media/libjpeg/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 #if JPEG_LIB_VERSION >= 70
  70     cinfo->q_scale_factor[i] = 100;
  71 #endif
  72   }
  73
  74   for (i = 0; i < NUM_HUFF_TBLS; i++) {
  75     cinfo->dc_huff_tbl_ptrs[i] = NULL;
  76     cinfo->ac_huff_tbl_ptrs[i] = NULL;
  77   }
  78
  79 #if JPEG_LIB_VERSION >= 80
  80   /* Must do it here for emit_dqt in case jpeg_write_tables is used */
  81   cinfo->block_size = DCTSIZE;
  82   cinfo->natural_order = jpeg_natural_order;
  83   cinfo->lim_Se = DCTSIZE2-1;
  84 #endif
  85
  86   cinfo->script_space = NULL;
  87
  88   cinfo->input_gamma = 1.0;     /* in case application forgets */
  89
  90   /* OK, I'm ready */
  91   cinfo->global_state = CSTATE_START;
  92 }
  93
  94
  95 /*
  96  * Destruction of a JPEG compression object
  97  */
  98
  99 GLOBAL(void)
 100 jpeg_destroy_compress (j_compress_ptr cinfo)
 101 {
 102   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
 103 }
 104
 105
 106 /*
 107  * Abort processing of a JPEG compression operation,
 108  * but don't destroy the object itself.
 109  */
 110
 111 GLOBAL(void)
 112 jpeg_abort_compress (j_compress_ptr cinfo)
 113 {
 114   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
 115 }
 116
 117
 118 /*
 119  * Forcibly suppress or un-suppress all quantization and Huffman tables.
 120  * Marks all currently defined tables as already written (if suppress)
 121  * or not written (if !suppress).  This will control whether they get emitted
 122  * by a subsequent jpeg_start_compress call.
 123  *
 124  * This routine is exported for use by applications that want to produce
 125  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
 126  * since it is called by jpeg_start_compress, we put it here --- otherwise
 127  * jcparam.o would be linked whether the application used it or not.
 128  */
 129
 130 GLOBAL(void)
 131 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
 132 {
 133   int i;
 134   JQUANT_TBL * qtbl;
 135   JHUFF_TBL * htbl;
 136
 137   for (i = 0; i < NUM_QUANT_TBLS; i++) {
 138     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
 139       qtbl->sent_table = suppress;
 140   }
 141
 142   for (i = 0; i < NUM_HUFF_TBLS; i++) {
 143     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
 144       htbl->sent_table = suppress;
 145     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
 146       htbl->sent_table = suppress;
 147   }
 148 }
 149
 150
 151 /*
 152  * Finish JPEG compression.
 153  *
 154  * If a multipass operating mode was selected, this may do a great deal of
 155  * work including most of the actual output.
 156  */
 157
 158 GLOBAL(void)
 159 jpeg_finish_compress (j_compress_ptr cinfo)
 160 {
 161   JDIMENSION iMCU_row;
 162
 163   if (cinfo->global_state == CSTATE_SCANNING ||
 164       cinfo->global_state == CSTATE_RAW_OK) {
 165     /* Terminate first pass */
 166     if (cinfo->next_scanline < cinfo->image_height)
 167       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
 168     (*cinfo->master->finish_pass) (cinfo);
 169   } else if (cinfo->global_state != CSTATE_WRCOEFS)
 170     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 171   /* Perform any remaining passes */
 172   while (! cinfo->master->is_last_pass) {
 173     (*cinfo->master->prepare_for_pass) (cinfo);
 174     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
 175       if (cinfo->progress != NULL) {
 176         cinfo->progress->pass_counter = (long) iMCU_row;
 177         cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
 178         (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
 179       }
 180       /* We bypass the main controller and invoke coef controller directly;
 181        * all work is being done from the coefficient buffer.
