/*-------------------------------------------------------------*//*--- Compression machinery (not incl block sorting) ---*//*--- compress.c ---*//*-------------------------------------------------------------*/ /*-- This file is a part of bzip2 and/or libbzip2, a program and library for lossless, block-sorting data compression. Copyright (C) 1996-2000 Julian R Seward. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 3. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 4. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Julian Seward, Cambridge, UK. jseward@acm.org bzip2/libbzip2 version 1.0 of 21 March 2000 This program is based on (at least) the work of: Mike Burrows David Wheeler Peter Fenwick Alistair Moffat Radford Neal Ian H. Witten Robert Sedgewick Jon L. Bentley For more information on these sources, see the manual.--*/ /*-- CHANGES ~~~~~~~ 0.9.0 -- original version. 0.9.0a/b -- no changes in this file. 0.9.0c * changed setting of nGroups in sendMTFValues() so as to do a bit better on small files--*/ #include "os.h"#include "bzlib.h"#include "bzlib_private.h" /*---------------------------------------------------*//*--- Bit stream I/O ---*//*---------------------------------------------------*/ /*---------------------------------------------------*/void BZ2_bsInitWrite ( EState* s ){ s->bsLive = 0; s->bsBuff = 0;} /*---------------------------------------------------*/staticvoid bsFinishWrite ( EState* s ){ while (s->bsLive > 0) { s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24); s->numZ++; s->bsBuff <<= 8; s->bsLive -= 8; }} /*---------------------------------------------------*/#define bsNEEDW(nz) \{ \ while (s->bsLive >= 8) { \ s->zbits[s->numZ] \ = (UChar)(s->bsBuff >> 24); \ s->numZ++; \ s->bsBuff <<= 8; \ s->bsLive -= 8; \ } \} /*---------------------------------------------------*/static__inline__void bsW ( EState* s, Int32 n, UInt32 v ){ bsNEEDW ( n ); s->bsBuff |= (v << (32 - s->bsLive - n)); s->bsLive += n;} /*---------------------------------------------------*/staticvoid bsPutUInt32 ( EState* s, UInt32 u ){ bsW ( s, 8, (u >> 24) & 0xffL ); bsW ( s, 8, (u >> 16) & 0xffL ); bsW ( s, 8, (u >> 8) & 0xffL ); bsW ( s, 8, u & 0xffL );} /*---------------------------------------------------*/staticvoid bsPutUChar ( EState* s, UChar c ){ bsW( s, 8, (UInt32)c );} /*---------------------------------------------------*//*--- The back end proper ---*//*---------------------------------------------------*/ /*---------------------------------------------------*/staticvoid makeMaps_e ( EState* s ){ Int32 i; s->nInUse = 0; for (i = 0; i < 256; i++) if (s->inUse[i]) { s->unseqToSeq[i] = s->nInUse; s->nInUse++; }} /*---------------------------------------------------*/staticvoid generateMTFValues ( EState* s ){ UChar yy[256]; Int32 i, j; Int32 zPend; Int32 wr; Int32 EOB; /* After sorting (eg, here), s->arr1 [ 0 .. s->nblock-1 ] holds sorted order, and ((UChar*)s->arr2) [ 0 .. s->nblock-1 ] holds the original block data. The first thing to do is generate the MTF values, and put them in ((UInt16*)s->arr1) [ 0 .. s->nblock-1 ]. Because there are strictly fewer or equal MTF values than block values, ptr values in this area are overwritten with MTF values only when they are no longer needed. The final compressed bitstream is generated into the area starting at (UChar*) (&((UChar*)s->arr2)[s->nblock]) These storage aliases are set up in bzCompressInit(), except for the last one, which is arranged in compressBlock(). */ UInt32* ptr = s->ptr; UChar* block = s->block; UInt16* mtfv = s->mtfv; makeMaps_e ( s ); EOB = s->nInUse+1; for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0; wr = 0; zPend = 0; for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i; for (i = 0; i < s->nblock; i++) { UChar ll_i; AssertD ( wr <= i, "generateMTFValues(1)" ); j = ptr[i]-1; if (j < 0) j += s->nblock; ll_i = s->unseqToSeq[block[j]]; AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" ); if (yy[0] == ll_i) { zPend++; } else { if (zPend > 0) { zPend--; while (True) { if (zPend & 1) { mtfv[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; } else { mtfv[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; zPend = (zPend - 2) / 2; }; zPend = 0; } { register