1 /* 2 * jcmarker.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1998, Thomas G. Lane. 6 * Modified 2003-2010 by Guido Vollbeding. 7 * libjpeg-turbo Modifications: 8 * Copyright (C) 2010, D. R. Commander. 9 * For conditions of distribution and use, see the accompanying README.ijg 10 * file. 11 * 12 * This file contains routines to write JPEG datastream markers. 13 */ 14 15 #define JPEG_INTERNALS 16 #include "jinclude.h" 17 #include "jpeglib.h" 18 #include "jpegcomp.h" 19 20 21 typedef enum { /* JPEG marker codes */ 22 M_SOF0 = 0xc0, 23 M_SOF1 = 0xc1, 24 M_SOF2 = 0xc2, 25 M_SOF3 = 0xc3, 26 27 M_SOF5 = 0xc5, 28 M_SOF6 = 0xc6, 29 M_SOF7 = 0xc7, 30 31 M_JPG = 0xc8, 32 M_SOF9 = 0xc9, 33 M_SOF10 = 0xca, 34 M_SOF11 = 0xcb, 35 36 M_SOF13 = 0xcd, 37 M_SOF14 = 0xce, 38 M_SOF15 = 0xcf, 39 40 M_DHT = 0xc4, 41 42 M_DAC = 0xcc, 43 44 M_RST0 = 0xd0, 45 M_RST1 = 0xd1, 46 M_RST2 = 0xd2, 47 M_RST3 = 0xd3, 48 M_RST4 = 0xd4, 49 M_RST5 = 0xd5, 50 M_RST6 = 0xd6, 51 M_RST7 = 0xd7, 52 53 M_SOI = 0xd8, 54 M_EOI = 0xd9, 55 M_SOS = 0xda, 56 M_DQT = 0xdb, 57 M_DNL = 0xdc, 58 M_DRI = 0xdd, 59 M_DHP = 0xde, 60 M_EXP = 0xdf, 61 62 M_APP0 = 0xe0, 63 M_APP1 = 0xe1, 64 M_APP2 = 0xe2, 65 M_APP3 = 0xe3, 66 M_APP4 = 0xe4, 67 M_APP5 = 0xe5, 68 M_APP6 = 0xe6, 69 M_APP7 = 0xe7, 70 M_APP8 = 0xe8, 71 M_APP9 = 0xe9, 72 M_APP10 = 0xea, 73 M_APP11 = 0xeb, 74 M_APP12 = 0xec, 75 M_APP13 = 0xed, 76 M_APP14 = 0xee, 77 M_APP15 = 0xef, 78 79 M_JPG0 = 0xf0, 80 M_JPG13 = 0xfd, 81 M_COM = 0xfe, 82 83 M_TEM = 0x01, 84 85 M_ERROR = 0x100 86 } JPEG_MARKER; 87 88 89 /* Private state */ 90 91 typedef struct { 92 struct jpeg_marker_writer pub; /* public fields */ 93 94 unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */ 95 } my_marker_writer; 96 97 typedef my_marker_writer *my_marker_ptr; 98 99 100 /* 101 * Basic output routines. 102 * 103 * Note that we do not support suspension while writing a marker. 104 * Therefore, an application using suspension must ensure that there is 105 * enough buffer space for the initial markers (typ. 600-700 bytes) before 106 * calling jpeg_start_compress, and enough space to write the trailing EOI 107 * (a few bytes) before calling jpeg_finish_compress. Multipass compression 108 * modes are not supported at all with suspension, so those two are the only 109 * points where markers will be written. 110 */ 111 112 LOCAL(void) 113 emit_byte (j_compress_ptr cinfo, int val) 114 /* Emit a byte */ 115 { 116 struct jpeg_destination_mgr *dest = cinfo->dest; 117 118 *(dest->next_output_byte)++ = (JOCTET) val; 119 if (--dest->free_in_buffer == 0) { 120 if (! (*dest->empty_output_buffer) (cinfo)) 121 ERREXIT(cinfo, JERR_CANT_SUSPEND); 122 } 123 } 124 125 126 LOCAL(void) 127 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark) 128 /* Emit a marker code */ 129 { 130 emit_byte(cinfo, 0xFF); 131 emit_byte(cinfo, (int) mark); 132 } 133 134 135 LOCAL(void) 136 emit_2bytes (j_compress_ptr cinfo, int value) 137 /* Emit a 2-byte integer; these are always MSB first in JPEG files */ 138 { 139 emit_byte(cinfo, (value >> 8) & 0xFF); 140 emit_byte(cinfo, value & 0xFF); 141 } 142 143 144 /* 145 * Routines to write specific marker types. 