jdinput.c File Reference

#include "jinclude.h"
#include "jpeglib.h"

Include dependency graph for jdinput.c:

Go to the source code of this file.

Classes
struct	my_input_controller

Macros
#define	JPEG_INTERNALS

Typedefs
typedef my_input_controller *	my_inputctl_ptr

Functions
	METHODDEF (int)
	initial_setup (j_decompress_ptr cinfo)
	per_scan_setup (j_decompress_ptr cinfo)
	latch_quant_tables (j_decompress_ptr cinfo)
	start_input_pass (j_decompress_ptr cinfo)
	finish_input_pass (j_decompress_ptr cinfo)
	consume_markers (j_decompress_ptr cinfo)
	reset_input_controller (j_decompress_ptr cinfo)
	jinit_input_controller (j_decompress_ptr cinfo)

Macro Definition Documentation

JPEG_INTERNALS

#define JPEG_INTERNALS

Definition at line 15 of file jdinput.c.

Typedef Documentation

my_inputctl_ptr

typedef my_input_controller* my_inputctl_ptr

Definition at line 28 of file jdinput.c.

Function Documentation

consume_markers()

consume_markers

(

j_decompress_ptr

cinfo

)

Definition at line 556 of file jdinput.c.

{
  my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
  int val;
 
  if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */
    return JPEG_REACHED_EOI;
 
  for (;;) {            /* Loop to pass pseudo SOS marker */
    val = (*cinfo->marker->read_markers) (cinfo);
 
    switch (val) {
    case JPEG_REACHED_SOS:  /* Found SOS */
      if (inputctl->inheaders) { /* 1st SOS */
    if (inputctl->inheaders == 1)
      initial_setup(cinfo);
    if (cinfo->comps_in_scan == 0) { /* pseudo SOS marker */
      inputctl->inheaders = 2;
      break;
    }
    inputctl->inheaders = 0;
    /* Note: start_input_pass must be called by jdmaster.c
     * before any more input can be consumed.  jdapimin.c is
     * responsible for enforcing this sequencing.
     */
      } else {          /* 2nd or later SOS marker */
    if (! inputctl->pub.has_multiple_scans)
      ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */
    if (cinfo->comps_in_scan == 0) /* unexpected pseudo SOS marker */
      break;
    start_input_pass(cinfo);
      }
      return val;
    case JPEG_REACHED_EOI:  /* Found EOI */
      inputctl->pub.eoi_reached = TRUE;
      if (inputctl->inheaders) { /* Tables-only datastream, apparently */
    if (cinfo->marker->saw_SOF)
      ERREXIT(cinfo, JERR_SOF_NO_SOS);
      } else {
    /* Prevent infinite loop in coef ctlr's decompress_data routine
     * if user set output_scan_number larger than number of scans.
     */
    if (cinfo->output_scan_number > cinfo->input_scan_number)
      cinfo->output_scan_number = cinfo->input_scan_number;
      }
      return val;
    case JPEG_SUSPENDED:
      return val;
    default:
      return val;
    }
  }
}

Referenced by finish_input_pass(), jinit_input_controller(), and reset_input_controller().

finish_input_pass()

finish_input_pass

(

j_decompress_ptr

cinfo

)

Definition at line 534 of file jdinput.c.

{
  (*cinfo->entropy->finish_pass) (cinfo);
  cinfo->inputctl->consume_input = consume_markers;
}

Referenced by jinit_input_controller().

initial_setup()

initial_setup

(

j_decompress_ptr

cinfo

)

Definition at line 208 of file jdinput.c.

{
  int ci;
  jpeg_component_info *compptr;
 
  /* Make sure image isn't bigger than I can handle */
  if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
      (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
    ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
 
  /* Only 8 to 12 bits data precision are supported for DCT based JPEG */
  if (cinfo->data_precision < 8 || cinfo->data_precision > 12)
    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
 
  /* Check that number of components won't exceed internal array sizes */
  if (cinfo->num_components > MAX_COMPONENTS)
    ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
         MAX_COMPONENTS);
 
