compiler/libjpeg/main/jcmarker.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * jcmarker.c
   7  *
   8  * Copyright (C) 1991-1998, Thomas G. Lane.
   9  * This file is part of the Independent JPEG Group's software.
  10  * For conditions of distribution and use, see the accompanying README 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
  19
  20 typedef enum {                  /* JPEG marker codes */
  21   M_SOF0  = 0xc0,
  22   M_SOF1  = 0xc1,
  23   M_SOF2  = 0xc2,
  24   M_SOF3  = 0xc3,
  25
  26   M_SOF5  = 0xc5,
  27   M_SOF6  = 0xc6,
  28   M_SOF7  = 0xc7,
  29
  30   M_JPG   = 0xc8,
  31   M_SOF9  = 0xc9,
  32   M_SOF10 = 0xca,
  33   M_SOF11 = 0xcb,
  34
  35   M_SOF13 = 0xcd,
  36   M_SOF14 = 0xce,
  37   M_SOF15 = 0xcf,
  38
  39   M_DHT   = 0xc4,
  40
  41   M_DAC   = 0xcc,
  42
  43   M_RST0  = 0xd0,
  44   M_RST1  = 0xd1,
  45   M_RST2  = 0xd2,
  46   M_RST3  = 0xd3,
  47   M_RST4  = 0xd4,
  48   M_RST5  = 0xd5,
  49   M_RST6  = 0xd6,
  50   M_RST7  = 0xd7,
  51
  52   M_SOI   = 0xd8,
  53   M_EOI   = 0xd9,
  54   M_SOS   = 0xda,
  55   M_DQT   = 0xdb,
  56   M_DNL   = 0xdc,
  57   M_DRI   = 0xdd,
  58   M_DHP   = 0xde,
  59   M_EXP   = 0xdf,
  60
  61   M_APP0  = 0xe0,
  62   M_APP1  = 0xe1,
  63   M_APP2  = 0xe2,
  64   M_APP3  = 0xe3,
  65   M_APP4  = 0xe4,
  66   M_APP5  = 0xe5,
  67   M_APP6  = 0xe6,
  68   M_APP7  = 0xe7,
  69   M_APP8  = 0xe8,
  70   M_APP9  = 0xe9,
  71   M_APP10 = 0xea,
  72   M_APP11 = 0xeb,
  73   M_APP12 = 0xec,
  74   M_APP13 = 0xed,
  75   M_APP14 = 0xee,
  76   M_APP15 = 0xef,
  77
  78   M_JPG0  = 0xf0,
  79   M_JPG13 = 0xfd,
  80   M_COM   = 0xfe,
  81
  82   M_TEM   = 0x01,
  83
  84   M_ERROR = 0x100
  85 } JPEG_MARKER;
  86
  87
  88 /* Private state */
  89
  90 typedef struct {
  91   struct jpeg_marker_writer pub; /* public fields */
  92
  93   unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
  94 } my_marker_writer;
  95
  96 typedef my_marker_writer * my_marker_ptr;
  97
  98
  99 /*
 100  * Basic output routines.
 101  *
 102  * Note that we do not support suspension while writing a marker.
 103  * Therefore, an application using suspension must ensure that there is
 104  * enough buffer space for the initial markers (typ. 600-700 bytes) before
 105  * calling jpeg_start_compress, and enough space to write the trailing EOI
 106  * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
 107  * modes are not supported at all with suspension, so those two are the only
 108  * points where markers will be written.
