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annotate libs/libjpeg/jdmarker.c @ 15:2d48f65da357

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assman
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 07 Jun 2015 20:40:37 +0300
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nuclear@14 1 /*
nuclear@14 2 * jdmarker.c
nuclear@14 3 *
nuclear@14 4 * Copyright (C) 1991-1998, Thomas G. Lane.
nuclear@14 5 * This file is part of the Independent JPEG Group's software.
nuclear@14 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@14 7 *
nuclear@14 8 * This file contains routines to decode JPEG datastream markers.
nuclear@14 9 * Most of the complexity arises from our desire to support input
nuclear@14 10 * suspension: if not all of the data for a marker is available,
nuclear@14 11 * we must exit back to the application. On resumption, we reprocess
nuclear@14 12 * the marker.
nuclear@14 13 */
nuclear@14 14
nuclear@14 15 #define JPEG_INTERNALS
nuclear@14 16 #include "jinclude.h"
nuclear@14 17 #include "jpeglib.h"
nuclear@14 18
nuclear@14 19
nuclear@14 20 typedef enum { /* JPEG marker codes */
nuclear@14 21 M_SOF0 = 0xc0,
nuclear@14 22 M_SOF1 = 0xc1,
nuclear@14 23 M_SOF2 = 0xc2,
nuclear@14 24 M_SOF3 = 0xc3,
nuclear@14 25
nuclear@14 26 M_SOF5 = 0xc5,
nuclear@14 27 M_SOF6 = 0xc6,
nuclear@14 28 M_SOF7 = 0xc7,
nuclear@14 29
nuclear@14 30 M_JPG = 0xc8,
nuclear@14 31 M_SOF9 = 0xc9,
nuclear@14 32 M_SOF10 = 0xca,
nuclear@14 33 M_SOF11 = 0xcb,
nuclear@14 34
nuclear@14 35 M_SOF13 = 0xcd,
nuclear@14 36 M_SOF14 = 0xce,
nuclear@14 37 M_SOF15 = 0xcf,
nuclear@14 38
nuclear@14 39 M_DHT = 0xc4,
nuclear@14 40
nuclear@14 41 M_DAC = 0xcc,
nuclear@14 42
nuclear@14 43 M_RST0 = 0xd0,
nuclear@14 44 M_RST1 = 0xd1,
nuclear@14 45 M_RST2 = 0xd2,
nuclear@14 46 M_RST3 = 0xd3,
nuclear@14 47 M_RST4 = 0xd4,
nuclear@14 48 M_RST5 = 0xd5,
nuclear@14 49 M_RST6 = 0xd6,
nuclear@14 50 M_RST7 = 0xd7,
nuclear@14 51
nuclear@14 52 M_SOI = 0xd8,
nuclear@14 53 M_EOI = 0xd9,
nuclear@14 54 M_SOS = 0xda,
nuclear@14 55 M_DQT = 0xdb,
nuclear@14 56 M_DNL = 0xdc,
nuclear@14 57 M_DRI = 0xdd,
nuclear@14 58 M_DHP = 0xde,
nuclear@14 59 M_EXP = 0xdf,
nuclear@14 60
nuclear@14 61 M_APP0 = 0xe0,
nuclear@14 62 M_APP1 = 0xe1,
nuclear@14 63 M_APP2 = 0xe2,
nuclear@14 64 M_APP3 = 0xe3,
nuclear@14 65 M_APP4 = 0xe4,
nuclear@14 66 M_APP5 = 0xe5,
nuclear@14 67 M_APP6 = 0xe6,
nuclear@14 68 M_APP7 = 0xe7,
nuclear@14 69 M_APP8 = 0xe8,
nuclear@14 70 M_APP9 = 0xe9,
nuclear@14 71 M_APP10 = 0xea,
nuclear@14 72 M_APP11 = 0xeb,
nuclear@14 73 M_APP12 = 0xec,
nuclear@14 74 M_APP13 = 0xed,
nuclear@14 75 M_APP14 = 0xee,
nuclear@14 76 M_APP15 = 0xef,
nuclear@14 77
nuclear@14 78 M_JPG0 = 0xf0,
nuclear@14 79 M_JPG13 = 0xfd,
nuclear@14 80 M_COM = 0xfe,
nuclear@14 81
nuclear@14 82 M_TEM = 0x01,
nuclear@14 83
nuclear@14 84 M_ERROR = 0x100
nuclear@14 85 } JPEG_MARKER;
nuclear@14 86
nuclear@14 87
nuclear@14 88 /* Private state */
nuclear@14 89
nuclear@14 90 typedef struct {
nuclear@14 91 struct jpeg_marker_reader pub; /* public fields */
nuclear@14 92
nuclear@14 93 /* Application-overridable marker processing methods */
nuclear@14 94 jpeg_marker_parser_method process_COM;
nuclear@14 95 jpeg_marker_parser_method process_APPn[16];
nuclear@14 96
nuclear@14 97 /* Limit on marker data length to save for each marker type */
nuclear@14 98 unsigned int length_limit_COM;
nuclear@14 99 unsigned int length_limit_APPn[16];
nuclear@14 100
nuclear@14 101 /* Status of COM/APPn marker saving */
nuclear@14 102 jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
nuclear@14 103 unsigned int bytes_read; /* data bytes read so far in marker */
nuclear@14 104 /* Note: cur_marker is not linked into marker_list until it's all read. */
nuclear@14 105 } my_marker_reader;
nuclear@14 106
nuclear@14 107 typedef my_marker_reader * my_marker_ptr;
nuclear@14 108
nuclear@14 109
nuclear@14 110 /*
nuclear@14 111 * Macros for fetching data from the data source module.
nuclear@14 112 *
nuclear@14 113 * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
nuclear@14 114 * the current restart point; we update them only when we have reached a
nuclear@14 115 * suitable place to restart if a suspension occurs.
nuclear@14 116 */
nuclear@14 117
nuclear@14 118 /* Declare and initialize local copies of input pointer/count */
nuclear@14 119 #define INPUT_VARS(cinfo) \
nuclear@14 120 struct jpeg_source_mgr * datasrc = (cinfo)->src; \
nuclear@14 121 const JOCTET * next_input_byte = datasrc->next_input_byte; \
nuclear@14 122 size_t bytes_in_buffer = datasrc->bytes_in_buffer
nuclear@14 123
nuclear@14 124 /* Unload the local copies --- do this only at a restart boundary */
nuclear@14 125 #define INPUT_SYNC(cinfo) \
nuclear@14 126 ( datasrc->next_input_byte = next_input_byte, \
nuclear@14 127 datasrc->bytes_in_buffer = bytes_in_buffer )
nuclear@14 128
nuclear@14 129 /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
nuclear@14 130 #define INPUT_RELOAD(cinfo) \
nuclear@14 131 ( next_input_byte = datasrc->next_input_byte, \
nuclear@14 132 bytes_in_buffer = datasrc->bytes_in_buffer )
nuclear@14 133
nuclear@14 134 /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
nuclear@14 135 * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
nuclear@14 136 * but we must reload the local copies after a successful fill.
nuclear@14 137 */
nuclear@14 138 #define MAKE_BYTE_AVAIL(cinfo,action) \
nuclear@14 139 if (bytes_in_buffer == 0) { \
nuclear@14 140 if (! (*datasrc->fill_input_buffer) (cinfo)) \
nuclear@14 141 { action; } \
nuclear@14 142 INPUT_RELOAD(cinfo); \
nuclear@14 143 }
nuclear@14 144
nuclear@14 145 /* Read a byte into variable V.
nuclear@14 146 * If must suspend, take the specified action (typically "return FALSE").
nuclear@14 147 */
nuclear@14 148 #define INPUT_BYTE(cinfo,V,action) \
nuclear@14 149 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@14 150 bytes_in_buffer--; \
nuclear@14 151 V = GETJOCTET(*next_input_byte++); )
nuclear@14 152
nuclear@14 153 /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
nuclear@14 154 * V should be declared unsigned int or perhaps INT32.
nuclear@14 155 */
nuclear@14 156 #define INPUT_2BYTES(cinfo,V,action) \
nuclear@14 157 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@14 158 bytes_in_buffer--; \
nuclear@14 159 V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
nuclear@14 160 MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@14 161 bytes_in_buffer--; \
nuclear@14 162 V += GETJOCTET(*next_input_byte++); )
nuclear@14 163
nuclear@14 164
nuclear@14 165 /*
nuclear@14 166 * Routines to process JPEG markers.
