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 1.0.6 of 6 September 2010
12 Copyright (C) 1996-2010 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 <sys/ccompile.h>
30 #include "bzlib_private.h"
31
32
33 /*---------------------------------------------------*/
34 /*--- Bit stream I/O ---*/
35 /*---------------------------------------------------*/
36
37 /*---------------------------------------------------*/
BZ2_bsInitWrite(EState * s)38 void BZ2_bsInitWrite ( EState* s )
39 {
40 s->bsLive = 0;
41 s->bsBuff = 0;
42 }
43
44
45 /*---------------------------------------------------*/
46 static
bsFinishWrite(EState * s)47 void bsFinishWrite ( EState* s )
48 {
49 while (s->bsLive > 0) {
50 s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24);
51 s->numZ++;
52 s->bsBuff <<= 8;
53 s->bsLive -= 8;
54 }
55 }
56
57
58 /*---------------------------------------------------*/
59 #define bsNEEDW(nz) \
60 { \
61 while (s->bsLive >= 8) { \
62 s->zbits[s->numZ] \
63 = (UChar)(s->bsBuff >> 24); \
64 s->numZ++; \
65 s->bsBuff <<= 8; \
66 s->bsLive -= 8; \
67 } \
68 }
69
70
71 /*---------------------------------------------------*/
72 static
73 __inline__
bsW(EState * s,Int32 n,UInt32 v)74 void bsW ( EState* s, Int32 n, UInt32 v )
75 {
76 bsNEEDW ( n );
77 s->bsBuff |= (v << (32 - s->bsLive - n));
78 s->bsLive += n;
79 }
80
81
82 /*---------------------------------------------------*/
83 static
bsPutUInt32(EState * s,UInt32 u)84 void bsPutUInt32 ( EState* s, UInt32 u )
85 {
86 bsW ( s, 8, (u >> 24) & 0xffL );
87 bsW ( s, 8, (u >> 16) & 0xffL );
88 bsW ( s, 8, (u >> 8) & 0xffL );
89 bsW ( s, 8, u & 0xffL );
90 }
91
92
93 /*---------------------------------------------------*/
94 static
bsPutUChar(EState * s,UChar c)95 void bsPutUChar ( EState* s, UChar c )
96 {
97 bsW( s, 8, (UInt32)c );
98 }
99
100
101 /*---------------------------------------------------*/
102 /*--- The back end proper ---*/
103 /*---------------------------------------------------*/
104
105 /*---------------------------------------------------*/
106 static
makeMaps_e(EState * s)107 void makeMaps_e ( EState* s )
108 {
109 Int32 i;
110 s->nInUse = 0;
111 for (i = 0; i < 256; i++)
112 if (s->inUse[i]) {
113 s->unseqToSeq[i] = s->nInUse;
114 s->nInUse++;
115 }
116 }
117
118
119 /*---------------------------------------------------*/
120 static
generateMTFValues(EState * s)121 void generateMTFValues ( EState* s )
122 {
123 UChar yy[256];
124 Int32 i, j;
125 Int32 zPend;
126 Int32 wr;
127 Int32 EOB;
128
129 /*
130 After sorting (eg, here),
131 s->arr1 [ 0 .. s->nblock-1 ] holds sorted order,
132 and
133 ((UChar*)s->arr2) [ 0 .. s->nblock-1 ]
134 holds the original block data.
135
136 The first thing to do is generate the MTF values,
137 and put them in
138 ((UInt16*)s->arr1) [ 0 .. s->nblock-1 ].
139 Because there are strictly fewer or equal MTF values
140 than block values, ptr values in this area are overwritten
141 with MTF values only when they are no longer needed.
142
143 The final compressed bitstream is generated into the
144 area starting at
145 (UChar*) (&((UChar*)s->arr2)[s->nblock])
146
147 These storage aliases are set up in bzCompressInit(),
148 except for the last one, which is arranged in
149 compressBlock().
