 2, JTRC_HUFFBITS, |
461 | bits[1], bits[2], bits[3], bits[4], |
462 | bits[5], bits[6], bits[7], bits[8]); |
463 | 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 | if (count > 256 || ((JLONG)count) > length) |
471 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
472 | |
473 | for (i = 0; i < count; i++) |
474 | INPUT_BYTE(cinfo, huffval[i], return FALSE); |
475 | |
476 | MEMZERO(&huffval[count], (256 - count) * sizeof(UINT8)); |
477 | |
478 | length -= count; |
479 | |
480 | if (index & 0x10) { /* AC table definition */ |
481 | index -= 0x10; |
482 | if (index < 0 || index >= NUM_HUFF_TBLS) |
483 | ERREXIT1(cinfo, JERR_DHT_INDEX, index); |
484 | htblptr = &cinfo->ac_huff_tbl_ptrs[index]; |
485 | } else { /* DC table definition */ |
486 | if (index < 0 || index >= NUM_HUFF_TBLS) |
487 | ERREXIT1(cinfo, JERR_DHT_INDEX, index); |
488 | htblptr = &cinfo->dc_huff_tbl_ptrs[index]; |
489 | } |
490 | |
491 | if (*htblptr == NULL) |
492 | *htblptr = jpeg_alloc_huff_table((j_common_ptr)cinfo); |
493 | |
494 | MEMCOPY((*htblptr)->bits, bits, sizeof((*htblptr)->bits)); |
495 | MEMCOPY((*htblptr)->huffval, huffval, sizeof((*htblptr)->huffval)); |
496 | } |
497 | |
498 | if (length != 0) |
499 | ERREXIT(cinfo, JERR_BAD_LENGTH); |
500 | |
501 | INPUT_SYNC(cinfo); |
502 | return TRUE; |
503 | } |
504 | |
505 | |
506 | LOCAL(boolean) |
507 | 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 | INPUT_VARS(cinfo); |
515 | |
516 | INPUT_2BYTES(cinfo, length, return FALSE); |
517 | length -= 2; |
518 | |
519 | while (length > 0) { |
520 | INPUT_BYTE(cinfo, n, return FALSE); |
521 | prec = n >> 4; |
522 | n &= 0x0F; |
523 | |
524 | TRACEMS2(cinfo, 1, JTRC_DQT, n, prec); |
525 | |
526 | if (n >= NUM_QUANT_TBLS) |
527 | ERREXIT1(cinfo, JERR_DQT_INDEX, n); |
528 | |
529 | if (cinfo->quant_tbl_ptrs[n] == NULL) |
530 | cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr)cinfo); |
531 | quant_ptr = cinfo->quant_tbl_ptrs[n]; |
532 | |
533 | for (i = 0; i < DCTSIZE2; i++) { |
534 | if (prec) |
535 | INPUT_2BYTES(cinfo, tmp, return FALSE); |
536 | else |
537 | INPUT_BYTE(cinfo, tmp, return FALSE); |
538 | /* We convert the zigzag-order table to natural array order. */ |
539 | quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16)tmp; |
540 | } |
541 | |
542 | if (cinfo->err->trace_level >= 2) { |
543 | for (i = 0; i < DCTSIZE2; i += 8) { |
544 | 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 | length -= DCTSIZE2 + 1; |
553 | if (prec) length -= DCTSIZE2; |
554 | } |
555 | |
556 | if (length != 0) |
557 | ERREXIT(cinfo, JERR_BAD_LENGTH); |
558 | |
559 | INPUT_SYNC(cinfo); |
560 | return TRUE; |
561 | } |
562 | |
563 | |
564 | LOCAL(boolean) |
565 | get_dri(j_decompress_ptr cinfo) |
566 | /* Process a DRI marker */ |
567 | { |
568 | JLONG length; |
569 | unsigned int tmp; |
570 | INPUT_VARS(cinfo); |
571 | |
572 | INPUT_2BYTES(cinfo, length, return FALSE); |
573 | |
574 | if (length != 4) |
575 | ERREXIT(cinfo, JERR_BAD_LENGTH); |
576 | |
577 | INPUT_2BYTES(cinfo, tmp, return FALSE); |
578 | |
579 | TRACEMS1(cinfo, 1, JTRC_DRI, tmp); |
580 | |
581 | cinfo->restart_interval = tmp; |
582 | |
583 | INPUT_SYNC(cinfo); |
584 | 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 | examine_app0(j_decompress_ptr cinfo, JOCTET *data, unsigned int datalen, |
602 | 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 | JLONG totallen = (JLONG)datalen + remaining; |
609 | |
610 | if (datalen >= APP0_DATA_LEN && |
611 | data[0] == 0x4A && |
612 | data[1] == 0x46 && |
613 | data[2] == 0x49 && |
614 | data[3] == 0x46 && |
615 | data[4] == 0) { |
616 | /* Found JFIF APP0 marker: save info */ |
617 | cinfo->saw_JFIF_marker = TRUE; |
618 | cinfo->JFIF_major_version = data[5]; |
619 | cinfo->JFIF_minor_version = data[6]; |
620 | cinfo->density_unit = data[7]; |
621 | cinfo->X_density = (data[8] << 8) + data[9]; |
622 | cinfo->Y_density = (data[10] << 8) + 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 | if (cinfo->JFIF_major_version != 1) |
