Coverage Report

Created: 2018-09-25 14:53

/src/mozilla-central/media/libjpeg/jdmarker.c
Line
Count
Source (jump to first uncovered line)
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
0
        struct jpeg_source_mgr *datasrc = (cinfo)->src;  \
124
0
        const JOCTET *next_input_byte = datasrc->next_input_byte;  \
125
0
        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
0
        ( datasrc->next_input_byte = next_input_byte,  \
130
0
          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
0
        ( next_input_byte = datasrc->next_input_byte,  \
135
0
          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
0
        if (bytes_in_buffer == 0) {  \
143
0
          if (! (*datasrc->fill_input_buffer) (cinfo))  \
144
0
            { action; }  \
145
0
          INPUT_RELOAD(cinfo);  \
146
0
        }
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
0
        MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
153
0
                  bytes_in_buffer--; \
154
0
                  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
0
        MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
161
0
                  bytes_in_buffer--; \
162
0
                  V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
163
0
                  MAKE_BYTE_AVAIL(cinfo,action); \
164
0
                  bytes_in_buffer--; \
165
0
                  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
get_soi (j_decompress_ptr cinfo)
201
/* Process an SOI marker */
202
0
{
203
0
  int i;
204
0
205
0
  TRACEMS(cinfo, 1, JTRC_SOI);
206
0
207
0
  if (cinfo->marker->saw_SOI)
208
0
    ERREXIT(cinfo, JERR_SOI_DUPLICATE);
209
0
210
0
  /* Reset all parameters that are defined to be reset by SOI */
211
0
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
0
  }
217
0
  cinfo->restart_interval = 0;
218
0
219
0
  /* Set initial assumptions for colorspace etc */
220
0
221
0
  cinfo->jpeg_color_space = JCS_UNKNOWN;
222
0
  cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
223
0
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
0
233
0
  cinfo->marker->saw_SOI = TRUE;
234
0
235
0
  return TRUE;
236
0
}
237
238
239
LOCAL(boolean)
240
get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
241
/* Process a SOFn marker */
242
0
{
243
0
  JLONG length;
244
0
  int c, ci;
245
0
  jpeg_component_info *compptr;
246
0
  INPUT_VARS(cinfo);
247
0
248
0
  cinfo->progressive_mode = is_prog;
249
0
  cinfo->arith_code = is_arith;
250
0
251
0
  INPUT_2BYTES(cinfo, length, return FALSE);
252
0
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
0
258
0
  length -= 8;
259
0
260
0
  TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
261
0
           (int) cinfo->image_width, (int) cinfo->image_height,
262
0
           cinfo->num_components);
263
0
264
0
  if (cinfo->marker->saw_SOF)
265
0
    ERREXIT(cinfo, JERR_SOF_DUPLICATE);
266
0
267
0
  /* We don't support files in which the image height is initially specified */
268
0
  /* as 0 and is later redefined by DNL.  As long as we have to check that,  */
269
0
  /* 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
0
274
0
  if (length != (cinfo->num_components * 3))
275
0
    ERREXIT(cinfo, JERR_BAD_LENGTH);
276
0
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
0
                        ((j_common_ptr) cinfo, JPOOL_IMAGE,
280
0
                         cinfo->num_components * sizeof(jpeg_component_info));
281
0
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
0
291
0
    TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
292
0
             compptr->component_id, compptr->h_samp_factor,
293
0
             compptr->v_samp_factor, compptr->quant_tbl_no);
294
0
  }
295
0
296
0
  cinfo->marker->saw_SOF = TRUE;
297
0
298
0
  INPUT_SYNC(cinfo);
299
0
  return TRUE;
300
0
}
301
302
303
LOCAL(boolean)
304
get_sos (j_decompress_ptr cinfo)
305
/* Process a SOS marker */
306
0
{
307
0
  JLONG length;
308
0
  int i, ci, n, c, cc, pi;
309
0
  jpeg_component_info *compptr;
310
0
  INPUT_VARS(cinfo);
311
0
312
0
  if (! cinfo->marker->saw_SOF)
313
0
    ERREXIT(cinfo, JERR_SOS_NO_SOF);
314
0
315
0
  INPUT_2BYTES(cinfo, length, return FALSE);
316
0
317
0
  INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
318
0
319
0
  TRACEMS1(cinfo, 1, JTRC_SOS, n);
320
0
321
0
  if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
