libs/jpeg/jcapimin.c

   1 /*
   2  * jcapimin.c
   3  *
   4  * Copyright (C) 1994-1998, 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 application interface code for the compression half
  10  * of the JPEG library.  These are the "minimum" API routines that may be
  11  * needed in either the normal full-compression case or the transcoding-only
  12  * case.
  13  *
  14  * Most of the routines intended to be called directly by an application
  15  * are in this file or in jcapistd.c.  But also see jcparam.c for
  16  * parameter-setup helper routines, jcomapi.c for routines shared by
  17  * compression and decompression, and jctrans.c for the transcoding case.
  18  */
  19
  20 #define JPEG_INTERNALS
  21 #include "jinclude.h"
  22 #include "jpeglib.h"
  23
  24
  25 /*
  26  * Initialization of a JPEG compression object.
  27  * The error manager must already be set up (in case memory manager fails).
  28  */
  29
  30 GLOBAL(void)
  31 jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
  32 {
  33   int i;
  34
  35   /* Guard against version mismatches between library and caller. */
  36   cinfo->mem = NULL;            /* so jpeg_destroy knows mem mgr not called */
  37   if (version != JPEG_LIB_VERSION)
  38     ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
  39   if (structsize != SIZEOF(struct jpeg_compress_struct))
  40     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
  41              (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
  42
  43   /* For debugging purposes, we zero the whole master structure.
  44    * But the application has already set the err pointer, and may have set
  45    * client_data, so we have to save and restore those fields.
  46    * Note: if application hasn't set client_data, tools like Purify may
  47    * complain here.
  48    */
  49   {
  50     struct jpeg_error_mgr * err = cinfo->err;
  51     void * client_data = cinfo->client_data; /* ignore Purify complaint here */
  52     MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
  53     cinfo->err = err;
  54     cinfo->client_data = client_data;
  55   }
  56   cinfo->is_decompressor = FALSE;
  57
  58   /* Initialize a memory manager instance for this object */
  59   jinit_memory_mgr((j_common_ptr) cinfo);
  60
  61   /* Zero out pointers to permanent structures. */
  62   cinfo->progress = NULL;
  63   cinfo->dest = NULL;
  64
  65   cinfo->comp_info = NULL;
  66
  67   for (i = 0; i < NUM_QUANT_TBLS; i++) {
  68     cinfo->quant_tbl_ptrs[i] = NULL;
  69     cinfo->q_scale_factor[i] = 100;
  70   }
  71
  72   for (i = 0; i < NUM_HUFF_TBLS; i++) {
  73     cinfo->dc_huff_tbl_ptrs[i] = NULL;
  74     cinfo->ac_huff_tbl_ptrs[i] = NULL;
  75   }
  76
  77   /* Must do it here for emit_dqt in case jpeg_write_tables is used */
  78   cinfo->block_size = DCTSIZE;
  79   cinfo->natural_order = jpeg_natural_order;
  80   cinfo->lim_Se = DCTSIZE2-1;
  81
  82   cinfo->script_space = NULL;
  83
  84   cinfo->input_gamma = 1.0;     /* in case application forgets */
  85
  86   /* OK, I'm ready */
  87   cinfo->global_state = CSTATE_START;
  88 }
  89
  90
  91 /*
  92  * Destruction of a JPEG compression object
  93  */
  94
  95 GLOBAL(void)
  96 jpeg_destroy_compress (j_compress_ptr cinfo)
  97 {
  98   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
  99 }
 100
 101
 102 /*
 103  * Abort processing of a JPEG compression operation,
 104  * but don't destroy the object itself.
 105  */
 106
 107 GLOBAL(void)
 108 jpeg_abort_compress (j_compress_ptr cinfo)
 109 {
 110   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
 111 }
 112
 113
 114 /*
 115  * Forcibly suppress or un-suppress all quantization and Huffman tables.
 116  * Marks all currently defined tables as already written (if suppress)
 117  * or not written (if !suppress).  This will control whether they get emitted
 118  * by a subsequent jpeg_start_compress call.
 119  *
 120  * This routine is exported for use by applications that want to produce
 121  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 122  * since it is called by jpeg_start_compress, we put it here --- otherwise
 123  * jcparam.o would be linked whether the application used it or not.
 124  */
 125
 126 GLOBAL(void)
 127 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
 128 {
 129   int i;
 130   JQUANT_TBL * qtbl;
 131   JHUFF_TBL * htbl;
 132
 133   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 134     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
 135       qtbl->sent_table = suppress;
 136   }
 137
 138   for (i = 0; i < NUM_HUFF_TBLS; i++) {
 139     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
 140       htbl->sent_table = suppress;
 141     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
 142       htbl->sent_table = suppress;
 143   }
 144 }
 145
 146
 147 /*
 148  * Finish JPEG compression.
 149  *
 150  * If a multipass operating mode was selected, this may do a great deal of
 151  * work including most of the actual output.
