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