dll/3rdparty/libjpeg/jcmarker.c

   1 /*
   2  * jcmarker.c
   3  *
   4  * Copyright (C) 1991-1998, Thomas G. Lane.
   5  * Modified 2003-2010 by Guido Vollbeding.
   6  * This file is part of the Independent JPEG Group's software.
   7  * For conditions of distribution and use, see the accompanying README file.
   8  *
   9  * This file contains routines to write JPEG datastream markers.
  10  */
  11
  12 #define JPEG_INTERNALS
  13 #include "jinclude.h"
  14 #include "jpeglib.h"
  15
  16
  17 typedef enum {                  /* JPEG marker codes */
  18   M_SOF0  = 0xc0,
  19   M_SOF1  = 0xc1,
  20   M_SOF2  = 0xc2,
  21   M_SOF3  = 0xc3,
  22
  23   M_SOF5  = 0xc5,
  24   M_SOF6  = 0xc6,
  25   M_SOF7  = 0xc7,
  26
  27   M_JPG   = 0xc8,
  28   M_SOF9  = 0xc9,
  29   M_SOF10 = 0xca,
  30   M_SOF11 = 0xcb,
  31
  32   M_SOF13 = 0xcd,
  33   M_SOF14 = 0xce,
  34   M_SOF15 = 0xcf,
  35
  36   M_DHT   = 0xc4,
  37
  38   M_DAC   = 0xcc,
  39
  40   M_RST0  = 0xd0,
  41   M_RST1  = 0xd1,
  42   M_RST2  = 0xd2,
  43   M_RST3  = 0xd3,
  44   M_RST4  = 0xd4,
  45   M_RST5  = 0xd5,
  46   M_RST6  = 0xd6,
  47   M_RST7  = 0xd7,
  48
  49   M_SOI   = 0xd8,
  50   M_EOI   = 0xd9,
  51   M_SOS   = 0xda,
  52   M_DQT   = 0xdb,
  53   M_DNL   = 0xdc,
  54   M_DRI   = 0xdd,
  55   M_DHP   = 0xde,
  56   M_EXP   = 0xdf,
  57
  58   M_APP0  = 0xe0,
  59   M_APP1  = 0xe1,
  60   M_APP2  = 0xe2,
  61   M_APP3  = 0xe3,
  62   M_APP4  = 0xe4,
  63   M_APP5  = 0xe5,
  64   M_APP6  = 0xe6,
  65   M_APP7  = 0xe7,
  66   M_APP8  = 0xe8,
  67   M_APP9  = 0xe9,
  68   M_APP10 = 0xea,
  69   M_APP11 = 0xeb,
  70   M_APP12 = 0xec,
  71   M_APP13 = 0xed,
  72   M_APP14 = 0xee,
  73   M_APP15 = 0xef,
  74
  75   M_JPG0  = 0xf0,
  76   M_JPG13 = 0xfd,
  77   M_COM   = 0xfe,
  78
  79   M_TEM   = 0x01,
  80
  81   M_ERROR = 0x100
  82 } JPEG_MARKER;
  83
  84
  85 /* Private state */
  86
  87 typedef struct {
  88   struct jpeg_marker_writer pub; /* public fields */
  89
  90   unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
  91 } my_marker_writer;
  92
  93 typedef my_marker_writer * my_marker_ptr;
  94
  95
  96 /*
  97  * Basic output routines.
  98  *
  99  * Note that we do not support suspension while writing a marker.
 100  * Therefore, an application using suspension must ensure that there is
 101  * enough buffer space for the initial markers (typ. 600-700 bytes) before
 102  * calling jpeg_start_compress, and enough space to write the trailing EOI
 103  * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
 104  * modes are not supported at all with suspension, so those two are the only
 105  * points where markers will be written.