 109  */
 110
 111 LOCAL(void)
 112 emit_byte (j_compress_ptr cinfo, int val)
 113 /* Emit a byte */
 114 {
 115   struct jpeg_destination_mgr * dest = cinfo->dest;
 116
 117   *(dest->next_output_byte)++ = (JOCTET) val;
 118   if (--dest->free_in_buffer == 0) {
 119     if (! (*dest->empty_output_buffer) (cinfo))
 120       ERREXIT(cinfo, JERR_CANT_SUSPEND);
 121   }
 122 }
 123
 124
 125 LOCAL(void)
 126 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
 127 /* Emit a marker code */
 128 {
 129   emit_byte(cinfo, 0xFF);
 130   emit_byte(cinfo, (int) mark);
 131 }
 132
 133
 134 LOCAL(void)
 135 emit_2bytes (j_compress_ptr cinfo, int value)
 136 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
 137 {
 138   emit_byte(cinfo, (value >> 8) & 0xFF);
 139   emit_byte(cinfo, value & 0xFF);
 140 }
 141
 142
 143 /*
 144  * Routines to write specific marker types.
 145  */
 146
 147 LOCAL(int)
 148 emit_dqt (j_compress_ptr cinfo, int index)
 149 /* Emit a DQT marker */
 150 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
 151 {
 152   JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
 153   int prec;
 154   int i;
 155
 156   if (qtbl == NULL)
 157     ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
 158
 159   prec = 0;
 160   for (i = 0; i < DCTSIZE2; i++) {
 161     if (qtbl->quantval[i] > 255)
 162       prec = 1;
 163   }
 164
 165   if (! qtbl->sent_table) {
 166     emit_marker(cinfo, M_DQT);
 167
 168     emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
 169
 170     emit_byte(cinfo, index + (prec<<4));
 171
 172     for (i = 0; i < DCTSIZE2; i++) {
 173       /* The table entries must be emitted in zigzag order. */
 174       unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
 175       if (prec)
 176         emit_byte(cinfo, (int) (qval >> 8));
 177       emit_byte(cinfo, (int) (qval & 0xFF));
 178     }
 179
 180     qtbl->sent_table = TRUE;
 181   }
 182
 183   return prec;
 184 }
 185
 186
 187 LOCAL(void)
 188 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
 189 /* Emit a DHT marker */
 190 {
 191   JHUFF_TBL * htbl;
 192   int length, i;
 193
 194   if (is_ac) {
 195     htbl = cinfo->ac_huff_tbl_ptrs[index];
 196     index += 0x10;              /* output index has AC bit set */
 197   } else {
 198     htbl = cinfo->dc_huff_tbl_ptrs[index];
 199   }
 200
 201   if (htbl == NULL)
 202     ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
 203
 204   if (! htbl->sent_table) {
 205     emit_marker(cinfo, M_DHT);
 206
 207     length = 0;
 208     for (i = 1; i <= 16; i++)
 209       length += htbl->bits[i];
 210
 211     emit_2bytes(cinfo, length + 2 + 1 + 16);
 212     emit_byte(cinfo, index);
 213
 214     for (i = 1; i <= 16; i++)
 215       emit_byte(cinfo, htbl->bits[i]);
 216
 217     for (i = 0; i < length; i++)
 218       emit_byte(cinfo, htbl->huffval[i]);
 219
 220     htbl->sent_table = TRUE;
 221   }
 222 }
 223
 224
 225 LOCAL(void)
 226 emit_dac (j_compress_ptr cinfo)
 227 /* Emit a DAC marker */
 228 /* Since the useful info is so small, we want to emit all the tables in */
 229 /* one DAC marker.  Therefore this routine does its own scan of the table. */
 230 {
 231 #ifdef C_ARITH_CODING_SUPPORTED
 232   char dc_in_use[NUM_ARITH_TBLS];
 233   char ac_in_use[NUM_ARITH_TBLS];
 234   int length, i;
 235   jpeg_component_info *compptr;
 236
 237   for (i = 0; i < NUM_ARITH_TBLS; i++)