150 */
151 UInt32* ptr = s->ptr;
152 UChar* block = s->block;
153 UInt16* mtfv = s->mtfv;
154
155 makeMaps_e ( s );
156 EOB = s->nInUse+1;
157
158 for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0;
159
160 wr = 0;
161 zPend = 0;
162 for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i;
163
164 for (i = 0; i < s->nblock; i++) {
165 UChar ll_i;
166 AssertD ( wr <= i, "generateMTFValues(1)" );
167 j = ptr[i]-1; if (j < 0) j += s->nblock;
168 ll_i = s->unseqToSeq[block[j]];
169 AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" );
170
171 if (yy[0] == ll_i) {
172 zPend++;
173 } else {
174
175 if (zPend > 0) {
176 zPend--;
177 while (True) {
178 if (zPend & 1) {
179 mtfv[wr] = BZ_RUNB; wr++;
180 s->mtfFreq[BZ_RUNB]++;
181 } else {
182 mtfv[wr] = BZ_RUNA; wr++;
183 s->mtfFreq[BZ_RUNA]++;
184 }
185 if (zPend < 2) break;
186 zPend = (zPend - 2) / 2;
187 };
188 zPend = 0;
189 }
190 {
191 register UChar rtmp;
192 register UChar* ryy_j;
193 register UChar rll_i;
194 rtmp = yy[1];
195 yy[1] = yy[0];
196 ryy_j = &(yy[1]);
197 rll_i = ll_i;
198 while ( rll_i != rtmp ) {
199 register UChar rtmp2;
200 ryy_j++;
201 rtmp2 = rtmp;
202 rtmp = *ryy_j;
203 *ryy_j = rtmp2;
204 };
205 yy[0] = rtmp;
206 j = ryy_j - &(yy[0]);
207 mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++;
208 }
209
210 }
211 }
212
213 if (zPend > 0) {
214 zPend--;
215 while (True) {
216 if (zPend & 1) {
217 mtfv[wr] = BZ_RUNB; wr++;
218 s->mtfFreq[BZ_RUNB]++;
219 } else {
220 mtfv[wr] = BZ_RUNA; wr++;
221 s->mtfFreq[BZ_RUNA]++;
222 }
223 if (zPend < 2) break;
224 zPend = (zPend - 2) / 2;
225 };
226 zPend = 0;
227 }
228
229 mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++;
230
231 s->nMTF = wr;
232 }
233
234
235 /*---------------------------------------------------*/
236 #define BZ_LESSER_ICOST 0
237 #define BZ_GREATER_ICOST 15
238
239 static
sendMTFValues(EState * s)240 void sendMTFValues ( EState* s )
241 {
242 Int32 v, t, i, j, gs, ge, totc, bt, bc, iter;
243 Int32 nSelectors, alphaSize, minLen, maxLen, selCtr;
244 Int32 nGroups, nBytes __unused;
245
246 /*--
247 UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
248 is a global since the decoder also needs it.
249
250 Int32 code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
251 Int32 rfreq[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE];
252 are also globals only used in this proc.
253 Made global to keep stack frame size small.
254 --*/
255
256
257 UInt16 cost[BZ_N_GROUPS];
258 Int32 fave[BZ_N_GROUPS];
259
260 UInt16* mtfv = s->mtfv;
261
262 if (s->verbosity >= 3)
263 VPrintf3( " %d in block, %d after MTF & 1-2 coding, "
264 "%d+2 syms in use\n",
265 s->nblock, s->nMTF, s->nInUse );
266
267 alphaSize = s->nInUse+2;
268 for (t = 0; t < BZ_N_GROUPS; t++)
269 for (v = 0; v < alphaSize; v++)
270 s->len[t][v] = BZ_GREATER_ICOST;
271
272 /*--- Decide how many coding tables to use ---*/
273 AssertH ( s->nMTF > 0, 3001 );
274 if (s->nMTF < 200) nGroups = 2; else
275 if (s->nMTF < 600) nGroups = 3; else
276 if (s->nMTF < 1200) nGroups = 4; else
277 if (s->nMTF < 2400) nGroups = 5; else
278 nGroups = 6;
279
280 /*--- Generate an initial set of coding tables ---*/
281 {
282 Int32 nPart, remF, tFreq, aFreq;
283
284 nPart = nGroups;
285 remF = s->nMTF;
286 gs = 0;
287 while (nPart > 0) {
288 tFreq = remF / nPart;
289 ge = gs-1;
290 aFreq = 0;
291 while (aFreq < tFreq && ge < alphaSize-1) {
292 ge++;
293 aFreq += s->mtfFreq[ge];
294 }
295
296 if (ge > gs
297 && nPart != nGroups && nPart != 1
298 && ((nGroups-nPart) % 2 == 1)) {
299 aFreq -= s->mtfFreq[ge];
300 ge--;
301 }
302
303 if (s->verbosity >= 3)
304 VPrintf5( " initial group %d, [%d .. %d], "
305 "has %d syms (%4.1f%%)\n",
306 nPart, gs, ge, aFreq,
307 (100.0 * (float)aFreq) / (float)(s->nMTF) );
308
309 for (v = 0; v < alphaSize; v++)
310 if (v >= gs && v <= ge)
311 s->len[nPart-1][v] = BZ_LESSER_ICOST; else
312 s->len[nPart-1][v] = BZ_GREATER_ICOST;
313
314 nPart--;
315 gs = ge+1;
316 remF -= aFreq;
317 }
318 }
319
320 /*---
321 Iterate up to BZ_N_ITERS times to improve the tables.
322 ---*/
323 for (iter = 0; iter < BZ_N_ITERS; iter++) {
324
325 for (t = 0; t < nGroups; t++) fave[t] = 0;
326
327 for (t = 0; t < nGroups; t++)
328 for (v = 0; v < alphaSize; v++)
329 s->rfreq[t][v] = 0;
330
331 /*---
332 Set up an auxiliary length table which is used to fast-track
333 the common case (nGroups == 6).