 106  */
 107
 108 LOCAL(void)
 109 emit_byte (j_compress_ptr cinfo, int val)
 110 /* Emit a byte */
 111 {
 112   struct jpeg_destination_mgr * dest = cinfo->dest;
 113
 114   *(dest->next_output_byte)++ = (JOCTET) val;
 115   if (--dest->free_in_buffer == 0) {
 116     if (! (*dest->empty_output_buffer) (cinfo))
 117       ERREXIT(cinfo, JERR_CANT_SUSPEND);
 118   }
 119 }
 120
 121
 122 LOCAL(void)
 123 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
 124 /* Emit a marker code */
 125 {
 126   emit_byte(cinfo, 0xFF);
 127   emit_byte(cinfo, (int) mark);
 128 }
 129
 130
 131 LOCAL(void)
 132 emit_2bytes (j_compress_ptr cinfo, int value)
 133 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
 134 {
 135   emit_byte(cinfo, (value >> 8) & 0xFF);
 136   emit_byte(cinfo, value & 0xFF);
 137 }
 138
 139
 140 /*
 141  * Routines to write specific marker types.
 142  */
 143
 144 LOCAL(int)
 145 emit_dqt (j_compress_ptr cinfo, int index)
 146 /* Emit a DQT marker */
 147 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
 148 {
 149   JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
 150   int prec;
 151   int i;
 152
 153   if (qtbl == NULL)
 154     ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
 155
 156   prec = 0;
 157   for (i = 0; i <= cinfo->lim_Se; i++) {
 158     if (qtbl->quantval[cinfo->natural_order[i]] > 255)
 159       prec = 1;
 160   }
 161
 162   if (! qtbl->sent_table) {
 163     emit_marker(cinfo, M_DQT);
 164
 165     emit_2bytes(cinfo,
 166       prec ? cinfo->lim_Se * 2 + 2 + 1 + 2 : cinfo->lim_Se + 1 + 1 + 2);
 167
 168     emit_byte(cinfo, index + (prec<<4));
 169
 170     for (i = 0; i <= cinfo->lim_Se; i++) {
 171       /* The table entries must be emitted in zigzag order. */
 172       unsigned int qval = qtbl->quantval[cinfo->natural_order[i]];
 173       if (prec)
 174         emit_byte(cinfo, (int) (qval >> 8));
 175       emit_byte(cinfo, (int) (qval & 0xFF));
 176     }
 177
 178     qtbl->sent_table = TRUE;
 179   }
 180
 181   return prec;
 182 }
 183
 184
 185 LOCAL(void)
 186 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
 187 /* Emit a DHT marker */
 188 {
 189   JHUFF_TBL * htbl;
 190   int length, i;
 191
 192   if (is_ac) {
 193     htbl = cinfo->ac_huff_tbl_ptrs[index];
 194     index += 0x10;              /* output index has AC bit set */
 195   } else {
 196     htbl = cinfo->dc_huff_tbl_ptrs[index];
 197   }
 198
 199   if (htbl == NULL)
 200     ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
 201
 202   if (! htbl->sent_table) {
 203     emit_marker(cinfo, M_DHT);
 204
 205     length = 0;
 206     for (i = 1; i <= 16; i++)
 207       length += htbl->bits[i];
 208
 209     emit_2bytes(cinfo, length + 2 + 1 + 16);
 210     emit_byte(cinfo, index);
 211
 212     for (i = 1; i <= 16; i++)
 213       emit_byte(cinfo, htbl->bits[i]);
 214
 215     for (i = 0; i < length; i++)
 216       emit_byte(cinfo, htbl->huffval[i]);
 217
 218     htbl->sent_table = TRUE;
 219   }
 220 }
 221
 222
 223 LOCAL(void)
 224 emit_dac (j_compress_ptr cinfo)
 225 /* Emit a DAC marker */
 226 /* Since the useful info is so small, we want to emit all the tables in */