630 | WARNMS2(cinfo, JWRN_JFIF_MAJOR, |
631 | cinfo->JFIF_major_version, cinfo->JFIF_minor_version); |
632 | /* Generate trace messages */ |
633 | 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 | if (data[12] | data[13]) |
638 | TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL, data[12], data[13]); |
639 | totallen -= APP0_DATA_LEN; |
640 | if (totallen != ((JLONG)data[12] * (JLONG)data[13] * (JLONG)3)) |
641 | TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int)totallen); |
642 | } else if (datalen >= 6 && |
643 | data[0] == 0x4A && |
644 | data[1] == 0x46 && |
645 | data[2] == 0x58 && |
646 | data[3] == 0x58 && |
647 | data[4] == 0) { |
648 | /* Found JFIF "JFXX" extension APP0 marker */ |
649 | /* The library doesn't actually do anything with these, |
650 | * but we try to produce a helpful trace message. |
651 | */ |
652 | switch (data[5]) { |
653 | case 0x10: |
654 | TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int)totallen); |
655 | break; |
656 | case 0x11: |
657 | TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int)totallen); |
658 | break; |
659 | case 0x13: |
660 | TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int)totallen); |
661 | break; |
662 | default: |
663 | TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION, data[5], (int)totallen); |
664 | break; |
665 | } |
666 | } else { |
667 | /* Start of APP0 does not match "JFIF" or "JFXX", or too short */ |
668 | TRACEMS1(cinfo, 1, JTRC_APP0, (int)totallen); |
669 | } |
670 | } |
671 | |
672 | |
673 | LOCAL(void) |
674 | examine_app14(j_decompress_ptr cinfo, JOCTET *data, unsigned int datalen, |
675 | JLONG remaining) |
676 | /* Examine first few bytes from an APP14. |
677 | * Take appropriate action if it is an Adobe marker. |
678 | * datalen is # of bytes at data[], remaining is length of rest of marker data. |
679 | */ |
680 | { |
681 | unsigned int version, flags0, flags1, transform; |
682 | |
683 | if (datalen >= APP14_DATA_LEN && |
684 | data[0] == 0x41 && |
685 | data[1] == 0x64 && |
686 | data[2] == 0x6F && |
687 | data[3] == 0x62 && |
688 | data[4] == 0x65) { |
689 | /* Found Adobe APP14 marker */ |
690 | version = (data[5] << 8) + data[6]; |
691 | flags0 = (data[7] << 8) + data[8]; |
692 | flags1 = (data[9] << 8) + data[10]; |
693 | transform = data[11]; |
694 | TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform); |
695 | cinfo->saw_Adobe_marker = TRUE; |
696 | cinfo->Adobe_transform = (UINT8)transform; |
697 | } else { |
698 | /* Start of APP14 does not match "Adobe", or too short */ |
699 | TRACEMS1(cinfo, 1, JTRC_APP14, (int)(datalen + remaining)); |
700 | } |
701 | } |
702 | |
703 | |
704 | METHODDEF(boolean) |
705 | get_interesting_appn(j_decompress_ptr cinfo) |
706 | /* Process an APP0 or APP14 marker without saving it */ |
707 | { |
708 | JLONG length; |
709 | JOCTET b[APPN_DATA_LEN]; |
710 | unsigned int i, numtoread; |
711 | INPUT_VARS(cinfo); |
712 | |
713 | INPUT_2BYTES(cinfo, length, return FALSE); |
714 | length -= 2; |
715 | |
716 | /* get the interesting part of the marker data */ |
717 | if (length >= APPN_DATA_LEN) |
718 | numtoread = APPN_DATA_LEN; |
719 | else if (length > 0) |
720 | numtoread = (unsigned int)length; |
721 | else |
722 | numtoread = 0; |
723 | for (i = 0; i < numtoread; i++) |
724 | INPUT_BYTE(cinfo, b[i], return FALSE); |
725 | length -= numtoread; |
726 | |
727 | /* process it */ |
728 | switch (cinfo->unread_marker) { |
729 | case M_APP0: |
730 | examine_app0(cinfo, (JOCTET *)b, numtoread, length); |
731 | break; |
732 | case M_APP14: |
733 | examine_app14(cinfo, (JOCTET *)b, numtoread, length); |
734 | break; |
735 | default: |
736 | /* can't get here unless jpeg_save_markers chooses wrong processor */ |
737 | ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker); |
738 | break; |
739 | } |
740 | |
741 | /* skip any remaining data -- could be lots */ |
742 | INPUT_SYNC(cinfo); |
743 | if (length > 0) |