322
0
    ERREXIT(cinfo, JERR_BAD_LENGTH);
323
0
324
0
  cinfo->comps_in_scan = n;
325
0
326
0
  /* Collect the component-spec parameters */
327
0
328
0
  for (i = 0; i < MAX_COMPS_IN_SCAN; i++)
329
0
    cinfo->cur_comp_info[i] = NULL;
330
0
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
0
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
0
    }
341
0
342
0
    ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
343
0
344
0
  id_found:
345
0
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
0
350
0
    TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
351
0
             compptr->dc_tbl_no, compptr->ac_tbl_no);
352
0
353
0
    /* 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
0
      }
358
0
    }
359
0
  }
360
0
361
0
  /* 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
0
370
0
  TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
371
0
           cinfo->Ah, cinfo->Al);
372
0
373
0
  /* Prepare to scan data & restart markers */
374
0
  cinfo->marker->next_restart_num = 0;
375
0
376
0
  /* Count another SOS marker */
377
0
  cinfo->input_scan_number++;
378
0
379
0
  INPUT_SYNC(cinfo);
380
0
  return TRUE;
381
0
}
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
0
#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
0
{
436
0
  JLONG length;
437
0
  UINT8 bits[17];
438
0
  UINT8 huffval[256];
439
0
  int i, index, count;
440
0
  JHUFF_TBL **htblptr;
441
0
  INPUT_VARS(cinfo);
442
0
443
0
  INPUT_2BYTES(cinfo, length, return FALSE);
444
0
  length -= 2;
445
0
446
0
  while (length > 16) {
447
0
    INPUT_BYTE(cinfo, index, return FALSE);
448
0
449
0
    TRACEMS1(cinfo, 1, JTRC_DHT, index);
450
0
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
0
    }
457
0
458
0
    length -= 1 + 16;
459
0
460
0
    TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
461
0
             bits[1], bits[2], bits[3], bits[4],
462
0
             bits[5], bits[6], bits[7], bits[8]);
463
0
    TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
464
0
             bits[9], bits[10], bits[11], bits[12],
465
0
             bits[13], bits[14], bits[15], bits[16]);
466
0
467
0
    /* Here we just do minimal validation of the counts to avoid walking
468
0
     * off the end of our table space.  jdhuff.c will check more carefully.
469
0
     */
470
0
    if (count > 256 || ((JLONG) count) > length)
471
0
      ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
472
0
473
0
    for (i = 0; i < count; i++)
474
0
      INPUT_BYTE(cinfo, huffval[i], return FALSE);
475
0
476
0
    MEMZERO(&huffval[count], (256 - count) * sizeof(UINT8));
477
0
478
0
    length -= count;
479
0
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
0
    } 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
0
    }
490
0
491
0
    if (*htblptr == NULL)
492
0
      *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
493
0
494
0
    MEMCOPY((*htblptr)->bits, bits, sizeof((*htblptr)->bits));
495
0
    MEMCOPY((*htblptr)->huffval, huffval, sizeof((*htblptr)->huffval));
496
0
  }
497
0
498
0
  if (length != 0)
499
0
    ERREXIT(cinfo, JERR_BAD_LENGTH);
500
0
501
0
  INPUT_SYNC(cinfo);
502
0
  return TRUE;
503
0
}
504
505
506
LOCAL(boolean)
507
get_dqt (j_decompress_ptr cinfo)
508
/* Process a DQT marker */
509
0
{
510
0
  JLONG length;
511
0
  int n, i, prec;
512
0
  unsigned int tmp;
513
0
  JQUANT_TBL *quant_ptr;
514
0
  INPUT_VARS(cinfo);
515
0
516
0
  INPUT_2BYTES(cinfo, length, return FALSE);
517
0
  length -= 2;
518
0
519
0
  while (length > 0) {
520
0
    INPUT_BYTE(cinfo, n, return FALSE);
521
0
    prec = n >> 4;
522
0
    n &= 0x0F;
523
0
524
0
    TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
525
0
526
0
    if (n >= NUM_QUANT_TBLS)
527
0
      ERREXIT1(cinfo, JERR_DQT_INDEX, n);
528
0
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
0
533
0
    for (i = 0; i < DCTSIZE2; i++) {
534
0
      if (prec)
535
0
        INPUT_2BYTES(cinfo, tmp, return FALSE);
536
0
      else
537
0
        INPUT_BYTE(cinfo, tmp, return FALSE);
538
0
      /* We convert the zigzag-order table to natural array order. */
539
0
      quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
540
0
    }
541
0
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
0
                 quant_ptr->quantval[i],   quant_ptr->quantval[i+1],
546
0
                 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