 227 /* one DAC marker.  Therefore this routine does its own scan of the table. */
 228 {
 229 #ifdef C_ARITH_CODING_SUPPORTED
 230   char dc_in_use[NUM_ARITH_TBLS];
 231   char ac_in_use[NUM_ARITH_TBLS];
 232   int length, i;
 233   jpeg_component_info *compptr;
 234
 235   for (i = 0; i < NUM_ARITH_TBLS; i++)
 236     dc_in_use[i] = ac_in_use[i] = 0;
 237
 238   for (i = 0; i < cinfo->comps_in_scan; i++) {
 239     compptr = cinfo->cur_comp_info[i];
 240     /* DC needs no table for refinement scan */
 241     if (cinfo->Ss == 0 && cinfo->Ah == 0)
 242       dc_in_use[compptr->dc_tbl_no] = 1;
 243     /* AC needs no table when not present */
 244     if (cinfo->Se)
 245       ac_in_use[compptr->ac_tbl_no] = 1;
 246   }
 247
 248   length = 0;
 249   for (i = 0; i < NUM_ARITH_TBLS; i++)
 250     length += dc_in_use[i] + ac_in_use[i];
 251
 252   if (length) {
 253     emit_marker(cinfo, M_DAC);
 254
 255     emit_2bytes(cinfo, length*2 + 2);
 256
 257     for (i = 0; i < NUM_ARITH_TBLS; i++) {
 258       if (dc_in_use[i]) {
 259         emit_byte(cinfo, i);
 260         emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
 261       }
 262       if (ac_in_use[i]) {
 263         emit_byte(cinfo, i + 0x10);
 264         emit_byte(cinfo, cinfo->arith_ac_K[i]);
 265       }
 266     }
 267   }
 268 #endif /* C_ARITH_CODING_SUPPORTED */
 269 }
 270
 271
 272 LOCAL(void)
 273 emit_dri (j_compress_ptr cinfo)
 274 /* Emit a DRI marker */
 275 {
 276   emit_marker(cinfo, M_DRI);
 277
 278   emit_2bytes(cinfo, 4);        /* fixed length */
 279
 280   emit_2bytes(cinfo, (int) cinfo->restart_interval);
 281 }
 282
 283
 284 LOCAL(void)
 285 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
 286 /* Emit a SOF marker */
 287 {
 288   int ci;
 289   jpeg_component_info *compptr;
 290
 291   emit_marker(cinfo, code);
 292
 293   emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
 294
 295   /* Make sure image isn't bigger than SOF field can handle */
 296   if ((long) cinfo->jpeg_height > 65535L ||
 297       (long) cinfo->jpeg_width > 65535L)
 298     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
 299
 300   emit_byte(cinfo, cinfo->data_precision);
 301   emit_2bytes(cinfo, (int) cinfo->jpeg_height);
 302   emit_2bytes(cinfo, (int) cinfo->jpeg_width);
 303
 304   emit_byte(cinfo, cinfo->num_components);
 305
 306   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 307        ci++, compptr++) {
 308     emit_byte(cinfo, compptr->component_id);
 309     emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
 310     emit_byte(cinfo, compptr->quant_tbl_no);
 311   }
 312 }
 313
 314
 315 LOCAL(void)
 316 emit_sos (j_compress_ptr cinfo)
 317 /* Emit a SOS marker */
 318 {
 319   int i, td, ta;
 320   jpeg_component_info *compptr;
 321
 322   emit_marker(cinfo, M_SOS);
 323
 324   emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
 325
 326   emit_byte(cinfo, cinfo->comps_in_scan);
 327
 328   for (i = 0; i < cinfo->comps_in_scan; i++) {
 329     compptr = cinfo->cur_comp_info[i];
 330     emit_byte(cinfo, compptr->component_id);
 331
 332     /* We emit 0 for unused field(s); this is recommended by the P&M text
 333      * but does not seem to be specified in the standard.
