Back to index

plt-scheme  4.2.1
jcmarker.c
Go to the documentation of this file.
00001 /*
00002  * jcmarker.c
00003  *
00004  * Copyright (C) 1991-1998, Thomas G. Lane.
00005  * This file is part of the Independent JPEG Group's software.
00006  * For conditions of distribution and use, see the accompanying README file.
00007  *
00008  * This file contains routines to write JPEG datastream markers.
00009  */
00010 
00011 #define JPEG_INTERNALS
00012 #include "jinclude.h"
00013 #include "jpeglib.h"
00014 
00015 
00016 typedef enum {                     /* JPEG marker codes */
00017   M_SOF0  = 0xc0,
00018   M_SOF1  = 0xc1,
00019   M_SOF2  = 0xc2,
00020   M_SOF3  = 0xc3,
00021   
00022   M_SOF5  = 0xc5,
00023   M_SOF6  = 0xc6,
00024   M_SOF7  = 0xc7,
00025   
00026   M_JPG   = 0xc8,
00027   M_SOF9  = 0xc9,
00028   M_SOF10 = 0xca,
00029   M_SOF11 = 0xcb,
00030   
00031   M_SOF13 = 0xcd,
00032   M_SOF14 = 0xce,
00033   M_SOF15 = 0xcf,
00034   
00035   M_DHT   = 0xc4,
00036   
00037   M_DAC   = 0xcc,
00038   
00039   M_RST0  = 0xd0,
00040   M_RST1  = 0xd1,
00041   M_RST2  = 0xd2,
00042   M_RST3  = 0xd3,
00043   M_RST4  = 0xd4,
00044   M_RST5  = 0xd5,
00045   M_RST6  = 0xd6,
00046   M_RST7  = 0xd7,
00047   
00048   M_SOI   = 0xd8,
00049   M_EOI   = 0xd9,
00050   M_SOS   = 0xda,
00051   M_DQT   = 0xdb,
00052   M_DNL   = 0xdc,
00053   M_DRI   = 0xdd,
00054   M_DHP   = 0xde,
00055   M_EXP   = 0xdf,
00056   
00057   M_APP0  = 0xe0,
00058   M_APP1  = 0xe1,
00059   M_APP2  = 0xe2,
00060   M_APP3  = 0xe3,
00061   M_APP4  = 0xe4,
00062   M_APP5  = 0xe5,
00063   M_APP6  = 0xe6,
00064   M_APP7  = 0xe7,
00065   M_APP8  = 0xe8,
00066   M_APP9  = 0xe9,
00067   M_APP10 = 0xea,
00068   M_APP11 = 0xeb,
00069   M_APP12 = 0xec,
00070   M_APP13 = 0xed,
00071   M_APP14 = 0xee,
00072   M_APP15 = 0xef,
00073   
00074   M_JPG0  = 0xf0,
00075   M_JPG13 = 0xfd,
00076   M_COM   = 0xfe,
00077   
00078   M_TEM   = 0x01,
00079   
00080   M_ERROR = 0x100
00081 } JPEG_MARKER;
00082 
00083 
00084 /* Private state */
00085 
00086 typedef struct {
00087   struct jpeg_marker_writer pub; /* public fields */
00088 
00089   unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
00090 } my_marker_writer;
00091 
00092 typedef my_marker_writer * my_marker_ptr;
00093 
00094 
00095 /*
00096  * Basic output routines.
00097  *
00098  * Note that we do not support suspension while writing a marker.
00099  * Therefore, an application using suspension must ensure that there is
00100  * enough buffer space for the initial markers (typ. 600-700 bytes) before
00101  * calling jpeg_start_compress, and enough space to write the trailing EOI
00102  * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
00103  * modes are not supported at all with suspension, so those two are the only
00104  * points where markers will be written.