 152  */
 153
 154 GLOBAL(void)
 155 jpeg_finish_compress (j_compress_ptr cinfo)
 156 {
 157   JDIMENSION iMCU_row;
 158
 159   if (cinfo->global_state == CSTATE_SCANNING ||
 160       cinfo->global_state == CSTATE_RAW_OK) {
 161     /* Terminate first pass */
 162     if (cinfo->next_scanline < cinfo->image_height)
 163       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
 164     (*cinfo->master->finish_pass) (cinfo);
 165   } else if (cinfo->global_state != CSTATE_WRCOEFS)
 166     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 167   /* Perform any remaining passes */
 168   while (! cinfo->master->is_last_pass) {
 169     (*cinfo->master->prepare_for_pass) (cinfo);
 170     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
 171       if (cinfo->progress != NULL) {
 172         cinfo->progress->pass_counter = (long) iMCU_row;
 173         cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
 174         (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
 175       }
 176       /* We bypass the main controller and invoke coef controller directly;
 177        * all work is being done from the coefficient buffer.
 178        */
 179       if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
 180         ERREXIT(cinfo, JERR_CANT_SUSPEND);
 181     }
 182     (*cinfo->master->finish_pass) (cinfo);
 183   }
 184   /* Write EOI, do final cleanup */
 185   (*cinfo->marker->write_file_trailer) (cinfo);
 186   (*cinfo->dest->term_destination) (cinfo);
 187   /* We can use jpeg_abort to release memory and reset global_state */
 188   jpeg_abort((j_common_ptr) cinfo);
 189 }
 190
 191
 192 /*
 193  * Write a special marker.
 194  * This is only recommended for writing COM or APPn markers.
 195  * Must be called after jpeg_start_compress() and before
 196  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 197  */
 198
 199 GLOBAL(void)
 200 jpeg_write_marker (j_compress_ptr cinfo, int marker,
 201                    const JOCTET *dataptr, unsigned int datalen)
 202 {
 203   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
 204
 205   if (cinfo->next_scanline != 0 ||
 206       (cinfo->global_state != CSTATE_SCANNING &&
 207        cinfo->global_state != CSTATE_RAW_OK &&
 208        cinfo->global_state != CSTATE_WRCOEFS))
 209     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 210
 211   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 212   write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
 213   while (datalen--) {
 214     (*write_marker_byte) (cinfo, *dataptr);
 215     dataptr++;
 216   }
 217 }
 218
 219 /* Same, but piecemeal. */
 220
 221 GLOBAL(void)
 222 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 223 {
 224   if (cinfo->next_scanline != 0 ||
 225       (cinfo->global_state != CSTATE_SCANNING &&
 226        cinfo->global_state != CSTATE_RAW_OK &&
 227        cinfo->global_state != CSTATE_WRCOEFS))
 228     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 229
 230   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 231 }
 232
 233 GLOBAL(void)
 234 jpeg_write_m_byte (j_compress_ptr cinfo, int val)
 235 {
 236   (*cinfo->marker->write_marker_byte) (cinfo, val);
 237 }
 238
 239
 240 /*
 241  * Alternate compression function: just write an abbreviated table file.
 242  * Before calling this, all parameters and a data destination must be set up.
 243  *
 244  * To produce a pair of files containing abbreviated tables and abbreviated
 245  * image data, one would proceed as follows:
 246  *
 247  *              initialize JPEG object
 248  *              set JPEG parameters
 249  *              set destination to table file
 250  *              jpeg_write_tables(cinfo);
 251  *              set destination to image file
 252  *              jpeg_start_compress(cinfo, FALSE);
 253  *              write data...
 254  *              jpeg_finish_compress(cinfo);
 255  *
 256  * jpeg_write_tables has the side effect of marking all tables written
 257  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 258  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 259  */
 260
 261 GLOBAL(void)
 262 jpeg_write_tables (j_compress_ptr cinfo)
 263 {
 264   if (cinfo->global_state != CSTATE_START)
 265     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 266
 267   /* (Re)initialize error mgr and destination modules */
 268   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
 269   (*cinfo->dest->init_destination) (cinfo);
 270   /* Initialize the marker writer ... bit of a crock to do it here. */
 271   jinit_marker_writer(cinfo);
 272   /* Write them tables! */
 273   (*cinfo->marker->write_tables_only) (cinfo);
 274   /* And clean up. */
 275   (*cinfo->dest->term_destination) (cinfo);
 276   /*
 277    * In library releases up through v6a, we called jpeg_abort() here to free
 278    * any working memory allocated by the destination manager and marker
 279    * writer.  Some applications had a problem with that: they allocated space
 280    * of their own from the library memory manager, and didn't want it to go
 281    * away during write_tables.  So now we do nothing.  This will cause a
 282    * memory leak if an app calls write_tables repeatedly without doing a full
 283    * compression cycle or otherwise resetting the JPEG object.  However, that
 284    * seems less bad than unexpectedly freeing memory in the normal case.
 285    * An app that prefers the old behavior can call jpeg_abort for itself after
 286    * each call to jpeg_write_tables().
 287    */
 288 }