/* $Xorg: jddeflts.c,v 1.4 2001/02/09 02:04:28 xorgcvs Exp $ */
/* AGE Logic - Oct 15 1995 - Larry Hare */
/* Module jddeflts.c */

/****************************************************************************

Copyright 1993, 1994, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.


				NOTICE
                              
This software is being provided by AGE Logic, Inc. under the
following license.  By obtaining, using and/or copying this software,
you agree that you have read, understood, and will comply with these
terms and conditions:

     Permission to use, copy, modify, distribute and sell this
     software and its documentation for any purpose and without
     fee or royalty and to grant others any or all rights granted
     herein is hereby granted, provided that you agree to comply
     with the following copyright notice and statements, including
     the disclaimer, and that the same appears on all copies and
     derivative works of the software and documentation you make.
     
     "Copyright 1993, 1994 by AGE Logic, Inc."
     
     THIS SOFTWARE IS PROVIDED "AS IS".  AGE LOGIC MAKES NO
     REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  By way of
     example, but not limitation, AGE LOGIC MAKE NO
     REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS
     FOR ANY PARTICULAR PURPOSE OR THAT THE SOFTWARE DOES NOT
     INFRINGE THIRD-PARTY PROPRIETARY RIGHTS.  AGE LOGIC 
     SHALL BEAR NO LIABILITY FOR ANY USE OF THIS SOFTWARE.  IN NO
     EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT,
     INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOSS
     OF PROFITS, REVENUE, DATA OR USE, INCURRED BY EITHER PARTY OR
     ANY THIRD PARTY, WHETHER IN AN ACTION IN CONTRACT OR TORT OR
     BASED ON A WARRANTY, EVEN IF AGE LOGIC LICENSEES
     HEREUNDER HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
     DAMAGES.
    
     The name of AGE Logic, Inc. may not be used in
     advertising or publicity pertaining to this software without
     specific, written prior permission from AGE Logic.

     Title to this software shall at all times remain with AGE
     Logic, Inc.
*****************************************************************************

	Gary Rogers, AGE Logic, Inc., October 1993

****************************************************************************/

/*
 * jddeflts.c
 *
 * Copyright (C) 1991, 1992, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains optional default-setting code for the JPEG decompressor.
 * User interfaces do not have to use this file, but those that don't use it
 * must know more about the innards of the JPEG code.
 */

#include "jinclude.h"

#ifndef XIE_SUPPORTED
/* Default do-nothing progress monitoring routine.
 * This can be overridden by a user interface that wishes to
 * provide progress monitoring; just set methods->progress_monitor
 * after j_d_defaults is done.  The routine will be called periodically
 * during the decompression process.
 *
 * During any one pass, loopcounter increases from 0 up to (not including)
 * looplimit; the step size is not necessarily 1.  Both the step size and
 * the limit may differ between passes.  The expected total number of passes
 * is in cinfo->total_passes, and the number of passes already completed is
 * in cinfo->completed_passes.  Thus the fraction of work completed may be
 * estimated as
 *		completed_passes + (loopcounter/looplimit)
 *		------------------------------------------
 *				total_passes
 * ignoring the fact that the passes may not be equal amounts of work.
 *
 * When decompressing, the total_passes figure is an estimate that may be
 * on the high side; completed_passes will jump by more than one if some
 * passes are skipped.
 */

METHODDEF void
progress_monitor (decompress_info_ptr cinfo, long loopcounter, long looplimit)
{
  /* do nothing */
}
#endif	/* XIE_SUPPORTED */

/* Default comment-block processing routine.
 * This can be overridden by an application that wishes to examine
 * COM blocks found in the JPEG file.  The default routine does nothing.
 * CAUTION: the comment processing routine MUST call JGETC() exactly
 * comment_length times to read the comment data, whether it intends
 * to do anything with the data or not!
 * Keep in mind that (a) there may be more than one COM block in a file;
 * (b) there's no guarantee that what's in the block is ASCII data.
 */

#ifdef XIE_SUPPORTED
METHODDEF int
#if NeedFunctionPrototypes
process_comment (decompress_info_ptr cinfo, long comment_length)
#else
process_comment (cinfo, comment_length)
	decompress_info_ptr cinfo;
	long comment_length;
#endif	/* NeedFunctionPrototypes */
#else
METHODDEF void
process_comment (decompress_info_ptr cinfo, long comment_length)
#endif	/* XIE_SUPPORTED */
{
#ifdef XIE_SUPPORTED
  int i;
#endif	/* XIE_SUPPORTED */

  while (comment_length-- > 0) {
#ifdef XIE_SUPPORTED
    if ((i = JGETC(cinfo)) < 0)
      return(-1);
#else
    (void) JGETC(cinfo);
#endif	/* XIE_SUPPORTED */
  }
#ifdef XIE_SUPPORTED
  return(0);
#endif	/* XIE_SUPPORTED */
}


#ifndef XIE_SUPPORTED
/*
 * Reload the input buffer after it's been emptied, and return the next byte.
 * See the JGETC macro for calling conditions.  Note in particular that
 * read_jpeg_data may NOT return EOF.  If no more data is available, it must
 * exit via ERREXIT, or perhaps synthesize fake data (such as an RST marker).
 * In the present implementation, we insert an EOI marker; this might not be
 * appropriate for non-JFIF file formats, but it usually allows us to handle
 * a truncated JFIF file.
 *
 * This routine can be overridden by the system-dependent user interface,
 * in case the data source is not a stdio stream or some other special
 * condition applies.  Note, however, that this capability only applies for
 * JFIF or similar serial-access JPEG file formats.  The input file control
 * module for a random-access format such as TIFF/JPEG would most likely
 * override the read_jpeg_data method with its own routine.
 */

