source: vendor/bzip2/1.0.4/compress.c

Last change on this file was 3318, checked in by bird, 18 years ago

bzip2 1.0.4
File size: 20.1 KB
RevLine 
[3318]1
2/*-------------------------------------------------------------*/
3/*--- Compression machinery (not incl block sorting) ---*/
4/*--- compress.c ---*/
5/*-------------------------------------------------------------*/
6
7/* ------------------------------------------------------------------
8 This file is part of bzip2/libbzip2, a program and library for
9 lossless, block-sorting data compression.
10
11 bzip2/libbzip2 version 1.0.4 of 20 December 2006
12 Copyright (C) 1996-2006 Julian Seward <jseward@bzip.org>
13
14 Please read the WARNING, DISCLAIMER and PATENTS sections in the
15 README file.
16
17 This program is released under the terms of the license contained
18 in the file LICENSE.
19 ------------------------------------------------------------------ */
20
21
22/* CHANGES
23 0.9.0 -- original version.
24 0.9.0a/b -- no changes in this file.
25 0.9.0c -- changed setting of nGroups in sendMTFValues()
26 so as to do a bit better on small files
27*/
28
29#include "bzlib_private.h"
30
31
32/*---------------------------------------------------*/
33/*--- Bit stream I/O ---*/
34/*---------------------------------------------------*/
35
36/*---------------------------------------------------*/
37void BZ2_bsInitWrite ( EState* s )
38{
39 s->bsLive = 0;
40 s->bsBuff = 0;
41}
42
43
44/*---------------------------------------------------*/
45static
46void bsFinishWrite ( EState* s )
47{
48 while (s->bsLive > 0) {
49 s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24);
50 s->numZ++;
51 s->bsBuff <<= 8;
52 s->bsLive -= 8;
53 }
54}
55
56
57/*---------------------------------------------------*/
58#define bsNEEDW(nz) \
59{ \
60 while (s->bsLive >= 8) { \
61 s->zbits[s->numZ] \
62 = (UChar)(s->bsBuff >> 24); \
63 s->numZ++; \
64 s->bsBuff <<= 8; \
65 s->bsLive -= 8; \
66 } \
67}
68
69
70/*---------------------------------------------------*/
71static
72__inline__
73void bsW ( EState* s, Int32 n, UInt32 v )
74{
75 bsNEEDW ( n );
76 s->bsBuff |= (v << (32 - s->bsLive - n));
77 s->bsLive += n;
78}
79
80
81/*---------------------------------------------------*/
82static
83void bsPutUInt32 ( EState* s, UInt32 u )
84{
85 bsW ( s, 8, (u >> 24) & 0xffL );
86 bsW ( s, 8, (u >> 16) & 0xffL );
87 bsW ( s, 8, (u >> 8) & 0xffL );
88 bsW ( s, 8, u & 0xffL );
89}
90
91
92/*---------------------------------------------------*/
93static
94void bsPutUChar ( EState* s, UChar c )
95{
96 bsW( s, 8, (UInt32)c );
97}
98
99
100/*---------------------------------------------------*/
101/*--- The back end proper ---*/
102/*---------------------------------------------------*/
103
104/*---------------------------------------------------*/
105static
106void makeMaps_e ( EState* s )
107{
108 Int32 i;
109 s->nInUse = 0;
110 for (i = 0; i < 256; i++)
111 if (s->inUse[i]) {
112 s->unseqToSeq[i] = s->nInUse;
113 s->nInUse++;
114 }
115}
116
117
118/*---------------------------------------------------*/
119static
120void generateMTFValues ( EState* s )
121{
122 UChar yy[256];
123 Int32 i, j;
124 Int32 zPend;
125 Int32 wr;
126 Int32 EOB;
127
128 /*
129 After sorting (eg, here),
130 s->arr1 [ 0 .. s->nblock-1 ] holds sorted order,
131 and
132 ((UChar*)s->arr2) [ 0 .. s->nblock-1 ]
133 holds the original block data.
