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annotate libs/libjpeg/jdmarker.c @ 0:b2f14e535253

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initial commit
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 01 Feb 2014 19:58:19 +0200
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nuclear@0 1 /*
nuclear@0 2 * jdmarker.c
nuclear@0 3 *
nuclear@0 4 * Copyright (C) 1991-1998, Thomas G. Lane.
nuclear@0 5 * This file is part of the Independent JPEG Group's software.
nuclear@0 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@0 7 *
nuclear@0 8 * This file contains routines to decode JPEG datastream markers.
nuclear@0 9 * Most of the complexity arises from our desire to support input
nuclear@0 10 * suspension: if not all of the data for a marker is available,
nuclear@0 11 * we must exit back to the application. On resumption, we reprocess
nuclear@0 12 * the marker.
nuclear@0 13 */
nuclear@0 14
nuclear@0 15 #define JPEG_INTERNALS
nuclear@0 16 #include "jinclude.h"
nuclear@0 17 #include "jpeglib.h"
nuclear@0 18
nuclear@0 19
nuclear@0 20 typedef enum { /* JPEG marker codes */
nuclear@0 21 M_SOF0 = 0xc0,
nuclear@0 22 M_SOF1 = 0xc1,
nuclear@0 23 M_SOF2 = 0xc2,
nuclear@0 24 M_SOF3 = 0xc3,
nuclear@0 25
nuclear@0 26 M_SOF5 = 0xc5,
nuclear@0 27 M_SOF6 = 0xc6,
nuclear@0 28 M_SOF7 = 0xc7,
nuclear@0 29
nuclear@0 30 M_JPG = 0xc8,
nuclear@0 31 M_SOF9 = 0xc9,
nuclear@0 32 M_SOF10 = 0xca,
nuclear@0 33 M_SOF11 = 0xcb,
nuclear@0 34
nuclear@0 35 M_SOF13 = 0xcd,
nuclear@0 36 M_SOF14 = 0xce,
nuclear@0 37 M_SOF15 = 0xcf,
nuclear@0 38
nuclear@0 39 M_DHT = 0xc4,
nuclear@0 40
nuclear@0 41 M_DAC = 0xcc,
nuclear@0 42
nuclear@0 43 M_RST0 = 0xd0,
nuclear@0 44 M_RST1 = 0xd1,
nuclear@0 45 M_RST2 = 0xd2,
nuclear@0 46 M_RST3 = 0xd3,
nuclear@0 47 M_RST4 = 0xd4,
nuclear@0 48 M_RST5 = 0xd5,
nuclear@0 49 M_RST6 = 0xd6,
nuclear@0 50 M_RST7 = 0xd7,
nuclear@0 51
nuclear@0 52 M_SOI = 0xd8,
nuclear@0 53 M_EOI = 0xd9,
nuclear@0 54 M_SOS = 0xda,
nuclear@0 55 M_DQT = 0xdb,
nuclear@0 56 M_DNL = 0xdc,
nuclear@0 57 M_DRI = 0xdd,
nuclear@0 58 M_DHP = 0xde,
nuclear@0 59 M_EXP = 0xdf,
nuclear@0 60
nuclear@0 61 M_APP0 = 0xe0,
nuclear@0 62 M_APP1 = 0xe1,
nuclear@0 63 M_APP2 = 0xe2,
nuclear@0 64 M_APP3 = 0xe3,
nuclear@0 65 M_APP4 = 0xe4,
nuclear@0 66 M_APP5 = 0xe5,
nuclear@0 67 M_APP6 = 0xe6,
nuclear@0 68 M_APP7 = 0xe7,
nuclear@0 69 M_APP8 = 0xe8,
nuclear@0 70 M_APP9 = 0xe9,
nuclear@0 71 M_APP10 = 0xea,
nuclear@0 72 M_APP11 = 0xeb,
nuclear@0 73 M_APP12 = 0xec,
nuclear@0 74 M_APP13 = 0xed,
nuclear@0 75 M_APP14 = 0xee,
nuclear@0 76 M_APP15 = 0xef,
nuclear@0 77
nuclear@0 78 M_JPG0 = 0xf0,
nuclear@0 79 M_JPG13 = 0xfd,
nuclear@0 80 M_COM = 0xfe,
nuclear@0 81
nuclear@0 82 M_TEM = 0x01,
nuclear@0 83
nuclear@0 84 M_ERROR = 0x100
nuclear@0 85 } JPEG_MARKER;
nuclear@0 86
nuclear@0 87
nuclear@0 88 /* Private state */
nuclear@0 89
nuclear@0 90 typedef struct {
nuclear@0 91 struct jpeg_marker_reader pub; /* public fields */
nuclear@0 92
nuclear@0 93 /* Application-overridable marker processing methods */
nuclear@0 94 jpeg_marker_parser_method process_COM;
nuclear@0 95 jpeg_marker_parser_method process_APPn[16];
nuclear@0 96
nuclear@0 97 /* Limit on marker data length to save for each marker type */
nuclear@0 98 unsigned int length_limit_COM;
nuclear@0 99 unsigned int length_limit_APPn[16];
nuclear@0 100
nuclear@0 101 /* Status of COM/APPn marker saving */
nuclear@0 102 jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
nuclear@0 103 unsigned int bytes_read; /* data bytes read so far in marker */
nuclear@0 104 /* Note: cur_marker is not linked into marker_list until it's all read. */
nuclear@0 105 } my_marker_reader;
nuclear@0 106
nuclear@0 107 typedef my_marker_reader * my_marker_ptr;
nuclear@0 108
nuclear@0 109
nuclear@0 110 /*
nuclear@0 111 * Macros for fetching data from the data source module.
nuclear@0 112 *
nuclear@0 113 * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
nuclear@0 114 * the current restart point; we update them only when we have reached a
nuclear@0 115 * suitable place to restart if a suspension occurs.
nuclear@0 116 */
nuclear@0 117
nuclear@0 118 /* Declare and initialize local copies of input pointer/count */
nuclear@0 119 #define INPUT_VARS(cinfo) \
nuclear@0 120 struct jpeg_source_mgr * datasrc = (cinfo)->src; \
nuclear@0 121 const JOCTET * next_input_byte = datasrc->next_input_byte; \
nuclear@0 122 size_t bytes_in_buffer = datasrc->bytes_in_buffer
nuclear@0 123
nuclear@0 124 /* Unload the local copies --- do this only at a restart boundary */
nuclear@0 125 #define INPUT_SYNC(cinfo) \
nuclear@0 126 ( datasrc->next_input_byte = next_input_byte, \
nuclear@0 127 datasrc->bytes_in_buffer = bytes_in_buffer )
nuclear@0 128
nuclear@0 129 /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
nuclear@0 130 #define INPUT_RELOAD(cinfo) \
nuclear@0 131 ( next_input_byte = datasrc->next_input_byte, \
nuclear@0 132 bytes_in_buffer = datasrc->bytes_in_buffer )
nuclear@0 133
nuclear@0 134 /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
nuclear@0 135 * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
nuclear@0 136 * but we must reload the local copies after a successful fill.
nuclear@0 137 */
nuclear@0 138 #define MAKE_BYTE_AVAIL(cinfo,action) \
nuclear@0 139 if (bytes_in_buffer == 0) { \
nuclear@0 140 if (! (*datasrc->fill_input_buffer) (cinfo)) \
nuclear@0 141 { action; } \
nuclear@0 142 INPUT_RELOAD(cinfo); \
nuclear@0 143 }
nuclear@0 144
nuclear@0 145 /* Read a byte into variable V.
nuclear@0 146 * If must suspend, take the specified action (typically "return FALSE").
nuclear@0 147 */
nuclear@0 148 #define INPUT_BYTE(cinfo,V,action) \
nuclear@0 149 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@0 150 bytes_in_buffer--; \
nuclear@0 151 V = GETJOCTET(*next_input_byte++); )
nuclear@0 152
nuclear@0 153 /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
nuclear@0 154 * V should be declared unsigned int or perhaps INT32.
nuclear@0 155 */
nuclear@0 156 #define INPUT_2BYTES(cinfo,V,action) \
nuclear@0 157 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@0 158 bytes_in_buffer--; \
nuclear@0 159 V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
nuclear@0 160 MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@0 161 bytes_in_buffer--; \
nuclear@0 162 V += GETJOCTET(*next_input_byte++); )
nuclear@0 163
nuclear@0 164
nuclear@0 165 /*
nuclear@0 166 * Routines to process JPEG markers.