nuclear@14 167 *
nuclear@14 168 * Entry condition: JPEG marker itself has been read and its code saved
nuclear@14 169 * in cinfo->unread_marker; input restart point is just after the marker.
nuclear@14 170 *
nuclear@14 171 * Exit: if return TRUE, have read and processed any parameters, and have
nuclear@14 172 * updated the restart point to point after the parameters.
nuclear@14 173 * If return FALSE, was forced to suspend before reaching end of
nuclear@14 174 * marker parameters; restart point has not been moved. Same routine
nuclear@14 175 * will be called again after application supplies more input data.
nuclear@14 176 *
nuclear@14 177 * This approach to suspension assumes that all of a marker's parameters
nuclear@14 178 * can fit into a single input bufferload. This should hold for "normal"
nuclear@14 179 * markers. Some COM/APPn markers might have large parameter segments
nuclear@14 180 * that might not fit. If we are simply dropping such a marker, we use
nuclear@14 181 * skip_input_data to get past it, and thereby put the problem on the
nuclear@14 182 * source manager's shoulders. If we are saving the marker's contents
nuclear@14 183 * into memory, we use a slightly different convention: when forced to
nuclear@14 184 * suspend, the marker processor updates the restart point to the end of
nuclear@14 185 * what it's consumed (ie, the end of the buffer) before returning FALSE.
nuclear@14 186 * On resumption, cinfo->unread_marker still contains the marker code,
nuclear@14 187 * but the data source will point to the next chunk of marker data.
nuclear@14 188 * The marker processor must retain internal state to deal with this.
nuclear@14 189 *
nuclear@14 190 * Note that we don't bother to avoid duplicate trace messages if a
nuclear@14 191 * suspension occurs within marker parameters. Other side effects
nuclear@14 192 * require more care.
nuclear@14 193 */
nuclear@14 194
nuclear@14 195
nuclear@14 196 LOCAL(boolean)
nuclear@14 197 get_soi (j_decompress_ptr cinfo)
nuclear@14 198 /* Process an SOI marker */
nuclear@14 199 {
nuclear@14 200 int i;
nuclear@14 201
nuclear@14 202 TRACEMS(cinfo, 1, JTRC_SOI);
nuclear@14 203
nuclear@14 204 if (cinfo->marker->saw_SOI)
nuclear@14 205 ERREXIT(cinfo, JERR_SOI_DUPLICATE);
nuclear@14 206
nuclear@14 207 /* Reset all parameters that are defined to be reset by SOI */
nuclear@14 208
nuclear@14 209 for (i = 0; i < NUM_ARITH_TBLS; i++) {
nuclear@14 210 cinfo->arith_dc_L[i] = 0;
nuclear@14 211 cinfo->arith_dc_U[i] = 1;
nuclear@14 212 cinfo->arith_ac_K[i] = 5;
nuclear@14 213 }
nuclear@14 214 cinfo->restart_interval = 0;
nuclear@14 215
nuclear@14 216 /* Set initial assumptions for colorspace etc */
nuclear@14 217
nuclear@14 218 cinfo->jpeg_color_space = JCS_UNKNOWN;
nuclear@14 219 cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
nuclear@14 220
nuclear@14 221 cinfo->saw_JFIF_marker = FALSE;
nuclear@14 222 cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
nuclear@14 223 cinfo->JFIF_minor_version = 1;
nuclear@14 224 cinfo->density_unit = 0;
nuclear@14 225 cinfo->X_density = 1;
nuclear@14 226 cinfo->Y_density = 1;
nuclear@14 227 cinfo->saw_Adobe_marker = FALSE;
nuclear@14 228 cinfo->Adobe_transform = 0;
nuclear@14 229
nuclear@14 230 cinfo->marker->saw_SOI = TRUE;
nuclear@14 231
nuclear@14 232 return TRUE;
nuclear@14 233 }
nuclear@14 234
nuclear@14 235
nuclear@14 236 LOCAL(boolean)
nuclear@14 237 get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
nuclear@14 238 /* Process a SOFn marker */
nuclear@14 239 {
nuclear@14 240 INT32 length;
nuclear@14 241 int c, ci;
nuclear@14 242 jpeg_component_info * compptr;
nuclear@14 243 INPUT_VARS(cinfo);
nuclear@14 244
nuclear@14 245 cinfo->progressive_mode = is_prog;
nuclear@14 246 cinfo->arith_code = is_arith;
nuclear@14 247
nuclear@14 248 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 249
nuclear@14 250 INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
nuclear@14 251 INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
nuclear@14 252 INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
nuclear@14 253 INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
nuclear@14 254
nuclear@14 255 length -= 8;
nuclear@14 256
nuclear@14 257 TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
nuclear@14 258 (int) cinfo->image_width, (int) cinfo->image_height,
nuclear@14 259 cinfo->num_components);
nuclear@14 260
nuclear@14 261 if (cinfo->marker->saw_SOF)
nuclear@14 262 ERREXIT(cinfo, JERR_SOF_DUPLICATE);
nuclear@14 263
nuclear@14 264 /* We don't support files in which the image height is initially specified */
nuclear@14 265 /* as 0 and is later redefined by DNL. As long as we have to check that, */
nuclear@14 266 /* might as well have a general sanity check. */
nuclear@14 267 if (cinfo->image_height <= 0 || cinfo->image_width <= 0
nuclear@14 268 || cinfo->num_components <= 0)
nuclear@14 269 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
nuclear@14 270
nuclear@14 271 if (length != (cinfo->num_components * 3))
nuclear@14 272 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 273
nuclear@14 274 if (cinfo->comp_info == NULL) /* do only once, even if suspend */
nuclear@14 275 cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
nuclear@14 276 ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@14 277 cinfo->num_components * SIZEOF(jpeg_component_info));
nuclear@14 278
nuclear@14 279 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@14 280 ci++, compptr++) {
nuclear@14 281 compptr->component_index = ci;
nuclear@14 282 INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
nuclear@14 283 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 284 compptr->h_samp_factor = (c >> 4) & 15;
nuclear@14 285 compptr->v_samp_factor = (c ) & 15;
nuclear@14 286 INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
nuclear@14 287
nuclear@14 288 TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
nuclear@14 289 compptr->component_id, compptr->h_samp_factor,
nuclear@14 290 compptr->v_samp_factor, compptr->quant_tbl_no);
nuclear@14 291 }
nuclear@14 292
nuclear@14 293 cinfo->marker->saw_SOF = TRUE;
nuclear@14 294
nuclear@14 295 INPUT_SYNC(cinfo);
nuclear@14 296 return TRUE;
nuclear@14 297 }
nuclear@14 298
nuclear@14 299
nuclear@14 300 LOCAL(boolean)
nuclear@14 301 get_sos (j_decompress_ptr cinfo)
nuclear@14 302 /* Process a SOS marker */
nuclear@14 303 {
nuclear@14 304 INT32 length;
nuclear@14 305 int i, ci, n, c, cc;
nuclear@14 306 jpeg_component_info * compptr;
nuclear@14 307 INPUT_VARS(cinfo);
nuclear@14 308
nuclear@14 309 if (! cinfo->marker->saw_SOF)
nuclear@14 310 ERREXIT(cinfo, JERR_SOS_NO_SOF);
nuclear@14 311
nuclear@14 312 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 313
nuclear@14 314 INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
nuclear@14 315
nuclear@14 316 TRACEMS1(cinfo, 1, JTRC_SOS, n);
nuclear@14 317
nuclear@14 318 if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
nuclear@14 319 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 320
nuclear@14 321 cinfo->comps_in_scan = n;
nuclear@14 322
nuclear@14 323 /* Collect the component-spec parameters */
nuclear@14 324
nuclear@14 325 for (i = 0; i < n; i++) {
nuclear@14 326 INPUT_BYTE(cinfo, cc, return FALSE);
nuclear@14 327 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 328
nuclear@14 329 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@14 330 ci++, compptr++) {
nuclear@14 331 if (cc == compptr->component_id)
nuclear@14 332 goto id_found;
nuclear@14 333 }
nuclear@14 334
nuclear@14 335 ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
nuclear@14 336
nuclear@14 337 id_found:
nuclear@14 338
nuclear@14 339 cinfo->cur_comp_info[i] = compptr;
nuclear@14 340 compptr->dc_tbl_no = (c >> 4) & 15;
nuclear@14 341 compptr->ac_tbl_no = (c ) & 15;
nuclear@14 342
nuclear@14 343 TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
nuclear@14 344 compptr->dc_tbl_no, compptr->ac_tbl_no);
nuclear@14 345 }
nuclear@14 346
nuclear@14 347 /* Collect the additional scan parameters Ss, Se, Ah/Al. */
nuclear@14 348 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 349 cinfo->Ss = c;