 334      */
 335
 336     /* DC needs no table for refinement scan */
 337     td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0;
 338     /* AC needs no table when not present */
 339     ta = cinfo->Se ? compptr->ac_tbl_no : 0;
 340
 341     emit_byte(cinfo, (td << 4) + ta);
 342   }
 343
 344   emit_byte(cinfo, cinfo->Ss);
 345   emit_byte(cinfo, cinfo->Se);
 346   emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
 347 }
 348
 349
 350 LOCAL(void)
 351 emit_pseudo_sos (j_compress_ptr cinfo)
 352 /* Emit a pseudo SOS marker */
 353 {
 354   emit_marker(cinfo, M_SOS);
 355
 356   emit_2bytes(cinfo, 2 + 1 + 3); /* length */
 357
 358   emit_byte(cinfo, 0); /* Ns */
 359
 360   emit_byte(cinfo, 0); /* Ss */
 361   emit_byte(cinfo, cinfo->block_size * cinfo->block_size - 1); /* Se */
 362   emit_byte(cinfo, 0); /* Ah/Al */
 363 }
 364
 365
 366 LOCAL(void)
 367 emit_jfif_app0 (j_compress_ptr cinfo)
 368 /* Emit a JFIF-compliant APP0 marker */
 369 {
 370   /*
 371    * Length of APP0 block       (2 bytes)
 372    * Block ID                   (4 bytes - ASCII "JFIF")
 373    * Zero byte                  (1 byte to terminate the ID string)
 374    * Version Major, Minor       (2 bytes - major first)
 375    * Units                      (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
 376    * Xdpu                       (2 bytes - dots per unit horizontal)
 377    * Ydpu                       (2 bytes - dots per unit vertical)
 378    * Thumbnail X size           (1 byte)
 379    * Thumbnail Y size           (1 byte)
 380    */
 381
 382   emit_marker(cinfo, M_APP0);
 383
 384   emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
 385
 386   emit_byte(cinfo, 0x4A);       /* Identifier: ASCII "JFIF" */
 387   emit_byte(cinfo, 0x46);
 388   emit_byte(cinfo, 0x49);
 389   emit_byte(cinfo, 0x46);
 390   emit_byte(cinfo, 0);
 391   emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
 392   emit_byte(cinfo, cinfo->JFIF_minor_version);
 393   emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
 394   emit_2bytes(cinfo, (int) cinfo->X_density);
 395   emit_2bytes(cinfo, (int) cinfo->Y_density);
 396   emit_byte(cinfo, 0);          /* No thumbnail image */
 397   emit_byte(cinfo, 0);
 398 }
 399
 400
 401 LOCAL(void)
 402 emit_adobe_app14 (j_compress_ptr cinfo)
 403 /* Emit an Adobe APP14 marker */
 404 {
 405   /*
 406    * Length of APP14 block      (2 bytes)
 407    * Block ID                   (5 bytes - ASCII "Adobe")
 408    * Version Number             (2 bytes - currently 100)
 409    * Flags0                     (2 bytes - currently 0)
 410    * Flags1                     (2 bytes - currently 0)
 411    * Color transform            (1 byte)
 412    *
 413    * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
 414    * now in circulation seem to use Version = 100, so that's what we write.
 415    *
 416    * We write the color transform byte as 1 if the JPEG color space is
 417    * YCbCr, 2 if it's YCCK, 0 otherwise.  Adobe's definition has to do with
 418    * whether the encoder performed a transformation, which is pretty useless.
 419    */
 420
 421   emit_marker(cinfo, M_APP14);
 422
 423   emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
 424
 425   emit_byte(cinfo, 0x41);       /* Identifier: ASCII "Adobe" */
 426   emit_byte(cinfo, 0x64);
 427   emit_byte(cinfo, 0x6F);
 428   emit_byte(cinfo, 0x62);
 429   emit_byte(cinfo, 0x65);
 430   emit_2bytes(cinfo, 100);      /* Version */
 431   emit_2bytes(cinfo, 0);        /* Flags0 */
 432   emit_2bytes(cinfo, 0);        /* Flags1 */
 433   switch (cinfo->jpeg_color_space) {
 434   case JCS_YCbCr:
 435     emit_byte(cinfo, 1);        /* Color transform = 1 */
 436     break;
 437   case JCS_YCCK:
 438     emit_byte(cinfo, 2);        /* Color transform = 2 */
 439     break;
 440   default:
 441     emit_byte(cinfo, 0);        /* Color transform = 0 */
 442     break;
 443   }
 444 }
 445
 446
 447 /*
 448  * These routines allow writing an arbitrary marker with parameters.
 449  * The only intended use is to emit COM or APPn markers after calling
 450  * write_file_header and before calling write_frame_header.
 451  * Other uses are not guaranteed to produce desirable results.
