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 || (long)cinfo->_jpeg_width > 65535L) 300 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int)65535); 301 302 emit_byte(cinfo, cinfo->data_precision); 303 emit_2bytes(cinfo, (int)cinfo->_jpeg_height); 304 emit_2bytes(cinfo, (int)cinfo->_jpeg_width); 305 306 emit_byte(cinfo, cinfo->num_components); 307 308 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 309 ci++, compptr++) { 310 emit_byte(cinfo, compptr->component_id); 311 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor); 312 emit_byte(cinfo, compptr->quant_tbl_no); 313 } 314 } 315 316 317 LOCAL(void) 318 emit_sos(j_compress_ptr cinfo) 319 /* Emit a SOS marker */ 320 { 321 int i, td, ta; 322 jpeg_component_info *compptr; 323 324 emit_marker(cinfo, M_SOS); 325 326 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */ 327 328 emit_byte(cinfo, cinfo->comps_in_scan); 329 330 for (i = 0; i < cinfo->comps_in_scan; i++) { 331 compptr = cinfo->cur_comp_info[i]; 332 emit_byte(cinfo, compptr->component_id); 333 334 /* We emit 0 for unused field(s); this is recommended by the P&M text 335 * but does not seem to be specified in the standard. 336 */ 337 338 /* DC needs no table for refinement scan */ 339 td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0; 340 /* AC needs no table when not present */ 341 ta = cinfo->Se ? compptr->ac_tbl_no : 0; 342 343 emit_byte(cinfo, (td << 4) + ta); 344 } 345 346 emit_byte(cinfo, cinfo->Ss); 347 emit_byte(cinfo, cinfo->Se); 348 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al); 349 } 350 351 352 LOCAL(void) 353 emit_jfif_app0(j_compress_ptr cinfo) 354 /* Emit a JFIF-compliant APP0 marker */ 355 { 356 /* 357 * Length of APP0 block (2 bytes) 358 * Block ID (4 bytes - ASCII "JFIF") 359 * Zero byte (1 byte to terminate the ID string) 360 * Version Major, Minor (2 bytes - major first) 361 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm) 362 * Xdpu (2 bytes - dots per unit horizontal) 363 * Ydpu (2 bytes - dots per unit vertical) 364 * Thumbnail X size (1 byte) 365 * Thumbnail Y size (1 byte) 366 */ 367 368 emit_marker(cinfo, M_APP0); 369 370 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */ 371 372 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */ 373 emit_byte(cinfo, 0x46); 374 emit_byte(cinfo, 0x49); 375 emit_byte(cinfo, 0x46); 376 emit_byte(cinfo, 0); 377 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */ 378 emit_byte(cinfo, cinfo->JFIF_minor_version); 379 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */ 380 emit_2bytes(cinfo, (int)cinfo->X_density); 381 emit_2bytes(cinfo, (int)cinfo->Y_density); 382 emit_byte(cinfo, 0); /* No thumbnail image */ 383 emit_byte(cinfo, 0); 384 } 385 386 387 LOCAL(void) 388 emit_adobe_app14(j_compress_ptr cinfo) 389 /* Emit an Adobe APP14 marker */ 390 { 391 /* 392 * Length of APP14 block (2 bytes) 393 * Block ID (5 bytes - ASCII "Adobe") 394 * Version Number (2 bytes - currently 100) 395 * Flags0 (2 bytes - currently 0) 396 * Flags1 (2 bytes - currently 0) 397 * Color transform (1 byte) 398 * 399 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files 400 * now in circulation seem to use Version = 100, so that's what we write. 401 * 402 * We write the color transform byte as 1 if the JPEG color space is 403 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with 404 * whether the encoder performed a transformation, which is pretty useless. 