nuclear@14 350 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 351 cinfo->Se = c;
nuclear@14 352 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 353 cinfo->Ah = (c >> 4) & 15;
nuclear@14 354 cinfo->Al = (c ) & 15;
nuclear@14 355
nuclear@14 356 TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
nuclear@14 357 cinfo->Ah, cinfo->Al);
nuclear@14 358
nuclear@14 359 /* Prepare to scan data & restart markers */
nuclear@14 360 cinfo->marker->next_restart_num = 0;
nuclear@14 361
nuclear@14 362 /* Count another SOS marker */
nuclear@14 363 cinfo->input_scan_number++;
nuclear@14 364
nuclear@14 365 INPUT_SYNC(cinfo);
nuclear@14 366 return TRUE;
nuclear@14 367 }
nuclear@14 368
nuclear@14 369
nuclear@14 370 #ifdef D_ARITH_CODING_SUPPORTED
nuclear@14 371
nuclear@14 372 LOCAL(boolean)
nuclear@14 373 get_dac (j_decompress_ptr cinfo)
nuclear@14 374 /* Process a DAC marker */
nuclear@14 375 {
nuclear@14 376 INT32 length;
nuclear@14 377 int index, val;
nuclear@14 378 INPUT_VARS(cinfo);
nuclear@14 379
nuclear@14 380 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 381 length -= 2;
nuclear@14 382
nuclear@14 383 while (length > 0) {
nuclear@14 384 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@14 385 INPUT_BYTE(cinfo, val, return FALSE);
nuclear@14 386
nuclear@14 387 length -= 2;
nuclear@14 388
nuclear@14 389 TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
nuclear@14 390
nuclear@14 391 if (index < 0 || index >= (2*NUM_ARITH_TBLS))
nuclear@14 392 ERREXIT1(cinfo, JERR_DAC_INDEX, index);
nuclear@14 393
nuclear@14 394 if (index >= NUM_ARITH_TBLS) { /* define AC table */
nuclear@14 395 cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
nuclear@14 396 } else { /* define DC table */
nuclear@14 397 cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
nuclear@14 398 cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
nuclear@14 399 if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
nuclear@14 400 ERREXIT1(cinfo, JERR_DAC_VALUE, val);
nuclear@14 401 }
nuclear@14 402 }
nuclear@14 403
nuclear@14 404 if (length != 0)
nuclear@14 405 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 406
nuclear@14 407 INPUT_SYNC(cinfo);
nuclear@14 408 return TRUE;
nuclear@14 409 }
nuclear@14 410
nuclear@14 411 #else /* ! D_ARITH_CODING_SUPPORTED */
nuclear@14 412
nuclear@14 413 #define get_dac(cinfo) skip_variable(cinfo)
nuclear@14 414
nuclear@14 415 #endif /* D_ARITH_CODING_SUPPORTED */
nuclear@14 416
nuclear@14 417
nuclear@14 418 LOCAL(boolean)
nuclear@14 419 get_dht (j_decompress_ptr cinfo)
nuclear@14 420 /* Process a DHT marker */
nuclear@14 421 {
nuclear@14 422 INT32 length;
nuclear@14 423 UINT8 bits[17];
nuclear@14 424 UINT8 huffval[256];
nuclear@14 425 int i, index, count;
nuclear@14 426 JHUFF_TBL **htblptr;
nuclear@14 427 INPUT_VARS(cinfo);
nuclear@14 428
nuclear@14 429 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 430 length -= 2;
nuclear@14 431
nuclear@14 432 while (length > 16) {
nuclear@14 433 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@14 434
nuclear@14 435 TRACEMS1(cinfo, 1, JTRC_DHT, index);
nuclear@14 436
nuclear@14 437 bits[0] = 0;
nuclear@14 438 count = 0;
nuclear@14 439 for (i = 1; i <= 16; i++) {
nuclear@14 440 INPUT_BYTE(cinfo, bits[i], return FALSE);
nuclear@14 441 count += bits[i];
nuclear@14 442 }
nuclear@14 443
nuclear@14 444 length -= 1 + 16;
nuclear@14 445
nuclear@14 446 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@14 447 bits[1], bits[2], bits[3], bits[4],
nuclear@14 448 bits[5], bits[6], bits[7], bits[8]);
nuclear@14 449 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@14 450 bits[9], bits[10], bits[11], bits[12],
nuclear@14 451 bits[13], bits[14], bits[15], bits[16]);
nuclear@14 452
nuclear@14 453 /* Here we just do minimal validation of the counts to avoid walking
nuclear@14 454 * off the end of our table space. jdhuff.c will check more carefully.
nuclear@14 455 */
nuclear@14 456 if (count > 256 || ((INT32) count) > length)
nuclear@14 457 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
nuclear@14 458
nuclear@14 459 for (i = 0; i < count; i++)
nuclear@14 460 INPUT_BYTE(cinfo, huffval[i], return FALSE);
nuclear@14 461
nuclear@14 462 length -= count;
nuclear@14 463
nuclear@14 464 if (index & 0x10) { /* AC table definition */
nuclear@14 465 index -= 0x10;
nuclear@14 466 htblptr = &cinfo->ac_huff_tbl_ptrs[index];
nuclear@14 467 } else { /* DC table definition */
nuclear@14 468 htblptr = &cinfo->dc_huff_tbl_ptrs[index];
nuclear@14 469 }
nuclear@14 470
nuclear@14 471 if (index < 0 || index >= NUM_HUFF_TBLS)
nuclear@14 472 ERREXIT1(cinfo, JERR_DHT_INDEX, index);
nuclear@14 473
nuclear@14 474 if (*htblptr == NULL)
nuclear@14 475 *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
nuclear@14 476
nuclear@14 477 MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
nuclear@14 478 MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
nuclear@14 479 }
nuclear@14 480
nuclear@14 481 if (length != 0)
nuclear@14 482 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 483
nuclear@14 484 INPUT_SYNC(cinfo);
nuclear@14 485 return TRUE;
nuclear@14 486 }
nuclear@14 487
nuclear@14 488
nuclear@14 489 LOCAL(boolean)
nuclear@14 490 get_dqt (j_decompress_ptr cinfo)
nuclear@14 491 /* Process a DQT marker */
nuclear@14 492 {
nuclear@14 493 INT32 length;
nuclear@14 494 int n, i, prec;
nuclear@14 495 unsigned int tmp;
nuclear@14 496 JQUANT_TBL *quant_ptr;
nuclear@14 497 INPUT_VARS(cinfo);
nuclear@14 498
nuclear@14 499 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 500 length -= 2;
nuclear@14 501
nuclear@14 502 while (length > 0) {
nuclear@14 503 INPUT_BYTE(cinfo, n, return FALSE);
nuclear@14 504 prec = n >> 4;
nuclear@14 505 n &= 0x0F;
nuclear@14 506
nuclear@14 507 TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
nuclear@14 508
nuclear@14 509 if (n >= NUM_QUANT_TBLS)
nuclear@14 510 ERREXIT1(cinfo, JERR_DQT_INDEX, n);
nuclear@14 511
nuclear@14 512 if (cinfo->quant_tbl_ptrs[n] == NULL)
nuclear@14 513 cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
nuclear@14 514 quant_ptr = cinfo->quant_tbl_ptrs[n];
nuclear@14 515
nuclear@14 516 for (i = 0; i < DCTSIZE2; i++) {
nuclear@14 517 if (prec)
nuclear@14 518 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@14 519 else
nuclear@14 520 INPUT_BYTE(cinfo, tmp, return FALSE);
nuclear@14 521 /* We convert the zigzag-order table to natural array order. */
nuclear@14 522 quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
nuclear@14 523 }
nuclear@14 524
nuclear@14 525 if (cinfo->err->trace_level >= 2) {
nuclear@14 526 for (i = 0; i < DCTSIZE2; i += 8) {
nuclear@14 527 TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
nuclear@14 528 quant_ptr->quantval[i], quant_ptr->quantval[i+1],
nuclear@14 529 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
nuclear@14 530 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
nuclear@14 531 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
nuclear@14 532 }
nuclear@14 533 }
nuclear@14 534
nuclear@14 535 length -= DCTSIZE2+1;
nuclear@14 536 if (prec) length -= DCTSIZE2;
nuclear@14 537 }
nuclear@14 538
nuclear@14 539 if (length != 0)
nuclear@14 540 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 541
nuclear@14 542 INPUT_SYNC(cinfo);
nuclear@14 543 return TRUE;
nuclear@14 544 }
nuclear@14 545
nuclear@14 546
nuclear@14 547 LOCAL(boolean)
nuclear@14 548 get_dri (j_decompress_ptr cinfo)
nuclear@14 549 /* Process a DRI marker */
nuclear@14 550 {
nuclear@14 551 INT32 length;
nuclear@14 552 unsigned int tmp;
nuclear@14 553 INPUT_VARS(cinfo);
nuclear@14 554
nuclear@14 555 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 556
nuclear@14 557 if (length != 4)
nuclear@14 558 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@14 559
nuclear@14 560 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@14 561
nuclear@14 562 TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
nuclear@14 563
nuclear@14 564 cinfo->restart_interval = tmp;
nuclear@14 565
nuclear@14 566 INPUT_SYNC(cinfo);
nuclear@14 567 return TRUE;
nuclear@14 568 }
nuclear@14 569
nuclear@14 570
nuclear@14 571 /*
nuclear@14 572 * Routines for processing APPn and COM markers.