146 */ 147 148 LOCAL(int) 149 emit_dqt (j_compress_ptr cinfo, int index) 150 /* Emit a DQT marker */ 151 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */ 152 { 153 JQUANT_TBL *qtbl = cinfo->quant_tbl_ptrs[index]; 154 int prec; 155 int i; 156 157 if (qtbl == NULL) 158 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index); 159 160 prec = 0; 161 for (i = 0; i < DCTSIZE2; i++) { 162 if (qtbl->quantval[i] > 255) 163 prec = 1; 164 } 165 166 if (! qtbl->sent_table) { 167 emit_marker(cinfo, M_DQT); 168 169 emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2); 170 171 emit_byte(cinfo, index + (prec<<4)); 172 173 for (i = 0; i < DCTSIZE2; i++) { 174 /* The table entries must be emitted in zigzag order. */ 175 unsigned int qval = qtbl->quantval[jpeg_natural_order[i]]; 176 if (prec) 177 emit_byte(cinfo, (int) (qval >> 8)); 178 emit_byte(cinfo, (int) (qval & 0xFF)); 179 } 180 181 qtbl->sent_table = TRUE; 182 } 183 184 return prec; 185 } 186 187 188 LOCAL(void) 189 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac) 190 /* Emit a DHT marker */ 191 { 192 JHUFF_TBL *htbl; 193 int length, i; 194 195 if (is_ac) { 196 htbl = cinfo->ac_huff_tbl_ptrs[index]; 197 index += 0x10; /* output index has AC bit set */ 198 } else { 199 htbl = cinfo->dc_huff_tbl_ptrs[index]; 200 } 201 202 if (htbl == NULL) 203 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index); 204 205 if (! htbl->sent_table) { 206 emit_marker(cinfo, M_DHT); 207 208 length = 0; 209 for (i = 1; i <= 16; i++) 210 length += htbl->bits[i]; 211 212 emit_2bytes(cinfo, length + 2 + 1 + 16); 213 emit_byte(cinfo, index); 214 215 for (i = 1; i <= 16; i++) 216 emit_byte(cinfo, htbl->bits[i]); 217 218 for (i = 0; i < length; i++) 219 emit_byte(cinfo, htbl->huffval[i]); 220 221 htbl->sent_table = TRUE; 222 } 223 } 224 225 226 LOCAL(void) 227 emit_dac (j_compress_ptr cinfo) 228 /* Emit a DAC marker */ 229 /* Since the useful info is so small, we want to emit all the tables in */ 230 /* one DAC marker. Therefore this routine does its own scan of the table. */ 231 { 232 #ifdef C_ARITH_CODING_SUPPORTED 233 char dc_in_use[NUM_ARITH_TBLS]; 234 char ac_in_use[NUM_ARITH_TBLS]; 235 int length, i; 236 jpeg_component_info *compptr; 237 238 for (i = 0; i < NUM_ARITH_TBLS; i++) 239 dc_in_use[i] = ac_in_use[i] = 0; 240 241 for (i = 0; i < cinfo->comps_in_scan; i++) { 242 compptr = cinfo->cur_comp_info[i]; 243 /* DC needs no table for refinement scan */ 244 if (cinfo->Ss == 0 && cinfo->Ah == 0) 245 dc_in_use[compptr->dc_tbl_no] = 1; 246 /* AC needs no table when not present */ 247 if (cinfo->Se) 248 ac_in_use[compptr->ac_tbl_no] = 1; 249 } 250 251 length = 0; 252 for (i = 0; i < NUM_ARITH_TBLS; i++) 253 length += dc_in_use[i] + ac_in_use[i]; 254 255 if (length) { 256 emit_marker(cinfo, M_DAC); 257 258 emit_2bytes(cinfo, length*2 + 2); 259 260 for (i = 0; i < NUM_ARITH_TBLS; i++) { 261 if (dc_in_use[i]) { 262 emit_byte(cinfo, i); 263 emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4)); 264 } 265 if (ac_in_use[i]) { 266 emit_byte(cinfo, i + 0x10); 267 emit_byte(cinfo, cinfo->arith_ac_K[i]); 268 } 269 } 270 } 271 #endif /* C_ARITH_CODING_SUPPORTED */ 272 } 273 274 275 LOCAL(void) 276 emit_dri (j_compress_ptr cinfo) 277 /* Emit a DRI marker */ 278 { 279 emit_marker(cinfo, M_DRI); 280 281 emit_2bytes(cinfo, 4); /* fixed length */ 282 283 emit_2bytes(cinfo, (int) cinfo->restart_interval); 284 } 285 286 287 LOCAL(void) 288 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code) 289 /* Emit a SOF marker */ 290 { 291 int ci; 292 jpeg_component_info *compptr; 293 294 emit_marker(cinfo, code); 295 296 emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */ 297 298 /* Make sure image isn't bigger than SOF field can handle */ 299 if ((long) cinfo->_jpeg_height > 65535L || 300 (long) cinfo->_jpeg_width > 65535L) 301 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535); 302 303 emit_byte(cinfo, cinfo->data_precision); 304 emit_2bytes(cinfo, (int) cinfo->_jpeg_height); 305 emit_2bytes(cinfo, (int) cinfo->_jpeg_width); 306 307 emit_byte(cinfo, cinfo->num_components); 