547
0
                 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
548
0
                 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
549
0
      }
550
0
    }
551
0
552
0
    length -= DCTSIZE2+1;
553
0
    if (prec) length -= DCTSIZE2;
554
0
  }
555
0
556
0
  if (length != 0)
557
0
    ERREXIT(cinfo, JERR_BAD_LENGTH);
558
0
559
0
  INPUT_SYNC(cinfo);
560
0
  return TRUE;
561
0
}
562
563
564
LOCAL(boolean)
565
get_dri (j_decompress_ptr cinfo)
566
/* Process a DRI marker */
567
0
{
568
0
  JLONG length;
569
0
  unsigned int tmp;
570
0
  INPUT_VARS(cinfo);
571
0
572
0
  INPUT_2BYTES(cinfo, length, return FALSE);
573
0
574
0
  if (length != 4)
575
0
    ERREXIT(cinfo, JERR_BAD_LENGTH);
576
0
577
0
  INPUT_2BYTES(cinfo, tmp, return FALSE);
578
0
579
0
  TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
580
0
581
0
  cinfo->restart_interval = tmp;
582
0
583
0
  INPUT_SYNC(cinfo);
584
0
  return TRUE;
585
0
}
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
0
#define APP0_DATA_LEN   14      /* Length of interesting data in APP0 */
596
0
#define APP14_DATA_LEN  12      /* Length of interesting data in APP14 */
597
0
#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,
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
0
{
608
0
  JLONG totallen = (JLONG) datalen + remaining;
609
0
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
0
    /* 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
0
    /* Check version.
624
0
     * Major version must be 1, anything else signals an incompatible change.
625
0
     * (We used to treat this as an error, but now it's a nonfatal warning,
626
0
     * because some bozo at Hijaak couldn't read the spec.)
627
0
     * Minor version should be 0..2, but process anyway if newer.
628
0
     */
629
0
    if (cinfo->JFIF_major_version != 1)
630
0
      WARNMS2(cinfo, JWRN_JFIF_MAJOR,
631
0
              cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
632
0
    /* Generate trace messages */
633
0
    TRACEMS5(cinfo, 1, JTRC_JFIF,
634
0
             cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
635
0
             cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
636
0
    /* 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
0
               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
0
    /* Found JFIF "JFXX" extension APP0 marker */
651
0
    /* The library doesn't actually do anything with these,
652
0
     * but we try to produce a helpful trace message.
653
0
     */
654
0
    switch (GETJOCTET(data[5])) {
655
0
    case 0x10:
656
0
      TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
657
0
      break;
658
0
    case 0x11:
659
0
      TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
660
0
      break;
661
0
    case 0x13:
662
0
      TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
663
0
      break;
664
0
    default:
665
0
      TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
666
0
               GETJOCTET(data[5]), (int) totallen);
667
0
      break;
668
0
    }
669
0
  } else {
670
0
    /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
671
0
    TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
672
0
  }
673
0
}
674
675
676
LOCAL(void)
677
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
0
{
684
0
  unsigned int version, flags0, flags1, transform;
685
0
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
0
    /* 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
0
  } else {
701
0
    /* Start of APP14 does not match "Adobe", or too short */
702
0
    TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
703
0
  }
704
0
}
705
706
707
METHODDEF(boolean)
708
get_interesting_appn (j_decompress_ptr cinfo)
709
/* Process an APP0 or APP14 marker without saving it */
710
0
{
711
0
  JLONG length;
712
0
  JOCTET b[APPN_DATA_LEN];
713
0
  unsigned int i, numtoread;
714
0
  INPUT_VARS(cinfo);
715
0
716
0
  INPUT_2BYTES(cinfo, length, return FALSE);
717
0
  length -= 2;
718
0
719
0
  /* 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
0
  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
0
730
0
  /* process it */
731
0
  switch (cinfo->unread_marker) {
732
0
  case M_APP0:
733
0
    examine_app0(cinfo, (JOCTET *) b, numtoread, length);
734
0
    break;
735
0
  case M_APP14:
736
0
    examine_app14(cinfo, (JOCTET *) b, numtoread, length);
737