744 | (*cinfo->src->skip_input_data) (cinfo, (long)length); |
745 | |
746 | return TRUE; |
747 | } |
748 | |
749 | |
750 | #ifdef SAVE_MARKERS_SUPPORTED |
751 | |
752 | METHODDEF(boolean) |
753 | save_marker(j_decompress_ptr cinfo) |
754 | /* Save an APPn or COM marker into the marker list */ |
755 | { |
756 | my_marker_ptr marker = (my_marker_ptr)cinfo->marker; |
757 | jpeg_saved_marker_ptr cur_marker = marker->cur_marker; |
758 | unsigned int bytes_read, data_length; |
759 | JOCTET *data; |
760 | JLONG length = 0; |
761 | INPUT_VARS(cinfo); |
762 | |
763 | if (cur_marker == NULL) { |
764 | /* begin reading a marker */ |
765 | INPUT_2BYTES(cinfo, length, return FALSE); |
766 | length -= 2; |
767 | if (length >= 0) { /* watch out for bogus length word */ |
768 | /* figure out how much we want to save */ |
769 | unsigned int limit; |
770 | if (cinfo->unread_marker == (int)M_COM) |
771 | limit = marker->length_limit_COM; |
772 | else |
773 | limit = marker->length_limit_APPn[cinfo->unread_marker - (int)M_APP0]; |
774 | if ((unsigned int)length < limit) |
775 | limit = (unsigned int)length; |
776 | /* allocate and initialize the marker item */ |
777 | cur_marker = (jpeg_saved_marker_ptr) |
778 | (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
779 | sizeof(struct jpeg_marker_struct) + limit); |
780 | cur_marker->next = NULL; |
781 | cur_marker->marker = (UINT8)cinfo->unread_marker; |
782 | cur_marker->original_length = (unsigned int)length; |
783 | cur_marker->data_length = limit; |
784 | /* data area is just beyond the jpeg_marker_struct */ |
785 | data = cur_marker->data = (JOCTET *)(cur_marker + 1); |
786 | marker->cur_marker = cur_marker; |
787 | marker->bytes_read = 0; |
788 | bytes_read = 0; |
789 | data_length = limit; |
790 | } else { |
791 | /* deal with bogus length word */ |
792 | bytes_read = data_length = 0; |
793 | data = NULL; |
794 | } |
795 | } else { |
796 | /* resume reading a marker */ |
797 | bytes_read = marker->bytes_read; |
798 | data_length = cur_marker->data_length; |
799 | data = cur_marker->data + bytes_read; |
800 | } |
801 | |
802 | while (bytes_read < data_length) { |
803 | INPUT_SYNC(cinfo); /* move the restart point to here */ |
804 | marker->bytes_read = bytes_read; |
805 | /* If there's not at least one byte in buffer, suspend */ |
806 | MAKE_BYTE_AVAIL(cinfo, return FALSE); |
807 | /* Copy bytes with reasonable rapidity */ |
808 | while (bytes_read < data_length && bytes_in_buffer > 0) { |
809 | *data++ = *next_input_byte++; |
810 | bytes_in_buffer--; |
811 | bytes_read++; |
812 | } |
813 | } |
814 | |
815 | /* Done reading what we want to read */ |
816 | if (cur_marker != NULL) { /* will be NULL if bogus length word */ |
817 | /* Add new marker to end of list */ |
818 | if (cinfo->marker_list == NULL) { |
819 | cinfo->marker_list = cur_marker; |
820 | } else { |
821 | jpeg_saved_marker_ptr prev = cinfo->marker_list; |
822 | while (prev->next != NULL) |
823 | prev = prev->next; |
824 | prev->next = cur_marker; |
825 | } |
826 | /* Reset pointer & calc remaining data length */ |
827 | data = cur_marker->data; |
828 | length = cur_marker->original_length - data_length; |
829 | } |
830 | /* Reset to initial state for next marker */ |
831 | marker->cur_marker = NULL; |
832 | |
833 | /* Process the marker if interesting; else just make a generic trace msg */ |
834 | switch (cinfo->unread_marker) { |
835 | case M_APP0: |
836 | examine_app0(cinfo, data, data_length, length); |
837 | break; |
838 | case M_APP14: |
839 | examine_app14(cinfo, data, data_length, length); |
840 | break; |
841 | default: |
842 | TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, |
843 | (int)(data_length + length)); |
844 | break; |
845 | } |
846 | |
847 | /* skip any remaining data -- could be lots */ |
848 | INPUT_SYNC(cinfo); /* do before skip_input_data */ |
849 | if (length > 0) |
850 | (*cinfo->src->skip_input_data) (cinfo, (long)length); |
851 | |
852 | return TRUE; |
853 | } |