  /* Compute maximum sampling factors; check factor validity */
  cinfo->max_h_samp_factor = 1;
  cinfo->max_v_samp_factor = 1;
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
    compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
      ERREXIT(cinfo, JERR_BAD_SAMPLING);
    cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
                   compptr->h_samp_factor);
    cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
                   compptr->v_samp_factor);
  }
 
  /* Derive block_size, natural_order, and lim_Se */
  if (cinfo->is_baseline || (cinfo->progressive_mode &&
      cinfo->comps_in_scan)) { /* no pseudo SOS marker */
    cinfo->block_size = DCTSIZE;
    cinfo->natural_order = jpeg_natural_order;
    cinfo->lim_Se = DCTSIZE2-1;
  } else
    switch (cinfo->Se) {
    case (1*1-1):
      cinfo->block_size = 1;
      cinfo->natural_order = jpeg_natural_order; /* not needed */
      cinfo->lim_Se = cinfo->Se;
      break;
    case (2*2-1):
      cinfo->block_size = 2;
      cinfo->natural_order = jpeg_natural_order2;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (3*3-1):
      cinfo->block_size = 3;
      cinfo->natural_order = jpeg_natural_order3;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (4*4-1):
      cinfo->block_size = 4;
      cinfo->natural_order = jpeg_natural_order4;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (5*5-1):
      cinfo->block_size = 5;
      cinfo->natural_order = jpeg_natural_order5;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (6*6-1):
      cinfo->block_size = 6;
      cinfo->natural_order = jpeg_natural_order6;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (7*7-1):
      cinfo->block_size = 7;
      cinfo->natural_order = jpeg_natural_order7;
      cinfo->lim_Se = cinfo->Se;
      break;
    case (8*8-1):
      cinfo->block_size = 8;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (9*9-1):
      cinfo->block_size = 9;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (10*10-1):
      cinfo->block_size = 10;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (11*11-1):
      cinfo->block_size = 11;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (12*12-1):
      cinfo->block_size = 12;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (13*13-1):
      cinfo->block_size = 13;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (14*14-1):
      cinfo->block_size = 14;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (15*15-1):
      cinfo->block_size = 15;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    case (16*16-1):
      cinfo->block_size = 16;
      cinfo->natural_order = jpeg_natural_order;
      cinfo->lim_Se = DCTSIZE2-1;
      break;
    default:
      ERREXIT4(cinfo, JERR_BAD_PROGRESSION,
           cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);
    }
 
  /* We initialize DCT_scaled_size and min_DCT_scaled_size to block_size.
   * In the full decompressor,
   * this will be overridden by jpeg_calc_output_dimensions in jdmaster.c;
   * but in the transcoder,
   * jpeg_calc_output_dimensions is not used, so we must do it here.
   */
  cinfo->min_DCT_h_scaled_size = cinfo->block_size;
  cinfo->min_DCT_v_scaled_size = cinfo->block_size;
 
  /* Compute dimensions of components */
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    compptr->DCT_h_scaled_size = cinfo->block_size;
    compptr->DCT_v_scaled_size = cinfo->block_size;
    /* Size in DCT blocks */
    compptr->width_in_blocks = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
            (long) (cinfo->max_h_samp_factor * cinfo->block_size));
    compptr->height_in_blocks = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
            (long) (cinfo->max_v_samp_factor * cinfo->block_size));
    /* downsampled_width and downsampled_height will also be overridden by
     * jdmaster.c if we are doing full decompression.  The transcoder library
     * doesn't use these values, but the calling application might.
     */
    /* Size in samples */
    compptr->downsampled_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
            (long) cinfo->max_h_samp_factor);
    compptr->downsampled_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
            (long) cinfo->max_v_samp_factor);
    /* Mark component needed, until color conversion says otherwise */
    compptr->component_needed = TRUE;
    /* Mark no quantization table yet saved for component */
    compptr->quant_table = NULL;
  }
 
  /* Compute number of fully interleaved MCU rows. */
  cinfo->total_iMCU_rows = (JDIMENSION)
    jdiv_round_up((long) cinfo->image_height,
              (long) (cinfo->max_v_samp_factor * cinfo->block_size));
 
  /* Decide whether file contains multiple scans */
  if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode)
    cinfo->inputctl->has_multiple_scans = TRUE;
  else
    cinfo->inputctl->has_multiple_scans = FALSE;
}

Referenced by consume_markers().

jinit_input_controller()

jinit_input_controller

(

j_decompress_ptr

cinfo

)

Definition at line 638 of file jdinput.c.