0
    break;
738
0
  default:
739
0
    /* 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
0
  }
743
0
744
0
  /* 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
0
749
0
  return TRUE;
750
0
}
751
752
753
#ifdef SAVE_MARKERS_SUPPORTED
754
755
METHODDEF(boolean)
756
save_marker (j_decompress_ptr cinfo)
757
/* Save an APPn or COM marker into the marker list */
758
0
{
759
0
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
760
0
  jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
761
0
  unsigned int bytes_read, data_length;
762
0
  JOCTET *data;
763
0
  JLONG length = 0;
764
0
  INPUT_VARS(cinfo);
765
0
766
0
  if (cur_marker == NULL) {
767
0
    /* 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
0
      /* figure out how much we want to save */
772
0
      unsigned int limit;
773
0
      if (cinfo->unread_marker == (int) M_COM)
774
0
        limit = marker->length_limit_COM;
775
0
      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
0
      /* 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
0
                                    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
0
      /* 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
0
    } else {
794
0
      /* deal with bogus length word */
795
0
      bytes_read = data_length = 0;
796
0
      data = NULL;
797
0
    }
798
0
  } else {
799
0
    /* 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
0
  }
804
0
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
0
    /* If there's not at least one byte in buffer, suspend */
809
0
    MAKE_BYTE_AVAIL(cinfo, return FALSE);
810
0
    /* 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
0
    }
816
0
  }
817
0
818
0
  /* Done reading what we want to read */
819
0
  if (cur_marker != NULL) {     /* will be NULL if bogus length word */
820
0
    /* Add new marker to end of list */
821
0
    if (cinfo->marker_list == NULL) {
822
0
      cinfo->marker_list = cur_marker;
823
0
    } 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
0
    }
829
0
    /* Reset pointer & calc remaining data length */
830
0
    data = cur_marker->data;
831
0
    length = cur_marker->original_length - data_length;
832
0
  }
833
0
  /* Reset to initial state for next marker */
834
0
  marker->cur_marker = NULL;
835
0
836
0
  /* Process the marker if interesting; else just make a generic trace msg */
837
0
  switch (cinfo->unread_marker) {
838
0
  case M_APP0:
839
0
    examine_app0(cinfo, data, data_length, length);
840
0
    break;
841
0
  case M_APP14:
842
0
    examine_app14(cinfo, data, data_length, length);
843
0
    break;
844
0
  default:
845
0
    TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
846
0
             (int) (data_length + length));
847
0
    break;
848
0
  }
849
0
850
0
  /* 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
0
855
0
  return TRUE;
856
0
}
857
858
#endif /* SAVE_MARKERS_SUPPORTED */
859
860
861
METHODDEF(boolean)
862
skip_variable (j_decompress_ptr cinfo)
863
/* Skip over an unknown or uninteresting variable-length marker */
864
0
{
865
0
  JLONG length;
866
0
  INPUT_VARS(cinfo);
867
0
868
0
  INPUT_2BYTES(cinfo, length, return FALSE);
869
0
  length -= 2;
870
0
871
0
  TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
872
0
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
0
877
0
  return TRUE;
878
0
}
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
next_marker (j_decompress_ptr cinfo)
892
0
{
893
0
  int c;
894
0
  INPUT_VARS(cinfo);
895
0
896
0
  for (;;) {
897
0
    INPUT_BYTE(cinfo, c, return FALSE);
898
0
    /* Skip any non-FF bytes.
899
0
     * This may look a bit inefficient, but it will not occur in a valid file.
900
0
     * We sync after each discarded byte so that a suspending data source
901
0
     * can discard the byte from its buffer.
902
0
     */
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
0
    }
908
0
    /* This loop swallows any duplicate FF bytes.  Extra FFs are legal as
909
0
     * pad bytes, so don't count them in discarded_bytes.  We assume there
910
0
     * will not be so many consecutive FF bytes as to overflow a suspending
911
0
     * data source's input buffer.
912
0
     */
913
0
    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
0
    /* Reach here if we found a stuffed-zero data sequence (FF/00).
919
0
     * Discard it and loop back to try again.