854 | |
855 | #endif /* SAVE_MARKERS_SUPPORTED */ |
856 | |
857 | |
858 | METHODDEF(boolean) |
859 | skip_variable(j_decompress_ptr cinfo) |
860 | /* Skip over an unknown or uninteresting variable-length marker */ |
861 | { |
862 | JLONG length; |
863 | INPUT_VARS(cinfo); |
864 | |
865 | INPUT_2BYTES(cinfo, length, return FALSE); |
866 | length -= 2; |
867 | |
868 | TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int)length); |
869 | |
870 | INPUT_SYNC(cinfo); /* do before skip_input_data */ |
871 | if (length > 0) |
872 | (*cinfo->src->skip_input_data) (cinfo, (long)length); |
873 | |
874 | return TRUE; |
875 | } |
876 | |
877 | |
878 | /* |
879 | * Find the next JPEG marker, save it in cinfo->unread_marker. |
880 | * Returns FALSE if had to suspend before reaching a marker; |
881 | * in that case cinfo->unread_marker is unchanged. |
882 | * |
883 | * Note that the result might not be a valid marker code, |
884 | * but it will never be 0 or FF. |
885 | */ |
886 | |
887 | LOCAL(boolean) |
888 | next_marker(j_decompress_ptr cinfo) |
889 | { |
890 | int c; |
891 | INPUT_VARS(cinfo); |
892 | |
893 | for (;;) { |
894 | INPUT_BYTE(cinfo, c, return FALSE); |
895 | /* Skip any non-FF bytes. |
896 | * This may look a bit inefficient, but it will not occur in a valid file. |
897 | * We sync after each discarded byte so that a suspending data source |
898 | * can discard the byte from its buffer. |
899 | */ |
900 | while (c != 0xFF) { |
901 | cinfo->marker->discarded_bytes++; |
902 | INPUT_SYNC(cinfo); |
903 | INPUT_BYTE(cinfo, c, return FALSE); |
904 | } |
905 | /* This loop swallows any duplicate FF bytes. Extra FFs are legal as |
906 | * pad bytes, so don't count them in discarded_bytes. We assume there |
907 | * will not be so many consecutive FF bytes as to overflow a suspending |
908 | * data source's input buffer. |
909 | */ |
910 | do { |
911 | INPUT_BYTE(cinfo, c, return FALSE); |
912 | } while (c == 0xFF); |
913 | if (c != 0) |
914 | break; /* found a valid marker, exit loop */ |
915 | /* Reach here if we found a stuffed-zero data sequence (FF/00). |
916 | * Discard it and loop back to try again. |
917 | */ |
918 | cinfo->marker->discarded_bytes += 2; |
919 | INPUT_SYNC(cinfo); |
920 | } |
921 | |
922 | if (cinfo->marker->discarded_bytes != 0) { |
923 | WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c); |
924 | cinfo->marker->discarded_bytes = 0; |
925 | } |
926 | |
927 | cinfo->unread_marker = c; |
928 | |
929 | INPUT_SYNC(cinfo); |
930 | return TRUE; |
931 | } |
932 | |
933 | |
934 | LOCAL(boolean) |
935 | first_marker(j_decompress_ptr cinfo) |
936 | /* Like next_marker, but used to obtain the initial SOI marker. */ |
937 | /* For this marker, we do not allow preceding garbage or fill; otherwise, |
938 | * we might well scan an entire input file before realizing it ain't JPEG. |
939 | * If an application wants to process non-JFIF files, it must seek to the |
940 | * SOI before calling the JPEG library. |
941 | */ |
942 | { |
943 | int c, c2; |
944 | INPUT_VARS(cinfo); |
945 | |
946 | INPUT_BYTE(cinfo, c, return FALSE); |
947 | INPUT_BYTE(cinfo, c2, return FALSE); |
948 | if (c != 0xFF || c2 != (int)M_SOI) |
949 | ERREXIT2(cinfo, JERR_NO_SOI, c, c2); |
950 | |
951 | cinfo->unread_marker = c2; |
952 | |
953 | INPUT_SYNC(cinfo); |
954 | return TRUE; |
955 | } |
956 | |
957 | |
958 | /* |
959 | * Read markers until SOS or EOI. |
960 | * |
961 | * Returns same codes as are defined for jpeg_consume_input: |
962 | * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI. |
963 | */ |
964 | |
965 | METHODDEF(int) |
966 | read_markers(j_decompress_ptr cinfo) |
967 | { |
968 | /* Outer loop repeats once for each marker. */ |
969 | for (;;) { |
970 | /* Collect the marker proper, unless we already did. */ |
971 | /* NB: first_marker() enforces the requirement that SOI appear first. */ |
972 | if (cinfo->unread_marker == 0) { |
973 | if (!cinfo->marker->saw_SOI) { |
974 | if (!first_marker(cinfo)) |
