summaryrefslogtreecommitdiff
path: root/base/scfdgen.c
blob: c42c345ac62417d01a4b4693c2a33626c6827f19 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/* Copyright (C) 2001-2023 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/


/* Generate the CCITTFaxDecode tables */
#include "stdio_.h"		/* includes std.h */
#include "scf.h"
#include "malloc_.h"
#include "memory_.h"

typedef void (*cfd_node_proc) (cfd_node *, cfd_node *, uint, int, int, int);
typedef void (*cfd_enum_proc) (cfd_node_proc, cfd_node *, cfd_node *, int);
static void cfd_build_tree(cfd_node *, cfd_enum_proc, int, FILE *);
static void cfd_enumerate_white(cfd_node_proc, cfd_node *, cfd_node *, int);
static void cfd_enumerate_black(cfd_node_proc, cfd_node *, cfd_node *, int);
static void cfd_enumerate_2d(cfd_node_proc, cfd_node *, cfd_node *, int);
static void cfd_enumerate_uncompressed(cfd_node_proc, cfd_node *, cfd_node *, int);

main()
{
    FILE *out = fopen("scfdtab.c", "w");
    cfd_node area[1 << max(cfd_white_initial_bits, cfd_black_initial_bits)];

    fputs("/* Tables for CCITTFaxDecode filter. */\n\n", out);
    fputs("/* This file was generated automatically.  It is governed by the same terms */\n", out);
    fputs("/* as the files scfetab.c and scfdgen.c from which it was derived. */\n", out);
    fputs("/* Consult those files for the licensing terms and conditions. */\n\n", out);
    fputs("#include \"std.h\"\n", out);
    fputs("#include \"scommon.h\"\t\t/* for scf.h */\n", out);
    fputs("#include \"scf.h\"\n\n", out);
    fputs("/* White decoding table. */\n", out);
    fputs("const cfd_node cf_white_decode[] = {\n", out);
    cfd_build_tree(area, cfd_enumerate_white, cfd_white_initial_bits, out);
    fputs("\n};\n\n", out);
    fputs("/* Black decoding table. */\n", out);
    fputs("const cfd_node cf_black_decode[] = {\n", out);
    cfd_build_tree(area, cfd_enumerate_black, cfd_black_initial_bits, out);
    fputs("\n};\n\n", out);
    fputs("/* 2-D decoding table. */\n", out);
    fputs("const cfd_node cf_2d_decode[] = {\n", out);
    cfd_build_tree(area, cfd_enumerate_2d, cfd_2d_initial_bits, out);
    fputs("\n};\n\n", out);
    fputs("/* Uncompresssed decoding table. */\n", out);
    fputs("const cfd_node cf_uncompressed_decode[] = {\n", out);
    cfd_build_tree(area, cfd_enumerate_uncompressed, cfd_uncompressed_initial_bits, out);
    fputs("\n};\n\n", out);
    fputs("/* Dummy executable code to pacify compilers. */\n", out);
    fputs("void scfdtab_dummy(void);\n", out);
    fputs("void\nscfdtab_dummy(void)\n{\n}\n", out);
    fclose(out);
    return 0;
}

/* Initialize first-level leaves, count second-level nodes. */
static void
cfd_count_nodes(cfd_node * tree, cfd_node * ignore_extn,
                uint code, int code_length, int run_length, int initial_bits)
{
    if (code_length <= initial_bits) {
        /* Initialize one or more first-level leaves. */
        int sh = initial_bits - code_length;
        cfd_node *np = &tree[code << sh];
        int i;

        for (i = 1 << sh; i > 0; i--, np++)
            np->run_length = run_length,
                np->code_length = code_length;
    } else {
        /* Note the need for a second level. */
        cfd_node *np = &tree[code >> (code_length - initial_bits)];

        np->code_length = max(np->code_length, code_length);
    }
}

/* Initialize second-level nodes. */
static void
cfd_init2_nodes(cfd_node * tree, cfd_node * extn,
                uint code, int code_length, int run_length, int initial_bits)
{
    int xbits = code_length - initial_bits;
    int xrep;
    cfd_node *np1, *np2;
    int i;

    if (xbits <= 0)
        return;
    np1 = &tree[code >> xbits];
    np2 = &extn[np1->run_length - (1 << initial_bits)];
    xrep = np1->code_length - code_length;
    i = 1 << xrep;
    np2 += (code & ((1 << xbits) - 1)) * i;
    for (; i > 0; i--, np2++)
        np2->run_length = run_length,
            np2->code_length = xbits;
}