UChar rtmp; register UChar* ryy_j; register UChar rll_i; rtmp = yy[1]; yy[1] = yy[0]; ryy_j = &(yy[1]); rll_i = ll_i; while ( rll_i != rtmp ) { register UChar rtmp2; ryy_j++; rtmp2 = rtmp; rtmp = *ryy_j; *ryy_j = rtmp2; }; yy[0] = rtmp; j = ryy_j - &(yy[0]); mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++; } } } if (zPend > 0) { zPend--; while (True) { if (zPend & 1) { mtfv[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; } else { mtfv[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; zPend = (zPend - 2) / 2; };//rsc: not used zPend = 0; } mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++; s->nMTF = wr;} /*---------------------------------------------------*/#define BZ_LESSER_ICOST 0#define BZ_GREATER_ICOST 15 staticvoid sendMTFValues ( EState* s ){ Int32 v, t, i, j, gs, ge, totc, bt, bc, iter; Int32 nSelectors, alphaSize, minLen, maxLen, selCtr; Int32 nGroups, nBytes; /*-- UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; is a global since the decoder also needs it. Int32 code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; Int32 rfreq[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; are also globals only used in this proc. Made global to keep stack frame size small. --*/ UInt16 cost[BZ_N_GROUPS]; Int32 fave[BZ_N_GROUPS]; UInt16* mtfv = s->mtfv; if (s->verbosity >= 3) VPrintf3( " %d in block, %d after MTF & 1-2 coding, " "%d+2 syms in use\n", s->nblock, s->nMTF, s->nInUse ); alphaSize = s->nInUse+2; for (t = 0; t < BZ_N_GROUPS; t++) for (v = 0; v < alphaSize; v++) s->len[t][v] = BZ_GREATER_ICOST; /*--- Decide how many coding tables to use ---*/ AssertH ( s->nMTF > 0, 3001 ); if (s->nMTF < 200) nGroups = 2; else if (s->nMTF < 600) nGroups = 3; else if (s->nMTF < 1200) nGroups = 4; else if (s->nMTF < 2400) nGroups = 5; else nGroups = 6; /*--- Generate an initial set of coding tables ---*/ { Int32 nPart, remF, tFreq, aFreq; nPart = nGroups; remF = s->nMTF; gs = 0; while (nPart > 0) { tFreq = remF / nPart; ge = gs-1; aFreq = 0; while (aFreq < tFreq && ge < alphaSize-1) { ge++; aFreq += s->mtfFreq[ge]; } if (ge > gs && nPart != nGroups && nPart != 1 && ((nGroups-nPart) % 2 == 1)) { aFreq -= s->mtfFreq[ge]; ge--; } if (s->verbosity >= 3) VPrintf5( " initial group %d, [%d .. %d], " "has %d syms (%4.1f%%)\n", nPart, gs, ge, aFreq, (100.0 * (float)aFreq) / (float)(s->nMTF) ); for (v = 0; v < alphaSize; v++) if (v >= gs && v <= ge) s->len[nPart-1][v] = BZ_LESSER_ICOST; else s->len[nPart-1][v] = BZ_GREATER_ICOST; nPart--; gs = ge+1; remF -= aFreq; } } /*--- Iterate up to BZ_N_ITERS times to improve the tables. ---*/ nSelectors = 40000; /* shut up some compilers' warnings about used and not set */ for (iter = 0; iter < BZ_N_ITERS; iter++) { for (t = 0; t < nGroups; t++) fave[t] = 0; for (t = 0; t < nGroups; t++) for (v = 0; v < alphaSize; v++) s->rfreq[t][v] = 0; /*--- Set up an auxiliary length table which is used to fast-track the common case (nGroups == 6). ---*/ if (nGroups == 6) { for (v = 0; v < alphaSize; v++) { s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v]; s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v]; s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v]; } } nSelectors = 0; totc = 0; gs = 0; while (True) { /*--- Set group start & end marks. --*/ if (gs >= s->nMTF) break; ge = gs + BZ_G_SIZE - 1; if (ge >= s->nMTF) ge = s->nMTF-1; /*-- Calculate the cost of this group as coded by each of the coding tables. --*/ for (t = 0; t < nGroups; t++) cost[t] = 0; if (nGroups == 6 && 50 == ge-gs+1) { /*--- fast track the common case ---*/ register UInt32 cost01, cost23, cost45; register UInt16 icv; cost01 = cost23 = cost45 = 0; # define BZ_ITER(nn) \ icv = mtfv[gs+(nn)]; \ cost01 += s->len_pack[icv][0]; \ cost23 += s->len_pack[icv][1]; \ cost45 += s->len_pack[icv][2]; \ BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4); BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9); BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14); BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19); BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24); BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29); BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34); BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39); BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44); BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49); # undef