134
135 The first thing to do is generate the MTF values,
136 and put them in
137 ((UInt16*)s->arr1) [ 0 .. s->nblock-1 ].
138 Because there are strictly fewer or equal MTF values
139 than block values, ptr values in this area are overwritten
140 with MTF values only when they are no longer needed.
141
142 The final compressed bitstream is generated into the
143 area starting at
144 (UChar*) (&((UChar*)s->arr2)[s->nblock])
145
146 These storage aliases are set up in bzCompressInit(),
147 except for the last one, which is arranged in
148 compressBlock().
149 */
150 UInt32* ptr = s->ptr;
151 UChar* block = s->block;
152 UInt16* mtfv = s->mtfv;
153
154 makeMaps_e ( s );
155 EOB = s->nInUse+1;
156
157 for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0;
158
159 wr = 0;
160 zPend = 0;
161 for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i;
162
163 for (i = 0; i < s->nblock; i++) {
164 UChar ll_i;
165 AssertD ( wr <= i, "generateMTFValues(1)" );
166 j = ptr[i]-1; if (j < 0) j += s->nblock;
167 ll_i = s->unseqToSeq[block[j]];
168 AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" );
169
170 if (yy[0] == ll_i) {
171 zPend++;
172 } else {
173
174 if (zPend > 0) {
175 zPend--;
176 while (True) {
177 if (zPend & 1) {
178 mtfv[wr] = BZ_RUNB; wr++;
179 s->mtfFreq[BZ_RUNB]++;
180 } else {
181 mtfv[wr] = BZ_RUNA; wr++;
182 s->mtfFreq[BZ_RUNA]++;
183 }
184 if (zPend < 2) break;
185 zPend = (zPend - 2) / 2;
186 };
187 zPend = 0;
188 }
189 {
190 register UChar rtmp;
191 register UChar* ryy_j;
192 register UChar rll_i;
193 rtmp = yy[1];
194 yy[1] = yy[0];
195 ryy_j = &(yy[1]);
196 rll_i = ll_i;
197 while ( rll_i != rtmp ) {
198 register UChar rtmp2;
199 ryy_j++;
200 rtmp2 = rtmp;
201 rtmp = *ryy_j;
202 *ryy_j = rtmp2;
203 };
204 yy[0] = rtmp;
205 j = ryy_j - &(yy[0]);
206 mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++;
207 }
208
209 }
210 }
211
212 if (zPend > 0) {
213 zPend--;
214 while (True) {
215 if (zPend & 1) {
216 mtfv[wr] = BZ_RUNB; wr++;
217 s->mtfFreq[BZ_RUNB]++;
218 } else {
219 mtfv[wr] = BZ_RUNA; wr++;
220 s->mtfFreq[BZ_RUNA]++;
221 }
222 if (zPend < 2) break;
223 zPend = (zPend - 2) / 2;
224 };
225 zPend = 0;
226 }
227
228 mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++;
229
230 s->nMTF = wr;
231}
232
233
234/*---------------------------------------------------*/
235#define BZ_LESSER_ICOST 0
236#define BZ_GREATER_ICOST 15
237
238static
239void sendMTFValues ( EState* s )
240{
241 Int32 v, t, i, j, gs, ge, totc, bt, bc, iter;
242 Int32 nSelectors, alphaSize, minLen, maxLen, selCtr;
243 Int32 nGroups, nBytes;
244
245 /*--
246 UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
247 is a global since the decoder also needs it.
248
249 Int32 code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
250 Int32 rfreq[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
251 are also globals only used in this proc.