nuclear@0 167 *
nuclear@0 168 * Entry condition: JPEG marker itself has been read and its code saved
nuclear@0 169 * in cinfo->unread_marker; input restart point is just after the marker.
nuclear@0 170 *
nuclear@0 171 * Exit: if return TRUE, have read and processed any parameters, and have
nuclear@0 172 * updated the restart point to point after the parameters.
nuclear@0 173 * If return FALSE, was forced to suspend before reaching end of
nuclear@0 174 * marker parameters; restart point has not been moved. Same routine
nuclear@0 175 * will be called again after application supplies more input data.
nuclear@0 176 *
nuclear@0 177 * This approach to suspension assumes that all of a marker's parameters
nuclear@0 178 * can fit into a single input bufferload. This should hold for "normal"
nuclear@0 179 * markers. Some COM/APPn markers might have large parameter segments
nuclear@0 180 * that might not fit. If we are simply dropping such a marker, we use
nuclear@0 181 * skip_input_data to get past it, and thereby put the problem on the
nuclear@0 182 * source manager's shoulders. If we are saving the marker's contents
nuclear@0 183 * into memory, we use a slightly different convention: when forced to
nuclear@0 184 * suspend, the marker processor updates the restart point to the end of
nuclear@0 185 * what it's consumed (ie, the end of the buffer) before returning FALSE.
nuclear@0 186 * On resumption, cinfo->unread_marker still contains the marker code,
nuclear@0 187 * but the data source will point to the next chunk of marker data.
nuclear@0 188 * The marker processor must retain internal state to deal with this.
nuclear@0 189 *
nuclear@0 190 * Note that we don't bother to avoid duplicate trace messages if a
nuclear@0 191 * suspension occurs within marker parameters. Other side effects
nuclear@0 192 * require more care.
nuclear@0 193 */
nuclear@0 194
nuclear@0 195
nuclear@0 196 LOCAL(boolean)
nuclear@0 197 get_soi (j_decompress_ptr cinfo)
nuclear@0 198 /* Process an SOI marker */
nuclear@0 199 {
nuclear@0 200 int i;
nuclear@0 201
nuclear@0 202 TRACEMS(cinfo, 1, JTRC_SOI);
nuclear@0 203
nuclear@0 204 if (cinfo->marker->saw_SOI)
nuclear@0 205 ERREXIT(cinfo, JERR_SOI_DUPLICATE);
nuclear@0 206
nuclear@0 207 /* Reset all parameters that are defined to be reset by SOI */
nuclear@0 208
nuclear@0 209 for (i = 0; i < NUM_ARITH_TBLS; i++) {
nuclear@0 210 cinfo->arith_dc_L[i] = 0;
nuclear@0 211 cinfo->arith_dc_U[i] = 1;
nuclear@0 212 cinfo->arith_ac_K[i] = 5;
nuclear@0 213 }
nuclear@0 214 cinfo->restart_interval = 0;
nuclear@0 215
nuclear@0 216 /* Set initial assumptions for colorspace etc */
nuclear@0 217
nuclear@0 218 cinfo->jpeg_color_space = JCS_UNKNOWN;
nuclear@0 219 cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
nuclear@0 220
nuclear@0 221 cinfo->saw_JFIF_marker = FALSE;
nuclear@0 222 cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
nuclear@0 223 cinfo->JFIF_minor_version = 1;
nuclear@0 224 cinfo->density_unit = 0;
nuclear@0 225 cinfo->X_density = 1;
nuclear@0 226 cinfo->Y_density = 1;
nuclear@0 227 cinfo->saw_Adobe_marker = FALSE;
nuclear@0 228 cinfo->Adobe_transform = 0;
nuclear@0 229
nuclear@0 230 cinfo->marker->saw_SOI = TRUE;
nuclear@0 231
nuclear@0 232 return TRUE;
nuclear@0 233 }
nuclear@0 234
nuclear@0 235
nuclear@0 236 LOCAL(boolean)
nuclear@0 237 get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
nuclear@0 238 /* Process a SOFn marker */
nuclear@0 239 {
nuclear@0 240 INT32 length;
nuclear@0 241 int c, ci;
nuclear@0 242 jpeg_component_info * compptr;
nuclear@0 243 INPUT_VARS(cinfo);
nuclear@0 244
nuclear@0 245 cinfo->progressive_mode = is_prog;
nuclear@0 246 cinfo->arith_code = is_arith;
nuclear@0 247
nuclear@0 248 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 249
nuclear@0 250 INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
nuclear@0 251 INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
nuclear@0 252 INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
nuclear@0 253 INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
nuclear@0 254
nuclear@0 255 length -= 8;
nuclear@0 256
nuclear@0 257 TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
nuclear@0 258 (int) cinfo->image_width, (int) cinfo->image_height,
nuclear@0 259 cinfo->num_components);
nuclear@0 260
nuclear@0 261 if (cinfo->marker->saw_SOF)
nuclear@0 262 ERREXIT(cinfo, JERR_SOF_DUPLICATE);
nuclear@0 263
nuclear@0 264 /* We don't support files in which the image height is initially specified */
nuclear@0 265 /* as 0 and is later redefined by DNL. As long as we have to check that, */
nuclear@0 266 /* might as well have a general sanity check. */
nuclear@0 267 if (cinfo->image_height <= 0 || cinfo->image_width <= 0
nuclear@0 268 || cinfo->num_components <= 0)
nuclear@0 269 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
nuclear@0 270
nuclear@0 271 if (length != (cinfo->num_components * 3))
nuclear@0 272 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 273
nuclear@0 274 if (cinfo->comp_info == NULL) /* do only once, even if suspend */
nuclear@0 275 cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
nuclear@0 276 ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@0 277 cinfo->num_components * SIZEOF(jpeg_component_info));
nuclear@0 278
nuclear@0 279 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@0 280 ci++, compptr++) {
nuclear@0 281 compptr->component_index = ci;
nuclear@0 282 INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
nuclear@0 283 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 284 compptr->h_samp_factor = (c >> 4) & 15;
nuclear@0 285 compptr->v_samp_factor = (c ) & 15;
nuclear@0 286 INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
nuclear@0 287
nuclear@0 288 TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
nuclear@0 289 compptr->component_id, compptr->h_samp_factor,
nuclear@0 290 compptr->v_samp_factor, compptr->quant_tbl_no);
nuclear@0 291 }
nuclear@0 292
nuclear@0 293 cinfo->marker->saw_SOF = TRUE;
nuclear@0 294
nuclear@0 295 INPUT_SYNC(cinfo);
nuclear@0 296 return TRUE;
nuclear@0 297 }
nuclear@0 298
nuclear@0 299
nuclear@0 300 LOCAL(boolean)
nuclear@0 301 get_sos (j_decompress_ptr cinfo)
nuclear@0 302 /* Process a SOS marker */
nuclear@0 303 {
nuclear@0 304 INT32 length;
nuclear@0 305 int i, ci, n, c, cc;
nuclear@0 306 jpeg_component_info * compptr;
nuclear@0 307 INPUT_VARS(cinfo);
nuclear@0 308
nuclear@0 309 if (! cinfo->marker->saw_SOF)
nuclear@0 310 ERREXIT(cinfo, JERR_SOS_NO_SOF);
nuclear@0 311
nuclear@0 312 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 313
nuclear@0 314 INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
nuclear@0 315
nuclear@0 316 TRACEMS1(cinfo, 1, JTRC_SOS, n);
nuclear@0 317
nuclear@0 318 if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
nuclear@0 319 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 320
nuclear@0 321 cinfo->comps_in_scan = n;
nuclear@0 322
nuclear@0 323 /* Collect the component-spec parameters */
nuclear@0 324
nuclear@0 325 for (i = 0; i < n; i++) {
nuclear@0 326 INPUT_BYTE(cinfo, cc, return FALSE);
nuclear@0 327 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 328
nuclear@0 329 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@0 330 ci++, compptr++) {
nuclear@0 331 if (cc == compptr->component_id)
nuclear@0 332 goto id_found;
nuclear@0 333 }
nuclear@0 334
nuclear@0 335 ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
nuclear@0 336
nuclear@0 337 id_found:
nuclear@0 338
nuclear@0 339 cinfo->cur_comp_info[i] = compptr;
nuclear@0 340 compptr->dc_tbl_no = (c >> 4) & 15;
nuclear@0 341 compptr->ac_tbl_no = (c ) & 15;
nuclear@0 342
nuclear@0 343 TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
nuclear@0 344 compptr->dc_tbl_no, compptr->ac_tbl_no);
nuclear@0 345 }
nuclear@0 346
nuclear@0 347 /* Collect the additional scan parameters Ss, Se, Ah/Al. */
nuclear@0 348 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 349 cinfo->Ss = c;