00105  */
00106 
00107 LOCAL(void)
00108 emit_byte (j_compress_ptr cinfo, int val)
00109 /* Emit a byte */
00110 {
00111   struct jpeg_destination_mgr * dest = cinfo->dest;
00112 
00113   *(dest->next_output_byte)++ = (JOCTET) val;
00114   if (--dest->free_in_buffer == 0) {
00115     if (! (*dest->empty_output_buffer) (cinfo))
00116       ERREXIT(cinfo, JERR_CANT_SUSPEND);
00117   }
00118 }
00119 
00120 
00121 LOCAL(void)
00122 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
00123 /* Emit a marker code */
00124 {
00125   emit_byte(cinfo, 0xFF);
00126   emit_byte(cinfo, (int) mark);
00127 }
00128 
00129 
00130 LOCAL(void)
00131 emit_2bytes (j_compress_ptr cinfo, int value)
00132 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
00133 {
00134   emit_byte(cinfo, (value >> 8) & 0xFF);
00135   emit_byte(cinfo, value & 0xFF);
00136 }
00137 
00138 
00139 /*
00140  * Routines to write specific marker types.
00141  */
00142 
00143 LOCAL(int)
00144 emit_dqt (j_compress_ptr cinfo, int index)
00145 /* Emit a DQT marker */
00146 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
00147 {
00148   JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
00149   int prec;
00150   int i;
00151 
00152   if (qtbl == NULL)
00153     ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
00154 
00155   prec = 0;
00156   for (i = 0; i < DCTSIZE2; i++) {
00157     if (qtbl->quantval[i] > 255)
00158       prec = 1;
00159   }
00160 
00161   if (! qtbl->sent_table) {
00162     emit_marker(cinfo, M_DQT);
00163 
00164     emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
00165 
00166     emit_byte(cinfo, index + (prec<<4));
00167 
00168     for (i = 0; i < DCTSIZE2; i++) {
00169       /* The table entries must be emitted in zigzag order. */
00170       unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
00171       if (prec)
00172        emit_byte(cinfo, (int) (qval >> 8));
00173       emit_byte(cinfo, (int) (qval & 0xFF));
00174     }
00175 
00176     qtbl->sent_table = TRUE;
00177   }
00178 
00179   return prec;
00180 }
00181 
00182 
00183 LOCAL(void)
00184 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
00185 /* Emit a DHT marker */
00186 {
00187   JHUFF_TBL * htbl;
00188   int length, i;
00189   
00190   if (is_ac) {
00191     htbl = cinfo->ac_huff_tbl_ptrs[index];
00192     index += 0x10;          /* output index has AC bit set */
00193   } else {
00194     htbl = cinfo->dc_huff_tbl_ptrs[index];
00195   }
00196 
00197   if (htbl == NULL)
00198     ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
00199   
00200   if (! htbl->sent_table) {
00201     emit_marker(cinfo, M_DHT);
00202     
00203     length = 0;
00204     for (i = 1; i <= 16; i++)
00205       length += htbl->bits[i];
00206     
00207     emit_2bytes(cinfo, length + 2 + 1 + 16);
00208     emit_byte(cinfo, index);
00209     
00210     for (i = 1; i <= 16; i++)
00211       emit_byte(cinfo, htbl->bits[i]);
00212     
00213     for (i = 0; i < length; i++)
00214       emit_byte(cinfo, htbl->huffval[i]);
00215     
00216     htbl->sent_table = TRUE;
00217   }
00218 }
00219 
00220 
00221 LOCAL(void)
00222 emit_dac (j_compress_ptr cinfo)
00223 /* Emit a DAC marker */
00224 /* Since the useful info is so small, we want to emit all the tables in */
00225 /* one DAC marker.  Therefore this routine does its own scan of the table. */