308 309 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 310 ci++, compptr++) { 311 emit_byte(cinfo, compptr->component_id); 312 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor); 313 emit_byte(cinfo, compptr->quant_tbl_no); 314 } 315 } 316 317 318 LOCAL(void) 319 emit_sos (j_compress_ptr cinfo) 320 /* Emit a SOS marker */ 321 { 322 int i, td, ta; 323 jpeg_component_info *compptr; 324 325 emit_marker(cinfo, M_SOS); 326 327 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */ 328 329 emit_byte(cinfo, cinfo->comps_in_scan); 330 331 for (i = 0; i < cinfo->comps_in_scan; i++) { 332 compptr = cinfo->cur_comp_info[i]; 333 emit_byte(cinfo, compptr->component_id); 334 335 /* We emit 0 for unused field(s); this is recommended by the P&M text 336 * but does not seem to be specified in the standard. 337 */ 338 339 /* DC needs no table for refinement scan */ 340 td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0; 341 /* AC needs no table when not present */ 342 ta = cinfo->Se ? compptr->ac_tbl_no : 0; 343 344 emit_byte(cinfo, (td << 4) + ta); 345 } 346 347 emit_byte(cinfo, cinfo->Ss); 348 emit_byte(cinfo, cinfo->Se); 349 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al); 350 } 351 352 353 LOCAL(void) 354 emit_jfif_app0 (j_compress_ptr cinfo) 355 /* Emit a JFIF-compliant APP0 marker */ 356 { 357 /* 358 * Length of APP0 block (2 bytes) 359 * Block ID (4 bytes - ASCII "JFIF") 360 * Zero byte (1 byte to terminate the ID string) 361 * Version Major, Minor (2 bytes - major first) 362 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm) 363 * Xdpu (2 bytes - dots per unit horizontal) 364 * Ydpu (2 bytes - dots per unit vertical) 365 * Thumbnail X size (1 byte) 366 * Thumbnail Y size (1 byte) 367 */ 368 369 emit_marker(cinfo, M_APP0); 370 371 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */ 372 373 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */ 374 emit_byte(cinfo, 0x46); 375 emit_byte(cinfo, 0x49); 376 emit_byte(cinfo, 0x46); 377 emit_byte(cinfo, 0); 378 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */ 379 emit_byte(cinfo, cinfo->JFIF_minor_version); 380 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */ 381 emit_2bytes(cinfo, (int) cinfo->X_density); 382 emit_2bytes(cinfo, (int) cinfo->Y_density); 383 emit_byte(cinfo, 0); /* No thumbnail image */ 384 emit_byte(cinfo, 0); 385 } 386 387 388 LOCAL(void) 389 emit_adobe_app14 (j_compress_ptr cinfo) 390 /* Emit an Adobe APP14 marker */ 391 { 392 /* 393 * Length of APP14 block (2 bytes) 394 * Block ID (5 bytes - ASCII "Adobe") 395 * Version Number (2 bytes - currently 100) 396 * Flags0 (2 bytes - currently 0) 397 * Flags1 (2 bytes - currently 0) 398 * Color transform (1 byte) 399 * 400 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files 401 * now in circulation seem to use Version = 100, so that's what we write. 402 * 403 * We write the color transform byte as 1 if the JPEG color space is 404 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with 405 * whether the encoder performed a transformation, which is pretty useless. 406 */ 407 408 emit_marker(cinfo, M_APP14); 409 410 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */ 411 412 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */ 413 emit_byte(cinfo, 0x64); 414 emit_byte(cinfo, 0x6F); 415 emit_byte(cinfo, 0x62); 416 emit_byte(cinfo, 0x65); 417 emit_2bytes(cinfo, 100); /* Version */ 418 emit_2bytes(cinfo, 0); /* Flags0 */ 419 emit_2bytes(cinfo, 0); /* Flags1 */ 420 switch (cinfo->jpeg_color_space) { 421 case JCS_YCbCr: 422 emit_byte(cinfo, 1); /* Color transform = 1 */ 423 break; 424 case JCS_YCCK: 425 emit_byte(cinfo, 2); /* Color transform = 2 */ 426 break; 427 default: 428 emit_byte(cinfo, 0); /* Color transform = 0 */ 429 break; 430 } 431 } 432 433 434 /* 435 * These routines allow writing an arbitrary marker with parameters. 