about summary refs log tree commit diff
path: root/converter/other/fiasco/output/weights.c
blob: 5aa1767470da0beef47d6da2bdd394e9ea5366c2 (plain) (blame)
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
/*
 *  weights.c:		Output of weights
 *
 *  Written by:		Ullrich Hafner
 *		
 *  This file is part of FIASCO («F»ractal «I»mage «A»nd «S»equence «CO»dec)
 *  Copyright (C) 1994-2000 Ullrich Hafner <hafner@bigfoot.de>
 */

/*
 *  $Date: 2000/06/14 20:50:31 $
 *  $Author: hafner $
 *  $Revision: 5.1 $
 *  $State: Exp $
 */

#include "config.h"

#include "pm_c_util.h"

#include "types.h"
#include "macros.h"
#include "error.h"

#include "wfa.h"
#include "misc.h"
#include "bit-io.h"
#include "arith.h"
#include "wfalib.h"

#include "weights.h"

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

				public code
  
*****************************************************************************/

void
write_weights (unsigned total, const wfa_t *wfa, bitfile_t *output)
/*
 *  Traverse the transition matrices of the 'wfa' and write #'total'
 *  weights != 0 to stream 'output'.
 *
 *  No return value.
 */
{
    unsigned  state, label;		/* current label */
    unsigned  offset1, offset2;		/* model offsets. */
    unsigned  offset3, offset4;		/* model offsets. */
    unsigned *weights_array;		/* array of weights to encode */
    unsigned *wptr;			/* pointer to current weight */
    unsigned *level_array;		/* array of corresponding levels */
    unsigned *lptr;			/* pointer to current corr. level */
    int	     min_level, max_level;	/* min and max range level */
    int	     d_min_level, d_max_level; 	/* min and max delta range level */
    bool_t    dc, d_dc;			/* true if dc or delta dc are used */
    bool_t    delta_approx = NO;		/* true if delta has been used */
    unsigned  delta_count  = 0;		/* number of delta ranges */
    unsigned  bits 	  = bits_processed (output);
   
    /*
     *  Check whether delta approximation has been used
     */
    for (state = wfa->basis_states; state < wfa->states; state++)
        if (wfa->delta_state [state])
        {
            delta_approx = YES;
            break;
        }
   
    /*
     *  Generate array of corresponding levels (context of probability model)
     */
    min_level = d_min_level = MAXLEVEL;
    max_level = d_max_level = 0;
    dc 	     = d_dc	   = NO;
   
    for (state = wfa->basis_states; state < wfa->states; state++)
        for (label = 0; label < MAXLABELS; label++)
            if (isrange (wfa->tree [state][label]))
            {
                if (delta_approx && wfa->delta_state [state]) /* delta approx. */
                {
                    d_min_level = MIN(d_min_level, wfa->level_of_state [state] - 1);
                    d_max_level = MAX(d_max_level, wfa->level_of_state [state] - 1);
                    if (wfa->into [state][label][0] == 0)
                        d_dc = YES;
                }
                else
                {
                    min_level = MIN(min_level, wfa->level_of_state [state] - 1);
                    max_level = MAX(max_level, wfa->level_of_state [state] - 1);
                    if (wfa->into [state][label][0] == 0)
                        dc = YES;
                }
            }
    if (min_level > max_level)		/* no lc found */
        max_level = min_level - 1;
    if (d_min_level > d_max_level)
        d_max_level = d_min_level - 1;

    /*
     *  Context model:
     *		0		DC weight
     *		1		Delta DC weight
     *		2-k		normal weights per level
     *		k+1 - m		Delta weights per level
     */

    offset1 = dc ? 1 : 0;
    offset2 = offset1 + (d_dc ? 1 : 0);
    offset3 = offset2 + (max_level - min_level + 1);
    offset4 = offset3 + (d_max_level - d_min_level + 1);
   
    /*
     *  Weights are encoded as follows:
     *  all weights of state n
     *     sorted by label
     *        sorted by domain number
     */

    wptr = weights_array = Calloc (total, sizeof (unsigned));
    lptr = level_array   = Calloc (total, sizeof (unsigned));

    for (state = wfa->basis_states; state < wfa->states; state++)
        for (label = 0; label < MAXLABELS; label++)
            if (isrange (wfa->tree [state][label]))
            {
                int	edge;			/* current edge */
                int	domain;			/* current domain (context of model) */
	    
                for (edge = 0; isedge (domain = wfa->into [state][label][edge]);
                     edge++)
                {
                    if (wptr - weights_array >= (int) total)
                        error ("Can't write more than %d weights.", total);
                    if (domain)		/* not DC component */
                    {
                        if (delta_approx && wfa->delta_state [state]) /* delta */
                        {
                            *wptr++ = rtob (wfa->weight [state][label][edge],
                                            wfa->wfainfo->d_rpf);
                            *lptr++ = offset3
                                + wfa->level_of_state [state] - 1 - d_min_level;
                            delta_count++;
                        }
                        else
                        {
                            *wptr++ = rtob (wfa->weight [state][label][edge],
                                            wfa->wfainfo->rpf);
                            *lptr++ = offset2
                                + wfa->level_of_state [state] - 1 - min_level;
                        }
                    }
                    else			/* DC component */
                    {
                        if (delta_approx && wfa->delta_state [state]) /* delta */
                        {
                            *wptr++ = rtob (wfa->weight [state][label][edge],
                                            wfa->wfainfo->d_dc_rpf);
                            *lptr++ = offset1;
                        }
                        else
                        {
                            *wptr++ = rtob (wfa->weight [state][label][edge],
                                            wfa->wfainfo->dc_rpf);
                            *lptr++ = 0;
                        }
                    }
                }
            }

    {
        unsigned	 i;
        unsigned	*c_symbols = Calloc (offset4, sizeof (int));
        const int	 scale 	   = 500;	/* scaling of probability model */

        c_symbols [0] = 1 << (wfa->wfainfo->dc_rpf->mantissa_bits + 1);
        if (offset1 != offset2)
            c_symbols [offset1] = 1 << (wfa->wfainfo->d_dc_rpf->mantissa_bits
                                        + 1);
        for (i = offset2; i < offset3; i++)
            c_symbols [i] = 1 << (wfa->wfainfo->rpf->mantissa_bits + 1);
        for (; i < offset4; i++)
            c_symbols [i] = 1 << (wfa->wfainfo->d_rpf->mantissa_bits + 1);
      
        encode_array (output, weights_array, level_array, c_symbols, offset4,
                      total, scale);
        Free (c_symbols);
    }
   
    debug_message ("%d delta weights out of %d.", delta_count, total);
    debug_message ("weights:      %5d bits. (%5d symbols => %5.2f bps)",
                   bits_processed (output) - bits, total,
                   (bits_processed (output) - bits) / (double) total);

    Free (weights_array);
    Free (level_array);
}