00226 {
00227 #ifdef C_ARITH_CODING_SUPPORTED
00228   char dc_in_use[NUM_ARITH_TBLS];
00229   char ac_in_use[NUM_ARITH_TBLS];
00230   int length, i;
00231   jpeg_component_info *compptr;
00232   
00233   for (i = 0; i < NUM_ARITH_TBLS; i++)
00234     dc_in_use[i] = ac_in_use[i] = 0;
00235   
00236   for (i = 0; i < cinfo->comps_in_scan; i++) {
00237     compptr = cinfo->cur_comp_info[i];
00238     dc_in_use[compptr->dc_tbl_no] = 1;
00239     ac_in_use[compptr->ac_tbl_no] = 1;
00240   }
00241   
00242   length = 0;
00243   for (i = 0; i < NUM_ARITH_TBLS; i++)
00244     length += dc_in_use[i] + ac_in_use[i];
00245   
00246   emit_marker(cinfo, M_DAC);
00247   
00248   emit_2bytes(cinfo, length*2 + 2);
00249   
00250   for (i = 0; i < NUM_ARITH_TBLS; i++) {
00251     if (dc_in_use[i]) {
00252       emit_byte(cinfo, i);
00253       emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
00254     }
00255     if (ac_in_use[i]) {
00256       emit_byte(cinfo, i + 0x10);
00257       emit_byte(cinfo, cinfo->arith_ac_K[i]);
00258     }
00259   }
00260 #endif /* C_ARITH_CODING_SUPPORTED */
00261 }
00262 
00263 
00264 LOCAL(void)
00265 emit_dri (j_compress_ptr cinfo)
00266 /* Emit a DRI marker */
00267 {
00268   emit_marker(cinfo, M_DRI);
00269   
00270   emit_2bytes(cinfo, 4);    /* fixed length */
00271 
00272   emit_2bytes(cinfo, (int) cinfo->restart_interval);
00273 }
00274 
00275 
00276 LOCAL(void)
00277 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
00278 /* Emit a SOF marker */
00279 {
00280   int ci;
00281   jpeg_component_info *compptr;
00282   
00283   emit_marker(cinfo, code);
00284   
00285   emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
00286 
00287   /* Make sure image isn't bigger than SOF field can handle */
00288   if ((long) cinfo->image_height > 65535L ||
00289       (long) cinfo->image_width > 65535L)
00290     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
00291 
00292   emit_byte(cinfo, cinfo->data_precision);
00293   emit_2bytes(cinfo, (int) cinfo->image_height);
00294   emit_2bytes(cinfo, (int) cinfo->image_width);
00295 
00296   emit_byte(cinfo, cinfo->num_components);
00297 
00298   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
00299        ci++, compptr++) {
00300     emit_byte(cinfo, compptr->component_id);
00301     emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
00302     emit_byte(cinfo, compptr->quant_tbl_no);
00303   }
00304 }
00305 
00306 
00307 LOCAL(void)
00308 emit_sos (j_compress_ptr cinfo)
00309 /* Emit a SOS marker */
00310 {
00311   int i, td, ta;
00312   jpeg_component_info *compptr;
00313   
00314   emit_marker(cinfo, M_SOS);
00315   
00316   emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
00317   
00318   emit_byte(cinfo, cinfo->comps_in_scan);
00319   
00320   for (i = 0; i < cinfo->comps_in_scan; i++) {
00321     compptr = cinfo->cur_comp_info[i];
00322     emit_byte(cinfo, compptr->component_id);
00323     td = compptr->dc_tbl_no;
00324     ta = compptr->ac_tbl_no;
00325     if (cinfo->progressive_mode) {
00326       /* Progressive mode: only DC or only AC tables are used in one scan;
00327        * furthermore, Huffman coding of DC refinement uses no table at all.
00328        * We emit 0 for unused field(s); this is recommended by the P&M text
00329        * but does not seem to be specified in the standard.