nuclear@14 573 * These are either saved in memory or discarded, per application request.
nuclear@14 574 * APP0 and APP14 are specially checked to see if they are
nuclear@14 575 * JFIF and Adobe markers, respectively.
nuclear@14 576 */
nuclear@14 577
nuclear@14 578 #define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
nuclear@14 579 #define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
nuclear@14 580 #define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
nuclear@14 581
nuclear@14 582
nuclear@14 583 LOCAL(void)
nuclear@14 584 examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@14 585 unsigned int datalen, INT32 remaining)
nuclear@14 586 /* Examine first few bytes from an APP0.
nuclear@14 587 * Take appropriate action if it is a JFIF marker.
nuclear@14 588 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@14 589 */
nuclear@14 590 {
nuclear@14 591 INT32 totallen = (INT32) datalen + remaining;
nuclear@14 592
nuclear@14 593 if (datalen >= APP0_DATA_LEN &&
nuclear@14 594 GETJOCTET(data[0]) == 0x4A &&
nuclear@14 595 GETJOCTET(data[1]) == 0x46 &&
nuclear@14 596 GETJOCTET(data[2]) == 0x49 &&
nuclear@14 597 GETJOCTET(data[3]) == 0x46 &&
nuclear@14 598 GETJOCTET(data[4]) == 0) {
nuclear@14 599 /* Found JFIF APP0 marker: save info */
nuclear@14 600 cinfo->saw_JFIF_marker = TRUE;
nuclear@14 601 cinfo->JFIF_major_version = GETJOCTET(data[5]);
nuclear@14 602 cinfo->JFIF_minor_version = GETJOCTET(data[6]);
nuclear@14 603 cinfo->density_unit = GETJOCTET(data[7]);
nuclear@14 604 cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
nuclear@14 605 cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
nuclear@14 606 /* Check version.
nuclear@14 607 * Major version must be 1, anything else signals an incompatible change.
nuclear@14 608 * (We used to treat this as an error, but now it's a nonfatal warning,
nuclear@14 609 * because some bozo at Hijaak couldn't read the spec.)
nuclear@14 610 * Minor version should be 0..2, but process anyway if newer.
nuclear@14 611 */
nuclear@14 612 if (cinfo->JFIF_major_version != 1)
nuclear@14 613 WARNMS2(cinfo, JWRN_JFIF_MAJOR,
nuclear@14 614 cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
nuclear@14 615 /* Generate trace messages */
nuclear@14 616 TRACEMS5(cinfo, 1, JTRC_JFIF,
nuclear@14 617 cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
nuclear@14 618 cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
nuclear@14 619 /* Validate thumbnail dimensions and issue appropriate messages */
nuclear@14 620 if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
nuclear@14 621 TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
nuclear@14 622 GETJOCTET(data[12]), GETJOCTET(data[13]));
nuclear@14 623 totallen -= APP0_DATA_LEN;
nuclear@14 624 if (totallen !=
nuclear@14 625 ((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
nuclear@14 626 TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
nuclear@14 627 } else if (datalen >= 6 &&
nuclear@14 628 GETJOCTET(data[0]) == 0x4A &&
nuclear@14 629 GETJOCTET(data[1]) == 0x46 &&
nuclear@14 630 GETJOCTET(data[2]) == 0x58 &&
nuclear@14 631 GETJOCTET(data[3]) == 0x58 &&
nuclear@14 632 GETJOCTET(data[4]) == 0) {
nuclear@14 633 /* Found JFIF "JFXX" extension APP0 marker */
nuclear@14 634 /* The library doesn't actually do anything with these,
nuclear@14 635 * but we try to produce a helpful trace message.
nuclear@14 636 */
nuclear@14 637 switch (GETJOCTET(data[5])) {
nuclear@14 638 case 0x10:
nuclear@14 639 TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
nuclear@14 640 break;
nuclear@14 641 case 0x11:
nuclear@14 642 TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
nuclear@14 643 break;
nuclear@14 644 case 0x13:
nuclear@14 645 TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
nuclear@14 646 break;
nuclear@14 647 default:
nuclear@14 648 TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
nuclear@14 649 GETJOCTET(data[5]), (int) totallen);
nuclear@14 650 break;
nuclear@14 651 }
nuclear@14 652 } else {
nuclear@14 653 /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
nuclear@14 654 TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
nuclear@14 655 }
nuclear@14 656 }
nuclear@14 657
nuclear@14 658
nuclear@14 659 LOCAL(void)
nuclear@14 660 examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@14 661 unsigned int datalen, INT32 remaining)
nuclear@14 662 /* Examine first few bytes from an APP14.
nuclear@14 663 * Take appropriate action if it is an Adobe marker.
