compiler/libjpeg/main/jcapimin.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * jcapimin.c
   7  *
   8  * Copyright (C) 1994-1998, 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 application interface code for the compression half
  13  * of the JPEG library.  These are the "minimum" API routines that may be
  14  * needed in either the normal full-compression case or the transcoding-only
  15  * case.
  16  *
  17  * Most of the routines intended to be called directly by an application
  18  * are in this file or in jcapistd.c.  But also see jcparam.c for
  19  * parameter-setup helper routines, jcomapi.c for routines shared by
  20  * compression and decompression, and jctrans.c for the transcoding case.
  21  */
  22
  23 #define JPEG_INTERNALS
  24 #include "jinclude.h"
  25 #include "jpeglib.h"
  26
  27
  28 /*
  29  * Initialization of a JPEG compression object.
  30  * The error manager must already be set up (in case memory manager fails).
  31  */
  32
  33 JGLOBAL(void)
  34 jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
  35 {
  36   int i;
  37
  38   /* Guard against version mismatches between library and caller. */
  39   cinfo->mem = NULL;            /* so jpeg_destroy knows mem mgr not called */
  40   if (version != JPEG_LIB_VERSION)
  41     ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
  42   if (structsize != SIZEOF(struct jpeg_compress_struct))
  43     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
  44              (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
  45
  46   /* For debugging purposes, we zero the whole master structure.
  47    * But the application has already set the err pointer, and may have set
  48    * client_data, so we have to save and restore those fields.
  49    * Note: if application hasn't set client_data, tools like Purify may
  50    * complain here.
  51    */
  52   {
  53     struct jpeg_error_mgr * err = cinfo->err;
  54     void * client_data = cinfo->client_data; /* ignore Purify complaint here */
  55     MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
  56     cinfo->err = err;
  57     cinfo->client_data = client_data;
  58   }
  59   cinfo->is_decompressor = FALSE;
  60
  61   /* Initialize a memory manager instance for this object */
  62   jinit_memory_mgr((j_common_ptr) cinfo);
  63
  64   /* Zero out pointers to permanent structures. */
  65   cinfo->progress = NULL;
  66   cinfo->dest = NULL;
  67
  68   cinfo->comp_info = NULL;
  69
  70   for (i = 0; i < NUM_QUANT_TBLS; i++)
  71     cinfo->quant_tbl_ptrs[i] = NULL;
  72
  73   for (i = 0; i < NUM_HUFF_TBLS; i++) {
  74     cinfo->dc_huff_tbl_ptrs[i] = NULL;
  75     cinfo->ac_huff_tbl_ptrs[i] = NULL;
  76   }
  77
  78   cinfo->script_space = NULL;
  79
  80   cinfo->input_gamma = 1.0;     /* in case application forgets */
  81
  82   /* OK, I'm ready */
  83   cinfo->global_state = CSTATE_START;
  84 }
  85
  86
  87 /*
  88  * Destruction of a JPEG compression object
  89  */
  90
  91 JGLOBAL(void)
  92 jpeg_destroy_compress (j_compress_ptr cinfo)
  93 {
  94   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
  95 }
  96
  97
  98 /*
  99  * Abort processing of a JPEG compression operation,
 100  * but don't destroy the object itself.
 101  */
 102
 103 JGLOBAL(void)
 104 jpeg_abort_compress (j_compress_ptr cinfo)
 105 {
 106   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
 107 }
 108
 109
 110 /*
 111  * Forcibly suppress or un-suppress all quantization and Huffman tables.
 112  * Marks all currently defined tables as already written (if suppress)
 113  * or not written (if !suppress).  This will control whether they get emitted
 114  * by a subsequent jpeg_start_compress call.
 115  *
 116  * This routine is exported for use by applications that want to produce
 117  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 118  * since it is called by jpeg_start_compress, we put it here --- otherwise
 119  * jcparam.o would be linked whether the application used it or not.
 120  */
 121
 122 JGLOBAL(void)
 123 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
 124 {
 125   int i;
 126   JQUANT_TBL * qtbl;
 127   JHUFF_TBL * htbl;
 128
 129   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 130     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
 131       qtbl->sent_table = suppress;
 132   }
 133
 134   for (i = 0; i < NUM_HUFF_TBLS; i++) {
 135     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
 136       htbl->sent_table = suppress;
 137     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
 138       htbl->sent_table = suppress;
 139   }
 140 }
 141
 142
 143 /*
 144  * Finish JPEG compression.
 145  *
 146  * If a multipass operating mode was selected, this may do a great deal of
 147  * work including most of the actual output.