00330        */
00331       if (cinfo->Ss == 0) {
00332        ta = 0;                     /* DC scan */
00333        if (cinfo->Ah != 0 && !cinfo->arith_code)
00334          td = 0;            /* no DC table either */
00335       } else {
00336        td = 0;                     /* AC scan */
00337       }
00338     }
00339     emit_byte(cinfo, (td << 4) + ta);
00340   }
00341 
00342   emit_byte(cinfo, cinfo->Ss);
00343   emit_byte(cinfo, cinfo->Se);
00344   emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
00345 }
00346 
00347 
00348 LOCAL(void)
00349 emit_jfif_app0 (j_compress_ptr cinfo)
00350 /* Emit a JFIF-compliant APP0 marker */
00351 {
00352   /*
00353    * Length of APP0 block   (2 bytes)
00354    * Block ID               (4 bytes - ASCII "JFIF")
00355    * Zero byte                     (1 byte to terminate the ID string)
00356    * Version Major, Minor   (2 bytes - major first)
00357    * Units                  (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
00358    * Xdpu                   (2 bytes - dots per unit horizontal)
00359    * Ydpu                   (2 bytes - dots per unit vertical)
00360    * Thumbnail X size              (1 byte)
00361    * Thumbnail Y size              (1 byte)
00362    */
00363   
00364   emit_marker(cinfo, M_APP0);
00365   
00366   emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
00367 
00368   emit_byte(cinfo, 0x4A);   /* Identifier: ASCII "JFIF" */
00369   emit_byte(cinfo, 0x46);
00370   emit_byte(cinfo, 0x49);
00371   emit_byte(cinfo, 0x46);
00372   emit_byte(cinfo, 0);
00373   emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
00374   emit_byte(cinfo, cinfo->JFIF_minor_version);
00375   emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
00376   emit_2bytes(cinfo, (int) cinfo->X_density);
00377   emit_2bytes(cinfo, (int) cinfo->Y_density);
00378   emit_byte(cinfo, 0);             /* No thumbnail image */
00379   emit_byte(cinfo, 0);
00380 }
00381 
00382 
00383 LOCAL(void)
00384 emit_adobe_app14 (j_compress_ptr cinfo)
00385 /* Emit an Adobe APP14 marker */
00386 {
00387   /*
00388    * Length of APP14 block  (2 bytes)
00389    * Block ID               (5 bytes - ASCII "Adobe")
00390    * Version Number         (2 bytes - currently 100)
00391    * Flags0                 (2 bytes - currently 0)
00392    * Flags1                 (2 bytes - currently 0)
00393    * Color transform        (1 byte)
00394    *
00395    * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
00396    * now in circulation seem to use Version = 100, so that's what we write.
00397    *
00398    * We write the color transform byte as 1 if the JPEG color space is
00399    * YCbCr, 2 if it's YCCK, 0 otherwise.  Adobe's definition has to do with
00400    * whether the encoder performed a transformation, which is pretty useless.
00401    */
00402   
00403   emit_marker(cinfo, M_APP14);
00404   
00405   emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
00406 
00407   emit_byte(cinfo, 0x41);   /* Identifier: ASCII "Adobe" */
00408   emit_byte(cinfo, 0x64);
00409   emit_byte(cinfo, 0x6F);
00410   emit_byte(cinfo, 0x62);
00411   emit_byte(cinfo, 0x65);
00412   emit_2bytes(cinfo, 100);  /* Version */
00413   emit_2bytes(cinfo, 0);    /* Flags0 */
00414   emit_2bytes(cinfo, 0);    /* Flags1 */
00415   switch (cinfo->jpeg_color_space) {
00416   case JCS_YCbCr:
00417     emit_byte(cinfo, 1);    /* Color transform = 1 */
00418     break;
00419   case JCS_YCCK:
00420     emit_byte(cinfo, 2);    /* Color transform = 2 */
00421     break;
00422   default:
00423     emit_byte(cinfo, 0);    /* Color transform = 0 */
00424     break;
00425   }
00426 }
00427 
00428 
00429 /*
00430  * These routines allow writing an arbitrary marker with parameters.
00431  * The only intended use is to emit COM or APPn markers after calling
00432  * write_file_header and before calling write_frame_header.
00433  * Other uses are not guaranteed to produce desirable results.
00434  * Counting the parameter bytes properly is the caller's responsibility.