BZ_ITER cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16; cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16; cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16; } else { /*--- slow version which correctly handles all situations ---*/ for (i = gs; i <= ge; i++) { UInt16 icv = mtfv[i]; for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv]; } } /*-- Find the coding table which is best for this group, and record its identity in the selector table. --*/ bc = 999999999; bt = -1; for (t = 0; t < nGroups; t++) if (cost[t] < bc) { bc = cost[t]; bt = t; }; totc += bc; fave[bt]++; s->selector[nSelectors] = bt; nSelectors++; /*-- Increment the symbol frequencies for the selected table. --*/ if (nGroups == 6 && 50 == ge-gs+1) { /*--- fast track the common case ---*/ # define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++ BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4); BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9); BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14); BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19); BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24); BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29); BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34); BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39); BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44); BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49); # undef BZ_ITUR } else { /*--- slow version which correctly handles all situations ---*/ for (i = gs; i <= ge; i++) s->rfreq[bt][ mtfv[i] ]++; } gs = ge+1; } if (s->verbosity >= 3) { VPrintf2 ( " pass %d: size is %d, grp uses are ", iter+1, totc/8 ); for (t = 0; t < nGroups; t++) VPrintf1 ( "%d ", fave[t] ); VPrintf0 ( "\n" ); } /*-- Recompute the tables based on the accumulated frequencies. --*/ for (t = 0; t < nGroups; t++) BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]), alphaSize, 20 ); } Lines 1–500 of 718. Load more
/*-------------------------------------------------------------*/ /*--- Compression machinery (not incl block sorting) ---*/ /*--- compress.c ---*/ /*-------------------------------------------------------------*/ /*-- This file is a part of bzip2 and/or libbzip2, a program and library for lossless, block-sorting data compression. Copyright (C) 1996-2000 Julian R Seward. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 3. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 4. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Julian Seward, Cambridge, UK. jseward@acm.org bzip2/libbzip2 version 1.0 of 21 March 2000 This program is based on (at least) the work of: Mike Burrows David Wheeler Peter Fenwick Alistair Moffat Radford Neal Ian H. Witten Robert Sedgewick Jon L. Bentley For more information on these sources, see the manual. --*/ /*-- CHANGES ~~~~~~~ 0.9.0 -- original version. 0.9.0a/b -- no changes in this file. 0.9.0c * changed setting of nGroups in sendMTFValues() so as to do a bit better on small files --*/ #include "os.h" #include "bzlib.h" #include "bzlib_private.h" /*---------------------------------------------------*/ /*--- Bit stream I/O ---*/ /*---------------------------------------------------*/ /*---------------------------------------------------*/ void BZ2_bsInitWrite ( EState* s ) { s->bsLive = 0; s->bsBuff = 0; } /*---------------------------------------------------*/ static void bsFinishWrite ( EState* s ) { while (s->bsLive > 0) { s->zbits[s->numZ] = (UChar)(s->bsBuff >> 24); s->numZ++; s->bsBuff <<= 8; s->bsLive -= 8; } } /*---------------------------------------------------*/ #define bsNEEDW(nz) \ { \ while (s->bsLive >= 8) { \ s->zbits[s->numZ] \ = (UChar)(s->bsBuff >> 24); \ s->numZ++; \ s->bsBuff <<= 8; \ s->bsLive -= 8; \ } \ } /*---------------------------------------------------*/ static __inline__ void bsW ( EState* s, Int32 n, UInt32 v ) { bsNEEDW ( n ); s->bsBuff |= (v << (32 - s->bsLive - n)); s->bsLive += n; } /*---------------------------------------------------*/ static void bsPutUInt32 ( EState* s, UInt32 u ) { bsW ( s, 8, (u >> 24) & 