920
0
     */
921
0
    cinfo->marker->discarded_bytes += 2;
922
0
    INPUT_SYNC(cinfo);
923
0
  }
924
0
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
0
  }
929
0
930
0
  cinfo->unread_marker = c;
931
0
932
0
  INPUT_SYNC(cinfo);
933
0
  return TRUE;
934
0
}
935
936
937
LOCAL(boolean)
938
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
0
{
946
0
  int c, c2;
947
0
  INPUT_VARS(cinfo);
948
0
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
0
954
0
  cinfo->unread_marker = c2;
955
0
956
0
  INPUT_SYNC(cinfo);
957
0
  return TRUE;
958
0
}
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
read_markers (j_decompress_ptr cinfo)
970
0
{
971
0
  /* Outer loop repeats once for each marker. */
972
0
  for (;;) {
973
0
    /* Collect the marker proper, unless we already did. */
974
0
    /* 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
0
      } else {
980
0
        if (! next_marker(cinfo))
981
0
          return JPEG_SUSPENDED;
982
0
      }
983
0
    }
984
0
    /* At this point cinfo->unread_marker contains the marker code and the
985
0
     * input point is just past the marker proper, but before any parameters.
986
0
     * A suspension will cause us to return with this state still true.
987
0
     */
988
0
    switch (cinfo->unread_marker) {
989
0
    case M_SOI:
990
0
      if (! get_soi(cinfo))
991
0
        return JPEG_SUSPENDED;
992
0
      break;
993
0
994
0
    case M_SOF0:                /* Baseline */
995
0
    case M_SOF1:                /* Extended sequential, Huffman */
996
0
      if (! get_sof(cinfo, FALSE, FALSE))
997
0
        return JPEG_SUSPENDED;
998
0
      break;
999
0
1000
0
    case M_SOF2:                /* Progressive, Huffman */
1001
0
      if (! get_sof(cinfo, TRUE, FALSE))
1002
0
        return JPEG_SUSPENDED;
1003
0
      break;
1004
0
1005
0
    case M_SOF9:                /* Extended sequential, arithmetic */
1006
0
      if (! get_sof(cinfo, FALSE, TRUE))
1007
0
        return JPEG_SUSPENDED;
1008
0
      break;
1009
0
1010
0
    case M_SOF10:               /* Progressive, arithmetic */
1011
0
      if (! get_sof(cinfo, TRUE, TRUE))
1012
0
        return JPEG_SUSPENDED;
1013
0
      break;
1014
0
1015
0
    /* Currently unsupported SOFn types */
1016
0
    case M_SOF3:                /* Lossless, Huffman */
1017
0
    case M_SOF5:                /* Differential sequential, Huffman */
1018
0
    case M_SOF6:                /* Differential progressive, Huffman */
1019
0
    case M_SOF7:                /* Differential lossless, Huffman */
1020
0
    case M_JPG:                 /* Reserved for JPEG extensions */
1021
0
    case M_SOF11:               /* Lossless, arithmetic */
1022
0
    case M_SOF13:               /* Differential sequential, arithmetic */
1023
0
    case M_SOF14:               /* Differential progressive, arithmetic */
1024
0
    case M_SOF15:               /* Differential lossless, arithmetic */
1025
0
      ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
1026
0
      break;
1027
0
1028
0
    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
0
1034
0
    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
0
1039
0
    case M_DAC:
1040
0
      if (! get_dac(cinfo))
1041
0
        return JPEG_SUSPENDED;
1042
0
      break;
1043
0
1044
0
    case M_DHT:
1045
0
      if (! get_dht(cinfo))
1046
0
        return JPEG_SUSPENDED;
1047
0
      break;
1048
0
1049
0
    case M_DQT:
1050
0
      if (! get_dqt(cinfo))
1051
0
        return JPEG_SUSPENDED;
1052
0
      break;
1053
0
1054
0
    case M_DRI:
1055
0
      if (! get_dri(cinfo))
1056
0
        return JPEG_SUSPENDED;
1057
0
      break;
1058
0
1059
0
    case M_APP0:
1060
0
    case M_APP1:
1061
0
    case M_APP2:
1062
0
    case M_APP3:
1063
0
    case M_APP4:
1064
0
    case M_APP5:
1065
0
    case M_APP6:
1066
0
    case M_APP7:
1067
0
    case M_APP8:
1068
0
    case M_APP9:
1069
0
    case M_APP10:
1070
0
    case M_APP11:
1071
0
    case M_APP12:
1072
0
    case M_APP13:
1073
0
    case M_APP14:
1074
0
    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
0
1080
0
    case M_COM:
1081
0
      if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
1082
0
        return JPEG_SUSPENDED;
1083
0
      break;
1084
0
1085
0
    case M_RST0:                /* these are all parameterless */
1086
0
    case M_RST1:
1087
0
    case M_RST2:
1088
0
    case M_RST3:
1089
0
    case M_RST4:
1090
0
    case M_RST5:
1091
0
    case M_RST6:
1092
0
    case M_RST7:
1093
0
    case M_TEM:
1094
0
      TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
1095
0
      break;
1096
0
1097
0
    case M_DNL:                 /* Ignore DNL ... perhaps the wrong thing */
1098
0
      if (! skip_variable(cinfo))
1099
0
        return JPEG_SUSPENDED;
1100
0
      break;
1101
0
1102
0
    default:                    /* must be DHP, EXP, JPGn, or RESn */
1103
0
      /* For now, we treat the reserved markers as fatal errors since they are
1104
0
       * likely to be used to signal incompatible JPEG Part 3 extensions.
