/* Copyright (C) 1994 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
*/

/*$RCSfile: shcgen.h,v $ $Revision: 1.2.2.1 $ */
/* Interface for Huffman code generation */
/* Requires shc.h */

#ifndef shcgen_INCLUDED
#  define shcgen_INCLUDED

/* Compute an optimal Huffman code from an input data set. */
/* The client must have set all the elements of *def. */
/* The definition is guaranteed to be well-behaved. */
int hc_compute(P3(hc_definition * def, const long *freqs, gs_memory_t * mem));

/* Convert a definition to a byte string. */
/* The caller must provide the byte string, of length def->num_values. */
/* Assume (do not check) that the definition is well-behaved. */
/* Return the actual length of the string. */
int hc_bytes_from_definition(P2(byte * dbytes, const hc_definition * def));

/* Extract num_counts and num_values from a byte string. */
void hc_sizes_from_bytes(P3(hc_definition * def, const byte * dbytes, int num_bytes));

/* Convert a byte string back to a definition. */
/* The caller must initialize *def, including allocating counts and values. */
void hc_definition_from_bytes(P2(hc_definition * def, const byte * dbytes));

/* Generate the encoding table from the definition. */
/* The size of the encode array is def->num_values. */
void hc_make_encoding(P2(hce_code * encode, const hc_definition * def));

/* Calculate the size of the decoding table. */
uint hc_sizeof_decoding(P2(const hc_definition * def, int initial_bits));

/* Generate the decoding tables. */
void hc_make_decoding(P3(hcd_code * decode, const hc_definition * def,
			 int initial_bits));

#endif /* shcgen_INCLUDED */