0xffL ); bsW ( s, 8, (u >> 16) & 0xffL ); bsW ( s, 8, (u >> 8) & 0xffL ); bsW ( s, 8, u & 0xffL ); } /*---------------------------------------------------*/ static void bsPutUChar ( EState* s, UChar c ) { bsW( s, 8, (UInt32)c ); } /*---------------------------------------------------*/ /*--- The back end proper ---*/ /*---------------------------------------------------*/ /*---------------------------------------------------*/ static void makeMaps_e ( EState* s ) { Int32 i; s->nInUse = 0; for (i = 0; i < 256; i++) if (s->inUse[i]) { s->unseqToSeq[i] = s->nInUse; s->nInUse++; } } /*---------------------------------------------------*/ static void generateMTFValues ( EState* s ) { UChar yy[256]; Int32 i, j; Int32 zPend; Int32 wr; Int32 EOB; /* After sorting (eg, here), s->arr1 [ 0 .. s->nblock-1 ] holds sorted order, and ((UChar*)s->arr2) [ 0 .. s->nblock-1 ] holds the original block data. The first thing to do is generate the MTF values, and put them in ((UInt16*)s->arr1) [ 0 .. s->nblock-1 ]. Because there are strictly fewer or equal MTF values than block values, ptr values in this area are overwritten with MTF values only when they are no longer needed. The final compressed bitstream is generated into the area starting at (UChar*) (&((UChar*)s->arr2)[s->nblock]) These storage aliases are set up in bzCompressInit(), except for the last one, which is arranged in compressBlock(). */ UInt32* ptr = s->ptr; UChar* block = s->block; UInt16* mtfv = s->mtfv; makeMaps_e ( s ); EOB = s->nInUse+1; for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0; wr = 0; zPend = 0; for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i; for (i = 0; i < s->nblock; i++) { UChar ll_i; AssertD ( wr <= i, "generateMTFValues(1)" ); j = ptr[i]-1; if (j < 0) j += s->nblock; ll_i = s->unseqToSeq[block[j]]; AssertD ( ll_i < s->nInUse, "generateMTFValues(2a)" ); if (yy[0] == ll_i) { zPend++; } else { if (zPend > 0) { zPend--; while (True) { if (zPend & 1) { mtfv[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; } else { mtfv[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; zPend = (zPend - 2) / 2; }; zPend = 0; } { register UChar rtmp; register UChar* ryy_j; register UChar rll_i; rtmp = yy[1]; yy[1] = yy[0]; ryy_j = &(yy[1]); rll_i = ll_i; while ( rll_i != rtmp ) { register UChar rtmp2; ryy_j++; rtmp2 = rtmp; rtmp = *ryy_j; *ryy_j = rtmp2; }; yy[0] = rtmp; j = ryy_j - &(yy[0]); mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++; } } } if (zPend > 0) { zPend--; while (True) { if (zPend & 1) { mtfv[wr] = BZ_RUNB; wr++; s->mtfFreq[BZ_RUNB]++; } else { mtfv[wr] = BZ_RUNA; wr++; s->mtfFreq[BZ_RUNA]++; } if (zPend < 2) break; zPend = (zPend - 2) / 2; }; //rsc: not used zPend = 0; } mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++; s->nMTF = wr; } /*---------------------------------------------------*/ #define BZ_LESSER_ICOST 0 #define BZ_GREATER_ICOST 15 static void sendMTFValues ( EState* s ) { Int32 v, t, i, j, gs, ge, totc, bt, bc, iter; Int32 nSelectors, alphaSize, minLen, maxLen, selCtr; Int32 nGroups, nBytes; /*-- UChar len [BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; is a global since the decoder also needs it. Int32 code[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; Int32 rfreq[BZ_N_GROUPS][BZ_MAX_ALPHA_SIZE]; are also globals only used in this proc. Made global to keep stack frame size small. --*/ UInt16 cost[BZ_N_GROUPS]; Int32 fave[BZ_N_GROUPS]; UInt16* mtfv = s->mtfv; if (s->verbosity >= 3) VPrintf3( " %d in block, %d after MTF & 1-2 coding, " "%d+2 syms in use\n", s->nblock, s->nMTF, s->nInUse ); alphaSize = s->nInUse+2; for (t = 0; t < BZ_N_GROUPS; t++) for (v = 0; v < alphaSize; v++) s->len[t][v] = BZ_GREATER_ICOST; /*--- Decide how many coding tables to use ---*/ AssertH ( s->nMTF > 0, 3001 ); if (s->nMTF < 200) nGroups = 2; else if (s->nMTF < 600) nGroups = 3; else if (s->nMTF < 1200) nGroups = 4; else if (s->nMTF < 2400) nGroups = 5; else nGroups = 6; /*--- Generate an initial set of coding tables ---*/ { Int32 nPart, remF, tFreq, aFreq; nPart = nGroups; remF = s->nMTF; gs = 0; while (nPart > 0) { tFreq = remF / nPart; ge = gs-1; aFreq = 0; while (aFreq < tFreq && ge < alphaSize-1) { ge++; aFreq += s->mtfFreq[ge]; } if (ge > gs && nPart != nGroups && nPart != 1 && ((nGroups-nPart) % 2 == 1)) { aFreq -= s->mtfFreq[ge]; ge--; } if (s->verbosity >= 3) VPrintf5( " initial group %d, [%d .. %d], " "has %d syms (%4.1f%%)\n", nPart, gs, ge, aFreq, (100.0 * (float)aFreq) / (float)(s->nMTF) ); for (v = 0; v < alphaSize; v++) if (v >= gs && v <= ge) s->len[nPart-1][v] = BZ_LESSER_ICOST; else s->len[nPart-1][v] = BZ_GREATER_ICOST; nPart--; gs = ge+1; remF -= aFreq; } } /*--- Iterate up to BZ_N_ITERS times to improve the tables. ---*/ nSelectors = 40000; /* shut up some compilers' warnings about used and not set */ for (iter = 0; iter < BZ_N_ITERS; iter++) { for (t = 0; t < nGroups; t++) fave[t] = 0; for (t = 0; t < nGroups; t++) for (v = 0; v < alphaSize; v++) s->rfreq[t][v] = 0; /*--- Set up an auxiliary length table which is used to fast-track the common case (nGroups == 6). ---*/ if (nGroups == 6) { for (v = 0; v < alphaSize; v++) { s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v]; s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v]; s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v]; } } nSelectors = 0; totc = 0; gs = 0; while (True) { /*--- Set group start & end marks. --*/ if (gs >= s->nMTF) break; ge = gs + BZ_G_SIZE - 1; if (ge >= s->nMTF) ge = s->nMTF-1; /*-- Calculate the cost of this group as coded by each of the coding tables. --*/ for (t = 0; t < nGroups; t++) cost[t] = 0; if (nGroups == 6 && 50 == ge-gs+1) { /*--- fast track the common case ---*/ register UInt32 cost01, cost23, cost45; register UInt16 icv; cost01 = cost23 = cost45 = 0; # define BZ_ITER(nn) \ icv = mtfv[gs+(nn)]; \ cost01 += s->len_pack[icv][0]; \ cost23 += s->len_pack[icv][1]; \ cost45 += s->len_pack[icv][2]; \ BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4); BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9); BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14); BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19); BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24); BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29); BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34); BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39); BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44); BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49); # undef BZ_ITER cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16; cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16; cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16; } else { /*--- slow version which correctly handles all situations ---*/ for (i = gs; i <= ge; i++) { UInt16 icv = mtfv[i]; for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv]; } } /*-- Find the coding table which is best for this group, and record its identity in the selector table. --*/ bc = 999999999; bt = -1; for (t = 0; t < nGroups; t++) if (cost[t] < bc) { bc = cost[t]; bt = t; }; totc += bc; fave[bt]++; s->selector[nSelectors] = bt; nSelectors++; /*-- Increment the symbol frequencies for the selected table. --*/ if (nGroups == 6 && 50 == ge-gs+1) { /*--- fast track the common case ---*/ # define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++ BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4); BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9); BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14); BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19); BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24); BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29); BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34); BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39); BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44); BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49); # undef BZ_ITUR } else { /*--- slow version which correctly handles all situations ---*/ for (i = gs; i <= ge; i++) s->rfreq[bt][ mtfv[i] ]++; } gs = ge+1; } if (s->verbosity >= 3) { VPrintf2 ( " pass %d: size is %d, grp uses are ", iter+1, totc/8 ); for (t = 0; t < nGroups; t++) VPrintf1 ( "%d ", fave[t] ); VPrintf0 ( "\n" ); } /*-- Recompute the tables based on the accumulated frequencies. --*/ for (t = 0; t < nGroups; t++) BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]), alphaSize, 20 ); }