334 ---*/
335 if (nGroups == 6) {
336 for (v = 0; v < alphaSize; v++) {
337 s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v];
338 s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v];
339 s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v];
340 }
341 }
342
343 nSelectors = 0;
344 totc = 0;
345 gs = 0;
346 while (True) {
347
348 /*--- Set group start & end marks. --*/
349 if (gs >= s->nMTF) break;
350 ge = gs + BZ_G_SIZE - 1;
351 if (ge >= s->nMTF) ge = s->nMTF-1;
352
353 /*--
354 Calculate the cost of this group as coded
355 by each of the coding tables.
356 --*/
357 for (t = 0; t < nGroups; t++) cost[t] = 0;
358
359 if (nGroups == 6 && 50 == ge-gs+1) {
360 /*--- fast track the common case ---*/
361 register UInt32 cost01, cost23, cost45;
362 register UInt16 icv;
363 cost01 = cost23 = cost45 = 0;
364
365 # define BZ_ITER(nn) \
366 icv = mtfv[gs+(nn)]; \
367 cost01 += s->len_pack[icv][0]; \
368 cost23 += s->len_pack[icv][1]; \
369 cost45 += s->len_pack[icv][2]; \
370
371 BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4);
372 BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9);
373 BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14);
374 BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19);
375 BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24);
376 BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29);
377 BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34);
378 BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39);
379 BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44);
380 BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49);
381
382 # undef BZ_ITER
383
384 cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16;
385 cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16;
386 cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16;
387
388 } else {
389 /*--- slow version which correctly handles all situations ---*/
390 for (i = gs; i <= ge; i++) {
391 UInt16 icv = mtfv[i];
392 for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv];
393 }
394 }
395
396 /*--
397 Find the coding table which is best for this group,
398 and record its identity in the selector table.
399 --*/
400 bc = 999999999; bt = -1;
401 for (t = 0; t < nGroups; t++)
402 if (cost[t] < bc) { bc = cost[t]; bt = t; };
403 totc += bc;
404 fave[bt]++;
405 s->selector[nSelectors] = bt;
406 nSelectors++;
407
408 /*--
409 Increment the symbol frequencies for the selected table.
410 --*/
411 if (nGroups == 6 && 50 == ge-gs+1) {
412 /*--- fast track the common case ---*/
413
414 # define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++
415
416 BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4);
417 BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9);
418 BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14);
419 BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19);
420 BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24);
421 BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29);
422 BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34);
423 BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39);
424 BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44);
425 BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49);
426
427 # undef BZ_ITUR
428
429 } else {
430 /*--- slow version which correctly handles all situations ---*/
431 for (i = gs; i <= ge; i++)
432 s->rfreq[bt][ mtfv[i] ]++;
433 }
434
435 gs = ge+1;
436 }
437 if (s->verbosity >= 3) {
438 VPrintf2 ( " pass %d: size is %d, grp uses are ",
439 iter+1, totc/8 );
440 for (t = 0; t < nGroups; t++)
