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annotate libs/libjpeg/jdmarker.c @ 33:33e9eedad390

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ah.. blunder
author John Tsiombikas <nuclear@mutantstargoat.com>
date Fri, 09 Sep 2011 00:03:37 +0300
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nuclear@26 1 /*
nuclear@26 2 * jdmarker.c
nuclear@26 3 *
nuclear@26 4 * Copyright (C) 1991-1998, Thomas G. Lane.
nuclear@26 5 * This file is part of the Independent JPEG Group's software.
nuclear@26 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@26 7 *
nuclear@26 8 * This file contains routines to decode JPEG datastream markers.
nuclear@26 9 * Most of the complexity arises from our desire to support input
nuclear@26 10 * suspension: if not all of the data for a marker is available,
nuclear@26 11 * we must exit back to the application. On resumption, we reprocess
nuclear@26 12 * the marker.
nuclear@26 13 */
nuclear@26 14
nuclear@26 15 #define JPEG_INTERNALS
nuclear@26 16 #include "jinclude.h"
nuclear@26 17 #include "jpeglib.h"
nuclear@26 18
nuclear@26 19
nuclear@26 20 typedef enum { /* JPEG marker codes */
nuclear@26 21 M_SOF0 = 0xc0,
nuclear@26 22 M_SOF1 = 0xc1,
nuclear@26 23 M_SOF2 = 0xc2,
nuclear@26 24 M_SOF3 = 0xc3,
nuclear@26 25
nuclear@26 26 M_SOF5 = 0xc5,
nuclear@26 27 M_SOF6 = 0xc6,
nuclear@26 28 M_SOF7 = 0xc7,
nuclear@26 29
nuclear@26 30 M_JPG = 0xc8,
nuclear@26 31 M_SOF9 = 0xc9,
nuclear@26 32 M_SOF10 = 0xca,
nuclear@26 33 M_SOF11 = 0xcb,
nuclear@26 34
nuclear@26 35 M_SOF13 = 0xcd,
nuclear@26 36 M_SOF14 = 0xce,
nuclear@26 37 M_SOF15 = 0xcf,
nuclear@26 38
nuclear@26 39 M_DHT = 0xc4,
nuclear@26 40
nuclear@26 41 M_DAC = 0xcc,
nuclear@26 42
nuclear@26 43 M_RST0 = 0xd0,
nuclear@26 44 M_RST1 = 0xd1,
nuclear@26 45 M_RST2 = 0xd2,
nuclear@26 46 M_RST3 = 0xd3,
nuclear@26 47 M_RST4 = 0xd4,
nuclear@26 48 M_RST5 = 0xd5,
nuclear@26 49 M_RST6 = 0xd6,
nuclear@26 50 M_RST7 = 0xd7,
nuclear@26 51
nuclear@26 52 M_SOI = 0xd8,
nuclear@26 53 M_EOI = 0xd9,
nuclear@26 54 M_SOS = 0xda,
nuclear@26 55 M_DQT = 0xdb,
nuclear@26 56 M_DNL = 0xdc,
nuclear@26 57 M_DRI = 0xdd,
nuclear@26 58 M_DHP = 0xde,
nuclear@26 59 M_EXP = 0xdf,
nuclear@26 60
nuclear@26 61 M_APP0 = 0xe0,
nuclear@26 62 M_APP1 = 0xe1,
nuclear@26 63 M_APP2 = 0xe2,
nuclear@26 64 M_APP3 = 0xe3,
nuclear@26 65 M_APP4 = 0xe4,
nuclear@26 66 M_APP5 = 0xe5,
nuclear@26 67 M_APP6 = 0xe6,
nuclear@26 68 M_APP7 = 0xe7,
nuclear@26 69 M_APP8 = 0xe8,
nuclear@26 70 M_APP9 = 0xe9,
nuclear@26 71 M_APP10 = 0xea,
nuclear@26 72 M_APP11 = 0xeb,
nuclear@26 73 M_APP12 = 0xec,
nuclear@26 74 M_APP13 = 0xed,
nuclear@26 75 M_APP14 = 0xee,
nuclear@26 76 M_APP15 = 0xef,
nuclear@26 77
nuclear@26 78 M_JPG0 = 0xf0,
nuclear@26 79 M_JPG13 = 0xfd,
nuclear@26 80 M_COM = 0xfe,
nuclear@26 81
nuclear@26 82 M_TEM = 0x01,
nuclear@26 83
nuclear@26 84 M_ERROR = 0x100
nuclear@26 85 } JPEG_MARKER;
nuclear@26 86
nuclear@26 87
nuclear@26 88 /* Private state */
nuclear@26 89
nuclear@26 90 typedef struct {
nuclear@26 91 struct jpeg_marker_reader pub; /* public fields */
nuclear@26 92
nuclear@26 93 /* Application-overridable marker processing methods */
nuclear@26 94 jpeg_marker_parser_method process_COM;
nuclear@26 95 jpeg_marker_parser_method process_APPn[16];
nuclear@26 96
nuclear@26 97 /* Limit on marker data length to save for each marker type */
nuclear@26 98 unsigned int length_limit_COM;
nuclear@26 99 unsigned int length_limit_APPn[16];
nuclear@26 100
nuclear@26 101 /* Status of COM/APPn marker saving */
nuclear@26 102 jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
nuclear@26 103 unsigned int bytes_read; /* data bytes read so far in marker */
nuclear@26 104 /* Note: cur_marker is not linked into marker_list until it's all read. */
nuclear@26 105 } my_marker_reader;
nuclear@26 106
nuclear@26 107 typedef my_marker_reader * my_marker_ptr;
nuclear@26 108
nuclear@26 109
nuclear@26 110 /*
nuclear@26 111 * Macros for fetching data from the data source module.
nuclear@26 112 *
nuclear@26 113 * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
nuclear@26 114 * the current restart point; we update them only when we have reached a
nuclear@26 115 * suitable place to restart if a suspension occurs.
nuclear@26 116 */
nuclear@26 117
nuclear@26 118 /* Declare and initialize local copies of input pointer/count */
nuclear@26 119 #define INPUT_VARS(cinfo) \
nuclear@26 120 struct jpeg_source_mgr * datasrc = (cinfo)->src; \
nuclear@26 121 const JOCTET * next_input_byte = datasrc->next_input_byte; \
nuclear@26 122 size_t bytes_in_buffer = datasrc->bytes_in_buffer
nuclear@26 123
nuclear@26 124 /* Unload the local copies --- do this only at a restart boundary */
nuclear@26 125 #define INPUT_SYNC(cinfo) \
nuclear@26 126 ( datasrc->next_input_byte = next_input_byte, \
nuclear@26 127 datasrc->bytes_in_buffer = bytes_in_buffer )
nuclear@26 128
nuclear@26 129 /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
nuclear@26 130 #define INPUT_RELOAD(cinfo) \
nuclear@26 131 ( next_input_byte = datasrc->next_input_byte, \
nuclear@26 132 bytes_in_buffer = datasrc->bytes_in_buffer )
nuclear@26 133
nuclear@26 134 /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
nuclear@26 135 * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
nuclear@26 136 * but we must reload the local copies after a successful fill.
nuclear@26 137 */
nuclear@26 138 #define MAKE_BYTE_AVAIL(cinfo,action) \
nuclear@26 139 if (bytes_in_buffer == 0) { \
nuclear@26 140 if (! (*datasrc->fill_input_buffer) (cinfo)) \
nuclear@26 141 { action; } \
nuclear@26 142 INPUT_RELOAD(cinfo); \
nuclear@26 143 }
nuclear@26 144
nuclear@26 145 /* Read a byte into variable V.
nuclear@26 146 * If must suspend, take the specified action (typically "return FALSE").
nuclear@26 147 */
nuclear@26 148 #define INPUT_BYTE(cinfo,V,action) \
nuclear@26 149 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@26 150 bytes_in_buffer--; \
nuclear@26 151 V = GETJOCTET(*next_input_byte++); )
nuclear@26 152
nuclear@26 153 /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
nuclear@26 154 * V should be declared unsigned int or perhaps INT32.