METHODDEF int
read_jpeg_data (decompress_info_ptr cinfo)
{
  cinfo->next_input_byte = cinfo->input_buffer + MIN_UNGET;

  cinfo->bytes_in_buffer = (int) JFREAD(cinfo->input_file,
					cinfo->next_input_byte,
					JPEG_BUF_SIZE);
  
  if (cinfo->bytes_in_buffer <= 0) {
    WARNMS(cinfo->emethods, "Premature EOF in JPEG file");
    cinfo->next_input_byte[0] = (char) 0xFF;
    cinfo->next_input_byte[1] = (char) 0xD9; /* EOI marker */
    cinfo->bytes_in_buffer = 2;
  }

  return JGETC(cinfo);
}
#endif	/* XIE_SUPPORTED */


/* Default parameter setup for decompression.
 *
 * User interfaces that don't choose to use this routine must do their
 * own setup of all these parameters.  Alternately, you can call this
 * to establish defaults and then alter parameters selectively.  This
 * is the recommended approach since, if we add any new parameters,
 * your code will still work (they'll be set to reasonable defaults).
 *
 * standard_buffering should be TRUE to cause an input buffer to be allocated
 * (the normal case); if FALSE, the user interface must provide a buffer.
 * This option is most useful in the case that the buffer must not be freed
 * at the end of an image.  (For example, when reading a sequence of images
 * from a single file, the remaining data in the buffer represents the
 * start of the next image and mustn't be discarded.)  To handle this,
 * allocate the input buffer yourself at startup, WITHOUT using alloc_small
 * (probably a direct call to malloc() instead).  Then pass FALSE on each
 * call to j_d_defaults to ensure the buffer state is not modified.
 *
 * If the source of the JPEG data is not a stdio stream, override the
 * read_jpeg_data method with your own routine after calling j_d_defaults.
 * You can still use the standard buffer if it's appropriate.
 *
 * CAUTION: if you want to decompress multiple images per run, it's necessary
 * to call j_d_defaults before *each* call to jpeg_decompress, since subsidiary
 * structures like the quantization tables are automatically freed during
 * cleanup.
 */

GLOBAL void
#ifdef XIE_SUPPORTED
#if NeedFunctionPrototypes
j_d_defaults (decompress_info_ptr cinfo, boolean standard_buffering)
#else
j_d_defaults (cinfo, standard_buffering)
	decompress_info_ptr cinfo;
	boolean standard_buffering;
#endif	/* NeedFunctionPrototypes */
#else
j_d_defaults (decompress_info_ptr cinfo, boolean standard_buffering)
#endif	/* XIE_SUPPORTED */
/* NB: the external methods must already be set up. */
{
  short i;

  /* Initialize pointers as needed to mark stuff unallocated. */
  /* Outer application may fill in default tables for abbreviated files... */
  cinfo->comp_info = NULL;
  for (i = 0; i < NUM_QUANT_TBLS; i++)
    cinfo->quant_tbl_ptrs[i] = NULL;
  for (i = 0; i < NUM_HUFF_TBLS; i++) {
    cinfo->dc_huff_tbl_ptrs[i] = NULL;
    cinfo->ac_huff_tbl_ptrs[i] = NULL;
  }
  cinfo->colormap = NULL;

  /* Default to RGB output */
  /* UI can override by changing out_color_space */
  cinfo->out_color_space = CS_RGB;
  cinfo->jpeg_color_space = CS_UNKNOWN;
  /* Setting any other value in jpeg_color_space overrides heuristics in */
  /* jrdjfif.c.  That might be useful when reading non-JFIF JPEG files, */
  /* but ordinarily the UI shouldn't change it. */
  
  /* Default to no gamma correction of output */
  cinfo->output_gamma = 1.0;
  
  /* Default to no color quantization */
  cinfo->quantize_colors = FALSE;
  /* but set reasonable default parameters for quantization, */
  /* so that turning on quantize_colors is sufficient to do something useful */
  cinfo->two_pass_quantize = TRUE;
  cinfo->use_dithering = TRUE;
  cinfo->desired_number_of_colors = 256;
  
  /* Default to no smoothing */
  cinfo->do_block_smoothing = FALSE;
  cinfo->do_pixel_smoothing = FALSE;
  
#ifndef XIE_SUPPORTED
  /* Allocate memory for input buffer, unless outer application provides it. */
  if (standard_buffering) {
    cinfo->input_buffer = (char *) (*cinfo->emethods->alloc_small)
					((size_t) (JPEG_BUF_SIZE + MIN_UNGET));
    cinfo->bytes_in_buffer = 0;	/* initialize buffer to empty */
  }

  /* Install standard buffer-reloading method (outer code may override). */
  cinfo->methods->read_jpeg_data = read_jpeg_data;

  /* Install default do-nothing progress monitoring method. */
  cinfo->methods->progress_monitor = progress_monitor;
#endif	/* XIE_SUPPORTED */  

  /* Install default comment-block processing method. */
  cinfo->methods->process_comment = process_comment;
}