nuclear@0 350 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 351 cinfo->Se = c;
nuclear@0 352 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 353 cinfo->Ah = (c >> 4) & 15;
nuclear@0 354 cinfo->Al = (c ) & 15;
nuclear@0 355
nuclear@0 356 TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
nuclear@0 357 cinfo->Ah, cinfo->Al);
nuclear@0 358
nuclear@0 359 /* Prepare to scan data & restart markers */
nuclear@0 360 cinfo->marker->next_restart_num = 0;
nuclear@0 361
nuclear@0 362 /* Count another SOS marker */
nuclear@0 363 cinfo->input_scan_number++;
nuclear@0 364
nuclear@0 365 INPUT_SYNC(cinfo);
nuclear@0 366 return TRUE;
nuclear@0 367 }
nuclear@0 368
nuclear@0 369
nuclear@0 370 #ifdef D_ARITH_CODING_SUPPORTED
nuclear@0 371
nuclear@0 372 LOCAL(boolean)
nuclear@0 373 get_dac (j_decompress_ptr cinfo)
nuclear@0 374 /* Process a DAC marker */
nuclear@0 375 {
nuclear@0 376 INT32 length;
nuclear@0 377 int index, val;
nuclear@0 378 INPUT_VARS(cinfo);
nuclear@0 379
nuclear@0 380 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 381 length -= 2;
nuclear@0 382
nuclear@0 383 while (length > 0) {
nuclear@0 384 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@0 385 INPUT_BYTE(cinfo, val, return FALSE);
nuclear@0 386
nuclear@0 387 length -= 2;
nuclear@0 388
nuclear@0 389 TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
nuclear@0 390
nuclear@0 391 if (index < 0 || index >= (2*NUM_ARITH_TBLS))
nuclear@0 392 ERREXIT1(cinfo, JERR_DAC_INDEX, index);
nuclear@0 393
nuclear@0 394 if (index >= NUM_ARITH_TBLS) { /* define AC table */
nuclear@0 395 cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
nuclear@0 396 } else { /* define DC table */
nuclear@0 397 cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
nuclear@0 398 cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
nuclear@0 399 if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
nuclear@0 400 ERREXIT1(cinfo, JERR_DAC_VALUE, val);
nuclear@0 401 }
nuclear@0 402 }
nuclear@0 403
nuclear@0 404 if (length != 0)
nuclear@0 405 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 406
nuclear@0 407 INPUT_SYNC(cinfo);
nuclear@0 408 return TRUE;
nuclear@0 409 }
nuclear@0 410
nuclear@0 411 #else /* ! D_ARITH_CODING_SUPPORTED */
nuclear@0 412
nuclear@0 413 #define get_dac(cinfo) skip_variable(cinfo)
nuclear@0 414
nuclear@0 415 #endif /* D_ARITH_CODING_SUPPORTED */
nuclear@0 416
nuclear@0 417
nuclear@0 418 LOCAL(boolean)
nuclear@0 419 get_dht (j_decompress_ptr cinfo)
nuclear@0 420 /* Process a DHT marker */
nuclear@0 421 {
nuclear@0 422 INT32 length;
nuclear@0 423 UINT8 bits[17];
nuclear@0 424 UINT8 huffval[256];
nuclear@0 425 int i, index, count;
nuclear@0 426 JHUFF_TBL **htblptr;
nuclear@0 427 INPUT_VARS(cinfo);
nuclear@0 428
nuclear@0 429 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 430 length -= 2;
nuclear@0 431
nuclear@0 432 while (length > 16) {
nuclear@0 433 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@0 434
nuclear@0 435 TRACEMS1(cinfo, 1, JTRC_DHT, index);
nuclear@0 436
nuclear@0 437 bits[0] = 0;
nuclear@0 438 count = 0;
nuclear@0 439 for (i = 1; i <= 16; i++) {
nuclear@0 440 INPUT_BYTE(cinfo, bits[i], return FALSE);
nuclear@0 441 count += bits[i];
nuclear@0 442 }
nuclear@0 443
nuclear@0 444 length -= 1 + 16;
nuclear@0 445
nuclear@0 446 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@0 447 bits[1], bits[2], bits[3], bits[4],
nuclear@0 448 bits[5], bits[6], bits[7], bits[8]);
nuclear@0 449 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@0 450 bits[9], bits[10], bits[11], bits[12],
nuclear@0 451 bits[13], bits[14], bits[15], bits[16]);
nuclear@0 452
nuclear@0 453 /* Here we just do minimal validation of the counts to avoid walking
nuclear@0 454 * off the end of our table space. jdhuff.c will check more carefully.
nuclear@0 455 */
nuclear@0 456 if (count > 256 || ((INT32) count) > length)
nuclear@0 457 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
nuclear@0 458
nuclear@0 459 for (i = 0; i < count; i++)
nuclear@0 460 INPUT_BYTE(cinfo, huffval[i], return FALSE);
nuclear@0 461
nuclear@0 462 length -= count;
nuclear@0 463
nuclear@0 464 if (index & 0x10) { /* AC table definition */
nuclear@0 465 index -= 0x10;
nuclear@0 466 htblptr = &cinfo->ac_huff_tbl_ptrs[index];
nuclear@0 467 } else { /* DC table definition */
nuclear@0 468 htblptr = &cinfo->dc_huff_tbl_ptrs[index];
nuclear@0 469 }
nuclear@0 470
nuclear@0 471 if (index < 0 || index >= NUM_HUFF_TBLS)
nuclear@0 472 ERREXIT1(cinfo, JERR_DHT_INDEX, index);
nuclear@0 473
nuclear@0 474 if (*htblptr == NULL)
nuclear@0 475 *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
nuclear@0 476
nuclear@0 477 MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
nuclear@0 478 MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
nuclear@0 479 }
nuclear@0 480
nuclear@0 481 if (length != 0)
nuclear@0 482 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 483
nuclear@0 484 INPUT_SYNC(cinfo);
nuclear@0 485 return TRUE;
nuclear@0 486 }
nuclear@0 487
nuclear@0 488
nuclear@0 489 LOCAL(boolean)
nuclear@0 490 get_dqt (j_decompress_ptr cinfo)
nuclear@0 491 /* Process a DQT marker */
nuclear@0 492 {
nuclear@0 493 INT32 length;
nuclear@0 494 int n, i, prec;
nuclear@0 495 unsigned int tmp;
nuclear@0 496 JQUANT_TBL *quant_ptr;
nuclear@0 497 INPUT_VARS(cinfo);
nuclear@0 498
nuclear@0 499 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 500 length -= 2;
nuclear@0 501
nuclear@0 502 while (length > 0) {
nuclear@0 503 INPUT_BYTE(cinfo, n, return FALSE);
nuclear@0 504 prec = n >> 4;
nuclear@0 505 n &= 0x0F;
nuclear@0 506
nuclear@0 507 TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
nuclear@0 508
nuclear@0 509 if (n >= NUM_QUANT_TBLS)
nuclear@0 510 ERREXIT1(cinfo, JERR_DQT_INDEX, n);
nuclear@0 511
nuclear@0 512 if (cinfo->quant_tbl_ptrs[n] == NULL)
nuclear@0 513 cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
nuclear@0 514 quant_ptr = cinfo->quant_tbl_ptrs[n];
nuclear@0 515
nuclear@0 516 for (i = 0; i < DCTSIZE2; i++) {
nuclear@0 517 if (prec)
nuclear@0 518 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@0 519 else
nuclear@0 520 INPUT_BYTE(cinfo, tmp, return FALSE);
nuclear@0 521 /* We convert the zigzag-order table to natural array order. */
nuclear@0 522 quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
nuclear@0 523 }
nuclear@0 524
nuclear@0 525 if (cinfo->err->trace_level >= 2) {
nuclear@0 526 for (i = 0; i < DCTSIZE2; i += 8) {
nuclear@0 527 TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
nuclear@0 528 quant_ptr->quantval[i], quant_ptr->quantval[i+1],
nuclear@0 529 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
nuclear@0 530 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
nuclear@0 531 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
nuclear@0 532 }
nuclear@0 533 }
nuclear@0 534
nuclear@0 535 length -= DCTSIZE2+1;
nuclear@0 536 if (prec) length -= DCTSIZE2;
nuclear@0 537 }
nuclear@0 538
nuclear@0 539 if (length != 0)
nuclear@0 540 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 541
nuclear@0 542 INPUT_SYNC(cinfo);
nuclear@0 543 return TRUE;
nuclear@0 544 }
nuclear@0 545
nuclear@0 546
nuclear@0 547 LOCAL(boolean)
nuclear@0 548 get_dri (j_decompress_ptr cinfo)
nuclear@0 549 /* Process a DRI marker */
nuclear@0 550 {
nuclear@0 551 INT32 length;
nuclear@0 552 unsigned int tmp;
nuclear@0 553 INPUT_VARS(cinfo);
nuclear@0 554
nuclear@0 555 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 556
nuclear@0 557 if (length != 4)
nuclear@0 558 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 559
nuclear@0 560 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@0 561
nuclear@0 562 TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
nuclear@0 563
nuclear@0 564 cinfo->restart_interval = tmp;
nuclear@0 565
nuclear@0 566 INPUT_SYNC(cinfo);
nuclear@0 567 return TRUE;
nuclear@0 568 }
nuclear@0 569
nuclear@0 570
nuclear@0 571 /*
nuclear@0 572 * Routines for processing APPn and COM markers.