nuclear@26 155 */
nuclear@26 156 #define INPUT_2BYTES(cinfo,V,action) \
nuclear@26 157 MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@26 158 bytes_in_buffer--; \
nuclear@26 159 V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
nuclear@26 160 MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@26 161 bytes_in_buffer--; \
nuclear@26 162 V += GETJOCTET(*next_input_byte++); )
nuclear@26 163
nuclear@26 164
nuclear@26 165 /*
nuclear@26 166 * Routines to process JPEG markers.
nuclear@26 167 *
nuclear@26 168 * Entry condition: JPEG marker itself has been read and its code saved
nuclear@26 169 * in cinfo->unread_marker; input restart point is just after the marker.
nuclear@26 170 *
nuclear@26 171 * Exit: if return TRUE, have read and processed any parameters, and have
nuclear@26 172 * updated the restart point to point after the parameters.
nuclear@26 173 * If return FALSE, was forced to suspend before reaching end of
nuclear@26 174 * marker parameters; restart point has not been moved. Same routine
nuclear@26 175 * will be called again after application supplies more input data.
nuclear@26 176 *
nuclear@26 177 * This approach to suspension assumes that all of a marker's parameters
nuclear@26 178 * can fit into a single input bufferload. This should hold for "normal"
nuclear@26 179 * markers. Some COM/APPn markers might have large parameter segments
nuclear@26 180 * that might not fit. If we are simply dropping such a marker, we use
nuclear@26 181 * skip_input_data to get past it, and thereby put the problem on the
nuclear@26 182 * source manager's shoulders. If we are saving the marker's contents
nuclear@26 183 * into memory, we use a slightly different convention: when forced to
nuclear@26 184 * suspend, the marker processor updates the restart point to the end of
nuclear@26 185 * what it's consumed (ie, the end of the buffer) before returning FALSE.
nuclear@26 186 * On resumption, cinfo->unread_marker still contains the marker code,
nuclear@26 187 * but the data source will point to the next chunk of marker data.
nuclear@26 188 * The marker processor must retain internal state to deal with this.
nuclear@26 189 *
nuclear@26 190 * Note that we don't bother to avoid duplicate trace messages if a
nuclear@26 191 * suspension occurs within marker parameters. Other side effects
nuclear@26 192 * require more care.
nuclear@26 193 */
nuclear@26 194
nuclear@26 195
nuclear@26 196 LOCAL(boolean)
nuclear@26 197 get_soi (j_decompress_ptr cinfo)
nuclear@26 198 /* Process an SOI marker */
nuclear@26 199 {
nuclear@26 200 int i;
nuclear@26 201
nuclear@26 202 TRACEMS(cinfo, 1, JTRC_SOI);
nuclear@26 203
nuclear@26 204 if (cinfo->marker->saw_SOI)
nuclear@26 205 ERREXIT(cinfo, JERR_SOI_DUPLICATE);
nuclear@26 206
nuclear@26 207 /* Reset all parameters that are defined to be reset by SOI */
nuclear@26 208
nuclear@26 209 for (i = 0; i < NUM_ARITH_TBLS; i++) {
nuclear@26 210 cinfo->arith_dc_L[i] = 0;
nuclear@26 211 cinfo->arith_dc_U[i] = 1;
nuclear@26 212 cinfo->arith_ac_K[i] = 5;
nuclear@26 213 }
nuclear@26 214 cinfo->restart_interval = 0;
nuclear@26 215
nuclear@26 216 /* Set initial assumptions for colorspace etc */
nuclear@26 217
nuclear@26 218 cinfo->jpeg_color_space = JCS_UNKNOWN;
nuclear@26 219 cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
nuclear@26 220
nuclear@26 221 cinfo->saw_JFIF_marker = FALSE;
nuclear@26 222 cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
nuclear@26 223 cinfo->JFIF_minor_version = 1;
nuclear@26 224 cinfo->density_unit = 0;
nuclear@26 225 cinfo->X_density = 1;
nuclear@26 226 cinfo->Y_density = 1;
nuclear@26 227 cinfo->saw_Adobe_marker = FALSE;
nuclear@26 228 cinfo->Adobe_transform = 0;
nuclear@26 229
nuclear@26 230 cinfo->marker->saw_SOI = TRUE;
nuclear@26 231
nuclear@26 232 return TRUE;
nuclear@26 233 }
nuclear@26 234
nuclear@26 235
nuclear@26 236 LOCAL(boolean)
nuclear@26 237 get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
nuclear@26 238 /* Process a SOFn marker */
nuclear@26 239 {
nuclear@26 240 INT32 length;
nuclear@26 241 int c, ci;
nuclear@26 242 jpeg_component_info * compptr;
nuclear@26 243 INPUT_VARS(cinfo);
nuclear@26 244
nuclear@26 245 cinfo->progressive_mode = is_prog;
nuclear@26 246 cinfo->arith_code = is_arith;
nuclear@26 247
nuclear@26 248 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 249
nuclear@26 250 INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
nuclear@26 251 INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
nuclear@26 252 INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
nuclear@26 253 INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
nuclear@26 254
nuclear@26 255 length -= 8;
nuclear@26 256
nuclear@26 257 TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
nuclear@26 258 (int) cinfo->image_width, (int) cinfo->image_height,
nuclear@26 259 cinfo->num_components);
nuclear@26 260
nuclear@26 261 if (cinfo->marker->saw_SOF)
nuclear@26 262 ERREXIT(cinfo, JERR_SOF_DUPLICATE);
nuclear@26 263
nuclear@26 264 /* We don't support files in which the image height is initially specified */
nuclear@26 265 /* as 0 and is later redefined by DNL. As long as we have to check that, */
nuclear@26 266 /* might as well have a general sanity check. */
nuclear@26 267 if (cinfo->image_height <= 0 || cinfo->image_width <= 0
nuclear@26 268 || cinfo->num_components <= 0)
nuclear@26 269 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
nuclear@26 270
nuclear@26 271 if (length != (cinfo->num_components * 3))
nuclear@26 272 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 273
nuclear@26 274 if (cinfo->comp_info == NULL) /* do only once, even if suspend */
nuclear@26 275 cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
nuclear@26 276 ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26 277 cinfo->num_components * SIZEOF(jpeg_component_info));
nuclear@26 278
nuclear@26 279 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@26 280 ci++, compptr++) {
nuclear@26 281 compptr->component_index = ci;
nuclear@26 282 INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
nuclear@26 283 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 284 compptr->h_samp_factor = (c >> 4) & 15;
nuclear@26 285 compptr->v_samp_factor = (c ) & 15;
nuclear@26 286 INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
nuclear@26 287
nuclear@26 288 TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
nuclear@26 289 compptr->component_id, compptr->h_samp_factor,
nuclear@26 290 compptr->v_samp_factor, compptr->quant_tbl_no);
nuclear@26 291 }
nuclear@26 292
nuclear@26 293 cinfo->marker->saw_SOF = TRUE;
nuclear@26 294
nuclear@26 295 INPUT_SYNC(cinfo);
nuclear@26 296 return TRUE;
nuclear@26 297 }
nuclear@26 298
nuclear@26 299
nuclear@26 300 LOCAL(boolean)
nuclear@26 301 get_sos (j_decompress_ptr cinfo)
nuclear@26 302 /* Process a SOS marker */
nuclear@26 303 {
nuclear@26 304 INT32 length;
nuclear@26 305 int i, ci, n, c, cc;
nuclear@26 306 jpeg_component_info * compptr;
nuclear@26 307 INPUT_VARS(cinfo);
nuclear@26 308
nuclear@26 309 if (! cinfo->marker->saw_SOF)
nuclear@26 310 ERREXIT(cinfo, JERR_SOS_NO_SOF);
nuclear@26 311
nuclear@26 312 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 313
nuclear@26 314 INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
nuclear@26 315
nuclear@26 316 TRACEMS1(cinfo, 1, JTRC_SOS, n);
nuclear@26 317
nuclear@26 318 if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
nuclear@26 319 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 320
nuclear@26 321 cinfo->comps_in_scan = n;
nuclear@26 322
nuclear@26 323 /* Collect the component-spec parameters */
nuclear@26 324
nuclear@26 325 for (i = 0; i < n; i++) {
nuclear@26 326 INPUT_BYTE(cinfo, cc, return FALSE);
nuclear@26 327 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 328
nuclear@26 329 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@26 330 ci++, compptr++) {
nuclear@26 331 if (cc == compptr->component_id)
nuclear@26 332 goto id_found;
nuclear@26 333 }
nuclear@26 334
nuclear@26 335 ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
nuclear@26 336
nuclear@26 337 id_found:
nuclear@26 338
nuclear@26 339 cinfo->cur_comp_info[i] = compptr;
nuclear@26 340 compptr->dc_tbl_no = (c >> 4) & 15;
nuclear@26 341 compptr->ac_tbl_no = (c ) & 15;
nuclear@26 342
nuclear@26 343 TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