 148  */
 149
 150 JGLOBAL(void)
 151 jpeg_finish_compress (j_compress_ptr cinfo)
 152 {
 153   JDIMENSION iMCU_row;
 154
 155   if (cinfo->global_state == CSTATE_SCANNING ||
 156       cinfo->global_state == CSTATE_RAW_OK) {
 157     /* Terminate first pass */
 158     if (cinfo->next_scanline < cinfo->image_height)
 159       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
 160     (*cinfo->master->finish_pass) (cinfo);
 161   } else if (cinfo->global_state != CSTATE_WRCOEFS)
 162     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 163   /* Perform any remaining passes */
 164   while (! cinfo->master->is_last_pass) {
 165     (*cinfo->master->prepare_for_pass) (cinfo);
 166     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
 167       if (cinfo->progress != NULL) {
 168         cinfo->progress->pass_counter = (long) iMCU_row;
 169         cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
 170         (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
 171       }
 172       /* We bypass the main controller and invoke coef controller directly;
 173        * all work is being done from the coefficient buffer.
 174        */
 175       if (! (*cinfo->codec->compress_data) (cinfo, (JSAMPIMAGE) NULL))
 176         ERREXIT(cinfo, JERR_CANT_SUSPEND);
 177     }
 178     (*cinfo->master->finish_pass) (cinfo);
 179   }
 180   /* Write EOI, do final cleanup */
 181   (*cinfo->marker->write_file_trailer) (cinfo);
 182   (*cinfo->dest->term_destination) (cinfo);
 183   /* We can use jpeg_abort to release memory and reset global_state */
 184   jpeg_abort((j_common_ptr) cinfo);
 185 }
 186
 187
 188 /*
 189  * Write a special marker.
 190  * This is only recommended for writing COM or APPn markers.
 191  * Must be called after jpeg_start_compress() and before
 192  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 193  */
 194
 195 JGLOBAL(void)
 196 jpeg_write_marker (j_compress_ptr cinfo, int marker,
 197                    const JOCTET *dataptr, unsigned int datalen)
 198 {
 199   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
 200
 201   if (cinfo->next_scanline != 0 ||
 202       (cinfo->global_state != CSTATE_SCANNING &&
 203        cinfo->global_state != CSTATE_RAW_OK &&
 204        cinfo->global_state != CSTATE_WRCOEFS))
 205     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 206
 207   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 208   write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
 209   while (datalen--) {
 210     (*write_marker_byte) (cinfo, *dataptr);
 211     dataptr++;
 212   }
 213 }
 214
 215 /* Same, but piecemeal. */
 216
 217 JGLOBAL(void)
 218 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 219 {
 220   if (cinfo->next_scanline != 0 ||
 221       (cinfo->global_state != CSTATE_SCANNING &&
 222        cinfo->global_state != CSTATE_RAW_OK &&
 223        cinfo->global_state != CSTATE_WRCOEFS))
 224     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 225
 226   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 227 }
 228
 229 JGLOBAL(void)
 230 jpeg_write_m_byte (j_compress_ptr cinfo, int val)
 231 {
 232   (*cinfo->marker->write_marker_byte) (cinfo, val);
 233 }
 234
 235
 236 /*
 237  * Alternate compression function: just write an abbreviated table file.
 238  * Before calling this, all parameters and a data destination must be set up.
 239  *
 240  * To produce a pair of files containing abbreviated tables and abbreviated
 241  * image data, one would proceed as follows:
 242  *
 243  *              initialize JPEG object
 244  *              set JPEG parameters
 245  *              set destination to table file
 246  *              jpeg_write_tables(cinfo);
 247  *              set destination to image file
 248  *              jpeg_start_compress(cinfo, FALSE);
 249  *              write data...
 250  *              jpeg_finish_compress(cinfo);
 251  *
 252  * jpeg_write_tables has the side effect of marking all tables written
 253  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 254  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 255  */
 256
 257 JGLOBAL(void)
 258 jpeg_write_tables (j_compress_ptr cinfo)
 259 {
 260   if (cinfo->global_state != CSTATE_START)
 261     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 262
 263   /* (Re)initialize error mgr and destination modules */
 264   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
 265   (*cinfo->dest->init_destination) (cinfo);
 266   /* Initialize the marker writer ... bit of a crock to do it here. */
 267   jinit_marker_writer(cinfo);
 268   /* Write them tables! */
 269   (*cinfo->marker->write_tables_only) (cinfo);
 270   /* And clean up. */
 271   (*cinfo->dest->term_destination) (cinfo);
 272   /*
 273    * In library releases up through v6a, we called jpeg_abort() here to free
 274    * any working memory allocated by the destination manager and marker
 275    * writer.  Some applications had a problem with that: they allocated space
 276    * of their own from the library memory manager, and didn't want it to go
 277    * away during write_tables.  So now we do nothing.  This will cause a
 278    * memory leak if an app calls write_tables repeatedly without doing a full
 279    * compression cycle or otherwise resetting the JPEG object.  However, that
 280    * seems less bad than unexpectedly freeing memory in the normal case.
 281    * An app that prefers the old behavior can call jpeg_abort for itself after
 282    * each call to jpeg_write_tables().
 283    */
 284 }