405 */ 406 407 emit_marker(cinfo, M_APP14); 408 409 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */ 410 411 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */ 412 emit_byte(cinfo, 0x64); 413 emit_byte(cinfo, 0x6F); 414 emit_byte(cinfo, 0x62); 415 emit_byte(cinfo, 0x65); 416 emit_2bytes(cinfo, 100); /* Version */ 417 emit_2bytes(cinfo, 0); /* Flags0 */ 418 emit_2bytes(cinfo, 0); /* Flags1 */ 419 switch (cinfo->jpeg_color_space) { 420 case JCS_YCbCr: 421 emit_byte(cinfo, 1); /* Color transform = 1 */ 422 break; 423 case JCS_YCCK: 424 emit_byte(cinfo, 2); /* Color transform = 2 */ 425 break; 426 default: 427 emit_byte(cinfo, 0); /* Color transform = 0 */ 428 break; 429 } 430 } 431 432 433 /* 434 * These routines allow writing an arbitrary marker with parameters. 435 * The only intended use is to emit COM or APPn markers after calling 436 * write_file_header and before calling write_frame_header. 437 * Other uses are not guaranteed to produce desirable results. 438 * Counting the parameter bytes properly is the caller's responsibility. 439 */ 440 441 METHODDEF(void) 442 write_marker_header(j_compress_ptr cinfo, int marker, unsigned int datalen) 443 /* Emit an arbitrary marker header */ 444 { 445 if (datalen > (unsigned int)65533) /* safety check */ 446 ERREXIT(cinfo, JERR_BAD_LENGTH); 447 448 emit_marker(cinfo, (JPEG_MARKER)marker); 449 450 emit_2bytes(cinfo, (int)(datalen + 2)); /* total length */ 451 } 452 453 METHODDEF(void) 454 write_marker_byte(j_compress_ptr cinfo, int val) 455 /* Emit one byte of marker parameters following write_marker_header */ 456 { 457 emit_byte(cinfo, val); 458 } 459 460 461 /* 462 * Write datastream header. 463 * This consists of an SOI and optional APPn markers. 464 * We recommend use of the JFIF marker, but not the Adobe marker, 465 * when using YCbCr or grayscale data. The JFIF marker should NOT 466 * be used for any other JPEG colorspace. The Adobe marker is helpful 467 * to distinguish RGB, CMYK, and YCCK colorspaces. 468 * Note that an application can write additional header markers after 469 * jpeg_start_compress returns. 470 */ 471 472 METHODDEF(void) 473 write_file_header(j_compress_ptr cinfo) 474 { 475 my_marker_ptr marker = (my_marker_ptr)cinfo->marker; 476 477 emit_marker(cinfo, M_SOI); /* first the SOI */ 478 479 /* SOI is defined to reset restart interval to 0 */ 480 marker->last_restart_interval = 0; 481 482 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */ 483 emit_jfif_app0(cinfo); 484 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */ 485 emit_adobe_app14(cinfo); 486 } 487 488 489 /* 490 * Write frame header. 491 * This consists of DQT and SOFn markers. 492 * Note that we do not emit the SOF until we have emitted the DQT(s). 493 * This avoids compatibility problems with incorrect implementations that 494 * try to error-check the quant table numbers as soon as they see the SOF. 495 */ 496 497 METHODDEF(void) 498 write_frame_header(j_compress_ptr cinfo) 499 { 500 int ci, prec; 501 boolean is_baseline; 502 jpeg_component_info *compptr; 503 504 /* Emit DQT for each quantization table. 505 * Note that emit_dqt() suppresses any duplicate tables. 506 */ 507 prec = 0; 508 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 509 ci++, compptr++) { 510 prec += emit_dqt(cinfo, compptr->quant_tbl_no); 511 } 512 /* now prec is nonzero iff there are any 16-bit quant tables. */ 513 514 /* Check for a non-baseline specification. 515 * Note we assume that Huffman table numbers won't be changed later. 