nuclear@26 344 compptr->dc_tbl_no, compptr->ac_tbl_no);
nuclear@26 345 }
nuclear@26 346
nuclear@26 347 /* Collect the additional scan parameters Ss, Se, Ah/Al. */
nuclear@26 348 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 349 cinfo->Ss = c;
nuclear@26 350 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 351 cinfo->Se = c;
nuclear@26 352 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 353 cinfo->Ah = (c >> 4) & 15;
nuclear@26 354 cinfo->Al = (c ) & 15;
nuclear@26 355
nuclear@26 356 TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
nuclear@26 357 cinfo->Ah, cinfo->Al);
nuclear@26 358
nuclear@26 359 /* Prepare to scan data & restart markers */
nuclear@26 360 cinfo->marker->next_restart_num = 0;
nuclear@26 361
nuclear@26 362 /* Count another SOS marker */
nuclear@26 363 cinfo->input_scan_number++;
nuclear@26 364
nuclear@26 365 INPUT_SYNC(cinfo);
nuclear@26 366 return TRUE;
nuclear@26 367 }
nuclear@26 368
nuclear@26 369
nuclear@26 370 #ifdef D_ARITH_CODING_SUPPORTED
nuclear@26 371
nuclear@26 372 LOCAL(boolean)
nuclear@26 373 get_dac (j_decompress_ptr cinfo)
nuclear@26 374 /* Process a DAC marker */
nuclear@26 375 {
nuclear@26 376 INT32 length;
nuclear@26 377 int index, val;
nuclear@26 378 INPUT_VARS(cinfo);
nuclear@26 379
nuclear@26 380 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 381 length -= 2;
nuclear@26 382
nuclear@26 383 while (length > 0) {
nuclear@26 384 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@26 385 INPUT_BYTE(cinfo, val, return FALSE);
nuclear@26 386
nuclear@26 387 length -= 2;
nuclear@26 388
nuclear@26 389 TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
nuclear@26 390
nuclear@26 391 if (index < 0 || index >= (2*NUM_ARITH_TBLS))
nuclear@26 392 ERREXIT1(cinfo, JERR_DAC_INDEX, index);
nuclear@26 393
nuclear@26 394 if (index >= NUM_ARITH_TBLS) { /* define AC table */
nuclear@26 395 cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
nuclear@26 396 } else { /* define DC table */
nuclear@26 397 cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
nuclear@26 398 cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
nuclear@26 399 if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
nuclear@26 400 ERREXIT1(cinfo, JERR_DAC_VALUE, val);
nuclear@26 401 }
nuclear@26 402 }
nuclear@26 403
nuclear@26 404 if (length != 0)
nuclear@26 405 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 406
nuclear@26 407 INPUT_SYNC(cinfo);
nuclear@26 408 return TRUE;
nuclear@26 409 }
nuclear@26 410
nuclear@26 411 #else /* ! D_ARITH_CODING_SUPPORTED */
nuclear@26 412
nuclear@26 413 #define get_dac(cinfo) skip_variable(cinfo)
nuclear@26 414
nuclear@26 415 #endif /* D_ARITH_CODING_SUPPORTED */
nuclear@26 416
nuclear@26 417
nuclear@26 418 LOCAL(boolean)
nuclear@26 419 get_dht (j_decompress_ptr cinfo)
nuclear@26 420 /* Process a DHT marker */
nuclear@26 421 {
nuclear@26 422 INT32 length;
nuclear@26 423 UINT8 bits[17];
nuclear@26 424 UINT8 huffval[256];
nuclear@26 425 int i, index, count;
nuclear@26 426 JHUFF_TBL **htblptr;
nuclear@26 427 INPUT_VARS(cinfo);
nuclear@26 428
nuclear@26 429 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 430 length -= 2;
nuclear@26 431
nuclear@26 432 while (length > 16) {
nuclear@26 433 INPUT_BYTE(cinfo, index, return FALSE);
nuclear@26 434
nuclear@26 435 TRACEMS1(cinfo, 1, JTRC_DHT, index);
nuclear@26 436
nuclear@26 437 bits[0] = 0;
nuclear@26 438 count = 0;
nuclear@26 439 for (i = 1; i <= 16; i++) {
nuclear@26 440 INPUT_BYTE(cinfo, bits[i], return FALSE);
nuclear@26 441 count += bits[i];
nuclear@26 442 }
nuclear@26 443
nuclear@26 444 length -= 1 + 16;
nuclear@26 445
nuclear@26 446 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@26 447 bits[1], bits[2], bits[3], bits[4],
nuclear@26 448 bits[5], bits[6], bits[7], bits[8]);
nuclear@26 449 TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@26 450 bits[9], bits[10], bits[11], bits[12],
nuclear@26 451 bits[13], bits[14], bits[15], bits[16]);
nuclear@26 452
nuclear@26 453 /* Here we just do minimal validation of the counts to avoid walking
nuclear@26 454 * off the end of our table space. jdhuff.c will check more carefully.
nuclear@26 455 */
nuclear@26 456 if (count > 256 || ((INT32) count) > length)
nuclear@26 457 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
nuclear@26 458
nuclear@26 459 for (i = 0; i < count; i++)
nuclear@26 460 INPUT_BYTE(cinfo, huffval[i], return FALSE);
nuclear@26 461
nuclear@26 462 length -= count;
nuclear@26 463
nuclear@26 464 if (index & 0x10) { /* AC table definition */
nuclear@26 465 index -= 0x10;
nuclear@26 466 htblptr = &cinfo->ac_huff_tbl_ptrs[index];
nuclear@26 467 } else { /* DC table definition */
nuclear@26 468 htblptr = &cinfo->dc_huff_tbl_ptrs[index];
nuclear@26 469 }
nuclear@26 470
nuclear@26 471 if (index < 0 || index >= NUM_HUFF_TBLS)
nuclear@26 472 ERREXIT1(cinfo, JERR_DHT_INDEX, index);
nuclear@26 473
nuclear@26 474 if (*htblptr == NULL)
nuclear@26 475 *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
nuclear@26 476
nuclear@26 477 MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
nuclear@26 478 MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
nuclear@26 479 }
nuclear@26 480
nuclear@26 481 if (length != 0)
nuclear@26 482 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 483
nuclear@26 484 INPUT_SYNC(cinfo);
nuclear@26 485 return TRUE;
nuclear@26 486 }
nuclear@26 487
nuclear@26 488
nuclear@26 489 LOCAL(boolean)
nuclear@26 490 get_dqt (j_decompress_ptr cinfo)
nuclear@26 491 /* Process a DQT marker */
nuclear@26 492 {
nuclear@26 493 INT32 length;
nuclear@26 494 int n, i, prec;
nuclear@26 495 unsigned int tmp;
nuclear@26 496 JQUANT_TBL *quant_ptr;
nuclear@26 497 INPUT_VARS(cinfo);
nuclear@26 498
nuclear@26 499 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 500 length -= 2;
nuclear@26 501
nuclear@26 502 while (length > 0) {
nuclear@26 503 INPUT_BYTE(cinfo, n, return FALSE);
nuclear@26 504 prec = n >> 4;
nuclear@26 505 n &= 0x0F;
nuclear@26 506
nuclear@26 507 TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
nuclear@26 508
nuclear@26 509 if (n >= NUM_QUANT_TBLS)
nuclear@26 510 ERREXIT1(cinfo, JERR_DQT_INDEX, n);
nuclear@26 511
nuclear@26 512 if (cinfo->quant_tbl_ptrs[n] == NULL)
nuclear@26 513 cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
nuclear@26 514 quant_ptr = cinfo->quant_tbl_ptrs[n];
nuclear@26 515
nuclear@26 516 for (i = 0; i < DCTSIZE2; i++) {
nuclear@26 517 if (prec)
nuclear@26 518 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@26 519 else
nuclear@26 520 INPUT_BYTE(cinfo, tmp, return FALSE);
nuclear@26 521 /* We convert the zigzag-order table to natural array order. */
nuclear@26 522 quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
nuclear@26 523 }
nuclear@26 524
nuclear@26 525 if (cinfo->err->trace_level >= 2) {
nuclear@26 526 for (i = 0; i < DCTSIZE2; i += 8) {
nuclear@26 527 TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
nuclear@26 528 quant_ptr->quantval[i], quant_ptr->quantval[i+1],
nuclear@26 529 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
nuclear@26 530 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
nuclear@26 531 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
nuclear@26 532 }
nuclear@26 533 }
nuclear@26 534
nuclear@26 535 length -= DCTSIZE2+1;
nuclear@26 536 if (prec) length -= DCTSIZE2;
nuclear@26 537 }
nuclear@26 538
nuclear@26 539 if (length != 0)
nuclear@26 540 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 541
nuclear@26 542 INPUT_SYNC(cinfo);
nuclear@26 543 return TRUE;
nuclear@26 544 }
nuclear@26 545
nuclear@26 546
nuclear@26 547 LOCAL(boolean)
nuclear@26 548 get_dri (j_decompress_ptr cinfo)
nuclear@26 549 /* Process a DRI marker */
nuclear@26 550 {
nuclear@26 551 INT32 length;
nuclear@26 552 unsigned int tmp;
nuclear@26 553 INPUT_VARS(cinfo);
nuclear@26 554
nuclear@26 555 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 556
nuclear@26 557 if (length != 4)
nuclear@26 558 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@26 559
nuclear@26 560 INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@26 561
nuclear@26 562 TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
nuclear@26 563
nuclear@26 564 cinfo->restart_interval = tmp;
nuclear@26 565
nuclear@26 566 INPUT_SYNC(cinfo);
nuclear@26 567 return TRUE;
nuclear@26 568 }
nuclear@26 569
nuclear@26 570
nuclear@26 571 /*
nuclear@26 572 * Routines for processing APPn and COM markers.
