1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/libjpeg/jdinput.c	Thu Sep 08 06:28:38 2011 +0300
     1.3 @@ -0,0 +1,381 @@
     1.4 +/*
     1.5 + * jdinput.c
     1.6 + *
     1.7 + * Copyright (C) 1991-1997, Thomas G. Lane.
     1.8 + * This file is part of the Independent JPEG Group's software.
     1.9 + * For conditions of distribution and use, see the accompanying README file.
    1.10 + *
    1.11 + * This file contains input control logic for the JPEG decompressor.
    1.12 + * These routines are concerned with controlling the decompressor's input
    1.13 + * processing (marker reading and coefficient decoding).  The actual input
    1.14 + * reading is done in jdmarker.c, jdhuff.c, and jdphuff.c.
    1.15 + */
    1.16 +
    1.17 +#define JPEG_INTERNALS
    1.18 +#include "jinclude.h"
    1.19 +#include "jpeglib.h"
    1.20 +
    1.21 +
    1.22 +/* Private state */
    1.23 +
    1.24 +typedef struct {
    1.25 +  struct jpeg_input_controller pub; /* public fields */
    1.26 +
    1.27 +  boolean inheaders;		/* TRUE until first SOS is reached */
    1.28 +} my_input_controller;
    1.29 +
    1.30 +typedef my_input_controller * my_inputctl_ptr;
    1.31 +
    1.32 +
    1.33 +/* Forward declarations */
    1.34 +METHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo));
    1.35 +
    1.36 +
    1.37 +/*
    1.38 + * Routines to calculate various quantities related to the size of the image.
    1.39 + */
    1.40 +
    1.41 +LOCAL(void)
    1.42 +initial_setup (j_decompress_ptr cinfo)
    1.43 +/* Called once, when first SOS marker is reached */
    1.44 +{
    1.45 +  int ci;
    1.46 +  jpeg_component_info *compptr;
    1.47 +
    1.48 +  /* Make sure image isn't bigger than I can handle */
    1.49 +  if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
    1.50 +      (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
    1.51 +    ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
    1.52 +
    1.53 +  /* For now, precision must match compiled-in value... */
    1.54 +  if (cinfo->data_precision != BITS_IN_JSAMPLE)
    1.55 +    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
    1.56 +
    1.57 +  /* Check that number of components won't exceed internal array sizes */
    1.58 +  if (cinfo->num_components > MAX_COMPONENTS)
    1.59 +    ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
    1.60 +	     MAX_COMPONENTS);
    1.61 +
    1.62 +  /* Compute maximum sampling factors; check factor validity */
    1.63 +  cinfo->max_h_samp_factor = 1;
    1.64 +  cinfo->max_v_samp_factor = 1;
    1.65 +  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
    1.66 +       ci++, compptr++) {
    1.67 +    if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
    1.68 +	compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
    1.69 +      ERREXIT(cinfo, JERR_BAD_SAMPLING);
    1.70 +    cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
    1.71 +				   compptr->h_samp_factor);
    1.72 +    cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
    1.73 +				   compptr->v_samp_factor);
    1.74 +  }
    1.75 +
    1.76 +  /* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
    1.77 +   * In the full decompressor, this will be overridden by jdmaster.c;
    1.78 +   * but in the transcoder, jdmaster.c is not used, so we must do it here.
    1.79 +   */
    1.80 +  cinfo->min_DCT_scaled_size = DCTSIZE;
    1.81 +
    1.82 +  /* Compute dimensions of components */
    1.83 +  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
    1.84 +       ci++, compptr++) {
    1.85 +    compptr->DCT_scaled_size = DCTSIZE;
    1.86 +    /* Size in DCT blocks */
    1.87 +    compptr->width_in_blocks = (JDIMENSION)
    1.88 +      jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
    1.89 +		    (long) (cinfo->max_h_samp_factor * DCTSIZE));
    1.90 +    compptr->height_in_blocks = (JDIMENSION)
    1.91 +      jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
    1.92 +		    (long) (cinfo->max_v_samp_factor * DCTSIZE));
    1.93 +    /* downsampled_width and downsampled_height will also be overridden by
    1.94 +     * jdmaster.c if we are doing full decompression.  The transcoder library
    1.95 +     * doesn't use these values, but the calling application might.