nuclear@0 573 * These are either saved in memory or discarded, per application request.
nuclear@0 574 * APP0 and APP14 are specially checked to see if they are
nuclear@0 575 * JFIF and Adobe markers, respectively.
nuclear@0 576 */
nuclear@0 577
nuclear@0 578 #define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
nuclear@0 579 #define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
nuclear@0 580 #define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
nuclear@0 581
nuclear@0 582
nuclear@0 583 LOCAL(void)
nuclear@0 584 examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@0 585 unsigned int datalen, INT32 remaining)
nuclear@0 586 /* Examine first few bytes from an APP0.
nuclear@0 587 * Take appropriate action if it is a JFIF marker.
nuclear@0 588 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@0 589 */
nuclear@0 590 {
nuclear@0 591 INT32 totallen = (INT32) datalen + remaining;
nuclear@0 592
nuclear@0 593 if (datalen >= APP0_DATA_LEN &&
nuclear@0 594 GETJOCTET(data[0]) == 0x4A &&
nuclear@0 595 GETJOCTET(data[1]) == 0x46 &&
nuclear@0 596 GETJOCTET(data[2]) == 0x49 &&
nuclear@0 597 GETJOCTET(data[3]) == 0x46 &&
nuclear@0 598 GETJOCTET(data[4]) == 0) {
nuclear@0 599 /* Found JFIF APP0 marker: save info */
nuclear@0 600 cinfo->saw_JFIF_marker = TRUE;
nuclear@0 601 cinfo->JFIF_major_version = GETJOCTET(data[5]);
nuclear@0 602 cinfo->JFIF_minor_version = GETJOCTET(data[6]);
nuclear@0 603 cinfo->density_unit = GETJOCTET(data[7]);
nuclear@0 604 cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
nuclear@0 605 cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
nuclear@0 606 /* Check version.
nuclear@0 607 * Major version must be 1, anything else signals an incompatible change.
nuclear@0 608 * (We used to treat this as an error, but now it's a nonfatal warning,
nuclear@0 609 * because some bozo at Hijaak couldn't read the spec.)
nuclear@0 610 * Minor version should be 0..2, but process anyway if newer.
nuclear@0 611 */
nuclear@0 612 if (cinfo->JFIF_major_version != 1)
nuclear@0 613 WARNMS2(cinfo, JWRN_JFIF_MAJOR,
nuclear@0 614 cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
nuclear@0 615 /* Generate trace messages */
nuclear@0 616 TRACEMS5(cinfo, 1, JTRC_JFIF,
nuclear@0 617 cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
nuclear@0 618 cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
nuclear@0 619 /* Validate thumbnail dimensions and issue appropriate messages */
nuclear@0 620 if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
nuclear@0 621 TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
nuclear@0 622 GETJOCTET(data[12]), GETJOCTET(data[13]));
nuclear@0 623 totallen -= APP0_DATA_LEN;
nuclear@0 624 if (totallen !=
nuclear@0 625 ((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
nuclear@0 626 TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
nuclear@0 627 } else if (datalen >= 6 &&
nuclear@0 628 GETJOCTET(data[0]) == 0x4A &&
nuclear@0 629 GETJOCTET(data[1]) == 0x46 &&
nuclear@0 630 GETJOCTET(data[2]) == 0x58 &&
nuclear@0 631 GETJOCTET(data[3]) == 0x58 &&
nuclear@0 632 GETJOCTET(data[4]) == 0) {
nuclear@0 633 /* Found JFIF "JFXX" extension APP0 marker */
nuclear@0 634 /* The library doesn't actually do anything with these,
nuclear@0 635 * but we try to produce a helpful trace message.
nuclear@0 636 */
nuclear@0 637 switch (GETJOCTET(data[5])) {
nuclear@0 638 case 0x10:
nuclear@0 639 TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
nuclear@0 640 break;
nuclear@0 641 case 0x11:
nuclear@0 642 TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
nuclear@0 643 break;
nuclear@0 644 case 0x13:
nuclear@0 645 TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
nuclear@0 646 break;
nuclear@0 647 default:
nuclear@0 648 TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
nuclear@0 649 GETJOCTET(data[5]), (int) totallen);
nuclear@0 650 break;
nuclear@0 651 }
nuclear@0 652 } else {
nuclear@0 653 /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
nuclear@0 654 TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
nuclear@0 655 }
nuclear@0 656 }
nuclear@0 657
nuclear@0 658
nuclear@0 659 LOCAL(void)
nuclear@0 660 examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@0 661 unsigned int datalen, INT32 remaining)
nuclear@0 662 /* Examine first few bytes from an APP14.
nuclear@0 663 * Take appropriate action if it is an Adobe marker.