252 Made global to keep stack frame size small.
253 --*/
254
255
256 UInt16 cost[BZ_N_GROUPS];
257 Int32 fave[BZ_N_GROUPS];
258
259 UInt16* mtfv = s->mtfv;
260
261 if (s->verbosity >= 3)
262 VPrintf3( " %d in block, %d after MTF & 1-2 coding, "
263 "%d+2 syms in use\n",
264 s->nblock, s->nMTF, s->nInUse );
265
266 alphaSize = s->nInUse+2;
267 for (t = 0; t < BZ_N_GROUPS; t++)
268 for (v = 0; v < alphaSize; v++)
269 s->len[t][v] = BZ_GREATER_ICOST;
270
271 /*--- Decide how many coding tables to use ---*/
272 AssertH ( s->nMTF > 0, 3001 );
273 if (s->nMTF < 200) nGroups = 2; else
274 if (s->nMTF < 600) nGroups = 3; else
275 if (s->nMTF < 1200) nGroups = 4; else
276 if (s->nMTF < 2400) nGroups = 5; else
277 nGroups = 6;
278
279 /*--- Generate an initial set of coding tables ---*/
280 {
281 Int32 nPart, remF, tFreq, aFreq;
282
283 nPart = nGroups;
284 remF = s->nMTF;
285 gs = 0;
286 while (nPart > 0) {
287 tFreq = remF / nPart;
288 ge = gs-1;
289 aFreq = 0;
290 while (aFreq < tFreq && ge < alphaSize-1) {
291 ge++;
292 aFreq += s->mtfFreq[ge];
293 }
294
295 if (ge > gs
296 && nPart != nGroups && nPart != 1
297 && ((nGroups-nPart) % 2 == 1)) {
298 aFreq -= s->mtfFreq[ge];
299 ge--;
300 }
301
302 if (s->verbosity >= 3)
303 VPrintf5( " initial group %d, [%d .. %d], "
304 "has %d syms (%4.1f%%)\n",
305 nPart, gs, ge, aFreq,
306 (100.0 * (float)aFreq) / (float)(s->nMTF) );
307
308 for (v = 0; v < alphaSize; v++)
309 if (v >= gs && v <= ge)
310 s->len[nPart-1][v] = BZ_LESSER_ICOST; else
311 s->len[nPart-1][v] = BZ_GREATER_ICOST;
312
313 nPart--;
314 gs = ge+1;
315 remF -= aFreq;
316 }
317 }
318
319 /*---
320 Iterate up to BZ_N_ITERS times to improve the tables.
321 ---*/
322 for (iter = 0; iter < BZ_N_ITERS; iter++) {
323
324 for (t = 0; t < nGroups; t++) fave[t] = 0;
325
326 for (t = 0; t < nGroups; t++)
327 for (v = 0; v < alphaSize; v++)
328 s->rfreq[t][v] = 0;
329
330 /*---
331 Set up an auxiliary length table which is used to fast-track
332 the common case (nGroups == 6).
333 ---*/
334 if (nGroups == 6) {
335 for (v = 0; v < alphaSize; v++) {
336 s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v];
337 s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v];
338 s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v];
339 }
340 }
341
342 nSelectors = 0;
343 totc = 0;
344 gs = 0;
345 while (True) {
346
347 /*--- Set group start & end marks. --*/
348 if (gs >= s->nMTF) break;
349 ge = gs + BZ_G_SIZE - 1;
350 if (ge >= s->nMTF) ge = s->nMTF-1;
351
352 /*--
353 Calculate the cost of this group as coded
354 by each of the coding tables.
355 --*/
356 for (t = 0; t < nGroups; t++) cost[t] = 0;
357
358 if (nGroups == 6 && 50 == ge-gs+1) {
359 /*--- fast track the common case ---*/
360 register UInt32 cost01, cost23, cost45;
361 register UInt16 icv;
362 cost01 = cost23 = cost45 = 0;
363
364# define BZ_ITER(nn) \
365 icv = mtfv[gs+(nn)]; \
366 cost01 += s->len_pack[icv][0]; \
367 cost23 += s->len_pack[icv][1]; \
368 cost45 += s->len_pack[icv][2]; \
369
370 BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4);
371 BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9);
372 BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14);
373 BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19);
374 BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24);
375 BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29);
376 BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34);
377 BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39);
378 BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44);
379 BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49);
380
381# undef BZ_ITER
382
383 cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16;
384 cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16;
385 cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16;
386
387 } else {
388 /*--- slow version which correctly handles all situations ---*/
389 for (i = gs; i <= ge; i++) {
390 UInt16 icv = mtfv[i];
391 for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv];
392 }
393 }
394
395 /*--
396 Find the coding table which is best for this group,
397 and record its identity in the selector table.