975 | return JPEG_SUSPENDED; |
976 | } else { |
977 | if (!next_marker(cinfo)) |
978 | return JPEG_SUSPENDED; |
979 | } |
980 | } |
981 | /* At this point cinfo->unread_marker contains the marker code and the |
982 | * input point is just past the marker proper, but before any parameters. |
983 | * A suspension will cause us to return with this state still true. |
984 | */ |
985 | switch (cinfo->unread_marker) { |
986 | case M_SOI: |
987 | if (!get_soi(cinfo)) |
988 | return JPEG_SUSPENDED; |
989 | break; |
990 | |
991 | case M_SOF0: /* Baseline */ |
992 | case M_SOF1: /* Extended sequential, Huffman */ |
993 | if (!get_sof(cinfo, FALSE, FALSE)) |
994 | return JPEG_SUSPENDED; |
995 | break; |
996 | |
997 | case M_SOF2: /* Progressive, Huffman */ |
998 | if (!get_sof(cinfo, TRUE, FALSE)) |
999 | return JPEG_SUSPENDED; |
1000 | break; |
1001 | |
1002 | case M_SOF9: /* Extended sequential, arithmetic */ |
1003 | if (!get_sof(cinfo, FALSE, TRUE)) |
1004 | return JPEG_SUSPENDED; |
1005 | break; |
1006 | |
1007 | case M_SOF10: /* Progressive, arithmetic */ |
1008 | if (!get_sof(cinfo, TRUE, TRUE)) |
1009 | return JPEG_SUSPENDED; |
1010 | break; |
1011 | |
1012 | /* Currently unsupported SOFn types */ |
1013 | case M_SOF3: /* Lossless, Huffman */ |
1014 | case M_SOF5: /* Differential sequential, Huffman */ |
1015 | case M_SOF6: /* Differential progressive, Huffman */ |
1016 | case M_SOF7: /* Differential lossless, Huffman */ |
1017 | case M_JPG: /* Reserved for JPEG extensions */ |
1018 | case M_SOF11: /* Lossless, arithmetic */ |
1019 | case M_SOF13: /* Differential sequential, arithmetic */ |
1020 | case M_SOF14: /* Differential progressive, arithmetic */ |
1021 | case M_SOF15: /* Differential lossless, arithmetic */ |
1022 | ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker); |
1023 | break; |
1024 | |
1025 | case M_SOS: |
1026 | if (!get_sos(cinfo)) |
1027 | return JPEG_SUSPENDED; |
1028 | cinfo->unread_marker = 0; /* processed the marker */ |
1029 | return JPEG_REACHED_SOS; |
1030 | |
1031 | case M_EOI: |
1032 | TRACEMS(cinfo, 1, JTRC_EOI); |
1033 | cinfo->unread_marker = 0; /* processed the marker */ |
1034 | return JPEG_REACHED_EOI; |
1035 | |
1036 | case M_DAC: |
1037 | if (!get_dac(cinfo)) |
1038 | return JPEG_SUSPENDED; |
1039 | break; |
1040 | |
1041 | case M_DHT: |
1042 | if (!get_dht(cinfo)) |
1043 | return JPEG_SUSPENDED; |
1044 | break; |
1045 | |
1046 | case M_DQT: |
1047 | if (!get_dqt(cinfo)) |
1048 | return JPEG_SUSPENDED; |
1049 | break; |
1050 | |
1051 | case M_DRI: |
1052 | if (!get_dri(cinfo)) |
1053 | return JPEG_SUSPENDED; |
1054 | break; |
1055 | |
1056 | case M_APP0: |
1057 | case M_APP1: |
1058 | case M_APP2: |
1059 | case M_APP3: |
1060 | case M_APP4: |
1061 | case M_APP5: |
1062 | case M_APP6: |
1063 | case M_APP7: |
1064 | case M_APP8: |
1065 | case M_APP9: |
1066 | case M_APP10: |
1067 | case M_APP11: |
1068 | case M_APP12: |
1069 | case M_APP13: |
1070 | case M_APP14: |
1071 | case M_APP15: |
1072 | if (!(*((my_marker_ptr)cinfo->marker)->process_APPn[ |
1073 | cinfo->unread_marker - (int)M_APP0]) (cinfo)) |
1074 | return JPEG_SUSPENDED; |
1075 | break; |
1076 | |
1077 | case M_COM: |
1078 | if (!(*((my_marker_ptr)cinfo->marker)->process_COM) (cinfo)) |
1079 | return JPEG_SUSPENDED; |
1080 | break; |
1081 | |
1082 | case M_RST0: /* these are all parameterless */ |
1083 | case M_RST1: |
1084 | case M_RST2: |
1085 | case M_RST3: |
1086 | case M_RST4: |
1087 | case M_RST5: |
1088 | case M_RST6: |
1089 | case M_RST7: |
1090 | case M_TEM: |
1091 | TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker); |
1092 | break; |
1093 | |
1094 | case M_DNL: /* Ignore DNL ... perhaps the wrong thing */ |
1095 | if (!skip_variable(cinfo)) |
1096 | return JPEG_SUSPENDED; |
1097 | break; |
1098 | |
1099 | default: /* must be DHP, EXP, JPGn, or RESn */ |
1100 | /* For now, we treat the reserved markers as fatal errors since they are |
1101 | * likely to be used to signal incompatible JPEG Part 3 extensions. |