516 */ 517 if (cinfo->arith_code || cinfo->progressive_mode || 518 cinfo->data_precision != 8) { 519 is_baseline = FALSE; 520 } else { 521 is_baseline = TRUE; 522 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; 523 ci++, compptr++) { 524 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1) 525 is_baseline = FALSE; 526 } 527 if (prec && is_baseline) { 528 is_baseline = FALSE; 529 /* If it's baseline except for quantizer size, warn the user */ 530 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES); 531 } 532 } 533 534 /* Emit the proper SOF marker */ 535 if (cinfo->arith_code) { 536 if (cinfo->progressive_mode) 537 emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */ 538 else 539 emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */ 540 } else { 541 if (cinfo->progressive_mode) 542 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */ 543 else if (is_baseline) 544 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */ 545 else 546 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */ 547 } 548 } 549 550 551 /* 552 * Write scan header. 553 * This consists of DHT or DAC markers, optional DRI, and SOS. 554 * Compressed data will be written following the SOS. 555 */ 556 557 METHODDEF(void) 558 write_scan_header(j_compress_ptr cinfo) 559 { 560 my_marker_ptr marker = (my_marker_ptr)cinfo->marker; 561 int i; 562 jpeg_component_info *compptr; 563 564 if (cinfo->arith_code) { 565 /* Emit arith conditioning info. We may have some duplication 566 * if the file has multiple scans, but it's so small it's hardly 567 * worth worrying about. 568 */ 569 emit_dac(cinfo); 570 } else { 571 /* Emit Huffman tables. 572 * Note that emit_dht() suppresses any duplicate tables. 573 */ 574 for (i = 0; i < cinfo->comps_in_scan; i++) { 575 compptr = cinfo->cur_comp_info[i]; 576 /* DC needs no table for refinement scan */ 577 if (cinfo->Ss == 0 && cinfo->Ah == 0) 578 emit_dht(cinfo, compptr->dc_tbl_no, FALSE); 579 /* AC needs no table when not present */ 580 if (cinfo->Se) 581 emit_dht(cinfo, compptr->ac_tbl_no, TRUE); 582 } 583 } 584 585 /* Emit DRI if required --- note that DRI value could change for each scan. 586 * We avoid wasting space with unnecessary DRIs, however. 587 */ 588 if (cinfo->restart_interval != marker->last_restart_interval) { 589 emit_dri(cinfo); 590 marker->last_restart_interval = cinfo->restart_interval; 591 } 592 593 emit_sos(cinfo); 594 } 595 596 597 /* 598 * Write datastream trailer. 599 */ 600 601 METHODDEF(void) 602 write_file_trailer(j_compress_ptr cinfo) 603 { 604 emit_marker(cinfo, M_EOI); 605 } 606 607 608 /* 609 * Write an abbreviated table-specification datastream. 610 * This consists of SOI, DQT and DHT tables, and EOI. 611 * Any table that is defined and not marked sent_table = TRUE will be 612 * emitted. Note that all tables will be marked sent_table = TRUE at exit. 613 */ 614 615 METHODDEF(void) 616 write_tables_only(j_compress_ptr cinfo) 617 { 618 int i; 619 620 emit_marker(cinfo, M_SOI); 621 622 for (i = 0; i < NUM_QUANT_TBLS; i++) { 623 if (cinfo->quant_tbl_ptrs[i] != NULL) 624 (void)emit_dqt(cinfo, i); 625 } 626 627 if (!cinfo->arith_code) { 628 for (i = 0; i < NUM_HUFF_TBLS; i++) { 629 if (cinfo->dc_huff_tbl_ptrs[i] != NULL) 630 emit_dht(cinfo, i, FALSE); 631 if (cinfo->ac_huff_tbl_ptrs[i] != NULL) 632 emit_dht(cinfo, i, TRUE); 633 } 634 } 635 636 emit_marker(cinfo, M_EOI); 637 } 638 639 640 /* 641 * Initialize the marker writer module. 642 */ 643 644 GLOBAL(void) 645 jinit_marker_writer(j_compress_ptr cinfo) 646 { 647 my_marker_ptr marker; 648 649 /* Create the subobject */ 650 marker = (my_marker_ptr) 651 (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, 652 sizeof(my_marker_writer)); 653 cinfo->marker = (struct jpeg_marker_writer *)marker; 654 /* Initialize method pointers */ 655 marker->pub.write_file_header = write_file_header; 656 marker->pub.write_frame_header = write_frame_header; 657 marker->pub.write_scan_header = write_scan_header; 658 marker->pub.write_file_trailer = write_file_trailer; 659 marker->pub.write_tables_only = write_tables_only; 660 marker->pub.write_marker_header = write_marker_header; 661 marker->pub.write_marker_byte = write_marker_byte; 662 /* Initialize private state */ 663 marker->last_restart_interval = 0; 664 } 665