00435  */
00436 
00437 METHODDEF(void)
00438 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
00439 /* Emit an arbitrary marker header */
00440 {
00441   if (datalen > (unsigned int) 65533)            /* safety check */
00442     ERREXIT(cinfo, JERR_BAD_LENGTH);
00443 
00444   emit_marker(cinfo, (JPEG_MARKER) marker);
00445 
00446   emit_2bytes(cinfo, (int) (datalen + 2));       /* total length */
00447 }
00448 
00449 METHODDEF(void)
00450 write_marker_byte (j_compress_ptr cinfo, int val)
00451 /* Emit one byte of marker parameters following write_marker_header */
00452 {
00453   emit_byte(cinfo, val);
00454 }
00455 
00456 
00457 /*
00458  * Write datastream header.
00459  * This consists of an SOI and optional APPn markers.
00460  * We recommend use of the JFIF marker, but not the Adobe marker,
00461  * when using YCbCr or grayscale data.  The JFIF marker should NOT
00462  * be used for any other JPEG colorspace.  The Adobe marker is helpful
00463  * to distinguish RGB, CMYK, and YCCK colorspaces.
00464  * Note that an application can write additional header markers after
00465  * jpeg_start_compress returns.
00466  */
00467 
00468 METHODDEF(void)
00469 write_file_header (j_compress_ptr cinfo)
00470 {
00471   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
00472 
00473   emit_marker(cinfo, M_SOI);       /* first the SOI */
00474 
00475   /* SOI is defined to reset restart interval to 0 */
00476   marker->last_restart_interval = 0;
00477 
00478   if (cinfo->write_JFIF_header)    /* next an optional JFIF APP0 */
00479     emit_jfif_app0(cinfo);
00480   if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
00481     emit_adobe_app14(cinfo);
00482 }
00483 
00484 
00485 /*
00486  * Write frame header.
00487  * This consists of DQT and SOFn markers.
00488  * Note that we do not emit the SOF until we have emitted the DQT(s).
00489  * This avoids compatibility problems with incorrect implementations that
00490  * try to error-check the quant table numbers as soon as they see the SOF.
00491  */
00492 
00493 METHODDEF(void)
00494 write_frame_header (j_compress_ptr cinfo)
00495 {
00496   int ci, prec;
00497   boolean is_baseline;
00498   jpeg_component_info *compptr;
00499   
00500   /* Emit DQT for each quantization table.
00501    * Note that emit_dqt() suppresses any duplicate tables.
00502    */
00503   prec = 0;
00504   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
00505        ci++, compptr++) {
00506     prec += emit_dqt(cinfo, compptr->quant_tbl_no);
00507   }
00508   /* now prec is nonzero iff there are any 16-bit quant tables. */
00509 
00510   /* Check for a non-baseline specification.
00511    * Note we assume that Huffman table numbers won't be changed later.
00512    */
00513   if (cinfo->arith_code || cinfo->progressive_mode ||
00514       cinfo->data_precision != 8) {
00515     is_baseline = FALSE;
00516   } else {
00517     is_baseline = TRUE;
00518     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
00519         ci++, compptr++) {
00520       if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
00521        is_baseline = FALSE;
00522     }
00523     if (prec && is_baseline) {
00524       is_baseline = FALSE;
00525       /* If it's baseline except for quantizer size, warn the user */
00526       TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
00527     }
00528   }
00529 
00530   /* Emit the proper SOF marker */
00531   if (cinfo->arith_code) {
00532     emit_sof(cinfo, M_SOF9);       /* SOF code for arithmetic coding */
00533   } else {
00534     if (cinfo->progressive_mode)
00535       emit_sof(cinfo, M_SOF2);     /* SOF code for progressive Huffman */
00536     else if (is_baseline)
00537       emit_sof(cinfo, M_SOF0);     /* SOF code for baseline implementation */
00538     else
00539       emit_sof(cinfo, M_SOF1);     /* SOF code for non-baseline Huffman file */
00540   }
00541 }
00542 
00543 
00544 /*
00545  * Write scan header.
00546  * This consists of DHT or DAC markers, optional DRI, and SOS.
00547  * Compressed data will be written following the SOS.