441 VPrintf1 ( "%d ", fave[t] );
442 VPrintf0 ( "\n" );
443 }
444
445 /*--
446 Recompute the tables based on the accumulated frequencies.
447 --*/
448 /* maxLen was changed from 20 to 17 in bzip2-1.0.3. See
449 comment in huffman.c for details. */
450 for (t = 0; t < nGroups; t++)
451 BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]),
452 alphaSize, 17 /*20*/ );
453 }
454
455
456 AssertH( nGroups < 8, 3002 );
457 AssertH( nSelectors < 32768 &&
458 nSelectors <= (2 + (900000 / BZ_G_SIZE)),
459 3003 );
460
461
462 /*--- Compute MTF values for the selectors. ---*/
463 {
464 UChar pos[BZ_N_GROUPS], ll_i, tmp2, tmp;
465 for (i = 0; i < nGroups; i++) pos[i] = i;
466 for (i = 0; i < nSelectors; i++) {
467 ll_i = s->selector[i];
468 j = 0;
469 tmp = pos[j];
470 while ( ll_i != tmp ) {
471 j++;
472 tmp2 = tmp;
473 tmp = pos[j];
474 pos[j] = tmp2;
475 };
476 pos[0] = tmp;
477 s->selectorMtf[i] = j;
478 }
479 };
480
481 /*--- Assign actual codes for the tables. --*/
482 for (t = 0; t < nGroups; t++) {
483 minLen = 32;
484 maxLen = 0;
485 for (i = 0; i < alphaSize; i++) {
486 if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
487 if (s->len[t][i] < minLen) minLen = s->len[t][i];
488 }
489 AssertH ( !(maxLen > 17 /*20*/ ), 3004 );
490 AssertH ( !(minLen < 1), 3005 );
491 BZ2_hbAssignCodes ( &(s->code[t][0]), &(s->len[t][0]),
492 minLen, maxLen, alphaSize );
493 }
494
495 /*--- Transmit the mapping table. ---*/
496 {
497 Bool inUse16[16];
498 for (i = 0; i < 16; i++) {
499 inUse16[i] = False;
500 for (j = 0; j < 16; j++)
501 if (s->inUse[i * 16 + j]) inUse16[i] = True;
502 }
503
504 nBytes = s->numZ;
505 for (i = 0; i < 16; i++)
506 if (inUse16[i]) bsW(s,1,1); else bsW(s,1,0);
507
508 for (i = 0; i < 16; i++)
509 if (inUse16[i])
510 for (j = 0; j < 16; j++) {
511 if (s->inUse[i * 16 + j]) bsW(s,1,1); else bsW(s,1,0);
512 }
513
514 if (s->verbosity >= 3)
515 VPrintf1( " bytes: mapping %d, ", s->numZ-nBytes );
516 }
517
518 /*--- Now the selectors. ---*/
519 nBytes = s->numZ;
520 bsW ( s, 3, nGroups );
521 bsW ( s, 15, nSelectors );
522 for (i = 0; i < nSelectors; i++) {
523 for (j = 0; j < s->selectorMtf[i]; j++) bsW(s,1,1);
524 bsW(s,1,0);
525 }
526 if (s->verbosity >= 3)
527 VPrintf1( "selectors %d, ", s->numZ-nBytes );
528
529 /*--- Now the coding tables. ---*/
530 nBytes = s->numZ;
531
532 for (t = 0; t < nGroups; t++) {
533 Int32 curr = s->len[t][0];
534 bsW ( s, 5, curr );
535 for (i = 0; i < alphaSize; i++) {
536 while (curr < s->len[t][i]) { bsW(s,2,2); curr++; /* 10 */ };
537 while (curr > s->len[t][i]) { bsW(s,2,3); curr--; /* 11 */ };
538 bsW ( s, 1, 0 );
539 }
540 }
541
542 if (s->verbosity >= 3)
543 VPrintf1 ( "code lengths %d, ", s->numZ-nBytes );
544
545 /*--- And finally, the block data proper ---*/
546 nBytes = s->numZ;
547 selCtr = 0;
548 gs = 0;
549 while (True) {
550 if (gs >= s->nMTF) break;
551 ge = gs + BZ_G_SIZE - 1;
552 if (ge >= s->nMTF) ge = s->nMTF-1;
553 AssertH ( s->selector[selCtr] < nGroups, 3006 );
554
555 if (nGroups == 6 && 50 == ge-gs+1) {
556 /*--- fast track the common case ---*/
557 UInt16 mtfv_i;
558 UChar* s_len_sel_selCtr
559 = &(s->len[s->selector[selCtr]][0]);
560 Int32* s_code_sel_selCtr
561 = &(s->code[s->selector[selCtr]][0]);
562
563 # define BZ_ITAH(nn) \
564 mtfv_i = mtfv[gs+(nn)]; \
565 bsW ( s, \
566 s_len_sel_selCtr[mtfv_i], \
567 s_code_sel_selCtr[mtfv_i] )
568
569 BZ_ITAH(0); BZ_ITAH(1); BZ_ITAH(2); BZ_ITAH(3); BZ_ITAH(4);