436 * The only intended use is to emit COM or APPn markers after calling 437 * write_file_header and before calling write_frame_header. 438 * Other uses are not guaranteed to produce desirable results. 439 * Counting the parameter bytes properly is the caller's responsibility. 440 */ 441 442 METHODDEF(void) 443 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen) 444 /* Emit an arbitrary marker header */ 445 { 446 if (datalen > (unsigned int) 65533) /* safety check */ 447 ERREXIT(cinfo, JERR_BAD_LENGTH); 448 449 emit_marker(cinfo, (JPEG_MARKER) marker); 450 451 emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */ 452 } 453 454 METHODDEF(void) 455 write_marker_byte (j_compress_ptr cinfo, int val) 456 /* Emit one byte of marker parameters following write_marker_header */ 457 { 458 emit_byte(cinfo, val); 459 } 460 461 462 /* 463 * Write datastream header. 464 * This consists of an SOI and optional APPn markers. 465 * We recommend use of the JFIF marker, but not the Adobe marker, 466 * when using YCbCr or grayscale data. The JFIF marker should NOT 467 * be used for any other JPEG colorspace. The Adobe marker is helpful 468 * to distinguish RGB, CMYK, and YCCK colorspaces. 469 * Note that an application can write additional header markers after 470 * jpeg_start_compress returns. 471 */ 472 473 METHODDEF(void) 474 write_file_header (j_compress_ptr cinfo) 475 { 476 my_marker_ptr marker = (my_marker_ptr) cinfo->marker; 477 478 emit_marker(cinfo, M_SOI); /* first the SOI */ 479 480 /* SOI is defined to reset restart interval to 0 */ 481 marker->last_restart_interval = 0; 482 483 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */ 484 emit_jfif_app0(cinfo); 485 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */ 486 emit_adobe_app14(cinfo); 487 } 488 489 490 /* 491 * Write frame header. 492 * This consists of DQT and SOFn markers. 493 * Note that we do not emit the SOF until we have emitted the DQT(s). 494 * This avoids compatibility problems with incorrect implementations that 495 * try to error-check the quant table numbers as soon as they see the SOF. 496 */ 497 498 METHODDEF(void) 499 write_frame_header (j_compress_ptr cinfo) 500 { 501 int ci, prec; 502 boolean is_baseline; 503 jpeg_component_info *compptr; 504 505 /* Emit DQT for each quantization table. 506 * Note that emit_dqt() suppresses any duplicate tables. 507 */ 508 prec = 0; 509 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 510 ci++, compptr++) { 511 prec += emit_dqt(cinfo, compptr->quant_tbl_no); 512 } 513 /* now prec is nonzero iff there are any 16-bit quant tables. */ 514 515 /* Check for a non-baseline specification. 516 * Note we assume that Huffman table numbers won't be changed later. 517 */ 518 if (cinfo->arith_code || cinfo->progressive_mode || 519 cinfo->data_precision != 8) { 520 is_baseline = FALSE; 521 } else { 522 is_baseline = TRUE; 523 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 524 ci++, compptr++) { 525 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1) 526 is_baseline = FALSE; 527 } 528 if (prec && is_baseline) { 529 is_baseline = FALSE; 530 /* If it's baseline except for quantizer size, warn the user */ 531 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES); 532 } 533 } 534 535 /* Emit the proper SOF marker */ 536 if (cinfo->arith_code) { 537 if (cinfo->progressive_mode) 538 emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */ 539 else 540 emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */ 541 } else { 542 if (cinfo->progressive_mode) 543 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */ 544 else if (is_baseline) 545 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */ 546 else 547 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */ 548 } 549 } 550 551 552 /* 553 * Write scan header. 