media/libjpeg/jdapimin.c

   1 /*
   2  * jdapimin.c
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1994-1998, Thomas G. Lane.
   6  * libjpeg-turbo Modifications:
   7  * Copyright (C) 2016, 2022, D. R. Commander.
   8  * For conditions of distribution and use, see the accompanying README.ijg
   9  * file.
  10  *
  11  * This file contains application interface code for the decompression half
  12  * of the JPEG library.  These are the "minimum" API routines that may be
  13  * needed in either the normal full-decompression case or the
  14  * transcoding-only case.
  15  *
  16  * Most of the routines intended to be called directly by an application
  17  * are in this file or in jdapistd.c.  But also see jcomapi.c for routines
  18  * shared by compression and decompression, and jdtrans.c for the transcoding
  19  * case.
  20  */
  21
  22 #define JPEG_INTERNALS
  23 #include "jinclude.h"
  24 #include "jpeglib.h"
  25 #include "jdmaster.h"
  26
  27
  28 /*
  29  * Initialization of a JPEG decompression object.
  30  * The error manager must already be set up (in case memory manager fails).
  31  */
  32
  33 GLOBAL(void)
  34 jpeg_CreateDecompress(j_decompress_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_decompress_struct))
  43     ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
  44              (int)sizeof(struct jpeg_decompress_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     memset(cinfo, 0, sizeof(struct jpeg_decompress_struct));
  56     cinfo->err = err;
  57     cinfo->client_data = client_data;
  58   }
  59   cinfo->is_decompressor = TRUE;
  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->src = NULL;
  67
  68   for (i = 0; i < NUM_QUANT_TBLS; i++)
  69     cinfo->quant_tbl_ptrs[i] = NULL;
  70
  71   for (i = 0; i < NUM_HUFF_TBLS; i++) {
  72     cinfo->dc_huff_tbl_ptrs[i] = NULL;
  73     cinfo->ac_huff_tbl_ptrs[i] = NULL;
  74   }
  75
  76   /* Initialize marker processor so application can override methods
  77    * for COM, APPn markers before calling jpeg_read_header.
  78    */
  79   cinfo->marker_list = NULL;
  80   jinit_marker_reader(cinfo);
  81
  82   /* And initialize the overall input controller. */
  83   jinit_input_controller(cinfo);
  84
  85   /* OK, I'm ready */
  86   cinfo->global_state = DSTATE_START;
  87
  88   /* The master struct is used to store extension parameters, so we allocate it
  89    * here.
  90    */
  91   cinfo->master = (struct jpeg_decomp_master *)
  92     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
  93                                 sizeof(my_decomp_master));
  94   memset(cinfo->master, 0, sizeof(my_decomp_master));
  95 }
  96
  97
  98 /*
  99  * Destruction of a JPEG decompression object
 100  */
 101
 102 GLOBAL(void)
 103 jpeg_destroy_decompress(j_decompress_ptr cinfo)
 104 {
 105   jpeg_destroy((j_common_ptr)cinfo); /* use common routine */
 106 }
 107
 108
 109 /*
 110  * Abort processing of a JPEG decompression operation,
 111  * but don't destroy the object itself.
 112  */
 113
 114 GLOBAL(void)
 115 jpeg_abort_decompress(j_decompress_ptr cinfo)
 116 {
 117   jpeg_abort((j_common_ptr)cinfo); /* use common routine */
 118 }
 119
 120
 121 /*
 122  * Set default decompression parameters.