 182        */
 183       if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
 184         ERREXIT(cinfo, JERR_CANT_SUSPEND);
 185     }
 186     (*cinfo->master->finish_pass) (cinfo);
 187   }
 188   /* Write EOI, do final cleanup */
 189   (*cinfo->marker->write_file_trailer) (cinfo);
 190   (*cinfo->dest->term_destination) (cinfo);
 191   /* We can use jpeg_abort to release memory and reset global_state */
 192   jpeg_abort((j_common_ptr) cinfo);
 193 }
 194
 195
 196 /*
 197  * Write a special marker.
 198  * This is only recommended for writing COM or APPn markers.
 199  * Must be called after jpeg_start_compress() and before
 200  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
 201  */
 202
 203 GLOBAL(void)
 204 jpeg_write_marker (j_compress_ptr cinfo, int marker,
 205                    const JOCTET *dataptr, unsigned int datalen)
 206 {
 207   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
 208
 209   if (cinfo->next_scanline != 0 ||
 210       (cinfo->global_state != CSTATE_SCANNING &&
 211        cinfo->global_state != CSTATE_RAW_OK &&
 212        cinfo->global_state != CSTATE_WRCOEFS))
 213     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 214
 215   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 216   write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
 217   while (datalen--) {
 218     (*write_marker_byte) (cinfo, *dataptr);
 219     dataptr++;
 220   }
 221 }
 222
 223 /* Same, but piecemeal. */
 224
 225 GLOBAL(void)
 226 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 227 {
 228   if (cinfo->next_scanline != 0 ||
 229       (cinfo->global_state != CSTATE_SCANNING &&
 230        cinfo->global_state != CSTATE_RAW_OK &&
 231        cinfo->global_state != CSTATE_WRCOEFS))
 232     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 233
 234   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
 235 }
 236
 237 GLOBAL(void)
 238 jpeg_write_m_byte (j_compress_ptr cinfo, int val)
 239 {
 240   (*cinfo->marker->write_marker_byte) (cinfo, val);
 241 }
 242
 243
 244 /*
 245  * Alternate compression function: just write an abbreviated table file.
 246  * Before calling this, all parameters and a data destination must be set up.
 247  *
 248  * To produce a pair of files containing abbreviated tables and abbreviated
 249  * image data, one would proceed as follows:
 250  *
 251  *              initialize JPEG object
 252  *              set JPEG parameters
 253  *              set destination to table file
 254  *              jpeg_write_tables(cinfo);
 255  *              set destination to image file
 256  *              jpeg_start_compress(cinfo, FALSE);
 257  *              write data...
 258  *              jpeg_finish_compress(cinfo);
 259  *
 260  * jpeg_write_tables has the side effect of marking all tables written
 261  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
 262  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
 263  */
 264
 265 GLOBAL(void)
 266 jpeg_write_tables (j_compress_ptr cinfo)
 267 {
 268   if (cinfo->global_state != CSTATE_START)
 269     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 270
 271   /* (Re)initialize error mgr and destination modules */
 272   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
 273   (*cinfo->dest->init_destination) (cinfo);
 274   /* Initialize the marker writer ... bit of a crock to do it here. */
 275   jinit_marker_writer(cinfo);
 276   /* Write them tables! */
 277   (*cinfo->marker->write_tables_only) (cinfo);
 278   /* And clean up. */
 279   (*cinfo->dest->term_destination) (cinfo);
 280   /*
 281    * In library releases up through v6a, we called jpeg_abort() here to free
 282    * any working memory allocated by the destination manager and marker
 283    * writer.  Some applications had a problem with that: they allocated space
 284    * of their own from the library memory manager, and didn't want it to go
 285    * away during write_tables.  So now we do nothing.  This will cause a
 286    * memory leak if an app calls write_tables repeatedly without doing a full
 287    * compression cycle or otherwise resetting the JPEG object.  However, that
 288    * seems less bad than unexpectedly freeing memory in the normal case.
 289    * An app that prefers the old behavior can call jpeg_abort for itself after
 290    * each call to jpeg_write_tables().
 291    */
 292 }