jpeg/jcapimin.c

   1 /*
   2  * jcapimin.c
   3  *
   4  * Copyright (C) 1994-1998, Thomas G. Lane.
   5  * This file is part of the Independent JPEG Group's software.
   6  * For conditions of distribution and use, see the accompanying README file.
   7  *
   8  * This file contains application interface code for the compression half
   9  * of the JPEG library.  These are the "minimum" API routines that may be
  10  * needed in either the normal full-compression case or the transcoding-only
  11  * case.
  12  *
  13  * Most of the routines intended to be called directly by an application
  14  * are in this file or in jcapistd.c.  But also see jcparam.c for
  15  * parameter-setup helper routines, jcomapi.c for routines shared by
  16  * compression and decompression, and jctrans.c for the transcoding case.
  17  */
  18
  19 #define JPEG_INTERNALS
  20 #include "jinclude.h"
  21 #include "jpeglib.h"
  22
  23
  24 /*
  25  * Initialization of a JPEG compression object.
  26  * The error manager must already be set up (in case memory manager fails).
  27  */
  28
  29 GLOBAL(void)
  30 jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
  31 {
  32   int i;
  33
  34   /* Guard against version mismatches between library and caller. */
  35   cinfo->mem = NULL;            /* so jpeg_destroy knows mem mgr not called */
  36   if (version != JPEG_LIB_VERSION)
  37     ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
  38   if (structsize != SIZEOF(struct jpeg_compress_struct))
  39     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
  40              (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
  41
  42   /* For debugging purposes, we zero the whole master structure.
  43    * But the application has already set the err pointer, and may have set
  44    * client_data, so we have to save and restore those fields.
  45    * Note: if application hasn't set client_data, tools like Purify may
  46    * complain here.
  47    */
  48   {
  49     struct jpeg_error_mgr * err = cinfo->err;
  50     void * client_data = cinfo->client_data; /* ignore Purify complaint here */
  51     MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
  52     cinfo->err = err;
  53     cinfo->client_data = client_data;
  54   }
  55   cinfo->is_decompressor = FALSE;
  56
  57   /* Initialize a memory manager instance for this object */
  58   jinit_memory_mgr((j_common_ptr) cinfo);
  59
  60   /* Zero out pointers to permanent structures. */
  61   cinfo->progress = NULL;
  62   cinfo->dest = NULL;
  63
  64   cinfo->comp_info = NULL;
  65
  66   for (i = 0; i < NUM_QUANT_TBLS; i++)
  67     cinfo->quant_tbl_ptrs[i] = NULL;
  68
  69   for (i = 0; i < NUM_HUFF_TBLS; i++) {
  70     cinfo->dc_huff_tbl_ptrs[i] = NULL;
  71     cinfo->ac_huff_tbl_ptrs[i] = NULL;
  72   }
  73
  74   cinfo->script_space = NULL;
  75
  76   cinfo->input_gamma = 1.0;     /* in case application forgets */
  77
  78   /* OK, I'm ready */
  79   cinfo->global_state = CSTATE_START;
  80 }
  81
  82
  83 /*
  84  * Destruction of a JPEG compression object
  85  */
  86
  87 GLOBAL(void)
  88 jpeg_destroy_compress (j_compress_ptr cinfo)
  89 {
  90   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
  91 }
  92
  93
  94 /*
  95  * Abort processing of a JPEG compression operation,
  96  * but don't destroy the object itself.
  97  */
  98
  99 GLOBAL(void)
 100 jpeg_abort_compress (j_compress_ptr cinfo)
 101 {
 102   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
 103 }
 104
 105
 106 /*
 107  * Forcibly suppress or un-suppress all quantization and Huffman tables.
 108  * Marks all currently defined tables as already written (if suppress)
 109  * or not written (if !suppress).  This will control whether they get emitted
 110  * by a subsequent jpeg_start_compress call.
 111  *
 112  * This routine is exported for use by applications that want to produce
 113  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 114  * since it is called by jpeg_start_compress, we put it here --- otherwise
 115  * jcparam.o would be linked whether the application used it or not.
 116  */
 117
 118 GLOBAL(void)
 119 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
 120 {
 121   int i;
 122   JQUANT_TBL * qtbl;
 123   JHUFF_TBL * htbl;
 124
 125   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 126     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
 127       qtbl->sent_table = suppress;
 128   }
 129
 130   for (i = 0; i < NUM_HUFF_TBLS; i++) {
 131     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
 132       htbl->sent_table = suppress;
 133     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
 134       htbl->sent_table = suppress;
 135   }
 136 }
 137
 138
 139 /*
 140  * Finish JPEG compression.
 141  *
 142  * If a multipass operating mode was selected, this may do a great deal of
 143  * work including most of the actual output.