    1.96 +     */
    1.97 +    /* Size in samples */
    1.98 +    compptr->downsampled_width = (JDIMENSION)
    1.99 +      jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
   1.100 +		    (long) cinfo->max_h_samp_factor);
   1.101 +    compptr->downsampled_height = (JDIMENSION)
   1.102 +      jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
   1.103 +		    (long) cinfo->max_v_samp_factor);
   1.104 +    /* Mark component needed, until color conversion says otherwise */
   1.105 +    compptr->component_needed = TRUE;
   1.106 +    /* Mark no quantization table yet saved for component */
   1.107 +    compptr->quant_table = NULL;
   1.108 +  }
   1.109 +
   1.110 +  /* Compute number of fully interleaved MCU rows. */
   1.111 +  cinfo->total_iMCU_rows = (JDIMENSION)
   1.112 +    jdiv_round_up((long) cinfo->image_height,
   1.113 +		  (long) (cinfo->max_v_samp_factor*DCTSIZE));
   1.114 +
   1.115 +  /* Decide whether file contains multiple scans */
   1.116 +  if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode)
   1.117 +    cinfo->inputctl->has_multiple_scans = TRUE;
   1.118 +  else
   1.119 +    cinfo->inputctl->has_multiple_scans = FALSE;
   1.120 +}
   1.121 +
   1.122 +
   1.123 +LOCAL(void)
   1.124 +per_scan_setup (j_decompress_ptr cinfo)
   1.125 +/* Do computations that are needed before processing a JPEG scan */
   1.126 +/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */
   1.127 +{
   1.128 +  int ci, mcublks, tmp;
   1.129 +  jpeg_component_info *compptr;
   1.130 +  
   1.131 +  if (cinfo->comps_in_scan == 1) {
   1.132 +    
   1.133 +    /* Noninterleaved (single-component) scan */
   1.134 +    compptr = cinfo->cur_comp_info[0];
   1.135 +    
   1.136 +    /* Overall image size in MCUs */
   1.137 +    cinfo->MCUs_per_row = compptr->width_in_blocks;
   1.138 +    cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
   1.139 +    
   1.140 +    /* For noninterleaved scan, always one block per MCU */
   1.141 +    compptr->MCU_width = 1;
   1.142 +    compptr->MCU_height = 1;
   1.143 +    compptr->MCU_blocks = 1;
   1.144 +    compptr->MCU_sample_width = compptr->DCT_scaled_size;
   1.145 +    compptr->last_col_width = 1;
   1.146 +    /* For noninterleaved scans, it is convenient to define last_row_height
   1.147 +     * as the number of block rows present in the last iMCU row.
   1.148 +     */
   1.149 +    tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
   1.150 +    if (tmp == 0) tmp = compptr->v_samp_factor;
   1.151 +    compptr->last_row_height = tmp;
   1.152 +    
   1.153 +    /* Prepare array describing MCU composition */
   1.154 +    cinfo->blocks_in_MCU = 1;
   1.155 +    cinfo->MCU_membership[0] = 0;
   1.156 +    
   1.157 +  } else {
   1.158 +    
   1.159 +    /* Interleaved (multi-component) scan */
   1.160 +    if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
   1.161 +      ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
   1.162 +	       MAX_COMPS_IN_SCAN);
   1.163 +    
   1.164 +    /* Overall image size in MCUs */
   1.165 +    cinfo->MCUs_per_row = (JDIMENSION)
   1.166 +      jdiv_round_up((long) cinfo->image_width,
   1.167 +		    (long) (cinfo->max_h_samp_factor*DCTSIZE));
   1.168 +    cinfo->MCU_rows_in_scan = (JDIMENSION)
   1.169 +      jdiv_round_up((long) cinfo->image_height,
   1.170 +		    (long) (cinfo->max_v_samp_factor*DCTSIZE));
   1.171 +    
   1.172 +    cinfo->blocks_in_MCU = 0;
   1.173 +    
   1.174 +    for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
   1.175 +      compptr = cinfo->cur_comp_info[ci];
   1.176 +      /* Sampling factors give # of blocks of component in each MCU */
   1.177 +      compptr->MCU_width = compptr->h_samp_factor;
   1.178 +      compptr->MCU_height = compptr->v_samp_factor;
   1.179 +      compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
   1.180 +      compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
   1.181 +      /* Figure number of non-dummy blocks in last MCU column & row */
   1.182 +      tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
   1.183 +      if (tmp == 0) tmp = compptr->MCU_width;
   1.184 +      compptr->last_col_width = tmp;
   1.185 +      tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
   1.186 +      if (tmp == 0) tmp = compptr->MCU_height;
   1.187 +      compptr->last_row_height = tmp;
   1.188 +      /* Prepare array describing MCU composition */
   1.189 +      mcublks = compptr->MCU_blocks;
   1.190 +      if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU)
   1.191 +	ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
   1.192 +      while (mcublks-- > 0) {
   1.193 +	cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
   1.194 +      }
   1.195 +    }
   1.196 +    
   1.197 +  }
   1.198 +}
   1.199 +
   1.200 +
   1.201 +/*
   1.202 + * Save away a copy of the Q-table referenced by each component present
   1.203 + * in the current scan, unless already saved during a prior scan.