554 * This consists of DHT or DAC markers, optional DRI, and SOS. 555 * Compressed data will be written following the SOS. 556 */ 557 558 METHODDEF(void) 559 write_scan_header (j_compress_ptr cinfo) 560 { 561 my_marker_ptr marker = (my_marker_ptr) cinfo->marker; 562 int i; 563 jpeg_component_info *compptr; 564 565 if (cinfo->arith_code) { 566 /* Emit arith conditioning info. We may have some duplication 567 * if the file has multiple scans, but it's so small it's hardly 568 * worth worrying about. 569 */ 570 emit_dac(cinfo); 571 } else { 572 /* Emit Huffman tables. 573 * Note that emit_dht() suppresses any duplicate tables. 574 */ 575 for (i = 0; i < cinfo->comps_in_scan; i++) { 576 compptr = cinfo->cur_comp_info[i]; 577 /* DC needs no table for refinement scan */ 578 if (cinfo->Ss == 0 && cinfo->Ah == 0) 579 emit_dht(cinfo, compptr->dc_tbl_no, FALSE); 580 /* AC needs no table when not present */ 581 if (cinfo->Se) 582 emit_dht(cinfo, compptr->ac_tbl_no, TRUE); 583 } 584 } 585 586 /* Emit DRI if required --- note that DRI value could change for each scan. 587 * We avoid wasting space with unnecessary DRIs, however. 588 */ 589 if (cinfo->restart_interval != marker->last_restart_interval) { 590 emit_dri(cinfo); 591 marker->last_restart_interval = cinfo->restart_interval; 592 } 593 594 emit_sos(cinfo); 595 } 596 597 598 /* 599 * Write datastream trailer. 600 */ 601 602 METHODDEF(void) 603 write_file_trailer (j_compress_ptr cinfo) 604 { 605 emit_marker(cinfo, M_EOI); 606 } 607 608 609 /* 610 * Write an abbreviated table-specification datastream. 611 * This consists of SOI, DQT and DHT tables, and EOI. 612 * Any table that is defined and not marked sent_table = TRUE will be 613 * emitted. Note that all tables will be marked sent_table = TRUE at exit. 614 */ 615 616 METHODDEF(void) 617 write_tables_only (j_compress_ptr cinfo) 618 { 619 int i; 620 621 emit_marker(cinfo, M_SOI); 622 623 for (i = 0; i < NUM_QUANT_TBLS; i++) { 624 if (cinfo->quant_tbl_ptrs[i] != NULL) 625 (void) emit_dqt(cinfo, i); 626 } 627 628 if (! cinfo->arith_code) { 629 for (i = 0; i < NUM_HUFF_TBLS; i++) { 630 if (cinfo->dc_huff_tbl_ptrs[i] != NULL) 631 emit_dht(cinfo, i, FALSE); 632 if (cinfo->ac_huff_tbl_ptrs[i] != NULL) 633 emit_dht(cinfo, i, TRUE); 634 } 635 } 636 637 emit_marker(cinfo, M_EOI); 638 } 639 640 641 /* 642 * Initialize the marker writer module. 643 */ 644 645 GLOBAL(void) 646 jinit_marker_writer (j_compress_ptr cinfo) 647 { 648 my_marker_ptr marker; 649 650 /* Create the subobject */ 651 marker = (my_marker_ptr) 652 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, 653 sizeof(my_marker_writer)); 654 cinfo->marker = (struct jpeg_marker_writer *) marker; 655 /* Initialize method pointers */ 656 marker->pub.write_file_header = write_file_header; 657 marker->pub.write_frame_header = write_frame_header; 658 marker->pub.write_scan_header = write_scan_header; 659 marker->pub.write_file_trailer = write_file_trailer; 660 marker->pub.write_tables_only = write_tables_only; 661 marker->pub.write_marker_header = write_marker_header; 662 marker->pub.write_marker_byte = write_marker_byte; 663 /* Initialize private state */ 664 marker->last_restart_interval = 0; 665 } 666