nuclear@26 573 * These are either saved in memory or discarded, per application request.
nuclear@26 574 * APP0 and APP14 are specially checked to see if they are
nuclear@26 575 * JFIF and Adobe markers, respectively.
nuclear@26 576 */
nuclear@26 577
nuclear@26 578 #define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
nuclear@26 579 #define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
nuclear@26 580 #define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
nuclear@26 581
nuclear@26 582
nuclear@26 583 LOCAL(void)
nuclear@26 584 examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@26 585 unsigned int datalen, INT32 remaining)
nuclear@26 586 /* Examine first few bytes from an APP0.
nuclear@26 587 * Take appropriate action if it is a JFIF marker.
nuclear@26 588 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@26 589 */
nuclear@26 590 {
nuclear@26 591 INT32 totallen = (INT32) datalen + remaining;
nuclear@26 592
nuclear@26 593 if (datalen >= APP0_DATA_LEN &&
nuclear@26 594 GETJOCTET(data[0]) == 0x4A &&
nuclear@26 595 GETJOCTET(data[1]) == 0x46 &&
nuclear@26 596 GETJOCTET(data[2]) == 0x49 &&
nuclear@26 597 GETJOCTET(data[3]) == 0x46 &&
nuclear@26 598 GETJOCTET(data[4]) == 0) {
nuclear@26 599 /* Found JFIF APP0 marker: save info */
nuclear@26 600 cinfo->saw_JFIF_marker = TRUE;
nuclear@26 601 cinfo->JFIF_major_version = GETJOCTET(data[5]);
nuclear@26 602 cinfo->JFIF_minor_version = GETJOCTET(data[6]);
nuclear@26 603 cinfo->density_unit = GETJOCTET(data[7]);
nuclear@26 604 cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
nuclear@26 605 cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
nuclear@26 606 /* Check version.
nuclear@26 607 * Major version must be 1, anything else signals an incompatible change.
nuclear@26 608 * (We used to treat this as an error, but now it's a nonfatal warning,
nuclear@26 609 * because some bozo at Hijaak couldn't read the spec.)
nuclear@26 610 * Minor version should be 0..2, but process anyway if newer.
nuclear@26 611 */
nuclear@26 612 if (cinfo->JFIF_major_version != 1)
nuclear@26 613 WARNMS2(cinfo, JWRN_JFIF_MAJOR,
nuclear@26 614 cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
nuclear@26 615 /* Generate trace messages */
nuclear@26 616 TRACEMS5(cinfo, 1, JTRC_JFIF,
nuclear@26 617 cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
nuclear@26 618 cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
nuclear@26 619 /* Validate thumbnail dimensions and issue appropriate messages */
nuclear@26 620 if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
nuclear@26 621 TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
nuclear@26 622 GETJOCTET(data[12]), GETJOCTET(data[13]));
nuclear@26 623 totallen -= APP0_DATA_LEN;
nuclear@26 624 if (totallen !=
nuclear@26 625 ((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
nuclear@26 626 TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
nuclear@26 627 } else if (datalen >= 6 &&
nuclear@26 628 GETJOCTET(data[0]) == 0x4A &&
nuclear@26 629 GETJOCTET(data[1]) == 0x46 &&
nuclear@26 630 GETJOCTET(data[2]) == 0x58 &&
nuclear@26 631 GETJOCTET(data[3]) == 0x58 &&
nuclear@26 632 GETJOCTET(data[4]) == 0) {
nuclear@26 633 /* Found JFIF "JFXX" extension APP0 marker */
nuclear@26 634 /* The library doesn't actually do anything with these,
nuclear@26 635 * but we try to produce a helpful trace message.
nuclear@26 636 */
nuclear@26 637 switch (GETJOCTET(data[5])) {
nuclear@26 638 case 0x10:
nuclear@26 639 TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
nuclear@26 640 break;
nuclear@26 641 case 0x11:
nuclear@26 642 TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
nuclear@26 643 break;
nuclear@26 644 case 0x13:
nuclear@26 645 TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
nuclear@26 646 break;
nuclear@26 647 default:
nuclear@26 648 TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
nuclear@26 649 GETJOCTET(data[5]), (int) totallen);
nuclear@26 650 break;
nuclear@26 651 }
nuclear@26 652 } else {
nuclear@26 653 /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
nuclear@26 654 TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
nuclear@26 655 }
nuclear@26 656 }
nuclear@26 657
nuclear@26 658
nuclear@26 659 LOCAL(void)
nuclear@26 660 examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@26 661 unsigned int datalen, INT32 remaining)
nuclear@26 662 /* Examine first few bytes from an APP14.
nuclear@26 663 * Take appropriate action if it is an Adobe marker.