nuclear@14 664 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@14 665 */
nuclear@14 666 {
nuclear@14 667 unsigned int version, flags0, flags1, transform;
nuclear@14 668
nuclear@14 669 if (datalen >= APP14_DATA_LEN &&
nuclear@14 670 GETJOCTET(data[0]) == 0x41 &&
nuclear@14 671 GETJOCTET(data[1]) == 0x64 &&
nuclear@14 672 GETJOCTET(data[2]) == 0x6F &&
nuclear@14 673 GETJOCTET(data[3]) == 0x62 &&
nuclear@14 674 GETJOCTET(data[4]) == 0x65) {
nuclear@14 675 /* Found Adobe APP14 marker */
nuclear@14 676 version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
nuclear@14 677 flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
nuclear@14 678 flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
nuclear@14 679 transform = GETJOCTET(data[11]);
nuclear@14 680 TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
nuclear@14 681 cinfo->saw_Adobe_marker = TRUE;
nuclear@14 682 cinfo->Adobe_transform = (UINT8) transform;
nuclear@14 683 } else {
nuclear@14 684 /* Start of APP14 does not match "Adobe", or too short */
nuclear@14 685 TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
nuclear@14 686 }
nuclear@14 687 }
nuclear@14 688
nuclear@14 689
nuclear@14 690 METHODDEF(boolean)
nuclear@14 691 get_interesting_appn (j_decompress_ptr cinfo)
nuclear@14 692 /* Process an APP0 or APP14 marker without saving it */
nuclear@14 693 {
nuclear@14 694 INT32 length;
nuclear@14 695 JOCTET b[APPN_DATA_LEN];
nuclear@14 696 unsigned int i, numtoread;
nuclear@14 697 INPUT_VARS(cinfo);
nuclear@14 698
nuclear@14 699 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 700 length -= 2;
nuclear@14 701
nuclear@14 702 /* get the interesting part of the marker data */
nuclear@14 703 if (length >= APPN_DATA_LEN)
nuclear@14 704 numtoread = APPN_DATA_LEN;
nuclear@14 705 else if (length > 0)
nuclear@14 706 numtoread = (unsigned int) length;
nuclear@14 707 else
nuclear@14 708 numtoread = 0;
nuclear@14 709 for (i = 0; i < numtoread; i++)
nuclear@14 710 INPUT_BYTE(cinfo, b[i], return FALSE);
nuclear@14 711 length -= numtoread;
nuclear@14 712
nuclear@14 713 /* process it */
nuclear@14 714 switch (cinfo->unread_marker) {
nuclear@14 715 case M_APP0:
nuclear@14 716 examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@14 717 break;
nuclear@14 718 case M_APP14:
nuclear@14 719 examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@14 720 break;
nuclear@14 721 default:
nuclear@14 722 /* can't get here unless jpeg_save_markers chooses wrong processor */
nuclear@14 723 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@14 724 break;
nuclear@14 725 }
nuclear@14 726
nuclear@14 727 /* skip any remaining data -- could be lots */
nuclear@14 728 INPUT_SYNC(cinfo);
nuclear@14 729 if (length > 0)
nuclear@14 730 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@14 731
nuclear@14 732 return TRUE;
nuclear@14 733 }
nuclear@14 734
nuclear@14 735
nuclear@14 736 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@14 737
nuclear@14 738 METHODDEF(boolean)
nuclear@14 739 save_marker (j_decompress_ptr cinfo)
nuclear@14 740 /* Save an APPn or COM marker into the marker list */
nuclear@14 741 {
nuclear@14 742 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@14 743 jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
nuclear@14 744 unsigned int bytes_read, data_length;
nuclear@14 745 JOCTET FAR * data;
nuclear@14 746 INT32 length = 0;
nuclear@14 747 INPUT_VARS(cinfo);
nuclear@14 748
nuclear@14 749 if (cur_marker == NULL) {
nuclear@14 750 /* begin reading a marker */
nuclear@14 751 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 752 length -= 2;
nuclear@14 753 if (length >= 0) { /* watch out for bogus length word */
nuclear@14 754 /* figure out how much we want to save */
nuclear@14 755 unsigned int limit;
nuclear@14 756 if (cinfo->unread_marker == (int) M_COM)
nuclear@14 757 limit = marker->length_limit_COM;
nuclear@14 758 else
nuclear@14 759 limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
nuclear@14 760 if ((unsigned int) length < limit)
nuclear@14 761 limit = (unsigned int) length;
nuclear@14 762 /* allocate and initialize the marker item */
nuclear@14 763 cur_marker = (jpeg_saved_marker_ptr)
nuclear@14 764 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@14 765 SIZEOF(struct jpeg_marker_struct) + limit);
nuclear@14 766 cur_marker->next = NULL;
nuclear@14 767 cur_marker->marker = (UINT8) cinfo->unread_marker;
nuclear@14 768 cur_marker->original_length = (unsigned int) length;
nuclear@14 769 cur_marker->data_length = limit;
nuclear@14 770 /* data area is just beyond the jpeg_marker_struct */
nuclear@14 771 data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
nuclear@14 772 marker->cur_marker = cur_marker;
nuclear@14 773 marker->bytes_read = 0;
nuclear@14 774 bytes_read = 0;
nuclear@14 775 data_length = limit;
nuclear@14 776 } else {
nuclear@14 777 /* deal with bogus length word */
nuclear@14 778 bytes_read = data_length = 0;
nuclear@14 779 data = NULL;
nuclear@14 780 }
nuclear@14 781 } else {
nuclear@14 782 /* resume reading a marker */
nuclear@14 783 bytes_read = marker->bytes_read;
nuclear@14 784 data_length = cur_marker->data_length;
nuclear@14 785 data = cur_marker->data + bytes_read;
nuclear@14 786 }
nuclear@14 787
nuclear@14 788 while (bytes_read < data_length) {
nuclear@14 789 INPUT_SYNC(cinfo); /* move the restart point to here */
nuclear@14 790 marker->bytes_read = bytes_read;
nuclear@14 791 /* If there's not at least one byte in buffer, suspend */
nuclear@14 792 MAKE_BYTE_AVAIL(cinfo, return FALSE);
nuclear@14 793 /* Copy bytes with reasonable rapidity */
nuclear@14 794 while (bytes_read < data_length && bytes_in_buffer > 0) {
nuclear@14 795 *data++ = *next_input_byte++;
nuclear@14 796 bytes_in_buffer--;
nuclear@14 797 bytes_read++;
nuclear@14 798 }
nuclear@14 799 }
nuclear@14 800
nuclear@14 801 /* Done reading what we want to read */
nuclear@14 802 if (cur_marker != NULL) { /* will be NULL if bogus length word */
nuclear@14 803 /* Add new marker to end of list */
nuclear@14 804 if (cinfo->marker_list == NULL) {
nuclear@14 805 cinfo->marker_list = cur_marker;
nuclear@14 806 } else {
nuclear@14 807 jpeg_saved_marker_ptr prev = cinfo->marker_list;
nuclear@14 808 while (prev->next != NULL)
nuclear@14 809 prev = prev->next;
nuclear@14 810 prev->next = cur_marker;
nuclear@14 811 }
nuclear@14 812 /* Reset pointer & calc remaining data length */
nuclear@14 813 data = cur_marker->data;
nuclear@14 814 length = cur_marker->original_length - data_length;
nuclear@14 815 }
nuclear@14 816 /* Reset to initial state for next marker */
nuclear@14 817 marker->cur_marker = NULL;
nuclear@14 818
nuclear@14 819 /* Process the marker if interesting; else just make a generic trace msg */
nuclear@14 820 switch (cinfo->unread_marker) {
nuclear@14 821 case M_APP0:
nuclear@14 822 examine_app0(cinfo, data, data_length, length);
nuclear@14 823 break;
nuclear@14 824 case M_APP14:
nuclear@14 825 examine_app14(cinfo, data, data_length, length);
nuclear@14 826 break;
nuclear@14 827 default:
nuclear@14 828 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
nuclear@14 829 (int) (data_length + length));
nuclear@14 830 break;
nuclear@14 831 }
nuclear@14 832
nuclear@14 833 /* skip any remaining data -- could be lots */
nuclear@14 834 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@14 835 if (length > 0)
nuclear@14 836 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@14 837
nuclear@14 838 return TRUE;
nuclear@14 839 }
nuclear@14 840
nuclear@14 841 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@14 842
nuclear@14 843
nuclear@14 844 METHODDEF(boolean)
nuclear@14 845 skip_variable (j_decompress_ptr cinfo)
nuclear@14 846 /* Skip over an unknown or uninteresting variable-length marker */
nuclear@14 847 {
nuclear@14 848 INT32 length;
nuclear@14 849 INPUT_VARS(cinfo);
nuclear@14 850
nuclear@14 851 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@14 852 length -= 2;
nuclear@14 853
nuclear@14 854 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
nuclear@14 855
nuclear@14 856 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@14 857 if (length > 0)
nuclear@14 858 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@14 859
nuclear@14 860 return TRUE;
nuclear@14 861 }
nuclear@14 862
nuclear@14 863
nuclear@14 864 /*
nuclear@14 865 * Find the next JPEG marker, save it in cinfo->unread_marker.
nuclear@14 866 * Returns FALSE if had to suspend before reaching a marker;
nuclear@14 867 * in that case cinfo->unread_marker is unchanged.
nuclear@14 868 *
nuclear@14 869 * Note that the result might not be a valid marker code,
nuclear@14 870 * but it will never be 0 or FF.
nuclear@14 871 */
nuclear@14 872
nuclear@14 873 LOCAL(boolean)
nuclear@14 874 next_marker (j_decompress_ptr cinfo)
nuclear@14 875 {
nuclear@14 876 int c;
nuclear@14 877 INPUT_VARS(cinfo);
nuclear@14 878
nuclear@14 879 for (;;) {
nuclear@14 880 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 881 /* Skip any non-FF bytes.
nuclear@14 882 * This may look a bit inefficient, but it will not occur in a valid file.
