1 /* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* ====================================================================
3 * Copyright (c) 2009 Carnegie Mellon University. All rights
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
18 * This work was supported in part by funding from the Defense Advanced
19 * Research Projects Agency and the National Science Foundation of the
20 * United States of America, and the CMU Sphinx Speech Consortium.
22 * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
23 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
26 * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 * ====================================================================
40 * @brief Huffman code and bitstream implementation
42 * This interface supports building canonical Huffman codes from
43 * string and integer values. It also provides support for encoding
44 * and decoding from strings and files, and for reading and writing
45 * codebooks from files.
48 #ifndef __HUFF_CODE_H__
49 #define __HUFF_CODE_H__
53 #include <sphinxbase/sphinxbase_export.h>
54 #include <sphinxbase/prim_type.h>
55 #include <sphinxbase/cmd_ln.h>
57 typedef struct huff_code_s huff_code_t;
60 * Create a codebook from 32-bit integer data.
63 huff_code_t *huff_code_build_int(int32 const *values, int32 const *frequencies, int nvals);
66 * Create a codebook from string data.
69 huff_code_t *huff_code_build_str(char * const *values, int32 const *frequencies, int nvals);
72 * Read a codebook from a file.
75 huff_code_t *huff_code_read(FILE *infh);
78 * Write a codebook to a file.
81 int huff_code_write(huff_code_t *hc, FILE *outfh);
84 * Print a codebook to a file as text (for debugging)
87 int huff_code_dump(huff_code_t *hc, FILE *dumpfh);
90 * Retain a pointer to a Huffman codec object.
93 huff_code_t *huff_code_retain(huff_code_t *hc);
96 * Release a pointer to a Huffman codec object.
99 int huff_code_free(huff_code_t *hc);
102 * Attach a Huffman codec to a file handle for input/output.
105 FILE *huff_code_attach(huff_code_t *hc, FILE *fh, char const *mode);
108 * Detach a Huffman codec from its file handle.
111 FILE *huff_code_detach(huff_code_t *hc);
114 * Encode an integer, writing it to the file handle, if any.
117 int huff_code_encode_int(huff_code_t *hc, int32 sym, uint32 *outcw);
120 * Encode a string, writing it to the file handle, if any.
123 int huff_code_encode_str(huff_code_t *hc, char const *sym, uint32 *outcw);
126 * Decode an integer, reading it from the file if no data given.
129 int huff_code_decode_int(huff_code_t *hc, int *outval,
130 char const **inout_data,
131 size_t *inout_data_len,
135 * Decode a string, reading it from the file if no data given.
138 char const *huff_code_decode_str(huff_code_t *hc,
139 char const **inout_data,
140 size_t *inout_data_len,
143 #endif /* __HUFF_CODE_H__ */