nuclear@26 664 * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@26 665 */
nuclear@26 666 {
nuclear@26 667 unsigned int version, flags0, flags1, transform;
nuclear@26 668
nuclear@26 669 if (datalen >= APP14_DATA_LEN &&
nuclear@26 670 GETJOCTET(data[0]) == 0x41 &&
nuclear@26 671 GETJOCTET(data[1]) == 0x64 &&
nuclear@26 672 GETJOCTET(data[2]) == 0x6F &&
nuclear@26 673 GETJOCTET(data[3]) == 0x62 &&
nuclear@26 674 GETJOCTET(data[4]) == 0x65) {
nuclear@26 675 /* Found Adobe APP14 marker */
nuclear@26 676 version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
nuclear@26 677 flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
nuclear@26 678 flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
nuclear@26 679 transform = GETJOCTET(data[11]);
nuclear@26 680 TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
nuclear@26 681 cinfo->saw_Adobe_marker = TRUE;
nuclear@26 682 cinfo->Adobe_transform = (UINT8) transform;
nuclear@26 683 } else {
nuclear@26 684 /* Start of APP14 does not match "Adobe", or too short */
nuclear@26 685 TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
nuclear@26 686 }
nuclear@26 687 }
nuclear@26 688
nuclear@26 689
nuclear@26 690 METHODDEF(boolean)
nuclear@26 691 get_interesting_appn (j_decompress_ptr cinfo)
nuclear@26 692 /* Process an APP0 or APP14 marker without saving it */
nuclear@26 693 {
nuclear@26 694 INT32 length;
nuclear@26 695 JOCTET b[APPN_DATA_LEN];
nuclear@26 696 unsigned int i, numtoread;
nuclear@26 697 INPUT_VARS(cinfo);
nuclear@26 698
nuclear@26 699 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 700 length -= 2;
nuclear@26 701
nuclear@26 702 /* get the interesting part of the marker data */
nuclear@26 703 if (length >= APPN_DATA_LEN)
nuclear@26 704 numtoread = APPN_DATA_LEN;
nuclear@26 705 else if (length > 0)
nuclear@26 706 numtoread = (unsigned int) length;
nuclear@26 707 else
nuclear@26 708 numtoread = 0;
nuclear@26 709 for (i = 0; i < numtoread; i++)
nuclear@26 710 INPUT_BYTE(cinfo, b[i], return FALSE);
nuclear@26 711 length -= numtoread;
nuclear@26 712
nuclear@26 713 /* process it */
nuclear@26 714 switch (cinfo->unread_marker) {
nuclear@26 715 case M_APP0:
nuclear@26 716 examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@26 717 break;
nuclear@26 718 case M_APP14:
nuclear@26 719 examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@26 720 break;
nuclear@26 721 default:
nuclear@26 722 /* can't get here unless jpeg_save_markers chooses wrong processor */
nuclear@26 723 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@26 724 break;
nuclear@26 725 }
nuclear@26 726
nuclear@26 727 /* skip any remaining data -- could be lots */
nuclear@26 728 INPUT_SYNC(cinfo);
nuclear@26 729 if (length > 0)
nuclear@26 730 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@26 731
nuclear@26 732 return TRUE;
nuclear@26 733 }
nuclear@26 734
nuclear@26 735
nuclear@26 736 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@26 737
nuclear@26 738 METHODDEF(boolean)
nuclear@26 739 save_marker (j_decompress_ptr cinfo)
nuclear@26 740 /* Save an APPn or COM marker into the marker list */
nuclear@26 741 {
nuclear@26 742 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@26 743 jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
nuclear@26 744 unsigned int bytes_read, data_length;
nuclear@26 745 JOCTET FAR * data;
nuclear@26 746 INT32 length = 0;
nuclear@26 747 INPUT_VARS(cinfo);
nuclear@26 748
nuclear@26 749 if (cur_marker == NULL) {
nuclear@26 750 /* begin reading a marker */
nuclear@26 751 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 752 length -= 2;
nuclear@26 753 if (length >= 0) { /* watch out for bogus length word */
nuclear@26 754 /* figure out how much we want to save */
nuclear@26 755 unsigned int limit;
nuclear@26 756 if (cinfo->unread_marker == (int) M_COM)
nuclear@26 757 limit = marker->length_limit_COM;
nuclear@26 758 else
nuclear@26 759 limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
nuclear@26 760 if ((unsigned int) length < limit)
nuclear@26 761 limit = (unsigned int) length;
nuclear@26 762 /* allocate and initialize the marker item */
nuclear@26 763 cur_marker = (jpeg_saved_marker_ptr)
nuclear@26 764 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26 765 SIZEOF(struct jpeg_marker_struct) + limit);
nuclear@26 766 cur_marker->next = NULL;
nuclear@26 767 cur_marker->marker = (UINT8) cinfo->unread_marker;
nuclear@26 768 cur_marker->original_length = (unsigned int) length;
nuclear@26 769 cur_marker->data_length = limit;
nuclear@26 770 /* data area is just beyond the jpeg_marker_struct */
nuclear@26 771 data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
nuclear@26 772 marker->cur_marker = cur_marker;
nuclear@26 773 marker->bytes_read = 0;
nuclear@26 774 bytes_read = 0;
nuclear@26 775 data_length = limit;
nuclear@26 776 } else {
nuclear@26 777 /* deal with bogus length word */
nuclear@26 778 bytes_read = data_length = 0;
nuclear@26 779 data = NULL;
nuclear@26 780 }
nuclear@26 781 } else {
nuclear@26 782 /* resume reading a marker */
nuclear@26 783 bytes_read = marker->bytes_read;
nuclear@26 784 data_length = cur_marker->data_length;
nuclear@26 785 data = cur_marker->data + bytes_read;
nuclear@26 786 }
nuclear@26 787
nuclear@26 788 while (bytes_read < data_length) {
nuclear@26 789 INPUT_SYNC(cinfo); /* move the restart point to here */
nuclear@26 790 marker->bytes_read = bytes_read;
nuclear@26 791 /* If there's not at least one byte in buffer, suspend */
nuclear@26 792 MAKE_BYTE_AVAIL(cinfo, return FALSE);
nuclear@26 793 /* Copy bytes with reasonable rapidity */
nuclear@26 794 while (bytes_read < data_length && bytes_in_buffer > 0) {
nuclear@26 795 *data++ = *next_input_byte++;
nuclear@26 796 bytes_in_buffer--;
nuclear@26 797 bytes_read++;
nuclear@26 798 }
nuclear@26 799 }
nuclear@26 800
nuclear@26 801 /* Done reading what we want to read */
nuclear@26 802 if (cur_marker != NULL) { /* will be NULL if bogus length word */
nuclear@26 803 /* Add new marker to end of list */
nuclear@26 804 if (cinfo->marker_list == NULL) {
nuclear@26 805 cinfo->marker_list = cur_marker;
nuclear@26 806 } else {
nuclear@26 807 jpeg_saved_marker_ptr prev = cinfo->marker_list;
nuclear@26 808 while (prev->next != NULL)
nuclear@26 809 prev = prev->next;
nuclear@26 810 prev->next = cur_marker;
nuclear@26 811 }
nuclear@26 812 /* Reset pointer & calc remaining data length */
nuclear@26 813 data = cur_marker->data;
nuclear@26 814 length = cur_marker->original_length - data_length;
nuclear@26 815 }
nuclear@26 816 /* Reset to initial state for next marker */
nuclear@26 817 marker->cur_marker = NULL;
nuclear@26 818
nuclear@26 819 /* Process the marker if interesting; else just make a generic trace msg */
nuclear@26 820 switch (cinfo->unread_marker) {
nuclear@26 821 case M_APP0:
nuclear@26 822 examine_app0(cinfo, data, data_length, length);
nuclear@26 823 break;
nuclear@26 824 case M_APP14:
nuclear@26 825 examine_app14(cinfo, data, data_length, length);
nuclear@26 826 break;
nuclear@26 827 default:
nuclear@26 828 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
nuclear@26 829 (int) (data_length + length));
nuclear@26 830 break;
nuclear@26 831 }
nuclear@26 832
nuclear@26 833 /* skip any remaining data -- could be lots */
nuclear@26 834 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@26 835 if (length > 0)
nuclear@26 836 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@26 837
nuclear@26 838 return TRUE;
nuclear@26 839 }
nuclear@26 840
nuclear@26 841 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@26 842
nuclear@26 843
nuclear@26 844 METHODDEF(boolean)
nuclear@26 845 skip_variable (j_decompress_ptr cinfo)
nuclear@26 846 /* Skip over an unknown or uninteresting variable-length marker */
nuclear@26 847 {
nuclear@26 848 INT32 length;
nuclear@26 849 INPUT_VARS(cinfo);
nuclear@26 850
nuclear@26 851 INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@26 852 length -= 2;
nuclear@26 853
nuclear@26 854 TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
nuclear@26 855
nuclear@26 856 INPUT_SYNC(cinfo); /* do before skip_input_data */
nuclear@26 857 if (length > 0)
nuclear@26 858 (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@26 859
nuclear@26 860 return TRUE;
nuclear@26 861 }
nuclear@26 862
nuclear@26 863
nuclear@26 864 /*
nuclear@26 865 * Find the next JPEG marker, save it in cinfo->unread_marker.
nuclear@26 866 * Returns FALSE if had to suspend before reaching a marker;
nuclear@26 867 * in that case cinfo->unread_marker is unchanged.
nuclear@26 868 *
nuclear@26 869 * Note that the result might not be a valid marker code,
nuclear@26 870 * but it will never be 0 or FF.
nuclear@26 871 */
nuclear@26 872
nuclear@26 873 LOCAL(boolean)
nuclear@26 874 next_marker (j_decompress_ptr cinfo)
nuclear@26 875 {
nuclear@26 876 int c;
nuclear@26 877 INPUT_VARS(cinfo);
nuclear@26 878
nuclear@26 879 for (;;) {
nuclear@26 880 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 881 /* Skip any non-FF bytes.
nuclear@26 882 * This may look a bit inefficient, but it will not occur in a valid file.
