Repository navigation
Expand file tree
/
Copy pathHuffEnc.c
More file actions
361 lines (338 loc) · 9.53 KB
/
Copy pathHuffEnc.c
File metadata and controls
361 lines (338 loc) · 9.53 KB
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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
/* HuffEnc.c -- functions for Huffman encoding
Igor Pavlov : Public domain */
#include "Precomp.h"
#include <string.h>
#include "HuffEnc.h"
#include "Sort.h"
#include "CpuArch.h"
#define kMaxLen Z7_HUFFMAN_LEN_MAX
#define NUM_BITS 10
#define MASK ((1u << NUM_BITS) - 1)
#define FREQ_MASK (~(UInt32)MASK)
#define NUM_COUNTERS (104 * 2) // (80 * 2) or (128 * 2) : ((prime_number + 1) * 2) for smaller code.
#if 1 && (defined(MY_CPU_LE) || defined(MY_CPU_BE))
#if defined(MY_CPU_LE)
#define HI_HALF_OFFSET 1
#else
#define HI_HALF_OFFSET 0
#endif
#define LOAD_PARENT(p) ((unsigned)*((const UInt16 *)(p) + HI_HALF_OFFSET))
#define STORE_PARENT(p, fb, val) *((UInt16 *)(p) + HI_HALF_OFFSET) = (UInt16)(val);
#define STORE_PARENT_DIRECT(p, fb, hi) STORE_PARENT(p, fb, hi)
#define UPDATE_E(eHi) eHi++;
#else
#define LOAD_PARENT(p) ((unsigned)(*(p) >> NUM_BITS))
#define STORE_PARENT_DIRECT(p, fb, hi) *(p) = ((fb) & MASK) | (hi); // set parent field
#define STORE_PARENT(p, fb, val) STORE_PARENT_DIRECT(p, fb, ((UInt32)(val) << NUM_BITS))
#define UPDATE_E(eHi) eHi += 1 << NUM_BITS;
#endif
void Huffman_Generate(const UInt32 *freqs, UInt32 *p, Byte *lens, unsigned numSymbols, unsigned maxLen)
{
#if NUM_COUNTERS > 2
unsigned counters[NUM_COUNTERS];
#endif
#if 1 && NUM_COUNTERS > (kMaxLen + 4) * 2
#define lenCounters (counters)
#define codes (counters + kMaxLen + 4)
#else
unsigned lenCounters[kMaxLen + 1];
UInt32 codes[kMaxLen + 1];
#endif
unsigned num;
{
unsigned i;
// UInt32 sum = 0;
#if NUM_COUNTERS > 2
#define CTR_ITEM_FOR_FREQ(freq) \
counters[(freq) >= NUM_COUNTERS - 1 ? NUM_COUNTERS - 1 : (unsigned)(freq)]
for (i = 0; i < NUM_COUNTERS; i++)
counters[i] = 0;
memset(lens, 0, numSymbols);
{
const UInt32 *fp = freqs + numSymbols;
#define NUM_UNROLLS 1
#if NUM_UNROLLS > 1 // use 1 if odd (numSymbols) is possisble
if (numSymbols & 1)
{
UInt32 f;
f = *--fp; CTR_ITEM_FOR_FREQ(f)++;
// sum += f;
}
#endif
do
{
UInt32 f;
fp -= NUM_UNROLLS;
f = fp[0]; CTR_ITEM_FOR_FREQ(f)++;
// sum += f;
#if NUM_UNROLLS > 1
f = fp[1]; CTR_ITEM_FOR_FREQ(f)++;
// sum += f;
#endif
}
while (fp != freqs);
}
#if 0
printf("\nsum=%8u numSymbols =%3u ctrs:", sum, numSymbols);
{
unsigned k = 0;
for (k = 0; k < NUM_COUNTERS; k++)
printf(" %u", counters[k]);
}
#endif
num = counters[1];
counters[1] = 0;
for (i = 2; i != NUM_COUNTERS; i += 2)
{
const unsigned c0 = (counters )[i];
const unsigned c1 = (counters + 1)[i];
(counters )[i] = num; num += c0;
(counters + 1)[i] = num; num += c1;
}
counters[0] = num; // we want to write (freq==0) symbols to the end of (p) array
{
i = 0;
do
{
const UInt32 f = freqs[i];
#if 0
if (f == 0) lens[i] = 0; else
#endif
p[CTR_ITEM_FOR_FREQ(f)++] = i | (f << NUM_BITS);
}
while (++i != numSymbols);
}
HeapSort(p + counters[NUM_COUNTERS - 2], counters[NUM_COUNTERS - 1] - counters[NUM_COUNTERS - 2]);
#else // NUM_COUNTERS <= 2
num = 0;
for (i = 0; i < numSymbols; i++)
{
const UInt32 freq = freqs[i];
if (freq == 0)
lens[i] = 0;
else
p[num++] = i | (freq << NUM_BITS);
}
HeapSort(p, num);
#endif
}
if (num <= 2)
{
unsigned minCode = 0;
unsigned maxCode = 1;
if (num)
{
maxCode = (unsigned)p[(size_t)num - 1] & MASK;
if (num == 2)
{
minCode = (unsigned)p[0] & MASK;
if (minCode > maxCode)
{
const unsigned temp = minCode;
minCode = maxCode;
maxCode = temp;
}
}
else if (maxCode == 0)
maxCode++;
}
p[minCode] = 0;
p[maxCode] = 1;
lens[minCode] = lens[maxCode] = 1;
return;
}
{
unsigned i;
for (i = 0; i <= kMaxLen; i++)
lenCounters[i] = 0;
lenCounters[1] = 2; // by default root node has 2 child leaves at level 1.