398 --*/
399 bc = 999999999; bt = -1;
400 for (t = 0; t < nGroups; t++)
401 if (cost[t] < bc) { bc = cost[t]; bt = t; };
402 totc += bc;
403 fave[bt]++;
404 s->selector[nSelectors] = bt;
405 nSelectors++;
406
407 /*--
408 Increment the symbol frequencies for the selected table.
409 --*/
410 if (nGroups == 6 && 50 == ge-gs+1) {
411 /*--- fast track the common case ---*/
412
413# define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++
414
415 BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4);
416 BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9);
417 BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14);
418 BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19);
419 BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24);
420 BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29);
421 BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34);
422 BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39);
423 BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44);
424 BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49);
425
426# undef BZ_ITUR
427
428 } else {
429 /*--- slow version which correctly handles all situations ---*/
430 for (i = gs; i <= ge; i++)
431 s->rfreq[bt][ mtfv[i] ]++;
432 }
433
434 gs = ge+1;
435 }
436 if (s->verbosity >= 3) {
437 VPrintf2 ( " pass %d: size is %d, grp uses are ",
438 iter+1, totc/8 );
439 for (t = 0; t < nGroups; t++)
440 VPrintf1 ( "%d ", fave[t] );
441 VPrintf0 ( "\n" );
442 }
443
444 /*--
445 Recompute the tables based on the accumulated frequencies.
446 --*/
447 /* maxLen was changed from 20 to 17 in bzip2-1.0.3. See
448 comment in huffman.c for details. */
449 for (t = 0; t < nGroups; t++)
450 BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]),
451 alphaSize, 17 /*20*/ );
452 }
453
454
455 AssertH( nGroups < 8, 3002 );
456 AssertH( nSelectors < 32768 &&
457 nSelectors <= (2 + (900000 / BZ_G_SIZE)),
458 3003 );
459
460
461 /*--- Compute MTF values for the selectors. ---*/
462 {
463 UChar pos[BZ_N_GROUPS], ll_i, tmp2, tmp;
464 for (i = 0; i < nGroups; i++) pos[i] = i;
465 for (i = 0; i < nSelectors; i++) {
466 ll_i = s->selector[i];
467 j = 0;
468 tmp = pos[j];
469 while ( ll_i != tmp ) {
470 j++;
471 tmp2 = tmp;
472 tmp = pos[j];
473 pos[j] = tmp2;
474 };
475 pos[0] = tmp;
476 s->selectorMtf[i] = j;
477 }
478 };
479
480 /*--- Assign actual codes for the tables. --*/
481 for (t = 0; t < nGroups; t++) {
482 minLen = 32;
483 maxLen = 0;
484 for (i = 0; i < alphaSize; i++) {
485 if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
486 if (s->len[t][i] < minLen) minLen = s->len[t][i];
487 }
488 AssertH ( !(maxLen > 17 /*20*/ ), 3004 );
489 AssertH ( !(minLen < 1), 3005 );
490 BZ2_hbAssignCodes ( &(s->code[t][0]), &(s->len[t][0]),