nuclear@0 664 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@0 665 */
nuclear@0 666 {
nuclear@0 667 unsigned int version, flags0, flags1, transform;
nuclear@0 668
nuclear@0 669 if (datalen >= APP14_DATA_LEN &&
nuclear@0 670 GETJOCTET(data[0]) == 0x41 &&
nuclear@0 671 GETJOCTET(data[1]) == 0x64 &&
nuclear@0 672 GETJOCTET(data[2]) == 0x6F &&
nuclear@0 673 GETJOCTET(data[3]) == 0x62 &&
nuclear@0 674 GETJOCTET(data[4]) == 0x65) {
nuclear@0 675 /* Found Adobe APP14 marker */
nuclear@0 676 version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
nuclear@0 677 flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
nuclear@0 678 flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
nuclear@0 679 transform = GETJOCTET(data[11]);
nuclear@0 680 TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
nuclear@0 681 cinfo->saw_Adobe_marker = TRUE;
nuclear@0 682 cinfo->Adobe_transform = (UINT8) transform;
nuclear@0 683 } else {
nuclear@0 684 /* Start of APP14 does not match "Adobe", or too short */
nuclear@0 685 TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
nuclear@0 686 }
nuclear@0 687 }
nuclear@0 688
nuclear@0 689
nuclear@0 690 METHODDEF(boolean)
nuclear@0 691 get_interesting_appn (j_decompress_ptr cinfo)
nuclear@0 692 /* Process an APP0 or APP14 marker without saving it */
nuclear@0 693 {
nuclear@0 694 INT32 length;
nuclear@0 695 JOCTET b[APPN_DATA_LEN];
nuclear@0 696 unsigned int i, numtoread;
nuclear@0 697 INPUT_VARS(cinfo);
nuclear@0 698
nuclear@0 699 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 700 length -= 2;
nuclear@0 701
nuclear@0 702 /* get the interesting part of the marker data */
nuclear@0 703 if (length >= APPN_DATA_LEN)
nuclear@0 704 numtoread = APPN_DATA_LEN;
nuclear@0 705 else if (length > 0)
nuclear@0 706 numtoread = (unsigned int) length;
nuclear@0 707 else
nuclear@0 708 numtoread = 0;
nuclear@0 709 for (i = 0; i < numtoread; i++)
nuclear@0 710 INPUT_BYTE(cinfo, b[i], return FALSE);
nuclear@0 711 length -= numtoread;
nuclear@0 712
nuclear@0 713 /* process it */
nuclear@0 714 switch (cinfo->unread_marker) {
nuclear@0 715 case M_APP0:
nuclear@0 716 examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@0 717 break;
nuclear@0 718 case M_APP14:
nuclear@0 719 examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@0 720 break;
nuclear@0 721 default:
nuclear@0 722 /* can't get here unless jpeg_save_markers chooses wrong processor */
nuclear@0 723 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@0 724 break;
nuclear@0 725 }
nuclear@0 726
nuclear@0 727 /* skip any remaining data -- could be lots */
nuclear@0 728 INPUT_SYNC(cinfo);
nuclear@0 729 if (length > 0)
nuclear@0 730 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@0 731
nuclear@0 732 return TRUE;
nuclear@0 733 }
nuclear@0 734
nuclear@0 735
nuclear@0 736 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@0 737
nuclear@0 738 METHODDEF(boolean)
nuclear@0 739 save_marker (j_decompress_ptr cinfo)
nuclear@0 740 /* Save an APPn or COM marker into the marker list */
nuclear@0 741 {
nuclear@0 742 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 743 jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
nuclear@0 744 unsigned int bytes_read, data_length;
nuclear@0 745 JOCTET FAR * data;
nuclear@0 746 INT32 length = 0;
nuclear@0 747 INPUT_VARS(cinfo);
nuclear@0 748
nuclear@0 749 if (cur_marker == NULL) {
nuclear@0 750 /* begin reading a marker */
nuclear@0 751 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 752 length -= 2;
nuclear@0 753 if (length >= 0) { /* watch out for bogus length word */
nuclear@0 754 /* figure out how much we want to save */
nuclear@0 755 unsigned int limit;
nuclear@0 756 if (cinfo->unread_marker == (int) M_COM)
nuclear@0 757 limit = marker->length_limit_COM;
nuclear@0 758 else
nuclear@0 759 limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
nuclear@0 760 if ((unsigned int) length < limit)
nuclear@0 761 limit = (unsigned int) length;
nuclear@0 762 /* allocate and initialize the marker item */
nuclear@0 763 cur_marker = (jpeg_saved_marker_ptr)
nuclear@0 764 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@0 765 SIZEOF(struct jpeg_marker_struct) + limit);
nuclear@0 766 cur_marker->next = NULL;
nuclear@0 767 cur_marker->marker = (UINT8) cinfo->unread_marker;
nuclear@0 768 cur_marker->original_length = (unsigned int) length;
nuclear@0 769 cur_marker->data_length = limit;
nuclear@0 770 /* data area is just beyond the jpeg_marker_struct */
nuclear@0 771 data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
nuclear@0 772 marker->cur_marker = cur_marker;
nuclear@0 773 marker->bytes_read = 0;
nuclear@0 774 bytes_read = 0;
nuclear@0 775 data_length = limit;
nuclear@0 776 } else {
nuclear@0 777 /* deal with bogus length word */
nuclear@0 778 bytes_read = data_length = 0;
nuclear@0 779 data = NULL;
nuclear@0 780 }
nuclear@0 781 } else {
nuclear@0 782 /* resume reading a marker */
nuclear@0 783 bytes_read = marker->bytes_read;
nuclear@0 784 data_length = cur_marker->data_length;
nuclear@0 785 data = cur_marker->data + bytes_read;
nuclear@0 786 }
nuclear@0 787
nuclear@0 788 while (bytes_read < data_length) {
nuclear@0 789 INPUT_SYNC(cinfo); /* move the restart point to here */
nuclear@0 790 marker->bytes_read = bytes_read;
nuclear@0 791 /* If there's not at least one byte in buffer, suspend */
nuclear@0 792 MAKE_BYTE_AVAIL(cinfo, return FALSE);
nuclear@0 793 /* Copy bytes with reasonable rapidity */
nuclear@0 794 while (bytes_read < data_length && bytes_in_buffer > 0) {
nuclear@0 795 *data++ = *next_input_byte++;
nuclear@0 796 bytes_in_buffer--;
nuclear@0 797 bytes_read++;
nuclear@0 798 }
nuclear@0 799 }
nuclear@0 800
nuclear@0 801 /* Done reading what we want to read */
nuclear@0 802 if (cur_marker != NULL) { /* will be NULL if bogus length word */
nuclear@0 803 /* Add new marker to end of list */
nuclear@0 804 if (cinfo->marker_list == NULL) {
nuclear@0 805 cinfo->marker_list = cur_marker;
nuclear@0 806 } else {
nuclear@0 807 jpeg_saved_marker_ptr prev = cinfo->marker_list;
nuclear@0 808 while (prev->next != NULL)
nuclear@0 809 prev = prev->next;
nuclear@0 810 prev->next = cur_marker;
nuclear@0 811 }
nuclear@0 812 /* Reset pointer & calc remaining data length */
nuclear@0 813 data = cur_marker->data;
nuclear@0 814 length = cur_marker->original_length - data_length;
nuclear@0 815 }
nuclear@0 816 /* Reset to initial state for next marker */
nuclear@0 817 marker->cur_marker = NULL;
nuclear@0 818
nuclear@0 819 /* Process the marker if interesting; else just make a generic trace msg */
nuclear@0 820 switch (cinfo->unread_marker) {
nuclear@0 821 case M_APP0:
nuclear@0 822 examine_app0(cinfo, data, data_length, length);
nuclear@0 823 break;
nuclear@0 824 case M_APP14:
nuclear@0 825 examine_app14(cinfo, data, data_length, length);
nuclear@0 826 break;
nuclear@0 827 default:
nuclear@0 828 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
nuclear@0 829 (int) (data_length + length));
nuclear@0 830 break;
nuclear@0 831 }
nuclear@0 832
nuclear@0 833 /* skip any remaining data -- could be lots */
nuclear@0 834 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@0 835 if (length > 0)
nuclear@0 836 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@0 837
nuclear@0 838 return TRUE;
nuclear@0 839 }
nuclear@0 840
nuclear@0 841 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@0 842
nuclear@0 843
nuclear@0 844 METHODDEF(boolean)
nuclear@0 845 skip_variable (j_decompress_ptr cinfo)
nuclear@0 846 /* Skip over an unknown or uninteresting variable-length marker */
nuclear@0 847 {
nuclear@0 848 INT32 length;
nuclear@0 849 INPUT_VARS(cinfo);
nuclear@0 850
nuclear@0 851 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@0 852 length -= 2;
nuclear@0 853
nuclear@0 854 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
nuclear@0 855
nuclear@0 856 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@0 857 if (length > 0)
nuclear@0 858 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@0 859
nuclear@0 860 return TRUE;
nuclear@0 861 }
nuclear@0 862
nuclear@0 863
nuclear@0 864 /*
nuclear@0 865 * Find the next JPEG marker, save it in cinfo->unread_marker.
nuclear@0 866 * Returns FALSE if had to suspend before reaching a marker;
nuclear@0 867 * in that case cinfo->unread_marker is unchanged.
nuclear@0 868 *
nuclear@0 869 * Note that the result might not be a valid marker code,
nuclear@0 870 * but it will never be 0 or FF.
nuclear@0 871 */
nuclear@0 872
nuclear@0 873 LOCAL(boolean)
nuclear@0 874 next_marker (j_decompress_ptr cinfo)
nuclear@0 875 {
nuclear@0 876 int c;
nuclear@0 877 INPUT_VARS(cinfo);
nuclear@0 878
nuclear@0 879 for (;;) {
nuclear@0 880 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 881 /* Skip any non-FF bytes.
nuclear@0 882 * This may look a bit inefficient, but it will not occur in a valid file.