 144  */
 145
 146 GLOBAL(void)
 147 jpeg_finish_compress (j_compress_ptr cinfo)
 148 {
 149   JDIMENSION iMCU_row;
 150
 151   if (cinfo->global_state == CSTATE_SCANNING ||
 152       cinfo->global_state == CSTATE_RAW_OK) {
 153     /* Terminate first pass */
 154     if (cinfo->next_scanline < cinfo->image_height)
 155       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
 156     (*cinfo->master->finish_pass) (cinfo);
 157   } else if (cinfo->global_state != CSTATE_WRCOEFS)
 158     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 159   /* Perform any remaining passes */
 160   while (! cinfo->master->is_last_pass) {
 161     (*cinfo->master->prepare_for_pass) (cinfo);
 162     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
 163       if (cinfo->progress != NULL) {
 164         cinfo->progress->pass_counter = (long) iMCU_row;
 165         cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
 166         (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
 167       }
 168       /* We bypass the main controller and invoke coef controller directly;
 169        * all work is being done from the coefficient buffer.
 170        */
 171       if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
 172         ERREXIT(cinfo, JERR_CANT_SUSPEND);
 173     }
 174     (*cinfo->master->finish_pass) (cinfo);
 175   }
 176   /* Write EOI, do final cleanup */
 177   (*cinfo->marker->write_file_trailer) (cinfo);
 178   (*cinfo->dest->term_destination) (cinfo);
 179   /* We can use jpeg_abort to release memory and reset global_state */
 180   jpeg_abort((j_common_ptr) cinfo);
 181 }
 182
 183
 184 /*
 185  * Write a special marker.
 186  * This is only recommended for writing COM or APPn markers.
 187  * Must be called after jpeg_start_compress() and before
 188  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 189  */
 190
 191 GLOBAL(void)
 192 jpeg_write_marker (j_compress_ptr cinfo, int marker,
 193                    const JOCTET *dataptr, unsigned int datalen)
 194 {
 195   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
 196
 197   if (cinfo->next_scanline != 0 ||
 198       (cinfo->global_state != CSTATE_SCANNING &&
 199        cinfo->global_state != CSTATE_RAW_OK &&
 200        cinfo->global_state != CSTATE_WRCOEFS))
 201     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 202
 203   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 204   write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
 205   while (datalen--) {
 206     (*write_marker_byte) (cinfo, *dataptr);
 207     dataptr++;
 208   }
 209 }
 210
 211 /* Same, but piecemeal. */
 212
 213 GLOBAL(void)
 214 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 215 {
 216   if (cinfo->next_scanline != 0 ||
 217       (cinfo->global_state != CSTATE_SCANNING &&
 218        cinfo->global_state != CSTATE_RAW_OK &&
 219        cinfo->global_state != CSTATE_WRCOEFS))
 220     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 221
 222   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 223 }
 224
 225 GLOBAL(void)
 226 jpeg_write_m_byte (j_compress_ptr cinfo, int val)
 227 {
 228   (*cinfo->marker->write_marker_byte) (cinfo, val);
 229 }
 230
 231
 232 /*
 233  * Alternate compression function: just write an abbreviated table file.
 234  * Before calling this, all parameters and a data destination must be set up.
 235  *
 236  * To produce a pair of files containing abbreviated tables and abbreviated
 237  * image data, one would proceed as follows:
 238  *
 239  *              initialize JPEG object
 240  *              set JPEG parameters
 241  *              set destination to table file
 242  *              jpeg_write_tables(cinfo);
 243  *              set destination to image file
 244  *              jpeg_start_compress(cinfo, FALSE);
 245  *              write data...
 246  *              jpeg_finish_compress(cinfo);
 247  *
 248  * jpeg_write_tables has the side effect of marking all tables written
 249  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 250  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 251  */
 252
 253 GLOBAL(void)
 254 jpeg_write_tables (j_compress_ptr cinfo)
 255 {
 256   if (cinfo->global_state != CSTATE_START)
 257     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 258
 259   /* (Re)initialize error mgr and destination modules */
 260   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
 261   (*cinfo->dest->init_destination) (cinfo);
 262   /* Initialize the marker writer ... bit of a crock to do it here. */
 263   jinit_marker_writer(cinfo);
 264   /* Write them tables! */
 265   (*cinfo->marker->write_tables_only) (cinfo);
 266   /* And clean up. */
 267   (*cinfo->dest->term_destination) (cinfo);
 268   /*
 269    * In library releases up through v6a, we called jpeg_abort() here to free
 270    * any working memory allocated by the destination manager and marker
 271    * writer.  Some applications had a problem with that: they allocated space
 272    * of their own from the library memory manager, and didn't want it to go
 273    * away during write_tables.  So now we do nothing.  This will cause a
 274    * memory leak if an app calls write_tables repeatedly without doing a full
 275    * compression cycle or otherwise resetting the JPEG object.  However, that
 276    * seems less bad than unexpectedly freeing memory in the normal case.
 277    * An app that prefers the old behavior can call jpeg_abort for itself after
 278    * each call to jpeg_write_tables().
 279    */
 280 }