jcapistd.cpp File Reference

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

Include dependency graph for jcapistd.cpp:

Macros
#define	JPEG_INTERNALS

Functions
void	jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
JDIMENSION	jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION num_lines)
JDIMENSION	jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data, JDIMENSION num_lines)

Macro Definition Documentation

#define JPEG_INTERNALS

Function Documentation

void jpeg_start_compress	(	j_compress_ptr	cinfo,
		boolean	write_all_tables
	)

{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (write_all_tables)
    jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */

  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Perform master selection of active modules */
  jinit_compress_master(cinfo);
  /* Set up for the first pass */
  (*cinfo->master->prepare_for_pass) (cinfo);
  /* Ready for application to drive first pass through jpeg_write_scanlines
   * or jpeg_write_raw_data.
   */
  cinfo->next_scanline = 0;
  cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
}

JDIMENSION jpeg_write_scanlines	(	j_compress_ptr	cinfo,
		JSAMPARRAY	scanlines,
		JDIMENSION	num_lines
	)

{
  JDIMENSION row_ctr, rows_left;

  if (cinfo->global_state != CSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_height)
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_scanlines.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_scanlines.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Ignore any extra scanlines at bottom of image. */
  rows_left = cinfo->image_height - cinfo->next_scanline;
  if (num_lines > rows_left)
    num_lines = rows_left;

  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
  cinfo->next_scanline += row_ctr;
  return row_ctr;
}

JDIMENSION jpeg_write_raw_data	(	j_compress_ptr	cinfo,
		JSAMPIMAGE	data,
		JDIMENSION	num_lines
	)

{
  JDIMENSION lines_per_iMCU_row;

  if (cinfo->global_state != CSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_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->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_raw_data.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_raw_data.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Verify that at least one iMCU row has been passed. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
  if (num_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);

  /* Directly compress the row. */
  if (! (*cinfo->coef->compress_data) (cinfo, data)) {
    /* If compressor did not consume the whole row, suspend processing. */
    return 0;
  }

  /* OK, we processed one iMCU row. */
  cinfo->next_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}