00548  */
00549 
00550 METHODDEF(void)
00551 write_scan_header (j_compress_ptr cinfo)
00552 {
00553   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
00554   int i;
00555   jpeg_component_info *compptr;
00556 
00557   if (cinfo->arith_code) {
00558     /* Emit arith conditioning info.  We may have some duplication
00559      * if the file has multiple scans, but it's so small it's hardly
00560      * worth worrying about.
00561      */
00562     emit_dac(cinfo);
00563   } else {
00564     /* Emit Huffman tables.
00565      * Note that emit_dht() suppresses any duplicate tables.
00566      */
00567     for (i = 0; i < cinfo->comps_in_scan; i++) {
00568       compptr = cinfo->cur_comp_info[i];
00569       if (cinfo->progressive_mode) {
00570        /* Progressive mode: only DC or only AC tables are used in one scan */
00571        if (cinfo->Ss == 0) {
00572          if (cinfo->Ah == 0)       /* DC needs no table for refinement scan */
00573            emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
00574        } else {
00575          emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
00576        }
00577       } else {
00578        /* Sequential mode: need both DC and AC tables */
00579        emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
00580        emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
00581       }
00582     }
00583   }
00584 
00585   /* Emit DRI if required --- note that DRI value could change for each scan.
00586    * We avoid wasting space with unnecessary DRIs, however.
00587    */
00588   if (cinfo->restart_interval != marker->last_restart_interval) {
00589     emit_dri(cinfo);
00590     marker->last_restart_interval = cinfo->restart_interval;
00591   }
00592 
00593   emit_sos(cinfo);
00594 }
00595 
00596 
00597 /*
00598  * Write datastream trailer.
00599  */
00600 
00601 METHODDEF(void)
00602 write_file_trailer (j_compress_ptr cinfo)
00603 {
00604   emit_marker(cinfo, M_EOI);
00605 }
00606 
00607 
00608 /*
00609  * Write an abbreviated table-specification datastream.
00610  * This consists of SOI, DQT and DHT tables, and EOI.
00611  * Any table that is defined and not marked sent_table = TRUE will be
00612  * emitted.  Note that all tables will be marked sent_table = TRUE at exit.
00613  */
00614 
00615 METHODDEF(void)
00616 write_tables_only (j_compress_ptr cinfo)
00617 {
00618   int i;
00619 
00620   emit_marker(cinfo, M_SOI);
00621 
00622   for (i = 0; i < NUM_QUANT_TBLS; i++) {
00623     if (cinfo->quant_tbl_ptrs[i] != NULL)
00624       (void) emit_dqt(cinfo, i);
00625   }
00626 
00627   if (! cinfo->arith_code) {
00628     for (i = 0; i < NUM_HUFF_TBLS; i++) {
00629       if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
00630        emit_dht(cinfo, i, FALSE);
00631       if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
00632        emit_dht(cinfo, i, TRUE);
00633     }
00634   }
00635 
00636   emit_marker(cinfo, M_EOI);
00637 }
00638 
00639 
00640 /*
00641  * Initialize the marker writer module.
00642  */
00643 
00644 GLOBAL(void)
00645 jinit_marker_writer (j_compress_ptr cinfo)
00646 {
00647   my_marker_ptr marker;
00648 
00649   /* Create the subobject */
00650   marker = (my_marker_ptr)
00651     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
00652                             SIZEOF(my_marker_writer));
00653   cinfo->marker = (struct jpeg_marker_writer *) marker;
00654   /* Initialize method pointers */
00655   marker->pub.write_file_header = write_file_header;
00656   marker->pub.write_frame_header = write_frame_header;
00657   marker->pub.write_scan_header = write_scan_header;
00658   marker->pub.write_file_trailer = write_file_trailer;
00659   marker->pub.write_tables_only = write_tables_only;
00660   marker->pub.write_marker_header = write_marker_header;
00661   marker->pub.write_marker_byte = write_marker_byte;
00662   /* Initialize private state */
00663   marker->last_restart_interval = 0;
00664 }