nuclear@0 883 * We sync after each discarded byte so that a suspending data source
nuclear@0 884 * can discard the byte from its buffer.
nuclear@0 885 */
nuclear@0 886 while (c != 0xFF) {
nuclear@0 887 cinfo->marker->discarded_bytes++;
nuclear@0 888 INPUT_SYNC(cinfo);
nuclear@0 889 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 890 }
nuclear@0 891 /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
nuclear@0 892 * pad bytes, so don't count them in discarded_bytes. We assume there
nuclear@0 893 * will not be so many consecutive FF bytes as to overflow a suspending
nuclear@0 894 * data source's input buffer.
nuclear@0 895 */
nuclear@0 896 do {
nuclear@0 897 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 898 } while (c == 0xFF);
nuclear@0 899 if (c != 0)
nuclear@0 900 break; /* found a valid marker, exit loop */
nuclear@0 901 /* Reach here if we found a stuffed-zero data sequence (FF/00).
nuclear@0 902 * Discard it and loop back to try again.
nuclear@0 903 */
nuclear@0 904 cinfo->marker->discarded_bytes += 2;
nuclear@0 905 INPUT_SYNC(cinfo);
nuclear@0 906 }
nuclear@0 907
nuclear@0 908 if (cinfo->marker->discarded_bytes != 0) {
nuclear@0 909 WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
nuclear@0 910 cinfo->marker->discarded_bytes = 0;
nuclear@0 911 }
nuclear@0 912
nuclear@0 913 cinfo->unread_marker = c;
nuclear@0 914
nuclear@0 915 INPUT_SYNC(cinfo);
nuclear@0 916 return TRUE;
nuclear@0 917 }
nuclear@0 918
nuclear@0 919
nuclear@0 920 LOCAL(boolean)
nuclear@0 921 first_marker (j_decompress_ptr cinfo)
nuclear@0 922 /* Like next_marker, but used to obtain the initial SOI marker. */
nuclear@0 923 /* For this marker, we do not allow preceding garbage or fill; otherwise,
nuclear@0 924 * we might well scan an entire input file before realizing it ain't JPEG.
nuclear@0 925 * If an application wants to process non-JFIF files, it must seek to the
nuclear@0 926 * SOI before calling the JPEG library.
nuclear@0 927 */
nuclear@0 928 {
nuclear@0 929 int c, c2;
nuclear@0 930 INPUT_VARS(cinfo);
nuclear@0 931
nuclear@0 932 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@0 933 INPUT_BYTE(cinfo, c2, return FALSE);
nuclear@0 934 if (c != 0xFF || c2 != (int) M_SOI)
nuclear@0 935 ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
nuclear@0 936
nuclear@0 937 cinfo->unread_marker = c2;
nuclear@0 938
nuclear@0 939 INPUT_SYNC(cinfo);
nuclear@0 940 return TRUE;
nuclear@0 941 }
nuclear@0 942
nuclear@0 943
nuclear@0 944 /*
nuclear@0 945 * Read markers until SOS or EOI.
nuclear@0 946 *
nuclear@0 947 * Returns same codes as are defined for jpeg_consume_input:
nuclear@0 948 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
nuclear@0 949 */
nuclear@0 950
nuclear@0 951 METHODDEF(int)
nuclear@0 952 read_markers (j_decompress_ptr cinfo)
nuclear@0 953 {
nuclear@0 954 /* Outer loop repeats once for each marker. */
nuclear@0 955 for (;;) {
nuclear@0 956 /* Collect the marker proper, unless we already did. */
nuclear@0 957 /* NB: first_marker() enforces the requirement that SOI appear first. */
nuclear@0 958 if (cinfo->unread_marker == 0) {
nuclear@0 959 if (! cinfo->marker->saw_SOI) {
nuclear@0 960 if (! first_marker(cinfo))
nuclear@0 961 return JPEG_SUSPENDED;
nuclear@0 962 } else {
nuclear@0 963 if (! next_marker(cinfo))
nuclear@0 964 return JPEG_SUSPENDED;
nuclear@0 965 }
nuclear@0 966 }
nuclear@0 967 /* At this point cinfo->unread_marker contains the marker code and the
nuclear@0 968 * input point is just past the marker proper, but before any parameters.
nuclear@0 969 * A suspension will cause us to return with this state still true.
nuclear@0 970 */
nuclear@0 971 switch (cinfo->unread_marker) {
nuclear@0 972 case M_SOI:
nuclear@0 973 if (! get_soi(cinfo))
nuclear@0 974 return JPEG_SUSPENDED;
nuclear@0 975 break;
nuclear@0 976
nuclear@0 977 case M_SOF0: /* Baseline */
nuclear@0 978 case M_SOF1: /* Extended sequential, Huffman */
nuclear@0 979 if (! get_sof(cinfo, FALSE, FALSE))
nuclear@0 980 return JPEG_SUSPENDED;
nuclear@0 981 break;
nuclear@0 982
nuclear@0 983 case M_SOF2: /* Progressive, Huffman */
nuclear@0 984 if (! get_sof(cinfo, TRUE, FALSE))
nuclear@0 985 return JPEG_SUSPENDED;
nuclear@0 986 break;
nuclear@0 987
nuclear@0 988 case M_SOF9: /* Extended sequential, arithmetic */
nuclear@0 989 if (! get_sof(cinfo, FALSE, TRUE))
nuclear@0 990 return JPEG_SUSPENDED;
nuclear@0 991 break;
nuclear@0 992
nuclear@0 993 case M_SOF10: /* Progressive, arithmetic */
nuclear@0 994 if (! get_sof(cinfo, TRUE, TRUE))
nuclear@0 995 return JPEG_SUSPENDED;
nuclear@0 996 break;
nuclear@0 997
nuclear@0 998 /* Currently unsupported SOFn types */
nuclear@0 999 case M_SOF3: /* Lossless, Huffman */
nuclear@0 1000 case M_SOF5: /* Differential sequential, Huffman */
nuclear@0 1001 case M_SOF6: /* Differential progressive, Huffman */
nuclear@0 1002 case M_SOF7: /* Differential lossless, Huffman */
nuclear@0 1003 case M_JPG: /* Reserved for JPEG extensions */
nuclear@0 1004 case M_SOF11: /* Lossless, arithmetic */
nuclear@0 1005 case M_SOF13: /* Differential sequential, arithmetic */
nuclear@0 1006 case M_SOF14: /* Differential progressive, arithmetic */
nuclear@0 1007 case M_SOF15: /* Differential lossless, arithmetic */
nuclear@0 1008 ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
nuclear@0 1009 break;
nuclear@0 1010
nuclear@0 1011 case M_SOS:
nuclear@0 1012 if (! get_sos(cinfo))
nuclear@0 1013 return JPEG_SUSPENDED;
nuclear@0 1014 cinfo->unread_marker = 0; /* processed the marker */
nuclear@0 1015 return JPEG_REACHED_SOS;
nuclear@0 1016
nuclear@0 1017 case M_EOI:
nuclear@0 1018 TRACEMS(cinfo, 1, JTRC_EOI);
nuclear@0 1019 cinfo->unread_marker = 0; /* processed the marker */
nuclear@0 1020 return JPEG_REACHED_EOI;
nuclear@0 1021
nuclear@0 1022 case M_DAC:
nuclear@0 1023 if (! get_dac(cinfo))
nuclear@0 1024 return JPEG_SUSPENDED;
nuclear@0 1025 break;
nuclear@0 1026
nuclear@0 1027 case M_DHT:
nuclear@0 1028 if (! get_dht(cinfo))
nuclear@0 1029 return JPEG_SUSPENDED;
nuclear@0 1030 break;
nuclear@0 1031
nuclear@0 1032 case M_DQT:
nuclear@0 1033 if (! get_dqt(cinfo))
nuclear@0 1034 return JPEG_SUSPENDED;
nuclear@0 1035 break;
nuclear@0 1036
nuclear@0 1037 case M_DRI:
nuclear@0 1038 if (! get_dri(cinfo))
nuclear@0 1039 return JPEG_SUSPENDED;
nuclear@0 1040 break;
nuclear@0 1041
nuclear@0 1042 case M_APP0:
nuclear@0 1043 case M_APP1:
nuclear@0 1044 case M_APP2:
nuclear@0 1045 case M_APP3:
nuclear@0 1046 case M_APP4:
nuclear@0 1047 case M_APP5:
nuclear@0 1048 case M_APP6:
nuclear@0 1049 case M_APP7:
nuclear@0 1050 case M_APP8:
nuclear@0 1051 case M_APP9:
nuclear@0 1052 case M_APP10:
nuclear@0 1053 case M_APP11:
nuclear@0 1054 case M_APP12:
nuclear@0 1055 case M_APP13:
nuclear@0 1056 case M_APP14:
nuclear@0 1057 case M_APP15:
nuclear@0 1058 if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
nuclear@0 1059 cinfo->unread_marker - (int) M_APP0]) (cinfo))
nuclear@0 1060 return JPEG_SUSPENDED;
nuclear@0 1061 break;
nuclear@0 1062
nuclear@0 1063 case M_COM:
nuclear@0 1064 if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
nuclear@0 1065 return JPEG_SUSPENDED;
nuclear@0 1066 break;
nuclear@0 1067
nuclear@0 1068 case M_RST0: /* these are all parameterless */
nuclear@0 1069 case M_RST1:
nuclear@0 1070 case M_RST2:
nuclear@0 1071 case M_RST3:
nuclear@0 1072 case M_RST4:
nuclear@0 1073 case M_RST5:
nuclear@0 1074 case M_RST6:
nuclear@0 1075 case M_RST7:
nuclear@0 1076 case M_TEM:
nuclear@0 1077 TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
nuclear@0 1078 break;
nuclear@0 1079
nuclear@0 1080 case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
nuclear@0 1081 if (! skip_variable(cinfo))
nuclear@0 1082 return JPEG_SUSPENDED;
nuclear@0 1083 break;
nuclear@0 1084
nuclear@0 1085 default: /* must be DHP, EXP, JPGn, or RESn */
nuclear@0 1086 /* For now, we treat the reserved markers as fatal errors since they are
nuclear@0 1087 * likely to be used to signal incompatible JPEG Part 3 extensions.