nuclear@26 883 * We sync after each discarded byte so that a suspending data source
nuclear@26 884 * can discard the byte from its buffer.
nuclear@26 885 */
nuclear@26 886 while (c != 0xFF) {
nuclear@26 887 cinfo->marker->discarded_bytes++;
nuclear@26 888 INPUT_SYNC(cinfo);
nuclear@26 889 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 890 }
nuclear@26 891 /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
nuclear@26 892 * pad bytes, so don't count them in discarded_bytes. We assume there
nuclear@26 893 * will not be so many consecutive FF bytes as to overflow a suspending
nuclear@26 894 * data source's input buffer.
nuclear@26 895 */
nuclear@26 896 do {
nuclear@26 897 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 898 } while (c == 0xFF);
nuclear@26 899 if (c != 0)
nuclear@26 900 break; /* found a valid marker, exit loop */
nuclear@26 901 /* Reach here if we found a stuffed-zero data sequence (FF/00).
nuclear@26 902 * Discard it and loop back to try again.
nuclear@26 903 */
nuclear@26 904 cinfo->marker->discarded_bytes += 2;
nuclear@26 905 INPUT_SYNC(cinfo);
nuclear@26 906 }
nuclear@26 907
nuclear@26 908 if (cinfo->marker->discarded_bytes != 0) {
nuclear@26 909 WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
nuclear@26 910 cinfo->marker->discarded_bytes = 0;
nuclear@26 911 }
nuclear@26 912
nuclear@26 913 cinfo->unread_marker = c;
nuclear@26 914
nuclear@26 915 INPUT_SYNC(cinfo);
nuclear@26 916 return TRUE;
nuclear@26 917 }
nuclear@26 918
nuclear@26 919
nuclear@26 920 LOCAL(boolean)
nuclear@26 921 first_marker (j_decompress_ptr cinfo)
nuclear@26 922 /* Like next_marker, but used to obtain the initial SOI marker. */
nuclear@26 923 /* For this marker, we do not allow preceding garbage or fill; otherwise,
nuclear@26 924 * we might well scan an entire input file before realizing it ain't JPEG.
nuclear@26 925 * If an application wants to process non-JFIF files, it must seek to the
nuclear@26 926 * SOI before calling the JPEG library.
nuclear@26 927 */
nuclear@26 928 {
nuclear@26 929 int c, c2;
nuclear@26 930 INPUT_VARS(cinfo);
nuclear@26 931
nuclear@26 932 INPUT_BYTE(cinfo, c, return FALSE);
nuclear@26 933 INPUT_BYTE(cinfo, c2, return FALSE);
nuclear@26 934 if (c != 0xFF || c2 != (int) M_SOI)
nuclear@26 935 ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
nuclear@26 936
nuclear@26 937 cinfo->unread_marker = c2;
nuclear@26 938
nuclear@26 939 INPUT_SYNC(cinfo);
nuclear@26 940 return TRUE;
nuclear@26 941 }
nuclear@26 942
nuclear@26 943
nuclear@26 944 /*
nuclear@26 945 * Read markers until SOS or EOI.
nuclear@26 946 *
nuclear@26 947 * Returns same codes as are defined for jpeg_consume_input:
nuclear@26 948 * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
nuclear@26 949 */
nuclear@26 950
nuclear@26 951 METHODDEF(int)
nuclear@26 952 read_markers (j_decompress_ptr cinfo)
nuclear@26 953 {
nuclear@26 954 /* Outer loop repeats once for each marker. */
nuclear@26 955 for (;;) {
nuclear@26 956 /* Collect the marker proper, unless we already did. */
nuclear@26 957 /* NB: first_marker() enforces the requirement that SOI appear first. */
nuclear@26 958 if (cinfo->unread_marker == 0) {
nuclear@26 959 if (! cinfo->marker->saw_SOI) {
nuclear@26 960 if (! first_marker(cinfo))
nuclear@26 961 return JPEG_SUSPENDED;
nuclear@26 962 } else {
nuclear@26 963 if (! next_marker(cinfo))
nuclear@26 964 return JPEG_SUSPENDED;
nuclear@26 965 }
nuclear@26 966 }
nuclear@26 967 /* At this point cinfo->unread_marker contains the marker code and the
nuclear@26 968 * input point is just past the marker proper, but before any parameters.
nuclear@26 969 * A suspension will cause us to return with this state still true.
nuclear@26 970 */
nuclear@26 971 switch (cinfo->unread_marker) {
nuclear@26 972 case M_SOI:
nuclear@26 973 if (! get_soi(cinfo))
nuclear@26 974 return JPEG_SUSPENDED;
nuclear@26 975 break;
nuclear@26 976
nuclear@26 977 case M_SOF0: /* Baseline */
nuclear@26 978 case M_SOF1: /* Extended sequential, Huffman */
nuclear@26 979 if (! get_sof(cinfo, FALSE, FALSE))
nuclear@26 980 return JPEG_SUSPENDED;
nuclear@26 981 break;
nuclear@26 982
nuclear@26 983 case M_SOF2: /* Progressive, Huffman */
nuclear@26 984 if (! get_sof(cinfo, TRUE, FALSE))
nuclear@26 985 return JPEG_SUSPENDED;
nuclear@26 986 break;
nuclear@26 987
nuclear@26 988 case M_SOF9: /* Extended sequential, arithmetic */
nuclear@26 989 if (! get_sof(cinfo, FALSE, TRUE))
nuclear@26 990 return JPEG_SUSPENDED;
nuclear@26 991 break;
nuclear@26 992
nuclear@26 993 case M_SOF10: /* Progressive, arithmetic */
nuclear@26 994 if (! get_sof(cinfo, TRUE, TRUE))
nuclear@26 995 return JPEG_SUSPENDED;
nuclear@26 996 break;
nuclear@26 997
nuclear@26 998 /* Currently unsupported SOFn types */
nuclear@26 999 case M_SOF3: /* Lossless, Huffman */
nuclear@26 1000 case M_SOF5: /* Differential sequential, Huffman */
nuclear@26 1001 case M_SOF6: /* Differential progressive, Huffman */
nuclear@26 1002 case M_SOF7: /* Differential lossless, Huffman */
nuclear@26 1003 case M_JPG: /* Reserved for JPEG extensions */
nuclear@26 1004 case M_SOF11: /* Lossless, arithmetic */
nuclear@26 1005 case M_SOF13: /* Differential sequential, arithmetic */
nuclear@26 1006 case M_SOF14: /* Differential progressive, arithmetic */
nuclear@26 1007 case M_SOF15: /* Differential lossless, arithmetic */
nuclear@26 1008 ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
nuclear@26 1009 break;
nuclear@26 1010
nuclear@26 1011 case M_SOS:
nuclear@26 1012 if (! get_sos(cinfo))
nuclear@26 1013 return JPEG_SUSPENDED;
nuclear@26 1014 cinfo->unread_marker = 0; /* processed the marker */
nuclear@26 1015 return JPEG_REACHED_SOS;
nuclear@26 1016
nuclear@26 1017 case M_EOI:
nuclear@26 1018 TRACEMS(cinfo, 1, JTRC_EOI);
nuclear@26 1019 cinfo->unread_marker = 0; /* processed the marker */
nuclear@26 1020 return JPEG_REACHED_EOI;
nuclear@26 1021
nuclear@26 1022 case M_DAC:
nuclear@26 1023 if (! get_dac(cinfo))
nuclear@26 1024 return JPEG_SUSPENDED;
nuclear@26 1025 break;
nuclear@26 1026
nuclear@26 1027 case M_DHT:
nuclear@26 1028 if (! get_dht(cinfo))
nuclear@26 1029 return JPEG_SUSPENDED;
nuclear@26 1030 break;
nuclear@26 1031
nuclear@26 1032 case M_DQT:
nuclear@26 1033 if (! get_dqt(cinfo))
nuclear@26 1034 return JPEG_SUSPENDED;
nuclear@26 1035 break;
nuclear@26 1036
nuclear@26 1037 case M_DRI:
nuclear@26 1038 if (! get_dri(cinfo))
nuclear@26 1039 return JPEG_SUSPENDED;
nuclear@26 1040 break;
nuclear@26 1041
nuclear@26 1042 case M_APP0:
nuclear@26 1043 case M_APP1:
nuclear@26 1044 case M_APP2:
nuclear@26 1045 case M_APP3:
nuclear@26 1046 case M_APP4:
nuclear@26 1047 case M_APP5:
nuclear@26 1048 case M_APP6:
nuclear@26 1049 case M_APP7:
nuclear@26 1050 case M_APP8:
nuclear@26 1051 case M_APP9:
nuclear@26 1052 case M_APP10:
nuclear@26 1053 case M_APP11:
nuclear@26 1054 case M_APP12:
nuclear@26 1055 case M_APP13:
nuclear@26 1056 case M_APP14:
nuclear@26 1057 case M_APP15:
nuclear@26 1058 if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
nuclear@26 1059 cinfo->unread_marker - (int) M_APP0]) (cinfo))
nuclear@26 1060 return JPEG_SUSPENDED;
nuclear@26 1061 break;
nuclear@26 1062
nuclear@26 1063 case M_COM:
nuclear@26 1064 if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
nuclear@26 1065 return JPEG_SUSPENDED;
nuclear@26 1066 break;
nuclear@26 1067
nuclear@26 1068 case M_RST0: /* these are all parameterless */
nuclear@26 1069 case M_RST1:
nuclear@26 1070 case M_RST2:
nuclear@26 1071 case M_RST3:
nuclear@26 1072 case M_RST4:
nuclear@26 1073 case M_RST5:
nuclear@26 1074 case M_RST6:
nuclear@26 1075 case M_RST7:
nuclear@26 1076 case M_TEM:
nuclear@26 1077 TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
nuclear@26 1078 break;
nuclear@26 1079
nuclear@26 1080 case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
nuclear@26 1081 if (! skip_variable(cinfo))
nuclear@26 1082 return JPEG_SUSPENDED;
nuclear@26 1083 break;
nuclear@26 1084
nuclear@26 1085 default: /* must be DHP, EXP, JPGn, or RESn */
nuclear@26 1086 /* For now, we treat the reserved markers as fatal errors since they are
nuclear@26 1087 * likely to be used to signal incompatible JPEG Part 3 extensions.