{
  my_inputctl_ptr inputctl;
 
  /* Create subobject in permanent pool */
  inputctl = (my_inputctl_ptr) (*cinfo->mem->alloc_small)
    ((j_common_ptr) cinfo, JPOOL_PERMANENT, SIZEOF(my_input_controller));
  cinfo->inputctl = &inputctl->pub;
  /* Initialize method pointers */
  inputctl->pub.consume_input = consume_markers;
  inputctl->pub.reset_input_controller = reset_input_controller;
  inputctl->pub.start_input_pass = start_input_pass;
  inputctl->pub.finish_input_pass = finish_input_pass;
  /* Initialize state: can't use reset_input_controller since we don't
   * want to try to reset other modules yet.
   */
  inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
  inputctl->pub.eoi_reached = FALSE;
  inputctl->inheaders = 1;
}

Referenced by jpeg_CreateDecompress().

latch_quant_tables()

latch_quant_tables

(

j_decompress_ptr

cinfo

)

Definition at line 484 of file jdinput.c.

{
  int ci, qtblno;
  jpeg_component_info *compptr;
  JQUANT_TBL * qtbl;
 
  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
    compptr = cinfo->cur_comp_info[ci];
    /* No work if we already saved Q-table for this component */
    if (compptr->quant_table != NULL)
      continue;
    /* Make sure specified quantization table is present */
    qtblno = compptr->quant_tbl_no;
    if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
    cinfo->quant_tbl_ptrs[qtblno] == NULL)
      ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
    /* OK, save away the quantization table */
    qtbl = (JQUANT_TBL *) (*cinfo->mem->alloc_small)
      ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(JQUANT_TBL));
    MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL));
    compptr->quant_table = qtbl;
  }
}

Referenced by start_input_pass().

METHODDEF()

METHODDEF

(

int

)

Definition at line 32 of file jdinput.c.

{
#ifdef IDCT_SCALING_SUPPORTED
  int ci;
  jpeg_component_info *compptr;
 
  /* Compute actual output image dimensions and DCT scaling choices. */
  if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom) {
    /* Provide 1/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 1;
    cinfo->min_DCT_v_scaled_size = 1;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 2) {
    /* Provide 2/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 2L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 2L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 2;
    cinfo->min_DCT_v_scaled_size = 2;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 3) {
    /* Provide 3/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 3L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 3L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 3;
    cinfo->min_DCT_v_scaled_size = 3;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 4) {
    /* Provide 4/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 4L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 4L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 4;
    cinfo->min_DCT_v_scaled_size = 4;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 5) {
    /* Provide 5/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 5L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 5L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 5;
    cinfo->min_DCT_v_scaled_size = 5;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 6) {
    /* Provide 6/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 6L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 6L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 6;
    cinfo->min_DCT_v_scaled_size = 6;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 7) {
    /* Provide 7/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 7L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 7L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 7;
    cinfo->min_DCT_v_scaled_size = 7;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 8) {
    /* Provide 8/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 8L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 8L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 8;
    cinfo->min_DCT_v_scaled_size = 8;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 9) {
    /* Provide 9/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 9L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 9L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 9;
    cinfo->min_DCT_v_scaled_size = 9;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 10) {
    /* Provide 10/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 10L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 10L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 10;
    cinfo->min_DCT_v_scaled_size = 10;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 11) {
    /* Provide 11/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 11L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 11L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 11;
    cinfo->min_DCT_v_scaled_size = 11;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 12) {
    /* Provide 12/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 12L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 12L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 12;
    cinfo->min_DCT_v_scaled_size = 12;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 13) {
    /* Provide 13/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 13L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 13L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 13;
    cinfo->min_DCT_v_scaled_size = 13;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 14) {
    /* Provide 14/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 14L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 14L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 14;
    cinfo->min_DCT_v_scaled_size = 14;
  } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 15) {
    /* Provide 15/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 15L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 15L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 15;
    cinfo->min_DCT_v_scaled_size = 15;
  } else {
    /* Provide 16/block_size scaling */
    cinfo->output_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * 16L, (long) cinfo->block_size);
    cinfo->output_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * 16L, (long) cinfo->block_size);
    cinfo->min_DCT_h_scaled_size = 16;
    cinfo->min_DCT_v_scaled_size = 16;
  }
 