 123  */
 124
 125 LOCAL(void)
 126 default_decompress_parms(j_decompress_ptr cinfo)
 127 {
 128   /* Guess the input colorspace, and set output colorspace accordingly. */
 129   /* (Wish JPEG committee had provided a real way to specify this...) */
 130   /* Note application may override our guesses. */
 131   switch (cinfo->num_components) {
 132   case 1:
 133     cinfo->jpeg_color_space = JCS_GRAYSCALE;
 134     cinfo->out_color_space = JCS_GRAYSCALE;
 135     break;
 136
 137   case 3:
 138     if (cinfo->saw_JFIF_marker) {
 139       cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */
 140     } else if (cinfo->saw_Adobe_marker) {
 141       switch (cinfo->Adobe_transform) {
 142       case 0:
 143         cinfo->jpeg_color_space = JCS_RGB;
 144         break;
 145       case 1:
 146         cinfo->jpeg_color_space = JCS_YCbCr;
 147         break;
 148       default:
 149         WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
 150         cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
 151         break;
 152       }
 153     } else {
 154       /* Saw no special markers, try to guess from the component IDs */
 155       int cid0 = cinfo->comp_info[0].component_id;
 156       int cid1 = cinfo->comp_info[1].component_id;
 157       int cid2 = cinfo->comp_info[2].component_id;
 158
 159       if (cid0 == 1 && cid1 == 2 && cid2 == 3)
 160         cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */
 161       else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
 162         cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
 163       else {
 164         TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
 165         cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
 166       }
 167     }
 168     /* Always guess RGB is proper output colorspace. */
 169     cinfo->out_color_space = JCS_RGB;
 170     break;
 171
 172   case 4:
 173     if (cinfo->saw_Adobe_marker) {
 174       switch (cinfo->Adobe_transform) {
 175       case 0:
 176         cinfo->jpeg_color_space = JCS_CMYK;
 177         break;
 178       case 2:
 179         cinfo->jpeg_color_space = JCS_YCCK;
 180         break;
 181       default:
 182         WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
 183         cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
 184         break;
 185       }
 186     } else {
 187       /* No special markers, assume straight CMYK. */
 188       cinfo->jpeg_color_space = JCS_CMYK;
 189     }
 190     cinfo->out_color_space = JCS_CMYK;
 191     break;
 192
 193   default:
 194     cinfo->jpeg_color_space = JCS_UNKNOWN;
 195     cinfo->out_color_space = JCS_UNKNOWN;
 196     break;
 197   }
 198
 199   /* Set defaults for other decompression parameters. */
 200   cinfo->scale_num = 1;         /* 1:1 scaling */
 201   cinfo->scale_denom = 1;
 202   cinfo->output_gamma = 1.0;
 203   cinfo->buffered_image = FALSE;
 204   cinfo->raw_data_out = FALSE;
 205   cinfo->dct_method = JDCT_DEFAULT;
 206   cinfo->do_fancy_upsampling = TRUE;
 207   cinfo->do_block_smoothing = TRUE;
 208   cinfo->quantize_colors = FALSE;
 209   /* We set these in case application only sets quantize_colors. */
 210   cinfo->dither_mode = JDITHER_FS;
 211 #ifdef QUANT_2PASS_SUPPORTED
 212   cinfo->two_pass_quantize = TRUE;
 213 #else
 214   cinfo->two_pass_quantize = FALSE;
 215 #endif
 216   cinfo->desired_number_of_colors = 256;
 217   cinfo->colormap = NULL;
 218   /* Initialize for no mode change in buffered-image mode. */
 219   cinfo->enable_1pass_quant = FALSE;
 220   cinfo->enable_external_quant = FALSE;
 221   cinfo->enable_2pass_quant = FALSE;
 222 }
 223
 224
 225 /*
 226  * Decompression startup: read start of JPEG datastream to see what's there.
 227  * Need only initialize JPEG object and supply a data source before calling.
 228  *
 229  * This routine will read as far as the first SOS marker (ie, actual start of
 230  * compressed data), and will save all tables and parameters in the JPEG
 231  * object.  It will also initialize the decompression parameters to default
 232  * values, and finally return JPEG_HEADER_OK.  On return, the application may
 233  * adjust the decompression parameters and then call jpeg_start_decompress.
 234  * (Or, if the application only wanted to determine the image parameters,
 235  * the data need not be decompressed.  In that case, call jpeg_abort or
 236  * jpeg_destroy to release any temporary space.)
 237  * If an abbreviated (tables only) datastream is presented, the routine will
 238  * return JPEG_HEADER_TABLES_ONLY upon reaching EOI.  The application may then
 239  * re-use the JPEG object to read the abbreviated image datastream(s).
 240  * It is unnecessary (but OK) to call jpeg_abort in this case.
 241  * The JPEG_SUSPENDED return code only occurs if the data source module
 242  * requests suspension of the decompressor.  In this case the application
 243  * should load more source data and then re-call jpeg_read_header to resume
 244  * processing.
 245  * If a non-suspending data source is used and require_image is TRUE, then the
 246  * return code need not be inspected since only JPEG_HEADER_OK is possible.
 247  *
 248  * This routine is now just a front end to jpeg_consume_input, with some
 249  * extra error checking.
 250  */
 251
 252 GLOBAL(int)
 253 jpeg_read_header(j_decompress_ptr cinfo, boolean require_image)
 254 {
 255   int retcode;
 256
 257   if (cinfo->global_state != DSTATE_START &&
 258       cinfo->global_state != DSTATE_INHEADER)
 259     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 260
 261   retcode = jpeg_consume_input(cinfo);
 262
 263   switch (retcode) {
 264   case JPEG_REACHED_SOS:
 265     retcode = JPEG_HEADER_OK;
 266     break;
 267   case JPEG_REACHED_EOI:
 268     if (require_image)          /* Complain if application wanted an image */
 269       ERREXIT(cinfo, JERR_NO_IMAGE);
 270     /* Reset to start state; it would be safer to require the application to
 271      * call jpeg_abort, but we can't change it now for compatibility reasons.
 272      * A side effect is to free any temporary memory (there shouldn't be any).