   1.204 + *
   1.205 + * In a multiple-scan JPEG file, the encoder could assign different components
   1.206 + * the same Q-table slot number, but change table definitions between scans
   1.207 + * so that each component uses a different Q-table.  (The IJG encoder is not
   1.208 + * currently capable of doing this, but other encoders might.)  Since we want
   1.209 + * to be able to dequantize all the components at the end of the file, this
   1.210 + * means that we have to save away the table actually used for each component.
   1.211 + * We do this by copying the table at the start of the first scan containing
   1.212 + * the component.
   1.213 + * The JPEG spec prohibits the encoder from changing the contents of a Q-table
   1.214 + * slot between scans of a component using that slot.  If the encoder does so
   1.215 + * anyway, this decoder will simply use the Q-table values that were current
   1.216 + * at the start of the first scan for the component.
   1.217 + *
   1.218 + * The decompressor output side looks only at the saved quant tables,
   1.219 + * not at the current Q-table slots.
   1.220 + */
   1.221 +
   1.222 +LOCAL(void)
   1.223 +latch_quant_tables (j_decompress_ptr cinfo)
   1.224 +{
   1.225 +  int ci, qtblno;
   1.226 +  jpeg_component_info *compptr;
   1.227 +  JQUANT_TBL * qtbl;
   1.228 +
   1.229 +  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
   1.230 +    compptr = cinfo->cur_comp_info[ci];
   1.231 +    /* No work if we already saved Q-table for this component */
   1.232 +    if (compptr->quant_table != NULL)
   1.233 +      continue;
   1.234 +    /* Make sure specified quantization table is present */
   1.235 +    qtblno = compptr->quant_tbl_no;
   1.236 +    if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
   1.237 +	cinfo->quant_tbl_ptrs[qtblno] == NULL)
   1.238 +      ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
   1.239 +    /* OK, save away the quantization table */
   1.240 +    qtbl = (JQUANT_TBL *)
   1.241 +      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
   1.242 +				  SIZEOF(JQUANT_TBL));
   1.243 +    MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL));
   1.244 +    compptr->quant_table = qtbl;
   1.245 +  }
   1.246 +}
   1.247 +
   1.248 +
   1.249 +/*
   1.250 + * Initialize the input modules to read a scan of compressed data.
   1.251 + * The first call to this is done by jdmaster.c after initializing
   1.252 + * the entire decompressor (during jpeg_start_decompress).
   1.253 + * Subsequent calls come from consume_markers, below.
   1.254 + */
   1.255 +
   1.256 +METHODDEF(void)
   1.257 +start_input_pass (j_decompress_ptr cinfo)
   1.258 +{
   1.259 +  per_scan_setup(cinfo);
   1.260 +  latch_quant_tables(cinfo);
   1.261 +  (*cinfo->entropy->start_pass) (cinfo);
   1.262 +  (*cinfo->coef->start_input_pass) (cinfo);
   1.263 +  cinfo->inputctl->consume_input = cinfo->coef->consume_data;
   1.264 +}
   1.265 +
   1.266 +
   1.267 +/*
   1.268 + * Finish up after inputting a compressed-data scan.
   1.269 + * This is called by the coefficient controller after it's read all
   1.270 + * the expected data of the scan.
   1.271 + */
   1.272 +
   1.273 +METHODDEF(void)
   1.274 +finish_input_pass (j_decompress_ptr cinfo)
   1.275 +{
   1.276 +  cinfo->inputctl->consume_input = consume_markers;
   1.277 +}
   1.278 +
   1.279 +
   1.280 +/*
   1.281 + * Read JPEG markers before, between, or after compressed-data scans.
   1.282 + * Change state as necessary when a new scan is reached.
   1.283 + * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
   1.284 + *
   1.285 + * The consume_input method pointer points either here or to the
   1.286 + * coefficient controller's consume_data routine, depending on whether
   1.287 + * we are reading a compressed data segment or inter-segment markers.