  /* Recompute dimensions of components */
  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++) {
    compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size;
    compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size;
  }
 
#else /* !IDCT_SCALING_SUPPORTED */
 
  /* Hardwire it to "no scaling" */
  cinfo->output_width = cinfo->image_width;
  cinfo->output_height = cinfo->image_height;
  /* initial_setup has already initialized DCT_scaled_size,
   * and has computed unscaled downsampled_width and downsampled_height.
   */
 
#endif /* IDCT_SCALING_SUPPORTED */
}

per_scan_setup()

per_scan_setup

(

j_decompress_ptr

cinfo

)

Definition at line 387 of file jdinput.c.

{
  int ci, mcublks, tmp;
  jpeg_component_info *compptr;
 
  if (cinfo->comps_in_scan == 1) {
 
    /* Noninterleaved (single-component) scan */
    compptr = cinfo->cur_comp_info[0];
 
    /* Overall image size in MCUs */
    cinfo->MCUs_per_row = compptr->width_in_blocks;
    cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
 
    /* For noninterleaved scan, always one block per MCU */
    compptr->MCU_width = 1;
    compptr->MCU_height = 1;
    compptr->MCU_blocks = 1;
    compptr->MCU_sample_width = compptr->DCT_h_scaled_size;
    compptr->last_col_width = 1;
    /* For noninterleaved scans, it is convenient to define last_row_height
     * as the number of block rows present in the last iMCU row.
     */
    tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
    if (tmp == 0) tmp = compptr->v_samp_factor;
    compptr->last_row_height = tmp;
 
    /* Prepare array describing MCU composition */
    cinfo->blocks_in_MCU = 1;
    cinfo->MCU_membership[0] = 0;
 
  } else {
 
    /* Interleaved (multi-component) scan */
    if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
      ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
           MAX_COMPS_IN_SCAN);
 
    /* Overall image size in MCUs */
    cinfo->MCUs_per_row = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width,
            (long) (cinfo->max_h_samp_factor * cinfo->block_size));
    cinfo->MCU_rows_in_scan = cinfo->total_iMCU_rows;
 
    cinfo->blocks_in_MCU = 0;
 
    for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
      compptr = cinfo->cur_comp_info[ci];
      /* Sampling factors give # of blocks of component in each MCU */
      compptr->MCU_width = compptr->h_samp_factor;
      compptr->MCU_height = compptr->v_samp_factor;
      compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
      compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size;
      /* Figure number of non-dummy blocks in last MCU column & row */
      tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
      if (tmp == 0) tmp = compptr->MCU_width;
      compptr->last_col_width = tmp;
      tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
      if (tmp == 0) tmp = compptr->MCU_height;
      compptr->last_row_height = tmp;
      /* Prepare array describing MCU composition */
      mcublks = compptr->MCU_blocks;
      if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU)
    ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
      while (mcublks-- > 0) {
    cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
      }
    }
 
  }
}

Referenced by start_input_pass().

reset_input_controller()

reset_input_controller

(

j_decompress_ptr

cinfo

)

Definition at line 616 of file jdinput.c.

{
  my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
 
  inputctl->pub.consume_input = consume_markers;
  inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
  inputctl->pub.eoi_reached = FALSE;
  inputctl->inheaders = 1;
  /* Reset other modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->marker->reset_marker_reader) (cinfo);
  /* Reset progression state -- would be cleaner if entropy decoder did this */
  cinfo->coef_bits = NULL;
}

Referenced by jinit_input_controller().

start_input_pass()

start_input_pass

(

j_decompress_ptr

cinfo

)

Definition at line 517 of file jdinput.c.

{
  per_scan_setup(cinfo);
  latch_quant_tables(cinfo);
  (*cinfo->entropy->start_pass) (cinfo);
  (*cinfo->coef->start_input_pass) (cinfo);
  cinfo->inputctl->consume_input = cinfo->coef->consume_data;
}

Referenced by consume_markers(), and jinit_input_controller().