nuclear@14 883 * We sync after each discarded byte so that a suspending data source
nuclear@14 884 * can discard the byte from its buffer.
nuclear@14 885 */
nuclear@14 886 while (c != 0xFF) {
nuclear@14 887 cinfo->marker->discarded_bytes++;
nuclear@14 888 INPUT_SYNC(cinfo);
nuclear@14 889 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 890 }
nuclear@14 891 /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
nuclear@14 892 * pad bytes, so don't count them in discarded_bytes. We assume there
nuclear@14 893 * will not be so many consecutive FF bytes as to overflow a suspending
nuclear@14 894 * data source's input buffer.
nuclear@14 895 */
nuclear@14 896 do {
nuclear@14 897 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 898 } while (c == 0xFF);
nuclear@14 899 if (c != 0)
nuclear@14 900 break; /* found a valid marker, exit loop */
nuclear@14 901 /* Reach here if we found a stuffed-zero data sequence (FF/00).
nuclear@14 902 * Discard it and loop back to try again.
nuclear@14 903 */
nuclear@14 904 cinfo->marker->discarded_bytes += 2;
nuclear@14 905 INPUT_SYNC(cinfo);
nuclear@14 906 }
nuclear@14 907
nuclear@14 908 if (cinfo->marker->discarded_bytes != 0) {
nuclear@14 909 WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
nuclear@14 910 cinfo->marker->discarded_bytes = 0;
nuclear@14 911 }
nuclear@14 912
nuclear@14 913 cinfo->unread_marker = c;
nuclear@14 914
nuclear@14 915 INPUT_SYNC(cinfo);
nuclear@14 916 return TRUE;
nuclear@14 917 }
nuclear@14 918
nuclear@14 919
nuclear@14 920 LOCAL(boolean)
nuclear@14 921 first_marker (j_decompress_ptr cinfo)
nuclear@14 922 /* Like next_marker, but used to obtain the initial SOI marker. */
nuclear@14 923 /* For this marker, we do not allow preceding garbage or fill; otherwise,
nuclear@14 924 * we might well scan an entire input file before realizing it ain't JPEG.
nuclear@14 925 * If an application wants to process non-JFIF files, it must seek to the
nuclear@14 926 * SOI before calling the JPEG library.
nuclear@14 927 */
nuclear@14 928 {
nuclear@14 929 int c, c2;
nuclear@14 930 INPUT_VARS(cinfo);
nuclear@14 931
nuclear@14 932 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@14 933 INPUT_BYTE(cinfo, c2, return FALSE);
nuclear@14 934 if (c != 0xFF || c2 != (int) M_SOI)
nuclear@14 935 ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
nuclear@14 936
nuclear@14 937 cinfo->unread_marker = c2;
nuclear@14 938
nuclear@14 939 INPUT_SYNC(cinfo);
nuclear@14 940 return TRUE;
nuclear@14 941 }
nuclear@14 942
nuclear@14 943
nuclear@14 944 /*
nuclear@14 945 * Read markers until SOS or EOI.
nuclear@14 946 *
nuclear@14 947 * Returns same codes as are defined for jpeg_consume_input:
nuclear@14 948 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
nuclear@14 949 */
nuclear@14 950
nuclear@14 951 METHODDEF(int)
nuclear@14 952 read_markers (j_decompress_ptr cinfo)
nuclear@14 953 {
nuclear@14 954 /* Outer loop repeats once for each marker. */
nuclear@14 955 for (;;) {
nuclear@14 956 /* Collect the marker proper, unless we already did. */
nuclear@14 957 /* NB: first_marker() enforces the requirement that SOI appear first. */
nuclear@14 958 if (cinfo->unread_marker == 0) {
nuclear@14 959 if (! cinfo->marker->saw_SOI) {
nuclear@14 960 if (! first_marker(cinfo))
nuclear@14 961 return JPEG_SUSPENDED;
nuclear@14 962 } else {
nuclear@14 963 if (! next_marker(cinfo))
nuclear@14 964 return JPEG_SUSPENDED;
nuclear@14 965 }
nuclear@14 966 }
nuclear@14 967 /* At this point cinfo->unread_marker contains the marker code and the
nuclear@14 968 * input point is just past the marker proper, but before any parameters.
nuclear@14 969 * A suspension will cause us to return with this state still true.
nuclear@14 970 */
nuclear@14 971 switch (cinfo->unread_marker) {
nuclear@14 972 case M_SOI:
nuclear@14 973 if (! get_soi(cinfo))
nuclear@14 974 return JPEG_SUSPENDED;
nuclear@14 975 break;
nuclear@14 976
nuclear@14 977 case M_SOF0: /* Baseline */
nuclear@14 978 case M_SOF1: /* Extended sequential, Huffman */
nuclear@14 979 if (! get_sof(cinfo, FALSE, FALSE))
nuclear@14 980 return JPEG_SUSPENDED;
nuclear@14 981 break;
nuclear@14 982
nuclear@14 983 case M_SOF2: /* Progressive, Huffman */
nuclear@14 984 if (! get_sof(cinfo, TRUE, FALSE))
nuclear@14 985 return JPEG_SUSPENDED;
nuclear@14 986 break;
nuclear@14 987
nuclear@14 988 case M_SOF9: /* Extended sequential, arithmetic */
nuclear@14 989 if (! get_sof(cinfo, FALSE, TRUE))
nuclear@14 990 return JPEG_SUSPENDED;
nuclear@14 991 break;
nuclear@14 992
nuclear@14 993 case M_SOF10: /* Progressive, arithmetic */
nuclear@14 994 if (! get_sof(cinfo, TRUE, TRUE))
nuclear@14 995 return JPEG_SUSPENDED;
nuclear@14 996 break;
nuclear@14 997
nuclear@14 998 /* Currently unsupported SOFn types */
nuclear@14 999 case M_SOF3: /* Lossless, Huffman */
nuclear@14 1000 case M_SOF5: /* Differential sequential, Huffman */
nuclear@14 1001 case M_SOF6: /* Differential progressive, Huffman */
nuclear@14 1002 case M_SOF7: /* Differential lossless, Huffman */
nuclear@14 1003 case M_JPG: /* Reserved for JPEG extensions */
nuclear@14 1004 case M_SOF11: /* Lossless, arithmetic */
nuclear@14 1005 case M_SOF13: /* Differential sequential, arithmetic */
nuclear@14 1006 case M_SOF14: /* Differential progressive, arithmetic */
nuclear@14 1007 case M_SOF15: /* Differential lossless, arithmetic */
nuclear@14 1008 ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
nuclear@14 1009 break;
nuclear@14 1010
nuclear@14 1011 case M_SOS:
nuclear@14 1012 if (! get_sos(cinfo))
nuclear@14 1013 return JPEG_SUSPENDED;
nuclear@14 1014 cinfo->unread_marker = 0; /* processed the marker */
nuclear@14 1015 return JPEG_REACHED_SOS;
nuclear@14 1016
nuclear@14 1017 case M_EOI:
nuclear@14 1018 TRACEMS(cinfo, 1, JTRC_EOI);
nuclear@14 1019 cinfo->unread_marker = 0; /* processed the marker */
nuclear@14 1020 return JPEG_REACHED_EOI;
nuclear@14 1021
nuclear@14 1022 case M_DAC:
nuclear@14 1023 if (! get_dac(cinfo))
nuclear@14 1024 return JPEG_SUSPENDED;
nuclear@14 1025 break;
nuclear@14 1026
nuclear@14 1027 case M_DHT:
nuclear@14 1028 if (! get_dht(cinfo))
nuclear@14 1029 return JPEG_SUSPENDED;
nuclear@14 1030 break;
nuclear@14 1031
nuclear@14 1032 case M_DQT:
nuclear@14 1033 if (! get_dqt(cinfo))
nuclear@14 1034 return JPEG_SUSPENDED;
nuclear@14 1035 break;
nuclear@14 1036
nuclear@14 1037 case M_DRI:
nuclear@14 1038 if (! get_dri(cinfo))
nuclear@14 1039 return JPEG_SUSPENDED;
nuclear@14 1040 break;
nuclear@14 1041
nuclear@14 1042 case M_APP0:
nuclear@14 1043 case M_APP1:
nuclear@14 1044 case M_APP2:
nuclear@14 1045 case M_APP3:
nuclear@14 1046 case M_APP4:
nuclear@14 1047 case M_APP5:
nuclear@14 1048 case M_APP6:
nuclear@14 1049 case M_APP7:
nuclear@14 1050 case M_APP8:
nuclear@14 1051 case M_APP9:
nuclear@14 1052 case M_APP10:
nuclear@14 1053 case M_APP11:
nuclear@14 1054 case M_APP12:
nuclear@14 1055 case M_APP13:
nuclear@14 1056 case M_APP14:
nuclear@14 1057 case M_APP15:
nuclear@14 1058 if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
nuclear@14 1059 cinfo->unread_marker - (int) M_APP0]) (cinfo))
nuclear@14 1060 return JPEG_SUSPENDED;
nuclear@14 1061 break;
nuclear@14 1062
nuclear@14 1063 case M_COM:
nuclear@14 1064 if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
nuclear@14 1065 return JPEG_SUSPENDED;
nuclear@14 1066 break;
nuclear@14 1067
nuclear@14 1068 case M_RST0: /* these are all parameterless */
nuclear@14 1069 case M_RST1:
nuclear@14 1070 case M_RST2:
nuclear@14 1071 case M_RST3:
nuclear@14 1072 case M_RST4:
nuclear@14 1073 case M_RST5:
nuclear@14 1074 case M_RST6:
nuclear@14 1075 case M_RST7:
nuclear@14 1076 case M_TEM:
nuclear@14 1077 TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
nuclear@14 1078 break;
nuclear@14 1079
nuclear@14 1080 case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
nuclear@14 1081 if (! skip_variable(cinfo))
nuclear@14 1082 return JPEG_SUSPENDED;
nuclear@14 1083 break;
nuclear@14 1084
nuclear@14 1085 default: /* must be DHP, EXP, JPGn, or RESn */
nuclear@14 1086 /* For now, we treat the reserved markers as fatal errors since they are
nuclear@14 1087 * likely to be used to signal incompatible JPEG Part 3 extensions.
