jdapistd.c File Reference

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

Include dependency graph for jdapistd.c:

Go to the source code of this file.

Macros
#define	JPEG_INTERNALS

Functions
	LOCAL (boolean)
	output_pass_setup (j_decompress_ptr cinfo)
	jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION max_lines)
	jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, JDIMENSION max_lines)

Macro Definition Documentation

JPEG_INTERNALS

#define JPEG_INTERNALS

Definition at line 18 of file jdapistd.c.

Function Documentation

jpeg_read_raw_data()

jpeg_read_raw_data	(	j_decompress_ptr	cinfo,
		JSAMPIMAGE	data,
		JDIMENSION	max_lines
	)

Definition at line 186 of file jdapistd.c.

{
  JDIMENSION lines_per_iMCU_row;
 
  if (cinfo->global_state != DSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }
 
  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }
 
  /* Verify that at least one iMCU row can be returned. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_v_scaled_size;
  if (max_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);
 
  /* Decompress directly into user's buffer. */
  if (! (*cinfo->coef->decompress_data) (cinfo, data))
    return 0;           /* suspension forced, can do nothing more */
 
  /* OK, we processed one iMCU row. */
  cinfo->output_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}

jpeg_read_scanlines()

jpeg_read_scanlines	(	j_decompress_ptr	cinfo,
		JSAMPARRAY	scanlines,
		JDIMENSION	max_lines
	)

Definition at line 153 of file jdapistd.c.

{
  JDIMENSION row_ctr;
 
  if (cinfo->global_state != DSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }
 
  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }
 
  /* Process some data */
  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
  cinfo->output_scanline += row_ctr;
  return row_ctr;
}

Referenced by main(), and read_JPEG_file().

LOCAL()

LOCAL

(

boolean

)

Definition at line 24 of file jdapistd.c.

{
  if (cinfo->global_state == DSTATE_READY) {
    /* First call: initialize master control, select active modules */
    jinit_master_decompress(cinfo);
    if (cinfo->buffered_image) {
      /* No more work here; expecting jpeg_start_output next */
      cinfo->global_state = DSTATE_BUFIMAGE;
      return TRUE;
    }
    cinfo->global_state = DSTATE_PRELOAD;
  }
  if (cinfo->global_state == DSTATE_PRELOAD) {
    /* If file has multiple scans, absorb them all into the coef buffer */
    if (cinfo->inputctl->has_multiple_scans) {
#ifdef D_MULTISCAN_FILES_SUPPORTED
      for (;;) {
    int retcode;
    /* Call progress monitor hook if present */
    if (cinfo->progress != NULL)
      (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
    /* Absorb some more input */
    retcode = (*cinfo->inputctl->consume_input) (cinfo);
    if (retcode == JPEG_SUSPENDED)
      return FALSE;
    if (retcode == JPEG_REACHED_EOI)
      break;
    /* Advance progress counter if appropriate */
    if (cinfo->progress != NULL &&
        (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
      if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
        /* jdmaster underestimated number of scans; ratchet up one scan */
        cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
      }
    }
      }
#else
      ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* D_MULTISCAN_FILES_SUPPORTED */
    }
    cinfo->output_scan_number = cinfo->input_scan_number;
  } else if (cinfo->global_state != DSTATE_PRESCAN)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Perform any dummy output passes, and set up for the final pass */
  return output_pass_setup(cinfo);
}

output_pass_setup()

output_pass_setup

(

j_decompress_ptr

cinfo

)

Definition at line 96 of file jdapistd.c.

{
  if (cinfo->global_state != DSTATE_PRESCAN) {
    /* First call: do pass setup */
    (*cinfo->master->prepare_for_output_pass) (cinfo);
    cinfo->output_scanline = 0;
    cinfo->global_state = DSTATE_PRESCAN;
  }
  /* Loop over any required dummy passes */
  while (cinfo->master->is_dummy_pass) {
#ifdef QUANT_2PASS_SUPPORTED
    /* Crank through the dummy pass */
    while (cinfo->output_scanline < cinfo->output_height) {
      JDIMENSION last_scanline;
      /* Call progress monitor hook if present */
      if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      }
      /* Process some data */
      last_scanline = cinfo->output_scanline;
      (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
                    &cinfo->output_scanline, (JDIMENSION) 0);
      if (cinfo->output_scanline == last_scanline)
    return FALSE;       /* No progress made, must suspend */
    }
    /* Finish up dummy pass, and set up for another one */
    (*cinfo->master->finish_output_pass) (cinfo);
    (*cinfo->master->prepare_for_output_pass) (cinfo);
    cinfo->output_scanline = 0;
#else
    ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* QUANT_2PASS_SUPPORTED */
  }
  /* Ready for application to drive output pass through
   * jpeg_read_scanlines or jpeg_read_raw_data.
   */
  cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
  return TRUE;
}