nuclear@26 1088 * Once the JPEG 3 version-number marker is well defined, this code
nuclear@26 1089 * ought to change!
nuclear@26 1090 */
nuclear@26 1091 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@26 1092 break;
nuclear@26 1093 }
nuclear@26 1094 /* Successfully processed marker, so reset state variable */
nuclear@26 1095 cinfo->unread_marker = 0;
nuclear@26 1096 } /* end loop */
nuclear@26 1097 }
nuclear@26 1098
nuclear@26 1099
nuclear@26 1100 /*
nuclear@26 1101 * Read a restart marker, which is expected to appear next in the datastream;
nuclear@26 1102 * if the marker is not there, take appropriate recovery action.
nuclear@26 1103 * Returns FALSE if suspension is required.
nuclear@26 1104 *
nuclear@26 1105 * This is called by the entropy decoder after it has read an appropriate
nuclear@26 1106 * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
nuclear@26 1107 * has already read a marker from the data source. Under normal conditions
nuclear@26 1108 * cinfo->unread_marker will be reset to 0 before returning; if not reset,
nuclear@26 1109 * it holds a marker which the decoder will be unable to read past.
nuclear@26 1110 */
nuclear@26 1111
nuclear@26 1112 METHODDEF(boolean)
nuclear@26 1113 read_restart_marker (j_decompress_ptr cinfo)
nuclear@26 1114 {
nuclear@26 1115 /* Obtain a marker unless we already did. */
nuclear@26 1116 /* Note that next_marker will complain if it skips any data. */
nuclear@26 1117 if (cinfo->unread_marker == 0) {
nuclear@26 1118 if (! next_marker(cinfo))
nuclear@26 1119 return FALSE;
nuclear@26 1120 }
nuclear@26 1121
nuclear@26 1122 if (cinfo->unread_marker ==
nuclear@26 1123 ((int) M_RST0 + cinfo->marker->next_restart_num)) {
nuclear@26 1124 /* Normal case --- swallow the marker and let entropy decoder continue */
nuclear@26 1125 TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
nuclear@26 1126 cinfo->unread_marker = 0;
nuclear@26 1127 } else {
nuclear@26 1128 /* Uh-oh, the restart markers have been messed up. */
nuclear@26 1129 /* Let the data source manager determine how to resync. */
nuclear@26 1130 if (! (*cinfo->src->resync_to_restart) (cinfo,
nuclear@26 1131 cinfo->marker->next_restart_num))
nuclear@26 1132 return FALSE;
nuclear@26 1133 }
nuclear@26 1134
nuclear@26 1135 /* Update next-restart state */
nuclear@26 1136 cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
nuclear@26 1137
nuclear@26 1138 return TRUE;
nuclear@26 1139 }
nuclear@26 1140
nuclear@26 1141
nuclear@26 1142 /*
nuclear@26 1143 * This is the default resync_to_restart method for data source managers
nuclear@26 1144 * to use if they don't have any better approach. Some data source managers
nuclear@26 1145 * may be able to back up, or may have additional knowledge about the data
nuclear@26 1146 * which permits a more intelligent recovery strategy; such managers would
nuclear@26 1147 * presumably supply their own resync method.
nuclear@26 1148 *
nuclear@26 1149 * read_restart_marker calls resync_to_restart if it finds a marker other than
nuclear@26 1150 * the restart marker it was expecting. (This code is *not* used unless
nuclear@26 1151 * a nonzero restart interval has been declared.) cinfo->unread_marker is
nuclear@26 1152 * the marker code actually found (might be anything, except 0 or FF).
nuclear@26 1153 * The desired restart marker number (0..7) is passed as a parameter.
nuclear@26 1154 * This routine is supposed to apply whatever error recovery strategy seems
nuclear@26 1155 * appropriate in order to position the input stream to the next data segment.
nuclear@26 1156 * Note that cinfo->unread_marker is treated as a marker appearing before
nuclear@26 1157 * the current data-source input point; usually it should be reset to zero
nuclear@26 1158 * before returning.
nuclear@26 1159 * Returns FALSE if suspension is required.
nuclear@26 1160 *
nuclear@26 1161 * This implementation is substantially constrained by wanting to treat the
nuclear@26 1162 * input as a data stream; this means we can't back up. Therefore, we have
nuclear@26 1163 * only the following actions to work with:
nuclear@26 1164 * 1. Simply discard the marker and let the entropy decoder resume at next
nuclear@26 1165 * byte of file.
nuclear@26 1166 * 2. Read forward until we find another marker, discarding intervening
nuclear@26 1167 * data. (In theory we could look ahead within the current bufferload,
nuclear@26 1168 * without having to discard data if we don't find the desired marker.
nuclear@26 1169 * This idea is not implemented here, in part because it makes behavior
nuclear@26 1170 * dependent on buffer size and chance buffer-boundary positions.)
nuclear@26 1171 * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
nuclear@26 1172 * This will cause the entropy decoder to process an empty data segment,
nuclear@26 1173 * inserting dummy zeroes, and then we will reprocess the marker.
nuclear@26 1174 *
nuclear@26 1175 * #2 is appropriate if we think the desired marker lies ahead, while #3 is
nuclear@26 1176 * appropriate if the found marker is a future restart marker (indicating
nuclear@26 1177 * that we have missed the desired restart marker, probably because it got
nuclear@26 1178 * corrupted).
nuclear@26 1179 * We apply #2 or #3 if the found marker is a restart marker no more than
nuclear@26 1180 * two counts behind or ahead of the expected one. We also apply #2 if the
nuclear@26 1181 * found marker is not a legal JPEG marker code (it's certainly bogus data).
nuclear@26 1182 * If the found marker is a restart marker more than 2 counts away, we do #1
nuclear@26 1183 * (too much risk that the marker is erroneous; with luck we will be able to
nuclear@26 1184 * resync at some future point).
nuclear@26 1185 * For any valid non-restart JPEG marker, we apply #3. This keeps us from
nuclear@26 1186 * overrunning the end of a scan. An implementation limited to single-scan
nuclear@26 1187 * files might find it better to apply #2 for markers other than EOI, since
nuclear@26 1188 * any other marker would have to be bogus data in that case.