491 minLen, maxLen, alphaSize );
492 }
493
494 /*--- Transmit the mapping table. ---*/
495 {
496 Bool inUse16[16];
497 for (i = 0; i < 16; i++) {
498 inUse16[i] = False;
499 for (j = 0; j < 16; j++)
500 if (s->inUse[i * 16 + j]) inUse16[i] = True;
501 }
502
503 nBytes = s->numZ;
504 for (i = 0; i < 16; i++)
505 if (inUse16[i]) bsW(s,1,1); else bsW(s,1,0);
506
507 for (i = 0; i < 16; i++)
508 if (inUse16[i])
509 for (j = 0; j < 16; j++) {
510 if (s->inUse[i * 16 + j]) bsW(s,1,1); else bsW(s,1,0);
511 }
512
513 if (s->verbosity >= 3)
514 VPrintf1( " bytes: mapping %d, ", s->numZ-nBytes );
515 }
516
517 /*--- Now the selectors. ---*/
518 nBytes = s->numZ;
519 bsW ( s, 3, nGroups );
520 bsW ( s, 15, nSelectors );
521 for (i = 0; i < nSelectors; i++) {
522 for (j = 0; j < s->selectorMtf[i]; j++) bsW(s,1,1);
523 bsW(s,1,0);
524 }
525 if (s->verbosity >= 3)
526 VPrintf1( "selectors %d, ", s->numZ-nBytes );
527
528 /*--- Now the coding tables. ---*/
529 nBytes = s->numZ;
530
531 for (t = 0; t < nGroups; t++) {
532 Int32 curr = s->len[t][0];
533 bsW ( s, 5, curr );
534 for (i = 0; i < alphaSize; i++) {
535 while (curr < s->len[t][i]) { bsW(s,2,2); curr++; /* 10 */ };
536 while (curr > s->len[t][i]) { bsW(s,2,3); curr--; /* 11 */ };
537 bsW ( s, 1, 0 );
538 }
539 }
540
541 if (s->verbosity >= 3)
542 VPrintf1 ( "code lengths %d, ", s->numZ-nBytes );
543
544 /*--- And finally, the block data proper ---*/
545 nBytes = s->numZ;
546 selCtr = 0;
547 gs = 0;
548 while (True) {
549 if (gs >= s->nMTF) break;
550 ge = gs + BZ_G_SIZE - 1;
551 if (ge >= s->nMTF) ge = s->nMTF-1;
552 AssertH ( s->selector[selCtr] < nGroups, 3006 );
553
554 if (nGroups == 6 && 50 == ge-gs+1) {
555 /*--- fast track the common case ---*/
556 UInt16 mtfv_i;
557 UChar* s_len_sel_selCtr
558 = &(s->len[s->selector[selCtr]][0]);
559 Int32* s_code_sel_selCtr
560 = &(s->code[s->selector[selCtr]][0]);
561
562# define BZ_ITAH(nn) \
563 mtfv_i = mtfv[gs+(nn)]; \
564 bsW ( s, \
565 s_len_sel_selCtr[mtfv_i], \
566 s_code_sel_selCtr[mtfv_i] )
567
568 BZ_ITAH(0); BZ_ITAH(1); BZ_ITAH(2); BZ_ITAH(3); BZ_ITAH(4);
569 BZ_ITAH(5); BZ_ITAH(6); BZ_ITAH(7); BZ_ITAH(8); BZ_ITAH(9);
570 BZ_ITAH(10); BZ_ITAH(11); BZ_ITAH(12); BZ_ITAH(13); BZ_ITAH(14);
571 BZ_ITAH(15); BZ_ITAH(16); BZ_ITAH(17); BZ_ITAH(18); BZ_ITAH(19);
572 BZ_ITAH(20); BZ_ITAH(21); BZ_ITAH(22); BZ_ITAH(23); BZ_ITAH(24);
573 BZ_ITAH(25); BZ_ITAH(26); BZ_ITAH(27); BZ_ITAH(28); BZ_ITAH(29);
574 BZ_ITAH(30); BZ_ITAH(31); BZ_ITAH(32); BZ_ITAH(33); BZ_ITAH(34);
575 BZ_ITAH(35); BZ_ITAH(36); BZ_ITAH(37); BZ_ITAH(38); BZ_ITAH(39);
576 BZ_ITAH(40); BZ_ITAH(41); BZ_ITAH(42); BZ_ITAH(43); BZ_ITAH(44);
577 BZ_ITAH(45); BZ_ITAH(46); BZ_ITAH(47); BZ_ITAH(48); BZ_ITAH(49);
578
579# undef BZ_ITAH