nuclear@14 1088 * Once the JPEG 3 version-number marker is well defined, this code
nuclear@14 1089 * ought to change!
nuclear@14 1090 */
nuclear@14 1091 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@14 1092 break;
nuclear@14 1093 }
nuclear@14 1094 /* Successfully processed marker, so reset state variable */
nuclear@14 1095 cinfo->unread_marker = 0;
nuclear@14 1096 } /* end loop */
nuclear@14 1097 }
nuclear@14 1098
nuclear@14 1099
nuclear@14 1100 /*
nuclear@14 1101 * Read a restart marker, which is expected to appear next in the datastream;
nuclear@14 1102 * if the marker is not there, take appropriate recovery action.
nuclear@14 1103 * Returns FALSE if suspension is required.
nuclear@14 1104 *
nuclear@14 1105 * This is called by the entropy decoder after it has read an appropriate
nuclear@14 1106 * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
nuclear@14 1107 * has already read a marker from the data source. Under normal conditions
nuclear@14 1108 * cinfo->unread_marker will be reset to 0 before returning; if not reset,
nuclear@14 1109 * it holds a marker which the decoder will be unable to read past.
nuclear@14 1110 */
nuclear@14 1111
nuclear@14 1112 METHODDEF(boolean)
nuclear@14 1113 read_restart_marker (j_decompress_ptr cinfo)
nuclear@14 1114 {
nuclear@14 1115 /* Obtain a marker unless we already did. */
nuclear@14 1116 /* Note that next_marker will complain if it skips any data. */
nuclear@14 1117 if (cinfo->unread_marker == 0) {
nuclear@14 1118 if (! next_marker(cinfo))
nuclear@14 1119 return FALSE;
nuclear@14 1120 }
nuclear@14 1121
nuclear@14 1122 if (cinfo->unread_marker ==
nuclear@14 1123 ((int) M_RST0 + cinfo->marker->next_restart_num)) {
nuclear@14 1124 /* Normal case --- swallow the marker and let entropy decoder continue */
nuclear@14 1125 TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
nuclear@14 1126 cinfo->unread_marker = 0;
nuclear@14 1127 } else {
nuclear@14 1128 /* Uh-oh, the restart markers have been messed up. */
nuclear@14 1129 /* Let the data source manager determine how to resync. */
nuclear@14 1130 if (! (*cinfo->src->resync_to_restart) (cinfo,
nuclear@14 1131 cinfo->marker->next_restart_num))
nuclear@14 1132 return FALSE;
nuclear@14 1133 }
nuclear@14 1134
nuclear@14 1135 /* Update next-restart state */
nuclear@14 1136 cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
nuclear@14 1137
nuclear@14 1138 return TRUE;
nuclear@14 1139 }
nuclear@14 1140
nuclear@14 1141
nuclear@14 1142 /*
nuclear@14 1143 * This is the default resync_to_restart method for data source managers
nuclear@14 1144 * to use if they don't have any better approach. Some data source managers
nuclear@14 1145 * may be able to back up, or may have additional knowledge about the data
nuclear@14 1146 * which permits a more intelligent recovery strategy; such managers would
nuclear@14 1147 * presumably supply their own resync method.
nuclear@14 1148 *
nuclear@14 1149 * read_restart_marker calls resync_to_restart if it finds a marker other than
nuclear@14 1150 * the restart marker it was expecting. (This code is *not* used unless
nuclear@14 1151 * a nonzero restart interval has been declared.) cinfo->unread_marker is
nuclear@14 1152 * the marker code actually found (might be anything, except 0 or FF).
nuclear@14 1153 * The desired restart marker number (0..7) is passed as a parameter.
nuclear@14 1154 * This routine is supposed to apply whatever error recovery strategy seems
nuclear@14 1155 * appropriate in order to position the input stream to the next data segment.
nuclear@14 1156 * Note that cinfo->unread_marker is treated as a marker appearing before
nuclear@14 1157 * the current data-source input point; usually it should be reset to zero
nuclear@14 1158 * before returning.
nuclear@14 1159 * Returns FALSE if suspension is required.
nuclear@14 1160 *
nuclear@14 1161 * This implementation is substantially constrained by wanting to treat the
nuclear@14 1162 * input as a data stream; this means we can't back up. Therefore, we have
nuclear@14 1163 * only the following actions to work with:
nuclear@14 1164 * 1. Simply discard the marker and let the entropy decoder resume at next
nuclear@14 1165 * byte of file.
nuclear@14 1166 * 2. Read forward until we find another marker, discarding intervening
nuclear@14 1167 * data. (In theory we could look ahead within the current bufferload,
nuclear@14 1168 * without having to discard data if we don't find the desired marker.
nuclear@14 1169 * This idea is not implemented here, in part because it makes behavior
nuclear@14 1170 * dependent on buffer size and chance buffer-boundary positions.)
nuclear@14 1171 * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
nuclear@14 1172 * This will cause the entropy decoder to process an empty data segment,
nuclear@14 1173 * inserting dummy zeroes, and then we will reprocess the marker.
nuclear@14 1174 *
nuclear@14 1175 * #2 is appropriate if we think the desired marker lies ahead, while #3 is
nuclear@14 1176 * appropriate if the found marker is a future restart marker (indicating
nuclear@14 1177 * that we have missed the desired restart marker, probably because it got
nuclear@14 1178 * corrupted).
nuclear@14 1179 * We apply #2 or #3 if the found marker is a restart marker no more than
nuclear@14 1180 * two counts behind or ahead of the expected one. We also apply #2 if the
nuclear@14 1181 * found marker is not a legal JPEG marker code (it's certainly bogus data).
nuclear@14 1182 * If the found marker is a restart marker more than 2 counts away, we do #1
nuclear@14 1183 * (too much risk that the marker is erroneous; with luck we will be able to
nuclear@14 1184 * resync at some future point).
nuclear@14 1185 * For any valid non-restart JPEG marker, we apply #3. This keeps us from
nuclear@14 1186 * overrunning the end of a scan. An implementation limited to single-scan
nuclear@14 1187 * files might find it better to apply #2 for markers other than EOI, since
nuclear@14 1188 * any other marker would have to be bogus data in that case.