1105
0
       * Once the JPEG 3 version-number marker is well defined, this code
1106
0
       * ought to change!
1107
0
       */
1108
0
      ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
1109
0
      break;
1110
0
    }
1111
0
    /* Successfully processed marker, so reset state variable */
1112
0
    cinfo->unread_marker = 0;
1113
0
  } /* end loop */
1114
0
}
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
read_restart_marker (j_decompress_ptr cinfo)
1131
0
{
1132
0
  /* Obtain a marker unless we already did. */
1133
0
  /* 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
0
  }
1138
0
1139
0
  if (cinfo->unread_marker ==
1140
0
      ((int) M_RST0 + cinfo->marker->next_restart_num)) {
1141
0
    /* 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
0
  } else {
1145
0
    /* Uh-oh, the restart markers have been messed up. */
1146
0
    /* 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
0
  }
1151
0
1152
0
  /* Update next-restart state */
1153
0
  cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
1154
0
1155
0
  return TRUE;
1156
0
}
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
jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
1210
0
{
1211
0
  int marker = cinfo->unread_marker;
1212
0
  int action = 1;
1213
0
1214
0
  /* Always put up a warning. */
1215
0
  WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
1216
0
1217
0
  /* Outer loop handles repeated decision after scanning forward. */
1218
0
  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
0
    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
0
      else
1231
0
        action = 1;             /* desired restart or too far away */
1232
0
    }
1233
0
    TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
1234
0
    switch (action) {
1235
0
    case 1:
1236
0
      /* Discard marker and let entropy decoder resume processing. */
1237
0
      cinfo->unread_marker = 0;
1238
0
      return TRUE;
1239
0
    case 2:
1240
0
      /* 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
0
    case 3:
1246
0
      /* Return without advancing past this marker. */
1247
0
      /* Entropy decoder will be forced to process an empty segment. */
1248
0
      return TRUE;
1249
0
    }
1250
0
  } /* end loop */
1251
0
}
1252
1253
1254
/*
1255
 * Reset marker processing state to begin a fresh datastream.
1256
 */
1257
1258
METHODDEF(void)
1259
reset_marker_reader (j_decompress_ptr cinfo)
1260
0
{
1261
0
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1262
0
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
jinit_marker_reader (j_decompress_ptr cinfo)
1280
0
{
1281
0
  my_marker_ptr marker;
1282
0
  int i;
1283
0
1284
0
  /* Create subobject in permanent pool */
1285
0
  marker = (my_marker_ptr)
1286
0
    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
1287
0
                                sizeof(my_marker_reader));
1288
0
  cinfo->marker = (struct jpeg_marker_reader *) marker;
1289
0
  /* 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
0
  /* Initialize COM/APPn processing.
1294
0
   * By default, we examine and then discard APP0 and APP14,
1295
0
   * but simply discard COM and all other APPn.
1296
0
   */
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
0
  }
1303
0
  marker->process_APPn[0] = get_interesting_appn;
1304
0
  marker->process_APPn[14] = get_interesting_appn;
1305
0
  /* 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
jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
1318
                   unsigned int length_limit)
1319
0
{
1320
0
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1321
0
  long maxlength;
1322
0
  jpeg_marker_parser_method processor;
1323
0
1324
0
  /* Length limit mustn't be larger than what we can allocate
1325
0
   * (should only be a concern in a 16-bit environment).
1326
0
   */
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
0
1331
0
  /* Choose processor routine to use.
1332
0
   * APP0/APP14 have special requirements.
1333
0
   */
1334
0
  if (length_limit) {
1335
0
    processor = save_marker;
1336
0
    /* 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
0
  } else {
1342
0
    processor = skip_variable;
1343
0
    /* 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
0
  }
1347
0
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
0
  } 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
jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
1367
                           jpeg_marker_parser_method routine)
1368
0
{
1369
0
  my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
1370
0
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
0
  else
1376
0
    ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
1377
0
}