nuclear@0 1088 * Once the JPEG 3 version-number marker is well defined, this code
nuclear@0 1089 * ought to change!
nuclear@0 1090 */
nuclear@0 1091 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@0 1092 break;
nuclear@0 1093 }
nuclear@0 1094 /* Successfully processed marker, so reset state variable */
nuclear@0 1095 cinfo->unread_marker = 0;
nuclear@0 1096 } /* end loop */
nuclear@0 1097 }
nuclear@0 1098
nuclear@0 1099
nuclear@0 1100 /*
nuclear@0 1101 * Read a restart marker, which is expected to appear next in the datastream;
nuclear@0 1102 * if the marker is not there, take appropriate recovery action.
nuclear@0 1103 * Returns FALSE if suspension is required.
nuclear@0 1104 *
nuclear@0 1105 * This is called by the entropy decoder after it has read an appropriate
nuclear@0 1106 * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
nuclear@0 1107 * has already read a marker from the data source. Under normal conditions
nuclear@0 1108 * cinfo->unread_marker will be reset to 0 before returning; if not reset,
nuclear@0 1109 * it holds a marker which the decoder will be unable to read past.
nuclear@0 1110 */
nuclear@0 1111
nuclear@0 1112 METHODDEF(boolean)
nuclear@0 1113 read_restart_marker (j_decompress_ptr cinfo)
nuclear@0 1114 {
nuclear@0 1115 /* Obtain a marker unless we already did. */
nuclear@0 1116 /* Note that next_marker will complain if it skips any data. */
nuclear@0 1117 if (cinfo->unread_marker == 0) {
nuclear@0 1118 if (! next_marker(cinfo))
nuclear@0 1119 return FALSE;
nuclear@0 1120 }
nuclear@0 1121
nuclear@0 1122 if (cinfo->unread_marker ==
nuclear@0 1123 ((int) M_RST0 + cinfo->marker->next_restart_num)) {
nuclear@0 1124 /* Normal case --- swallow the marker and let entropy decoder continue */
nuclear@0 1125 TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
nuclear@0 1126 cinfo->unread_marker = 0;
nuclear@0 1127 } else {
nuclear@0 1128 /* Uh-oh, the restart markers have been messed up. */
nuclear@0 1129 /* Let the data source manager determine how to resync. */
nuclear@0 1130 if (! (*cinfo->src->resync_to_restart) (cinfo,
nuclear@0 1131 cinfo->marker->next_restart_num))
nuclear@0 1132 return FALSE;
nuclear@0 1133 }
nuclear@0 1134
nuclear@0 1135 /* Update next-restart state */
nuclear@0 1136 cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
nuclear@0 1137
nuclear@0 1138 return TRUE;
nuclear@0 1139 }
nuclear@0 1140
nuclear@0 1141
nuclear@0 1142 /*
nuclear@0 1143 * This is the default resync_to_restart method for data source managers
nuclear@0 1144 * to use if they don't have any better approach. Some data source managers
nuclear@0 1145 * may be able to back up, or may have additional knowledge about the data
nuclear@0 1146 * which permits a more intelligent recovery strategy; such managers would
nuclear@0 1147 * presumably supply their own resync method.
nuclear@0 1148 *
nuclear@0 1149 * read_restart_marker calls resync_to_restart if it finds a marker other than
nuclear@0 1150 * the restart marker it was expecting. (This code is *not* used unless
nuclear@0 1151 * a nonzero restart interval has been declared.) cinfo->unread_marker is
nuclear@0 1152 * the marker code actually found (might be anything, except 0 or FF).
nuclear@0 1153 * The desired restart marker number (0..7) is passed as a parameter.
nuclear@0 1154 * This routine is supposed to apply whatever error recovery strategy seems
nuclear@0 1155 * appropriate in order to position the input stream to the next data segment.
nuclear@0 1156 * Note that cinfo->unread_marker is treated as a marker appearing before
nuclear@0 1157 * the current data-source input point; usually it should be reset to zero
nuclear@0 1158 * before returning.
nuclear@0 1159 * Returns FALSE if suspension is required.
nuclear@0 1160 *
nuclear@0 1161 * This implementation is substantially constrained by wanting to treat the
nuclear@0 1162 * input as a data stream; this means we can't back up. Therefore, we have
nuclear@0 1163 * only the following actions to work with:
nuclear@0 1164 * 1. Simply discard the marker and let the entropy decoder resume at next
nuclear@0 1165 * byte of file.
nuclear@0 1166 * 2. Read forward until we find another marker, discarding intervening
nuclear@0 1167 * data. (In theory we could look ahead within the current bufferload,
nuclear@0 1168 * without having to discard data if we don't find the desired marker.
nuclear@0 1169 * This idea is not implemented here, in part because it makes behavior
nuclear@0 1170 * dependent on buffer size and chance buffer-boundary positions.)
nuclear@0 1171 * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
nuclear@0 1172 * This will cause the entropy decoder to process an empty data segment,
nuclear@0 1173 * inserting dummy zeroes, and then we will reprocess the marker.
nuclear@0 1174 *
nuclear@0 1175 * #2 is appropriate if we think the desired marker lies ahead, while #3 is
nuclear@0 1176 * appropriate if the found marker is a future restart marker (indicating
nuclear@0 1177 * that we have missed the desired restart marker, probably because it got
nuclear@0 1178 * corrupted).
nuclear@0 1179 * We apply #2 or #3 if the found marker is a restart marker no more than
nuclear@0 1180 * two counts behind or ahead of the expected one. We also apply #2 if the
nuclear@0 1181 * found marker is not a legal JPEG marker code (it's certainly bogus data).
nuclear@0 1182 * If the found marker is a restart marker more than 2 counts away, we do #1
nuclear@0 1183 * (too much risk that the marker is erroneous; with luck we will be able to
nuclear@0 1184 * resync at some future point).
nuclear@0 1185 * For any valid non-restart JPEG marker, we apply #3. This keeps us from
nuclear@0 1186 * overrunning the end of a scan. An implementation limited to single-scan
nuclear@0 1187 * files might find it better to apply #2 for markers other than EOI, since
nuclear@0 1188 * any other marker would have to be bogus data in that case.