nuclear@26 1189 */
nuclear@26 1190
nuclear@26 1191 GLOBAL(boolean)
nuclear@26 1192 jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
nuclear@26 1193 {
nuclear@26 1194 int marker = cinfo->unread_marker;
nuclear@26 1195 int action = 1;
nuclear@26 1196
nuclear@26 1197 /* Always put up a warning. */
nuclear@26 1198 WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
nuclear@26 1199
nuclear@26 1200 /* Outer loop handles repeated decision after scanning forward. */
nuclear@26 1201 for (;;) {
nuclear@26 1202 if (marker < (int) M_SOF0)
nuclear@26 1203 action = 2; /* invalid marker */
nuclear@26 1204 else if (marker < (int) M_RST0 || marker > (int) M_RST7)
nuclear@26 1205 action = 3; /* valid non-restart marker */
nuclear@26 1206 else {
nuclear@26 1207 if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
nuclear@26 1208 marker == ((int) M_RST0 + ((desired+2) & 7)))
nuclear@26 1209 action = 3; /* one of the next two expected restarts */
nuclear@26 1210 else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
nuclear@26 1211 marker == ((int) M_RST0 + ((desired-2) & 7)))
nuclear@26 1212 action = 2; /* a prior restart, so advance */
nuclear@26 1213 else
nuclear@26 1214 action = 1; /* desired restart or too far away */
nuclear@26 1215 }
nuclear@26 1216 TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
nuclear@26 1217 switch (action) {
nuclear@26 1218 case 1:
nuclear@26 1219 /* Discard marker and let entropy decoder resume processing. */
nuclear@26 1220 cinfo->unread_marker = 0;
nuclear@26 1221 return TRUE;
nuclear@26 1222 case 2:
nuclear@26 1223 /* Scan to the next marker, and repeat the decision loop. */
nuclear@26 1224 if (! next_marker(cinfo))
nuclear@26 1225 return FALSE;
nuclear@26 1226 marker = cinfo->unread_marker;
nuclear@26 1227 break;
nuclear@26 1228 case 3:
nuclear@26 1229 /* Return without advancing past this marker. */
nuclear@26 1230 /* Entropy decoder will be forced to process an empty segment. */
nuclear@26 1231 return TRUE;
nuclear@26 1232 }
nuclear@26 1233 } /* end loop */
nuclear@26 1234 }
nuclear@26 1235
nuclear@26 1236
nuclear@26 1237 /*
nuclear@26 1238 * Reset marker processing state to begin a fresh datastream.
nuclear@26 1239 */
nuclear@26 1240
nuclear@26 1241 METHODDEF(void)
nuclear@26 1242 reset_marker_reader (j_decompress_ptr cinfo)
nuclear@26 1243 {
nuclear@26 1244 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@26 1245
nuclear@26 1246 cinfo->comp_info = NULL; /* until allocated by get_sof */
nuclear@26 1247 cinfo->input_scan_number = 0; /* no SOS seen yet */
nuclear@26 1248 cinfo->unread_marker = 0; /* no pending marker */
nuclear@26 1249 marker->pub.saw_SOI = FALSE; /* set internal state too */
nuclear@26 1250 marker->pub.saw_SOF = FALSE;
nuclear@26 1251 marker->pub.discarded_bytes = 0;
nuclear@26 1252 marker->cur_marker = NULL;
nuclear@26 1253 }
nuclear@26 1254
nuclear@26 1255
nuclear@26 1256 /*
nuclear@26 1257 * Initialize the marker reader module.
nuclear@26 1258 * This is called only once, when the decompression object is created.
nuclear@26 1259 */
nuclear@26 1260
nuclear@26 1261 GLOBAL(void)
nuclear@26 1262 jinit_marker_reader (j_decompress_ptr cinfo)
nuclear@26 1263 {
nuclear@26 1264 my_marker_ptr marker;
nuclear@26 1265 int i;
nuclear@26 1266
nuclear@26 1267 /* Create subobject in permanent pool */
nuclear@26 1268 marker = (my_marker_ptr)
nuclear@26 1269 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
nuclear@26 1270 SIZEOF(my_marker_reader));
nuclear@26 1271 cinfo->marker = (struct jpeg_marker_reader *) marker;
nuclear@26 1272 /* Initialize public method pointers */
nuclear@26 1273 marker->pub.reset_marker_reader = reset_marker_reader;
nuclear@26 1274 marker->pub.read_markers = read_markers;
nuclear@26 1275 marker->pub.read_restart_marker = read_restart_marker;
nuclear@26 1276 /* Initialize COM/APPn processing.
nuclear@26 1277 * By default, we examine and then discard APP0 and APP14,
nuclear@26 1278 * but simply discard COM and all other APPn.
nuclear@26 1279 */
nuclear@26 1280 marker->process_COM = skip_variable;
nuclear@26 1281 marker->length_limit_COM = 0;
nuclear@26 1282 for (i = 0; i < 16; i++) {
nuclear@26 1283 marker->process_APPn[i] = skip_variable;
nuclear@26 1284 marker->length_limit_APPn[i] = 0;
nuclear@26 1285 }
nuclear@26 1286 marker->process_APPn[0] = get_interesting_appn;
nuclear@26 1287 marker->process_APPn[14] = get_interesting_appn;
nuclear@26 1288 /* Reset marker processing state */
nuclear@26 1289 reset_marker_reader(cinfo);
nuclear@26 1290 }
nuclear@26 1291
nuclear@26 1292
nuclear@26 1293 /*
nuclear@26 1294 * Control saving of COM and APPn markers into marker_list.
nuclear@26 1295 */
nuclear@26 1296
nuclear@26 1297 #ifdef SAVE_MARKERS_SUPPORTED
nuclear@26 1298
nuclear@26 1299 GLOBAL(void)
nuclear@26 1300 jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
nuclear@26 1301 unsigned int length_limit)
nuclear@26 1302 {
nuclear@26 1303 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@26 1304 long maxlength;
nuclear@26 1305 jpeg_marker_parser_method processor;
nuclear@26 1306
nuclear@26 1307 /* Length limit mustn't be larger than what we can allocate
nuclear@26 1308 * (should only be a concern in a 16-bit environment).
nuclear@26 1309 */
nuclear@26 1310 maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
nuclear@26 1311 if (((long) length_limit) > maxlength)
nuclear@26 1312 length_limit = (unsigned int) maxlength;
nuclear@26 1313
nuclear@26 1314 /* Choose processor routine to use.
nuclear@26 1315 * APP0/APP14 have special requirements.
nuclear@26 1316 */
nuclear@26 1317 if (length_limit) {
nuclear@26 1318 processor = save_marker;
nuclear@26 1319 /* If saving APP0/APP14, save at least enough for our internal use. */
nuclear@26 1320 if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
nuclear@26 1321 length_limit = APP0_DATA_LEN;
nuclear@26 1322 else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
nuclear@26 1323 length_limit = APP14_DATA_LEN;
nuclear@26 1324 } else {
nuclear@26 1325 processor = skip_variable;
nuclear@26 1326 /* If discarding APP0/APP14, use our regular on-the-fly processor. */
nuclear@26 1327 if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
nuclear@26 1328 processor = get_interesting_appn;
nuclear@26 1329 }
nuclear@26 1330
nuclear@26 1331 if (marker_code == (int) M_COM) {
nuclear@26 1332 marker->process_COM = processor;
nuclear@26 1333 marker->length_limit_COM = length_limit;
nuclear@26 1334 } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
nuclear@26 1335 marker->process_APPn[marker_code - (int) M_APP0] = processor;
nuclear@26 1336 marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
nuclear@26 1337 } else
nuclear@26 1338 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@26 1339 }
nuclear@26 1340
nuclear@26 1341 #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@26 1342
nuclear@26 1343
nuclear@26 1344 /*
nuclear@26 1345 * Install a special processing method for COM or APPn markers.
nuclear@26 1346 */
nuclear@26 1347
nuclear@26 1348 GLOBAL(void)
nuclear@26 1349 jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
nuclear@26 1350 jpeg_marker_parser_method routine)
nuclear@26 1351 {
nuclear@26 1352 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@26 1353
nuclear@26 1354 if (marker_code == (int) M_COM)
nuclear@26 1355 marker->process_COM = routine;
nuclear@26 1356 else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
nuclear@26 1357 marker->process_APPn[marker_code - (int) M_APP0] = routine;
nuclear@26 1358 else
nuclear@26 1359 ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@26 1360 }