 452  * Counting the parameter bytes properly is the caller's responsibility.
 453  */
 454
 455 METHODDEF(void)
 456 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 457 /* Emit an arbitrary marker header */
 458 {
 459   if (datalen > (unsigned int) 65533)           /* safety check */
 460     ERREXIT(cinfo, JERR_BAD_LENGTH);
 461
 462   emit_marker(cinfo, (JPEG_MARKER) marker);
 463
 464   emit_2bytes(cinfo, (int) (datalen + 2));      /* total length */
 465 }
 466
 467 METHODDEF(void)
 468 write_marker_byte (j_compress_ptr cinfo, int val)
 469 /* Emit one byte of marker parameters following write_marker_header */
 470 {
 471   emit_byte(cinfo, val);
 472 }
 473
 474
 475 /*
 476  * Write datastream header.
 477  * This consists of an SOI and optional APPn markers.
 478  * We recommend use of the JFIF marker, but not the Adobe marker,
 479  * when using YCbCr or grayscale data.  The JFIF marker should NOT
 480  * be used for any other JPEG colorspace.  The Adobe marker is helpful
 481  * to distinguish RGB, CMYK, and YCCK colorspaces.
 482  * Note that an application can write additional header markers after
 483  * jpeg_start_compress returns.
 484  */
 485
 486 METHODDEF(void)
 487 write_file_header (j_compress_ptr cinfo)
 488 {
 489   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
 490
 491   emit_marker(cinfo, M_SOI);    /* first the SOI */
 492
 493   /* SOI is defined to reset restart interval to 0 */
 494   marker->last_restart_interval = 0;
 495
 496   if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
 497     emit_jfif_app0(cinfo);
 498   if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
 499     emit_adobe_app14(cinfo);
 500 }
 501
 502
 503 /*
 504  * Write frame header.
 505  * This consists of DQT and SOFn markers, and a conditional pseudo SOS marker.
 506  * Note that we do not emit the SOF until we have emitted the DQT(s).
 507  * This avoids compatibility problems with incorrect implementations that
 508  * try to error-check the quant table numbers as soon as they see the SOF.
 509  */
 510
 511 METHODDEF(void)
 512 write_frame_header (j_compress_ptr cinfo)
 513 {
 514   int ci, prec;
 515   boolean is_baseline;
 516   jpeg_component_info *compptr;
 517
 518   /* Emit DQT for each quantization table.
 519    * Note that emit_dqt() suppresses any duplicate tables.
 520    */
 521   prec = 0;
 522   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 523        ci++, compptr++) {
 524     prec += emit_dqt(cinfo, compptr->quant_tbl_no);
 525   }
 526   /* now prec is nonzero iff there are any 16-bit quant tables. */
 527
 528   /* Check for a non-baseline specification.
 529    * Note we assume that Huffman table numbers won't be changed later.
 530    */
 531   if (cinfo->arith_code || cinfo->progressive_mode ||
 532       cinfo->data_precision != 8 || cinfo->block_size != DCTSIZE) {
 533     is_baseline = FALSE;
 534   } else {
 535     is_baseline = TRUE;
 536     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 537          ci++, compptr++) {
 538       if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
 539         is_baseline = FALSE;
 540     }
 541     if (prec && is_baseline) {
 542       is_baseline = FALSE;
 543       /* If it's baseline except for quantizer size, warn the user */
 544       TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
 545     }
 546   }
 547
 548   /* Emit the proper SOF marker */
 549   if (cinfo->arith_code) {
 550     if (cinfo->progressive_mode)
 551       emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */
 552     else
 553       emit_sof(cinfo, M_SOF9);  /* SOF code for sequential arithmetic */
 554   } else {
 555     if (cinfo->progressive_mode)
 556       emit_sof(cinfo, M_SOF2);  /* SOF code for progressive Huffman */
 557     else if (is_baseline)
 558       emit_sof(cinfo, M_SOF0);  /* SOF code for baseline implementation */
 559     else
 560       emit_sof(cinfo, M_SOF1);  /* SOF code for non-baseline Huffman file */
 561   }
 562
 563   /* Check to emit pseudo SOS marker */
 564   if (cinfo->progressive_mode && cinfo->block_size != DCTSIZE)
 565     emit_pseudo_sos(cinfo);
 566 }
 567
 568
 569 /*
 570  * Write scan header.