 238     dc_in_use[i] = ac_in_use[i] = 0;
 239
 240   for (i = 0; i < cinfo->comps_in_scan; i++) {
 241     compptr = cinfo->cur_comp_info[i];
 242     dc_in_use[compptr->dc_tbl_no] = 1;
 243     ac_in_use[compptr->ac_tbl_no] = 1;
 244   }
 245
 246   length = 0;
 247   for (i = 0; i < NUM_ARITH_TBLS; i++)
 248     length += dc_in_use[i] + ac_in_use[i];
 249
 250   emit_marker(cinfo, M_DAC);
 251
 252   emit_2bytes(cinfo, length*2 + 2);
 253
 254   for (i = 0; i < NUM_ARITH_TBLS; i++) {
 255     if (dc_in_use[i]) {
 256       emit_byte(cinfo, i);
 257       emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
 258     }
 259     if (ac_in_use[i]) {
 260       emit_byte(cinfo, i + 0x10);
 261       emit_byte(cinfo, cinfo->arith_ac_K[i]);
 262     }
 263   }
 264 #endif /* C_ARITH_CODING_SUPPORTED */
 265 }
 266
 267
 268 LOCAL(void)
 269 emit_dri (j_compress_ptr cinfo)
 270 /* Emit a DRI marker */
 271 {
 272   emit_marker(cinfo, M_DRI);
 273
 274   emit_2bytes(cinfo, 4);        /* fixed length */
 275
 276   emit_2bytes(cinfo, (int) cinfo->restart_interval);
 277 }
 278
 279
 280 LOCAL(void)
 281 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
 282 /* Emit a SOF marker */
 283 {
 284   int ci;
 285   jpeg_component_info *compptr;
 286
 287   emit_marker(cinfo, code);
 288
 289   emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
 290
 291   /* Make sure image isn't bigger than SOF field can handle */
 292   if ((long) cinfo->image_height > 65535L ||
 293       (long) cinfo->image_width > 65535L)
 294     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
 295
 296   emit_byte(cinfo, cinfo->data_precision);
 297   emit_2bytes(cinfo, (int) cinfo->image_height);
 298   emit_2bytes(cinfo, (int) cinfo->image_width);
 299
 300   emit_byte(cinfo, cinfo->num_components);
 301
 302   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 303        ci++, compptr++) {
 304     emit_byte(cinfo, compptr->component_id);
 305     emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
 306     emit_byte(cinfo, compptr->quant_tbl_no);
 307   }
 308 }
 309
 310
 311 LOCAL(void)
 312 emit_sos (j_compress_ptr cinfo)
 313 /* Emit a SOS marker */
 314 {
 315   int i, td, ta;
 316   jpeg_component_info *compptr;
 317
 318   emit_marker(cinfo, M_SOS);
 319
 320   emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
 321
 322   emit_byte(cinfo, cinfo->comps_in_scan);
 323
 324   for (i = 0; i < cinfo->comps_in_scan; i++) {
 325     compptr = cinfo->cur_comp_info[i];
 326     emit_byte(cinfo, compptr->component_id);
 327     td = compptr->dc_tbl_no;
 328     ta = compptr->ac_tbl_no;
 329     if (cinfo->process == JPROC_PROGRESSIVE) {
 330       /* Progressive mode: only DC or only AC tables are used in one scan;
 331        * furthermore, Huffman coding of DC refinement uses no table at all.
 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       if (cinfo->Ss == 0) {
 336         ta = 0;                 /* DC scan */
 337         if (cinfo->Ah != 0 && !cinfo->arith_code)
 338           td = 0;               /* no DC table either */
 339       } else {
 340         td = 0;                 /* AC scan */
 341       }
 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   if (cinfo->process != JPROC_LOSSLESS) {
 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
 516   /* Check for a non-baseline specification.
 517    * Note we assume that Huffman table numbers won't be changed later.