nuclear@0 1189 */
nuclear@0 1190
nuclear@0 1191 GLOBAL(boolean)
nuclear@0 1192 jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
nuclear@0 1193 {
nuclear@0 1194 int marker = cinfo->unread_marker;
nuclear@0 1195 int action = 1;
nuclear@0 1196
nuclear@0 1197 /* Always put up a warning. */
nuclear@0 1198 WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
nuclear@0 1199
nuclear@0 1200 /* Outer loop handles repeated decision after scanning forward. */
nuclear@0 1201 for (;;) {
nuclear@0 1202 if (marker < (int) M_SOF0)
nuclear@0 1203 action = 2; /* invalid marker */
nuclear@0 1204 else if (marker < (int) M_RST0 || marker > (int) M_RST7)
nuclear@0 1205 action = 3; /* valid non-restart marker */
nuclear@0 1206 else {
nuclear@0 1207 if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
nuclear@0 1208 marker == ((int) M_RST0 + ((desired+2) & 7)))
nuclear@0 1209 action = 3; /* one of the next two expected restarts */
nuclear@0 1210 else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
nuclear@0 1211 marker == ((int) M_RST0 + ((desired-2) & 7)))
nuclear@0 1212 action = 2; /* a prior restart, so advance */
nuclear@0 1213 else
nuclear@0 1214 action = 1; /* desired restart or too far away */
nuclear@0 1215 }
nuclear@0 1216 TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
nuclear@0 1217 switch (action) {
nuclear@0 1218 case 1:
nuclear@0 1219 /* Discard marker and let entropy decoder resume processing. */
nuclear@0 1220 cinfo->unread_marker = 0;
nuclear@0 1221 return TRUE;
nuclear@0 1222 case 2:
nuclear@0 1223 /* Scan to the next marker, and repeat the decision loop. */
nuclear@0 1224 if (! next_marker(cinfo))
nuclear@0 1225 return FALSE;
nuclear@0 1226 marker = cinfo->unread_marker;
nuclear@0 1227 break;
nuclear@0 1228 case 3:
nuclear@0 1229 /* Return without advancing past this marker. */
nuclear@0 1230 /* Entropy decoder will be forced to process an empty segment. */
nuclear@0 1231 return TRUE;
nuclear@0 1232 }
nuclear@0 1233 } /* end loop */
nuclear@0 1234 }
nuclear@0 1235
nuclear@0 1236
nuclear@0 1237 /*
nuclear@0 1238 * Reset marker processing state to begin a fresh datastream.
nuclear@0 1239 */
nuclear@0 1240
nuclear@0 1241 METHODDEF(void)
nuclear@0 1242 reset_marker_reader (j_decompress_ptr cinfo)
nuclear@0 1243 {
nuclear@0 1244 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 1245
nuclear@0 1246 cinfo->comp_info = NULL; /* until allocated by get_sof */
nuclear@0 1247 cinfo->input_scan_number = 0; /* no SOS seen yet */
nuclear@0 1248 cinfo->unread_marker = 0; /* no pending marker */
nuclear@0 1249 marker->pub.saw_SOI = FALSE; /* set internal state too */
nuclear@0 1250 marker->pub.saw_SOF = FALSE;
nuclear@0 1251 marker->pub.discarded_bytes = 0;
nuclear@0 1252 marker->cur_marker = NULL;
nuclear@0 1253 }
nuclear@0 1254
nuclear@0 1255
nuclear@0 1256 /*
nuclear@0 1257 * Initialize the marker reader module.
nuclear@0 1258 * This is called only once, when the decompression object is created.
nuclear@0 1259 */
nuclear@0 1260
nuclear@0 1261 GLOBAL(void)
nuclear@0 1262 jinit_marker_reader (j_decompress_ptr cinfo)
nuclear@0 1263 {
nuclear@0 1264 my_marker_ptr marker;
nuclear@0 1265 int i;
nuclear@0 1266
nuclear@0 1267 /* Create subobject in permanent pool */
nuclear@0 1268 marker = (my_marker_ptr)
nuclear@0 1269 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
nuclear@0 1270 SIZEOF(my_marker_reader));
nuclear@0 1271 cinfo->marker = (struct jpeg_marker_reader *) marker;
nuclear@0 1272 /* Initialize public method pointers */
nuclear@0 1273 marker->pub.reset_marker_reader = reset_marker_reader;
nuclear@0 1274 marker->pub.read_markers = read_markers;
nuclear@0 1275 marker->pub.read_restart_marker = read_restart_marker;
nuclear@0 1276 /* Initialize COM/APPn processing.
nuclear@0 1277 * By default, we examine and then discard APP0 and APP14,
nuclear@0 1278 * but simply discard COM and all other APPn.
nuclear@0 1279 */
nuclear@0 1280 marker->process_COM = skip_variable;
nuclear@0 1281 marker->length_limit_COM = 0;
nuclear@0 1282 for (i = 0; i < 16; i++) {
nuclear@0 1283 marker->process_APPn[i] = skip_variable;
nuclear@0 1284 marker->length_limit_APPn[i] = 0;
nuclear@0 1285 }
nuclear@0 1286 marker->process_APPn[0] = get_interesting_appn;
nuclear@0 1287 marker->process_APPn[14] = get_interesting_appn;
nuclear@0 1288 /* Reset marker processing state */
nuclear@0 1289 reset_marker_reader(cinfo);
nuclear@0 1290 }
nuclear@0 1291
nuclear@0 1292
nuclear@0 1293 /*
nuclear@0 1294 * Control saving of COM and APPn markers into marker_list.
nuclear@0 1295 */
nuclear@0 1296
nuclear@0 1297 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@0 1298
nuclear@0 1299 GLOBAL(void)
nuclear@0 1300 jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
nuclear@0 1301 unsigned int length_limit)
nuclear@0 1302 {
nuclear@0 1303 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 1304 long maxlength;
nuclear@0 1305 jpeg_marker_parser_method processor;
nuclear@0 1306
nuclear@0 1307 /* Length limit mustn't be larger than what we can allocate
nuclear@0 1308 * (should only be a concern in a 16-bit environment).
nuclear@0 1309 */
nuclear@0 1310 maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
nuclear@0 1311 if (((long) length_limit) > maxlength)
nuclear@0 1312 length_limit = (unsigned int) maxlength;
nuclear@0 1313
nuclear@0 1314 /* Choose processor routine to use.
nuclear@0 1315 * APP0/APP14 have special requirements.
nuclear@0 1316 */
nuclear@0 1317 if (length_limit) {
nuclear@0 1318 processor = save_marker;
nuclear@0 1319 /* If saving APP0/APP14, save at least enough for our internal use. */
nuclear@0 1320 if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
nuclear@0 1321 length_limit = APP0_DATA_LEN;
nuclear@0 1322 else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
nuclear@0 1323 length_limit = APP14_DATA_LEN;
nuclear@0 1324 } else {
nuclear@0 1325 processor = skip_variable;
nuclear@0 1326 /* If discarding APP0/APP14, use our regular on-the-fly processor. */
nuclear@0 1327 if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
nuclear@0 1328 processor = get_interesting_appn;
nuclear@0 1329 }
nuclear@0 1330
nuclear@0 1331 if (marker_code == (int) M_COM) {
nuclear@0 1332 marker->process_COM = processor;
nuclear@0 1333 marker->length_limit_COM = length_limit;
nuclear@0 1334 } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
nuclear@0 1335 marker->process_APPn[marker_code - (int) M_APP0] = processor;
nuclear@0 1336 marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
nuclear@0 1337 } else
nuclear@0 1338 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@0 1339 }
nuclear@0 1340
nuclear@0 1341 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@0 1342
nuclear@0 1343
nuclear@0 1344 /*
nuclear@0 1345 * Install a special processing method for COM or APPn markers.
nuclear@0 1346 */
nuclear@0 1347
nuclear@0 1348 GLOBAL(void)
nuclear@0 1349 jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
nuclear@0 1350 jpeg_marker_parser_method routine)
nuclear@0 1351 {
nuclear@0 1352 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 1353
nuclear@0 1354 if (marker_code == (int) M_COM)
nuclear@0 1355 marker->process_COM = routine;
nuclear@0 1356 else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
nuclear@0 1357 marker->process_APPn[marker_code - (int) M_APP0] = routine;
nuclear@0 1358 else
nuclear@0 1359 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@0 1360 }