nuclear@14 1189 */
nuclear@14 1190
nuclear@14 1191 GLOBAL(boolean)
nuclear@14 1192 jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
nuclear@14 1193 {
nuclear@14 1194 int marker = cinfo->unread_marker;
nuclear@14 1195 int action = 1;
nuclear@14 1196
nuclear@14 1197 /* Always put up a warning. */
nuclear@14 1198 WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
nuclear@14 1199
nuclear@14 1200 /* Outer loop handles repeated decision after scanning forward. */
nuclear@14 1201 for (;;) {
nuclear@14 1202 if (marker < (int) M_SOF0)
nuclear@14 1203 action = 2; /* invalid marker */
nuclear@14 1204 else if (marker < (int) M_RST0 || marker > (int) M_RST7)
nuclear@14 1205 action = 3; /* valid non-restart marker */
nuclear@14 1206 else {
nuclear@14 1207 if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
nuclear@14 1208 marker == ((int) M_RST0 + ((desired+2) & 7)))
nuclear@14 1209 action = 3; /* one of the next two expected restarts */
nuclear@14 1210 else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
nuclear@14 1211 marker == ((int) M_RST0 + ((desired-2) & 7)))
nuclear@14 1212 action = 2; /* a prior restart, so advance */
nuclear@14 1213 else
nuclear@14 1214 action = 1; /* desired restart or too far away */
nuclear@14 1215 }
nuclear@14 1216 TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
nuclear@14 1217 switch (action) {
nuclear@14 1218 case 1:
nuclear@14 1219 /* Discard marker and let entropy decoder resume processing. */
nuclear@14 1220 cinfo->unread_marker = 0;
nuclear@14 1221 return TRUE;
nuclear@14 1222 case 2:
nuclear@14 1223 /* Scan to the next marker, and repeat the decision loop. */
nuclear@14 1224 if (! next_marker(cinfo))
nuclear@14 1225 return FALSE;
nuclear@14 1226 marker = cinfo->unread_marker;
nuclear@14 1227 break;
nuclear@14 1228 case 3:
nuclear@14 1229 /* Return without advancing past this marker. */
nuclear@14 1230 /* Entropy decoder will be forced to process an empty segment. */
nuclear@14 1231 return TRUE;
nuclear@14 1232 }
nuclear@14 1233 } /* end loop */
nuclear@14 1234 }
nuclear@14 1235
nuclear@14 1236
nuclear@14 1237 /*
nuclear@14 1238 * Reset marker processing state to begin a fresh datastream.
nuclear@14 1239 */
nuclear@14 1240
nuclear@14 1241 METHODDEF(void)
nuclear@14 1242 reset_marker_reader (j_decompress_ptr cinfo)
nuclear@14 1243 {
nuclear@14 1244 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@14 1245
nuclear@14 1246 cinfo->comp_info = NULL; /* until allocated by get_sof */
nuclear@14 1247 cinfo->input_scan_number = 0; /* no SOS seen yet */
nuclear@14 1248 cinfo->unread_marker = 0; /* no pending marker */
nuclear@14 1249 marker->pub.saw_SOI = FALSE; /* set internal state too */
nuclear@14 1250 marker->pub.saw_SOF = FALSE;
nuclear@14 1251 marker->pub.discarded_bytes = 0;
nuclear@14 1252 marker->cur_marker = NULL;
nuclear@14 1253 }
nuclear@14 1254
nuclear@14 1255
nuclear@14 1256 /*
nuclear@14 1257 * Initialize the marker reader module.
nuclear@14 1258 * This is called only once, when the decompression object is created.
nuclear@14 1259 */
nuclear@14 1260
nuclear@14 1261 GLOBAL(void)
nuclear@14 1262 jinit_marker_reader (j_decompress_ptr cinfo)
nuclear@14 1263 {
nuclear@14 1264 my_marker_ptr marker;
nuclear@14 1265 int i;
nuclear@14 1266
nuclear@14 1267 /* Create subobject in permanent pool */
nuclear@14 1268 marker = (my_marker_ptr)
nuclear@14 1269 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
nuclear@14 1270 SIZEOF(my_marker_reader));
nuclear@14 1271 cinfo->marker = (struct jpeg_marker_reader *) marker;
nuclear@14 1272 /* Initialize public method pointers */
nuclear@14 1273 marker->pub.reset_marker_reader = reset_marker_reader;
nuclear@14 1274 marker->pub.read_markers = read_markers;
nuclear@14 1275 marker->pub.read_restart_marker = read_restart_marker;
nuclear@14 1276 /* Initialize COM/APPn processing.
nuclear@14 1277 * By default, we examine and then discard APP0 and APP14,
nuclear@14 1278 * but simply discard COM and all other APPn.
nuclear@14 1279 */
nuclear@14 1280 marker->process_COM = skip_variable;
nuclear@14 1281 marker->length_limit_COM = 0;
nuclear@14 1282 for (i = 0; i < 16; i++) {
nuclear@14 1283 marker->process_APPn[i] = skip_variable;
nuclear@14 1284 marker->length_limit_APPn[i] = 0;
nuclear@14 1285 }
nuclear@14 1286 marker->process_APPn[0] = get_interesting_appn;
nuclear@14 1287 marker->process_APPn[14] = get_interesting_appn;
nuclear@14 1288 /* Reset marker processing state */
nuclear@14 1289 reset_marker_reader(cinfo);
nuclear@14 1290 }
nuclear@14 1291
nuclear@14 1292
nuclear@14 1293 /*
nuclear@14 1294 * Control saving of COM and APPn markers into marker_list.
nuclear@14 1295 */
nuclear@14 1296
nuclear@14 1297 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@14 1298
nuclear@14 1299 GLOBAL(void)
nuclear@14 1300 jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
nuclear@14 1301 unsigned int length_limit)
nuclear@14 1302 {
nuclear@14 1303 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@14 1304 long maxlength;
nuclear@14 1305 jpeg_marker_parser_method processor;
nuclear@14 1306
nuclear@14 1307 /* Length limit mustn't be larger than what we can allocate
nuclear@14 1308 * (should only be a concern in a 16-bit environment).
nuclear@14 1309 */
nuclear@14 1310 maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
nuclear@14 1311 if (((long) length_limit) > maxlength)
nuclear@14 1312 length_limit = (unsigned int) maxlength;
nuclear@14 1313
nuclear@14 1314 /* Choose processor routine to use.
nuclear@14 1315 * APP0/APP14 have special requirements.
nuclear@14 1316 */
nuclear@14 1317 if (length_limit) {
nuclear@14 1318 processor = save_marker;
nuclear@14 1319 /* If saving APP0/APP14, save at least enough for our internal use. */
nuclear@14 1320 if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
nuclear@14 1321 length_limit = APP0_DATA_LEN;
nuclear@14 1322 else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
nuclear@14 1323 length_limit = APP14_DATA_LEN;
nuclear@14 1324 } else {
nuclear@14 1325 processor = skip_variable;
nuclear@14 1326 /* If discarding APP0/APP14, use our regular on-the-fly processor. */
nuclear@14 1327 if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
nuclear@14 1328 processor = get_interesting_appn;
nuclear@14 1329 }
nuclear@14 1330
nuclear@14 1331 if (marker_code == (int) M_COM) {
nuclear@14 1332 marker->process_COM = processor;
nuclear@14 1333 marker->length_limit_COM = length_limit;
nuclear@14 1334 } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
nuclear@14 1335 marker->process_APPn[marker_code - (int) M_APP0] = processor;
nuclear@14 1336 marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
nuclear@14 1337 } else
nuclear@14 1338 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@14 1339 }
nuclear@14 1340
nuclear@14 1341 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@14 1342
nuclear@14 1343
nuclear@14 1344 /*
nuclear@14 1345 * Install a special processing method for COM or APPn markers.
nuclear@14 1346 */
nuclear@14 1347
nuclear@14 1348 GLOBAL(void)
nuclear@14 1349 jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
nuclear@14 1350 jpeg_marker_parser_method routine)
nuclear@14 1351 {
nuclear@14 1352 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@14 1353
nuclear@14 1354 if (marker_code == (int) M_COM)
nuclear@14 1355 marker->process_COM = routine;
nuclear@14 1356 else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
nuclear@14 1357 marker->process_APPn[marker_code - (int) M_APP0] = routine;
nuclear@14 1358 else
nuclear@14 1359 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@14 1360 }