 518    */
 519   if (cinfo->arith_code || cinfo->process != JPROC_SEQUENTIAL ||
 520       cinfo->data_precision != 8) {
 521     is_baseline = FALSE;
 522   } else {
 523     is_baseline = TRUE;
 524     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 525          ci++, compptr++) {
 526       if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
 527         is_baseline = FALSE;
 528     }
 529     if (prec && is_baseline) {
 530       is_baseline = FALSE;
 531       /* If it's baseline except for quantizer size, warn the user */
 532       TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
 533     }
 534   }
 535
 536   /* Emit the proper SOF marker */
 537   if (cinfo->arith_code) {
 538     emit_sof(cinfo, M_SOF9);    /* SOF code for arithmetic coding */
 539   } else {
 540     if (cinfo->process == JPROC_PROGRESSIVE)
 541       emit_sof(cinfo, M_SOF2);  /* SOF code for progressive Huffman */
 542     else if (cinfo->process == JPROC_LOSSLESS)
 543       emit_sof(cinfo, M_SOF3);  /* SOF code for lossless 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       if (cinfo->process == JPROC_PROGRESSIVE) {
 578         /* Progressive mode: only DC or only AC tables are used in one scan */
 579         if (cinfo->Ss == 0) {
 580           if (cinfo->Ah == 0)   /* DC needs no table for refinement scan */
 581             emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
 582         } else {
 583           emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
 584         }
 585       } else if (cinfo->process == JPROC_LOSSLESS) {
 586         /* Lossless mode: only DC tables are used */
 587         emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
 588       } else {
 589         /* Sequential mode: need both DC and AC tables */
 590         emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
 591         emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
 592       }
 593     }
 594   }
 595
 596   /* Emit DRI if required --- note that DRI value could change for each scan.
 597    * We avoid wasting space with unnecessary DRIs, however.
 598    */
 599   if (cinfo->restart_interval != marker->last_restart_interval) {
 600     emit_dri(cinfo);
 601     marker->last_restart_interval = cinfo->restart_interval;
 602   }
 603
 604   emit_sos(cinfo);
 605 }
 606
 607
 608 /*
 609  * Write datastream trailer.
 610  */
 611
 612 METHODDEF(void)
 613 write_file_trailer (j_compress_ptr cinfo)
 614 {
 615   emit_marker(cinfo, M_EOI);
 616 }
 617
 618
 619 /*
 620  * Write an abbreviated table-specification datastream.
 621  * This consists of SOI, DQT and DHT tables, and EOI.
 622  * Any table that is defined and not marked sent_table = TRUE will be
 623  * emitted.  Note that all tables will be marked sent_table = TRUE at exit.
 624  */
 625
 626 METHODDEF(void)
 627 write_tables_only (j_compress_ptr cinfo)
 628 {
 629   int i;
 630
 631   emit_marker(cinfo, M_SOI);
 632
 633   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 634     if (cinfo->quant_tbl_ptrs[i] != NULL)
 635       (void) emit_dqt(cinfo, i);
 636   }
 637
 638   if (! cinfo->arith_code) {
 639     for (i = 0; i < NUM_HUFF_TBLS; i++) {
 640       if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
 641         emit_dht(cinfo, i, FALSE);
 642       if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
 643         emit_dht(cinfo, i, TRUE);
 644     }
 645   }
 646
 647   emit_marker(cinfo, M_EOI);
 648 }
 649
 650
 651 /*
 652  * Initialize the marker writer module.
 653  */
 654
 655 JGLOBAL(void)
 656 jinit_marker_writer (j_compress_ptr cinfo)
 657 {
 658   my_marker_ptr marker;
 659
 660   /* Create the subobject */
 661   marker = (my_marker_ptr)
 662     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 663                                 SIZEOF(my_marker_writer));
 664   cinfo->marker = (struct jpeg_marker_writer *) marker;
 665   /* Initialize method pointers */
 666   marker->pub.write_file_header = write_file_header;
 667   marker->pub.write_frame_header = write_frame_header;
 668   marker->pub.write_scan_header = write_scan_header;
 669   marker->pub.write_file_trailer = write_file_trailer;
 670   marker->pub.write_tables_only = write_tables_only;
 671   marker->pub.write_marker_header = write_marker_header;
 672   marker->pub.write_marker_byte = write_marker_byte;
 673   /* Initialize private state */
 674   marker->last_restart_interval = 0;
 675 }