580
581 } else {
582 /*--- slow version which correctly handles all situations ---*/
583 for (i = gs; i <= ge; i++) {
584 bsW ( s,
585 s->len [s->selector[selCtr]] [mtfv[i]],
586 s->code [s->selector[selCtr]] [mtfv[i]] );
587 }
588 }
589
590
591 gs = ge+1;
592 selCtr++;
593 }
594 AssertH( selCtr == nSelectors, 3007 );
595
596 if (s->verbosity >= 3)
597 VPrintf1( "codes %d\n", s->numZ-nBytes );
598}
599
600
601/*---------------------------------------------------*/
602void BZ2_compressBlock ( EState* s, Bool is_last_block )
603{
604 if (s->nblock > 0) {
605
606 BZ_FINALISE_CRC ( s->blockCRC );
607 s->combinedCRC = (s->combinedCRC << 1) | (s->combinedCRC >> 31);
608 s->combinedCRC ^= s->blockCRC;
609 if (s->blockNo > 1) s->numZ = 0;
610
611 if (s->verbosity >= 2)
612 VPrintf4( " block %d: crc = 0x%08x, "
613 "combined CRC = 0x%08x, size = %d\n",
614 s->blockNo, s->blockCRC, s->combinedCRC, s->nblock );
615
616 BZ2_blockSort ( s );
617 }
618
619 s->zbits = (UChar*) (&((UChar*)s->arr2)[s->nblock]);
620
621 /*-- If this is the first block, create the stream header. --*/
622 if (s->blockNo == 1) {
623 BZ2_bsInitWrite ( s );
624 bsPutUChar ( s, BZ_HDR_B );
625 bsPutUChar ( s, BZ_HDR_Z );
626 bsPutUChar ( s, BZ_HDR_h );
627 bsPutUChar ( s, (UChar)(BZ_HDR_0 + s->blockSize100k) );
628 }
629
630 if (s->nblock > 0) {
631
632 bsPutUChar ( s, 0x31 ); bsPutUChar ( s, 0x41 );
633 bsPutUChar ( s, 0x59 ); bsPutUChar ( s, 0x26 );
634 bsPutUChar ( s, 0x53 ); bsPutUChar ( s, 0x59 );
635
636 /*-- Now the block's CRC, so it is in a known place. --*/
637 bsPutUInt32 ( s, s->blockCRC );
638
639 /*--
640 Now a single bit indicating (non-)randomisation.
641 As of version 0.9.5, we use a better sorting algorithm
642 which makes randomisation unnecessary. So always set
643 the randomised bit to 'no'. Of course, the decoder
644 still needs to be able to handle randomised blocks
645 so as to maintain backwards compatibility with
646 older versions of bzip2.
647 --*/
648 bsW(s,1,0);
649
650 bsW ( s, 24, s->origPtr );
651 generateMTFValues ( s );
652 sendMTFValues ( s );
653 }
654
655
656 /*-- If this is the last block, add the stream trailer. --*/
657 if (is_last_block) {
658
659 bsPutUChar ( s, 0x17 ); bsPutUChar ( s, 0x72 );
660 bsPutUChar ( s, 0x45 ); bsPutUChar ( s, 0x38 );
661 bsPutUChar ( s, 0x50 ); bsPutUChar ( s, 0x90 );
662 bsPutUInt32 ( s, s->combinedCRC );
663 if (s->verbosity >= 2)
664 VPrintf1( " final combined CRC = 0x%08x\n ", s->combinedCRC );
665 bsFinishWrite ( s );
666 }
667}
668
669
670/*-------------------------------------------------------------*/
671/*--- end compress.c ---*/
672/*-------------------------------------------------------------*/
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