 273      */
 274     jpeg_abort((j_common_ptr)cinfo); /* sets state = DSTATE_START */
 275     retcode = JPEG_HEADER_TABLES_ONLY;
 276     break;
 277   case JPEG_SUSPENDED:
 278     /* no work */
 279     break;
 280   }
 281
 282   return retcode;
 283 }
 284
 285
 286 /*
 287  * Consume data in advance of what the decompressor requires.
 288  * This can be called at any time once the decompressor object has
 289  * been created and a data source has been set up.
 290  *
 291  * This routine is essentially a state machine that handles a couple
 292  * of critical state-transition actions, namely initial setup and
 293  * transition from header scanning to ready-for-start_decompress.
 294  * All the actual input is done via the input controller's consume_input
 295  * method.
 296  */
 297
 298 GLOBAL(int)
 299 jpeg_consume_input(j_decompress_ptr cinfo)
 300 {
 301   int retcode = JPEG_SUSPENDED;
 302
 303   /* NB: every possible DSTATE value should be listed in this switch */
 304   switch (cinfo->global_state) {
 305   case DSTATE_START:
 306     /* Start-of-datastream actions: reset appropriate modules */
 307     (*cinfo->inputctl->reset_input_controller) (cinfo);
 308     /* Initialize application's data source module */
 309     (*cinfo->src->init_source) (cinfo);
 310     cinfo->global_state = DSTATE_INHEADER;
 311     FALLTHROUGH                 /*FALLTHROUGH*/
 312   case DSTATE_INHEADER:
 313     retcode = (*cinfo->inputctl->consume_input) (cinfo);
 314     if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
 315       /* Set up default parameters based on header data */
 316       default_decompress_parms(cinfo);
 317       /* Set global state: ready for start_decompress */
 318       cinfo->global_state = DSTATE_READY;
 319     }
 320     break;
 321   case DSTATE_READY:
 322     /* Can't advance past first SOS until start_decompress is called */
 323     retcode = JPEG_REACHED_SOS;
 324     break;
 325   case DSTATE_PRELOAD:
 326   case DSTATE_PRESCAN:
 327   case DSTATE_SCANNING:
 328   case DSTATE_RAW_OK:
 329   case DSTATE_BUFIMAGE:
 330   case DSTATE_BUFPOST:
 331   case DSTATE_STOPPING:
 332     retcode = (*cinfo->inputctl->consume_input) (cinfo);
 333     break;
 334   default:
 335     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 336   }
 337   return retcode;
 338 }
 339
 340
 341 /*
 342  * Have we finished reading the input file?
 343  */
 344
 345 GLOBAL(boolean)
 346 jpeg_input_complete(j_decompress_ptr cinfo)
 347 {
 348   /* Check for valid jpeg object */
 349   if (cinfo->global_state < DSTATE_START ||
 350       cinfo->global_state > DSTATE_STOPPING)
 351     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 352   return cinfo->inputctl->eoi_reached;
 353 }
 354
 355
 356 /*
 357  * Is there more than one scan?
 358  */
 359
 360 GLOBAL(boolean)
 361 jpeg_has_multiple_scans(j_decompress_ptr cinfo)
 362 {
 363   /* Only valid after jpeg_read_header completes */
 364   if (cinfo->global_state < DSTATE_READY ||
 365       cinfo->global_state > DSTATE_STOPPING)
 366     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 367   return cinfo->inputctl->has_multiple_scans;
 368 }
 369
 370
 371 /*
 372  * Finish JPEG decompression.
 373  *
 374  * This will normally just verify the file trailer and release temp storage.
 375  *
 376  * Returns FALSE if suspended.  The return value need be inspected only if
 377  * a suspending data source is used.
 378  */
 379
 380 GLOBAL(boolean)
 381 jpeg_finish_decompress(j_decompress_ptr cinfo)
 382 {
 383   if ((cinfo->global_state == DSTATE_SCANNING ||
 384        cinfo->global_state == DSTATE_RAW_OK) && !cinfo->buffered_image) {
 385     /* Terminate final pass of non-buffered mode */
 386     if (cinfo->output_scanline < cinfo->output_height)
 387       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
 388     (*cinfo->master->finish_output_pass) (cinfo);
 389     cinfo->global_state = DSTATE_STOPPING;
 390   } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
 391     /* Finishing after a buffered-image operation */
 392     cinfo->global_state = DSTATE_STOPPING;
 393   } else if (cinfo->global_state != DSTATE_STOPPING) {
 394     /* STOPPING = repeat call after a suspension, anything else is error */
 395     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
 396   }
 397   /* Read until EOI */
 398   while (!cinfo->inputctl->eoi_reached) {
 399     if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
 400       return FALSE;             /* Suspend, come back later */
 401   }
 402   /* Do final cleanup */
 403   (*cinfo->src->term_source) (cinfo);
 404   /* We can use jpeg_abort to release memory and reset global_state */
 405   jpeg_abort((j_common_ptr)cinfo);
 406   return TRUE;
 407 }