 571  * This consists of DHT or DAC markers, optional DRI, and SOS.
 572  * Compressed data will be written following the SOS.
 573  */
 574
 575 METHODDEF(void)
 576 write_scan_header (j_compress_ptr cinfo)
 577 {
 578   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
 579   int i;
 580   jpeg_component_info *compptr;
 581
 582   if (cinfo->arith_code) {
 583     /* Emit arith conditioning info.  We may have some duplication
 584      * if the file has multiple scans, but it's so small it's hardly
 585      * worth worrying about.
 586      */
 587     emit_dac(cinfo);
 588   } else {
 589     /* Emit Huffman tables.
 590      * Note that emit_dht() suppresses any duplicate tables.
 591      */
 592     for (i = 0; i < cinfo->comps_in_scan; i++) {
 593       compptr = cinfo->cur_comp_info[i];
 594       /* DC needs no table for refinement scan */
 595       if (cinfo->Ss == 0 && cinfo->Ah == 0)
 596         emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
 597       /* AC needs no table when not present */
 598       if (cinfo->Se)
 599         emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
 600     }
 601   }
 602
 603   /* Emit DRI if required --- note that DRI value could change for each scan.
 604    * We avoid wasting space with unnecessary DRIs, however.
 605    */
 606   if (cinfo->restart_interval != marker->last_restart_interval) {
 607     emit_dri(cinfo);
 608     marker->last_restart_interval = cinfo->restart_interval;
 609   }
 610
 611   emit_sos(cinfo);
 612 }
 613
 614
 615 /*
 616  * Write datastream trailer.
 617  */
 618
 619 METHODDEF(void)
 620 write_file_trailer (j_compress_ptr cinfo)
 621 {
 622   emit_marker(cinfo, M_EOI);
 623 }
 624
 625
 626 /*
 627  * Write an abbreviated table-specification datastream.
 628  * This consists of SOI, DQT and DHT tables, and EOI.
 629  * Any table that is defined and not marked sent_table = TRUE will be
 630  * emitted.  Note that all tables will be marked sent_table = TRUE at exit.
 631  */
 632
 633 METHODDEF(void)
 634 write_tables_only (j_compress_ptr cinfo)
 635 {
 636   int i;
 637
 638   emit_marker(cinfo, M_SOI);
 639
 640   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 641     if (cinfo->quant_tbl_ptrs[i] != NULL)
 642       (void) emit_dqt(cinfo, i);
 643   }
 644
 645   if (! cinfo->arith_code) {
 646     for (i = 0; i < NUM_HUFF_TBLS; i++) {
 647       if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
 648         emit_dht(cinfo, i, FALSE);
 649       if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
 650         emit_dht(cinfo, i, TRUE);
 651     }
 652   }
 653
 654   emit_marker(cinfo, M_EOI);
 655 }
 656
 657
 658 /*
 659  * Initialize the marker writer module.
 660  */
 661
 662 GLOBAL(void)
 663 jinit_marker_writer (j_compress_ptr cinfo)
 664 {
 665   my_marker_ptr marker;
 666
 667   /* Create the subobject */
 668   marker = (my_marker_ptr)
 669     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 670                                 SIZEOF(my_marker_writer));
 671   cinfo->marker = (struct jpeg_marker_writer *) marker;
 672   /* Initialize method pointers */
 673   marker->pub.write_file_header = write_file_header;
 674   marker->pub.write_frame_header = write_frame_header;
 675   marker->pub.write_scan_header = write_scan_header;
 676   marker->pub.write_file_trailer = write_file_trailer;
 677   marker->pub.write_tables_only = write_tables_only;
 678   marker->pub.write_marker_header = write_marker_header;
 679   marker->pub.write_marker_byte = write_marker_byte;
 680   /* Initialize private state */
 681   marker->last_restart_interval = 0;
 682 }