1102 | * Once the JPEG 3 version-number marker is well defined, this code |
1103 | * ought to change! |
1104 | */ |
1105 | ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker); |
1106 | break; |
1107 | } |
1108 | /* Successfully processed marker, so reset state variable */ |
1109 | cinfo->unread_marker = 0; |
1110 | } /* end loop */ |
1111 | } |
1112 | |
1113 | |
1114 | /* |
1115 | * Read a restart marker, which is expected to appear next in the datastream; |
1116 | * if the marker is not there, take appropriate recovery action. |
1117 | * Returns FALSE if suspension is required. |
1118 | * |
1119 | * This is called by the entropy decoder after it has read an appropriate |
1120 | * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder |
1121 | * has already read a marker from the data source. Under normal conditions |
1122 | * cinfo->unread_marker will be reset to 0 before returning; if not reset, |
1123 | * it holds a marker which the decoder will be unable to read past. |
1124 | */ |
1125 | |
1126 | METHODDEF(boolean) |
1127 | read_restart_marker(j_decompress_ptr cinfo) |
1128 | { |
1129 | /* Obtain a marker unless we already did. */ |
1130 | /* Note that next_marker will complain if it skips any data. */ |
1131 | if (cinfo->unread_marker == 0) { |
1132 | if (!next_marker(cinfo)) |
1133 | return FALSE; |
1134 | } |
1135 | |
1136 | if (cinfo->unread_marker == |
1137 | ((int)M_RST0 + cinfo->marker->next_restart_num)) { |
1138 | /* Normal case --- swallow the marker and let entropy decoder continue */ |
1139 | TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num); |
1140 | cinfo->unread_marker = 0; |
1141 | } else { |
1142 | /* Uh-oh, the restart markers have been messed up. */ |
1143 | /* Let the data source manager determine how to resync. */ |
1144 | if (!(*cinfo->src->resync_to_restart) (cinfo, |
1145 | cinfo->marker->next_restart_num)) |
1146 | return FALSE; |
1147 | } |
1148 | |
1149 | /* Update next-restart state */ |
1150 | cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7; |
1151 | |
1152 | return TRUE; |
1153 | } |
1154 | |
1155 | |
1156 | /* |
1157 | * This is the default resync_to_restart method for data source managers |
1158 | * to use if they don't have any better approach. Some data source managers |
1159 | * may be able to back up, or may have additional knowledge about the data |
1160 | * which permits a more intelligent recovery strategy; such managers would |
1161 | * presumably supply their own resync method. |
1162 | * |
1163 | * read_restart_marker calls resync_to_restart if it finds a marker other than |
1164 | * the restart marker it was expecting. (This code is *not* used unless |
1165 | * a nonzero restart interval has been declared.) cinfo->unread_marker is |
1166 | * the marker code actually found (might be anything, except 0 or FF). |
1167 | * The desired restart marker number (0..7) is passed as a parameter. |
1168 | * This routine is supposed to apply whatever error recovery strategy seems |
1169 | * appropriate in order to position the input stream to the next data segment. |
1170 | * Note that cinfo->unread_marker is treated as a marker appearing before |
1171 | * the current data-source input point; usually it should be reset to zero |
1172 | * before returning. |
1173 | * Returns FALSE if suspension is required. |
1174 | * |
1175 | * This implementation is substantially constrained by wanting to treat the |
1176 | * input as a data stream; this means we can't back up. Therefore, we have |
1177 | * only the following actions to work with: |
1178 | * 1. Simply discard the marker and let the entropy decoder resume at next |
1179 | * byte of file. |
1180 | * 2. Read forward until we find another marker, discarding intervening |
1181 | * data. (In theory we could look ahead within the current bufferload, |
1182 | * without having to discard data if we don't find the desired marker. |