   1.288 + */
   1.289 +
   1.290 +METHODDEF(int)
   1.291 +consume_markers (j_decompress_ptr cinfo)
   1.292 +{
   1.293 +  my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
   1.294 +  int val;
   1.295 +
   1.296 +  if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */
   1.297 +    return JPEG_REACHED_EOI;
   1.298 +
   1.299 +  val = (*cinfo->marker->read_markers) (cinfo);
   1.300 +
   1.301 +  switch (val) {
   1.302 +  case JPEG_REACHED_SOS:	/* Found SOS */
   1.303 +    if (inputctl->inheaders) {	/* 1st SOS */
   1.304 +      initial_setup(cinfo);
   1.305 +      inputctl->inheaders = FALSE;
   1.306 +      /* Note: start_input_pass must be called by jdmaster.c
   1.307 +       * before any more input can be consumed.  jdapimin.c is
   1.308 +       * responsible for enforcing this sequencing.
   1.309 +       */
   1.310 +    } else {			/* 2nd or later SOS marker */
   1.311 +      if (! inputctl->pub.has_multiple_scans)
   1.312 +	ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */
   1.313 +      start_input_pass(cinfo);
   1.314 +    }
   1.315 +    break;
   1.316 +  case JPEG_REACHED_EOI:	/* Found EOI */
   1.317 +    inputctl->pub.eoi_reached = TRUE;
   1.318 +    if (inputctl->inheaders) {	/* Tables-only datastream, apparently */
   1.319 +      if (cinfo->marker->saw_SOF)
   1.320 +	ERREXIT(cinfo, JERR_SOF_NO_SOS);
   1.321 +    } else {
   1.322 +      /* Prevent infinite loop in coef ctlr's decompress_data routine
   1.323 +       * if user set output_scan_number larger than number of scans.
   1.324 +       */
   1.325 +      if (cinfo->output_scan_number > cinfo->input_scan_number)
   1.326 +	cinfo->output_scan_number = cinfo->input_scan_number;
   1.327 +    }
   1.328 +    break;
   1.329 +  case JPEG_SUSPENDED:
   1.330 +    break;
   1.331 +  }
   1.332 +
   1.333 +  return val;
   1.334 +}
   1.335 +
   1.336 +
   1.337 +/*
   1.338 + * Reset state to begin a fresh datastream.
   1.339 + */
   1.340 +
   1.341 +METHODDEF(void)
   1.342 +reset_input_controller (j_decompress_ptr cinfo)
   1.343 +{
   1.344 +  my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
   1.345 +
   1.346 +  inputctl->pub.consume_input = consume_markers;
   1.347 +  inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
   1.348 +  inputctl->pub.eoi_reached = FALSE;
   1.349 +  inputctl->inheaders = TRUE;
   1.350 +  /* Reset other modules */
   1.351 +  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
   1.352 +  (*cinfo->marker->reset_marker_reader) (cinfo);
   1.353 +  /* Reset progression state -- would be cleaner if entropy decoder did this */
   1.354 +  cinfo->coef_bits = NULL;
   1.355 +}
   1.356 +
   1.357 +
   1.358 +/*
   1.359 + * Initialize the input controller module.
   1.360 + * This is called only once, when the decompression object is created.
   1.361 + */
   1.362 +
   1.363 +GLOBAL(void)
   1.364 +jinit_input_controller (j_decompress_ptr cinfo)
   1.365 +{
   1.366 +  my_inputctl_ptr inputctl;
   1.367 +
   1.368 +  /* Create subobject in permanent pool */
   1.369 +  inputctl = (my_inputctl_ptr)
   1.370 +    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
   1.371 +				SIZEOF(my_input_controller));
   1.372 +  cinfo->inputctl = (struct jpeg_input_controller *) inputctl;
   1.373 +  /* Initialize method pointers */
   1.374 +  inputctl->pub.consume_input = consume_markers;
   1.375 +  inputctl->pub.reset_input_controller = reset_input_controller;
   1.376 +  inputctl->pub.start_input_pass = start_input_pass;
   1.377 +  inputctl->pub.finish_input_pass = finish_input_pass;
   1.378 +  /* Initialize state: can't use reset_input_controller since we don't
   1.379 +   * want to try to reset other modules yet.
   1.380 +   */
   1.381 +  inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
   1.382 +  inputctl->pub.eoi_reached = FALSE;
   1.383 +  inputctl->inheaders = TRUE;
   1.384 +}