570 BZ_ITAH(5); BZ_ITAH(6); BZ_ITAH(7); BZ_ITAH(8); BZ_ITAH(9);
571 BZ_ITAH(10); BZ_ITAH(11); BZ_ITAH(12); BZ_ITAH(13); BZ_ITAH(14);
572 BZ_ITAH(15); BZ_ITAH(16); BZ_ITAH(17); BZ_ITAH(18); BZ_ITAH(19);
573 BZ_ITAH(20); BZ_ITAH(21); BZ_ITAH(22); BZ_ITAH(23); BZ_ITAH(24);
574 BZ_ITAH(25); BZ_ITAH(26); BZ_ITAH(27); BZ_ITAH(28); BZ_ITAH(29);
575 BZ_ITAH(30); BZ_ITAH(31); BZ_ITAH(32); BZ_ITAH(33); BZ_ITAH(34);
576 BZ_ITAH(35); BZ_ITAH(36); BZ_ITAH(37); BZ_ITAH(38); BZ_ITAH(39);
577 BZ_ITAH(40); BZ_ITAH(41); BZ_ITAH(42); BZ_ITAH(43); BZ_ITAH(44);
578 BZ_ITAH(45); BZ_ITAH(46); BZ_ITAH(47); BZ_ITAH(48); BZ_ITAH(49);
579
580 # undef BZ_ITAH
581
582 } else {
583 /*--- slow version which correctly handles all situations ---*/
584 for (i = gs; i <= ge; i++) {
585 bsW ( s,
586 s->len [s->selector[selCtr]] [mtfv[i]],
587 s->code [s->selector[selCtr]] [mtfv[i]] );
588 }
589 }
590
591
592 gs = ge+1;
593 selCtr++;
594 }
595 AssertH( selCtr == nSelectors, 3007 );
596
597 if (s->verbosity >= 3)
598 VPrintf1( "codes %d\n", s->numZ-nBytes );
599 }
600
601
602 /*---------------------------------------------------*/
BZ2_compressBlock(EState * s,Bool is_last_block)603 void BZ2_compressBlock ( EState* s, Bool is_last_block )
604 {
605 if (s->nblock > 0) {
606
607 BZ_FINALISE_CRC ( s->blockCRC );
608 s->combinedCRC = (s->combinedCRC << 1) | (s->combinedCRC >> 31);
609 s->combinedCRC ^= s->blockCRC;
610 if (s->blockNo > 1) s->numZ = 0;
611
612 if (s->verbosity >= 2)
613 VPrintf4( " block %d: crc = 0x%08x, "
614 "combined CRC = 0x%08x, size = %d\n",
615 s->blockNo, s->blockCRC, s->combinedCRC, s->nblock );
616
617 BZ2_blockSort ( s );
618 }
619
620 s->zbits = (UChar*) (&((UChar*)s->arr2)[s->nblock]);
621
622 /*-- If this is the first block, create the stream header. --*/
623 if (s->blockNo == 1) {
624 BZ2_bsInitWrite ( s );
625 bsPutUChar ( s, BZ_HDR_B );
626 bsPutUChar ( s, BZ_HDR_Z );
627 bsPutUChar ( s, BZ_HDR_h );
628 bsPutUChar ( s, (UChar)(BZ_HDR_0 + s->blockSize100k) );
629 }
630
631 if (s->nblock > 0) {
632
633 bsPutUChar ( s, 0x31 ); bsPutUChar ( s, 0x41 );
634 bsPutUChar ( s, 0x59 ); bsPutUChar ( s, 0x26 );
635 bsPutUChar ( s, 0x53 ); bsPutUChar ( s, 0x59 );
636
637 /*-- Now the block's CRC, so it is in a known place. --*/
638 bsPutUInt32 ( s, s->blockCRC );
639
640 /*--
641 Now a single bit indicating (non-)randomisation.
642 As of version 0.9.5, we use a better sorting algorithm
643 which makes randomisation unnecessary. So always set
644 the randomised bit to 'no'. Of course, the decoder
645 still needs to be able to handle randomised blocks
646 so as to maintain backwards compatibility with
647 older versions of bzip2.
648 --*/
649 bsW(s,1,0);
650
651 bsW ( s, 24, s->origPtr );
652 generateMTFValues ( s );
653 sendMTFValues ( s );
654 }
655
656
657 /*-- If this is the last block, add the stream trailer. --*/
658 if (is_last_block) {
659
660 bsPutUChar ( s, 0x17 ); bsPutUChar ( s, 0x72 );
661 bsPutUChar ( s, 0x45 ); bsPutUChar ( s, 0x38 );
662 bsPutUChar ( s, 0x50 ); bsPutUChar ( s, 0x90 );
663 bsPutUInt32 ( s, s->combinedCRC );
664 if (s->verbosity >= 2)
665 VPrintf1( " final combined CRC = 0x%08x\n ", s->combinedCRC );
666 bsFinishWrite ( s );
667 }
668 }
669
670
671 /*-------------------------------------------------------------*/
672 /*--- end compress.c ---*/
673 /*-------------------------------------------------------------*/
674