1183 | * This idea is not implemented here, in part because it makes behavior |
1184 | * dependent on buffer size and chance buffer-boundary positions.) |
1185 | * 3. Leave the marker unread (by failing to zero cinfo->unread_marker). |
1186 | * This will cause the entropy decoder to process an empty data segment, |
1187 | * inserting dummy zeroes, and then we will reprocess the marker. |
1188 | * |
1189 | * #2 is appropriate if we think the desired marker lies ahead, while #3 is |
1190 | * appropriate if the found marker is a future restart marker (indicating |
1191 | * that we have missed the desired restart marker, probably because it got |
1192 | * corrupted). |
1193 | * We apply #2 or #3 if the found marker is a restart marker no more than |
1194 | * two counts behind or ahead of the expected one. We also apply #2 if the |
1195 | * found marker is not a legal JPEG marker code (it's certainly bogus data). |
1196 | * If the found marker is a restart marker more than 2 counts away, we do #1 |
1197 | * (too much risk that the marker is erroneous; with luck we will be able to |
1198 | * resync at some future point). |
1199 | * For any valid non-restart JPEG marker, we apply #3. This keeps us from |
1200 | * overrunning the end of a scan. An implementation limited to single-scan |
1201 | * files might find it better to apply #2 for markers other than EOI, since |
1202 | * any other marker would have to be bogus data in that case. |
1203 | */ |
1204 | |
1205 | GLOBAL(boolean) |
1206 | jpeg_resync_to_restart(j_decompress_ptr cinfo, int desired) |
1207 | { |
1208 | int marker = cinfo->unread_marker; |
1209 | int action = 1; |
1210 | |
1211 | /* Always put up a warning. */ |
1212 | WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired); |
1213 | |
1214 | /* Outer loop handles repeated decision after scanning forward. */ |
1215 | for (;;) { |
1216 | if (marker < (int)M_SOF0) |
1217 | action = 2; /* invalid marker */ |
1218 | else if (marker < (int)M_RST0 || marker > (int)M_RST7) |
1219 | action = 3; /* valid non-restart marker */ |
1220 | else { |
1221 | if (marker == ((int)M_RST0 + ((desired + 1) & 7)) || |
1222 | marker == ((int)M_RST0 + ((desired + 2) & 7))) |
1223 | action = 3; /* one of the next two expected restarts */ |
1224 | else if (marker == ((int)M_RST0 + ((desired - 1) & 7)) || |
1225 | marker == ((int)M_RST0 + ((desired - 2) & 7))) |
1226 | action = 2; /* a prior restart, so advance */ |
1227 | else |
1228 | action = 1; /* desired restart or too far away */ |
1229 | } |
1230 | TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action); |
1231 | switch (action) { |
1232 | case 1: |
1233 | /* Discard marker and let entropy decoder resume processing. */ |
1234 | cinfo->unread_marker = 0; |
1235 | return TRUE; |
1236 | case 2: |
1237 | /* Scan to the next marker, and repeat the decision loop. */ |
1238 | if (!next_marker(cinfo)) |
1239 | return FALSE; |
1240 | marker = cinfo->unread_marker; |
1241 | break; |
1242 | case 3: |
1243 | /* Return without advancing past this marker. */ |
1244 | /* Entropy decoder will be forced to process an empty segment. */ |
1245 | return TRUE; |
1246 | } |
1247 | } /* end loop */ |
1248 | } |
1249 | |
1250 | |
1251 | /* |
1252 | * Reset marker processing state to begin a fresh datastream. |
1253 | */ |
1254 | |
1255 | METHODDEF(void) |
1256 | reset_marker_reader(j_decompress_ptr cinfo) |
1257 | { |
1258 | my_marker_ptr marker = (my_marker_ptr)cinfo->marker; |
1259 | |
1260 | cinfo->comp_info = NULL; /* until allocated by get_sof */ |
1261 | cinfo->input_scan_number = 0; /* no SOS seen yet */ |
1262 | cinfo->unread_marker = 0; /* no pending marker */ |
1263 | marker->pub.saw_SOI = FALSE; /* set internal state too */ |
1264 | marker->pub.saw_SOF = FALSE; |
1265 | marker->pub.discarded_bytes = 0; |
1266 | marker->cur_marker = NULL; |
1267 | } |
1268 | |
1269 | |
1270 | /* |
1271 | * Initialize the marker reader module. |
1272 | * This is called only once, when the decompression object is created. |