/* Enumerate all the relevant white or black codes. */
static void
cfd_enumerate_codes(cfd_node_proc proc, cfd_node * tree, cfd_node * extn,
                  int initial_bits, const cfe_run * tt, const cfe_run * mut)
{
    int i;
    const cfe_run *ep;

    for (i = 0, ep = tt; i < 64; i++, ep++)
        (*proc) (tree, extn, ep->code, ep->code_length, i, initial_bits);
    for (i = 1, ep = mut + 1; i < 41; i++, ep++)
        (*proc) (tree, extn, ep->code, ep->code_length, i << 6, initial_bits);
    (*proc) (tree, extn,
             cf1_run_uncompressed.code, cf1_run_uncompressed.code_length,
             run_uncompressed, initial_bits);
    (*proc) (tree, extn,
             0, run_eol_code_length - 1,
             run_zeros, initial_bits);
}
static void
cfd_enumerate_white(cfd_node_proc proc, cfd_node * tree, cfd_node * extn,
                    int initial_bits)
{
    cfd_enumerate_codes(proc, tree, extn, initial_bits,
                        cf_white_runs.termination, cf_white_runs.make_up);
}
static void
cfd_enumerate_black(cfd_node_proc proc, cfd_node * tree, cfd_node * extn,
                    int initial_bits)
{
    cfd_enumerate_codes(proc, tree, extn, initial_bits,
                        cf_black_runs.termination, cf_black_runs.make_up);
}

/* Enumerate the 2-D codes. */
static void
cfd_enumerate_2d(cfd_node_proc proc, cfd_node * tree, cfd_node * extn,
                 int initial_bits)
{
    int i;
    const cfe_run *ep;

    (*proc) (tree, extn, cf2_run_pass.code, cf2_run_pass.code_length,
             run2_pass, initial_bits);
    (*proc) (tree, extn, cf2_run_horizontal.code, cf2_run_horizontal.code_length,
             run2_horizontal, initial_bits);
    for (i = 0; i < countof(cf2_run_vertical); i++) {
        ep = &cf2_run_vertical[i];
        (*proc) (tree, extn, ep->code, ep->code_length, i, initial_bits);
    }
    (*proc) (tree, extn, cf2_run_uncompressed.code, cf2_run_uncompressed.code_length,
             run_uncompressed, initial_bits);
    (*proc) (tree, extn, 0, run_eol_code_length - 1, run_zeros, initial_bits);
}

/* Enumerate the uncompressed codes. */
static void
cfd_enumerate_uncompressed(cfd_node_proc proc, cfd_node * tree, cfd_node * extn,
                           int initial_bits)
{
    int i;
    const cfe_run *ep;

    for (i = 0; i < countof(cf_uncompressed); i++) {
        ep = &cf_uncompressed[i];
        (*proc) (tree, extn, ep->code, ep->code_length, i, initial_bits);
    }
    for (i = 0; i < countof(cf_uncompressed_exit); i++) {
        ep = &cf_uncompressed_exit[i];
        (*proc) (tree, extn, ep->code, ep->code_length, i, initial_bits);
    }
}

/* Build and write out the table. */
static void
cfd_build_tree(cfd_node * tree, cfd_enum_proc enum_proc, int initial_bits,
               FILE * f)
{
    cfd_node *np;
    const char *prev = "";
    int i, next;
    cfd_node *extn;

    memset(tree, 0, sizeof(cfd_node) << initial_bits);
    /* Construct and write the first level of the tree. */
    (*enum_proc) (cfd_count_nodes, tree, (cfd_node *) 0, initial_bits);
    next = 0;
    for (i = 0, np = tree; i < 1 << initial_bits; i++, np++) {
        if (np->code_length > initial_bits) {	/* second level needed */
            np->run_length = next + (1 << initial_bits);
            next += 1 << (np->code_length - initial_bits);
        }
        fprintf(f, "%s\t{ %d, %d }", prev, np->run_length, np->code_length);
        prev = ",\n";
    }
    /* Construct and write the second level. */
    extn = (cfd_node *) malloc(sizeof(cfd_node) * next);
    for (i = 0, np = extn; i < next; i++, np++)
        np->run_length = run_error,
            np->code_length = 0;
    (*enum_proc) (cfd_init2_nodes, tree, extn, initial_bits);
    for (i = 0, np = extn; i < next; i++, np++)
        fprintf(f, ",\n\t{ %d, %d }", np->run_length, np->code_length);
    free((char *)extn);
}