}
// if (num != 2)
{
// num > 2
// the binary tree will contain (num - 1) internal nodes.
// p[num - 2] will be root node of binary tree.
UInt32 *b;
UInt32 *n;
// first node will have two leaf childs: p[0] and p[1]:
// p[0] += p[1] & FREQ_MASK; // set frequency sum of child leafs
// if (pi == n) exit(0);
// if (pi != n)
{
UInt32 fb = (p[1] & FREQ_MASK) + p[0];
UInt32 f = p[2] & FREQ_MASK;
const UInt32 *pi = p + 2;
UInt32 *e = p;
UInt32 eHi = 0;
n = p + num;
b = p;
// p[0] = fb;
for (;;)
{
// (b <= e)
UInt32 sum;
e++;
UPDATE_E(eHi)
// (b < e)
// p range : high bits
// [0, b) : parent : processed nodes that have parent and childs
// [b, e) : FREQ : non-processed nodes that have no parent but have childs
// [e, pi) : FREQ : processed leaves for which parent node was created
// [pi, n) : FREQ : non-processed leaves for which parent node was not created
// first child
// note : (*b < f) is same result as ((*b & FREQ_MASK) < f)
if (fb < f)
{
// node freq is smaller
sum = fb & FREQ_MASK;
STORE_PARENT_DIRECT (b, fb, eHi)
b++;
fb = *b;
if (b == e)
{
if (++pi == n)
break;
sum += f;
fb &= MASK;
fb |= sum;
*e = fb;
f = *pi & FREQ_MASK;
continue;
}
}
else if (++pi == n)
{
STORE_PARENT_DIRECT (b, fb, eHi)
b++;
break;
}
else
{
sum = f;
f = *pi & FREQ_MASK;
}
// (b < e)
// second child
if (fb < f)
{
sum += fb;
sum &= FREQ_MASK;
STORE_PARENT_DIRECT (b, fb, eHi)
b++;
*e = (*e & MASK) | sum; // set frequency sum
// (b <= e) is possible here
fb = *b;
}
else if (++pi == n)
break;
else
{
sum += f;
f = *pi & FREQ_MASK;
*e = (*e & MASK) | sum; // set frequency sum
}
}
}
// printf("\nnum-e=%3u, numSymbols=%3u, num=%3u, b=%3u", n - e, numSymbols, n - p, b - p);
{
n -= 2;
*n &= MASK; // root node : we clear high bits (zero bits mean level == 0)
if (n != b)
{
// We go here, if we have some number of non-created nodes up to root.
// We process them in simplified code:
// position of parent for each pair of nodes is known.
// n[-2], n[-1] : current pair of child nodes
// (p1) : parent node for current pair.
UInt32 *p1 = n;
do
{
const unsigned len = LOAD_PARENT(p1) + 1;
p1--;
(lenCounters )[len] -= 2; // we remove 2 leaves from level (len)
(lenCounters + 1)[len] += 2 * 2; // we add 4 leaves at level (len + 1)
n -= 2;
STORE_PARENT (n , n[0], len)
STORE_PARENT (n + 1, n[1], len)
}
while (n != b);
}
}
if (b != p)
{
// we detect level of each node (realtive to root),
// and update lenCounters[].
// We process only intermediate nodes and we don't process leaves.
do
{
// if (ii < b) : parent_bits_of (p[ii]) == index of parent node : ii < (p[ii])
// if (ii >= b) : parent_bits_of (p[ii]) == level of this (ii) node in tree
unsigned len;
b--;
len = (unsigned)LOAD_PARENT(p + LOAD_PARENT(b)) + 1;
STORE_PARENT (b, *b, len)
if (len >= maxLen)
{
// We are not allowed to create node at level (maxLen) and higher,
// because all leaves must be placed to level (maxLen) or lower.
// We find nearest allowed leaf and place current node to level of that leaf:
for (len = maxLen - 1; lenCounters[len] == 0; len--) {}
}
lenCounters[len]--; // we remove 1 leaf from level (len)
(lenCounters + 1)[len] += 2; // we add 2 leaves at level (len + 1)
}
while (b != p);
}
}
{
{
unsigned len = maxLen;
const UInt32 *p2 = p;
do
{
unsigned k = lenCounters[len];
if (k)
do
lens[(unsigned)*p2++ & MASK] = (Byte)len;
while (--k);
}
while (--len);
}
codes[0] = 0; // we don't want garbage values to be written to p[] array.
// codes[1] = 0;
{
UInt32 code = 0;
unsigned len;
for (len = 0; len < kMaxLen; len++)
(codes + 1)[len] = code = (code + lenCounters[len]) << 1;
}
/* if (code + lenCounters[kMaxLen] - 1 != (1 << kMaxLen) - 1) throw 1; */
{
const Byte * const limit = lens + numSymbols;
do
{
unsigned len;
UInt32 c;
len = lens[0]; c = codes[len]; p[0] = c; codes[len] = c + 1;
// len = lens[1]; c = codes[len]; p[1] = c; codes[len] = c + 1;
p += 1;
lens += 1;
}
while (lens != limit);
}
}
}
#undef kMaxLen
#undef NUM_BITS
#undef MASK
#undef FREQ_MASK
#undef NUM_COUNTERS
#undef CTR_ITEM_FOR_FREQ
#undef LOAD_PARENT
#undef STORE_PARENT
#undef STORE_PARENT_DIRECT
#undef UPDATE_E
#undef HI_HALF_OFFSET
#undef NUM_UNROLLS
#undef lenCounters
#undef codes