1273 | */ |
1274 | |
1275 | GLOBAL(void) |
1276 | jinit_marker_reader(j_decompress_ptr cinfo) |
1277 | { |
1278 | my_marker_ptr marker; |
1279 | int i; |
1280 | |
1281 | /* Create subobject in permanent pool */ |
1282 | marker = (my_marker_ptr) |
1283 | (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT, |
1284 | sizeof(my_marker_reader)); |
1285 | cinfo->marker = (struct jpeg_marker_reader *)marker; |
1286 | /* Initialize public method pointers */ |
1287 | marker->pub.reset_marker_reader = reset_marker_reader; |
1288 | marker->pub.read_markers = read_markers; |
1289 | marker->pub.read_restart_marker = read_restart_marker; |
1290 | /* Initialize COM/APPn processing. |
1291 | * By default, we examine and then discard APP0 and APP14, |
1292 | * but simply discard COM and all other APPn. |
1293 | */ |
1294 | marker->process_COM = skip_variable; |
1295 | marker->length_limit_COM = 0; |
1296 | for (i = 0; i < 16; i++) { |
1297 | marker->process_APPn[i] = skip_variable; |
1298 | marker->length_limit_APPn[i] = 0; |
1299 | } |
1300 | marker->process_APPn[0] = get_interesting_appn; |
1301 | marker->process_APPn[14] = get_interesting_appn; |
1302 | /* Reset marker processing state */ |
1303 | reset_marker_reader(cinfo); |
1304 | } |
1305 | |
1306 | |
1307 | /* |
1308 | * Control saving of COM and APPn markers into marker_list. |
1309 | */ |
1310 | |
1311 | #ifdef SAVE_MARKERS_SUPPORTED |
1312 | |
1313 | GLOBAL(void) |
1314 | jpeg_save_markers(j_decompress_ptr cinfo, int marker_code, |
1315 | unsigned int length_limit) |
1316 | { |
1317 | my_marker_ptr marker = (my_marker_ptr)cinfo->marker; |
1318 | long maxlength; |
1319 | jpeg_marker_parser_method processor; |
1320 | |
1321 | /* Length limit mustn't be larger than what we can allocate |
1322 | * (should only be a concern in a 16-bit environment). |
1323 | */ |
1324 | maxlength = cinfo->mem->max_alloc_chunk - sizeof(struct jpeg_marker_struct); |
1325 | if (((long)length_limit) > maxlength) |
1326 | length_limit = (unsigned int)maxlength; |
1327 | |
1328 | /* Choose processor routine to use. |
1329 | * APP0/APP14 have special requirements. |
1330 | */ |
1331 | if (length_limit) { |
1332 | processor = save_marker; |
1333 | /* If saving APP0/APP14, save at least enough for our internal use. */ |
1334 | if (marker_code == (int)M_APP0 && length_limit < APP0_DATA_LEN) |
1335 | length_limit = APP0_DATA_LEN; |
1336 | else if (marker_code == (int)M_APP14 && length_limit < APP14_DATA_LEN) |
1337 | length_limit = APP14_DATA_LEN; |
1338 | } else { |
1339 | processor = skip_variable; |
1340 | /* If discarding APP0/APP14, use our regular on-the-fly processor. */ |
1341 | if (marker_code == (int)M_APP0 || marker_code == (int)M_APP14) |
1342 | processor = get_interesting_appn; |
1343 | } |
1344 | |
1345 | if (marker_code == (int)M_COM) { |
1346 | marker->process_COM = processor; |
1347 | marker->length_limit_COM = length_limit; |
1348 | } else if (marker_code >= (int)M_APP0 && marker_code <= (int)M_APP15) { |
1349 | marker->process_APPn[marker_code - (int)M_APP0] = processor; |
1350 | marker->length_limit_APPn[marker_code - (int)M_APP0] = length_limit; |
1351 | } else |
1352 | ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code); |
1353 | } |
1354 | |
1355 | #endif /* SAVE_MARKERS_SUPPORTED */ |
1356 | |
1357 | |
1358 | /* |
1359 | * Install a special processing method for COM or APPn markers. |
1360 | */ |
1361 | |
1362 | GLOBAL(void) |
1363 | jpeg_set_marker_processor(j_decompress_ptr cinfo, int marker_code, |
1364 | jpeg_marker_parser_method routine) |
1365 | { |
1366 | my_marker_ptr marker = (my_marker_ptr)cinfo->marker; |
1367 | |
1368 | if (marker_code == (int)M_COM) |
1369 | marker->process_COM = routine; |
1370 | else if (marker_code >= (int)M_APP0 && marker_code <= (int)M_APP15) |
1371 | marker->process_APPn[marker_code - (int)M_APP0] = routine; |
1372 | else |
1373 | ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code); |
1374 | } |
1375 | |