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Diffstat (limited to 'depends/patchlib/huffman.c')
| -rw-r--r-- | depends/patchlib/huffman.c | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/depends/patchlib/huffman.c b/depends/patchlib/huffman.c deleted file mode 100644 index 2283fdbc..00000000 --- a/depends/patchlib/huffman.c +++ /dev/null @@ -1,205 +0,0 @@ - -/*-------------------------------------------------------------*/ -/*--- Huffman coding low-level stuff ---*/ -/*--- huffman.c ---*/ -/*-------------------------------------------------------------*/ - -/* ------------------------------------------------------------------ - This file is part of bzip2/libbzip2, a program and library for - lossless, block-sorting data compression. - - bzip2/libbzip2 version 1.0.6 of 6 September 2010 - Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org> - - Please read the WARNING, DISCLAIMER and PATENTS sections in the - README file. - - This program is released under the terms of the license contained - in the file LICENSE. - ------------------------------------------------------------------ */ - - -#include "bzlib_private.h" - -/*---------------------------------------------------*/ -#define WEIGHTOF(zz0) ((zz0) & 0xffffff00) -#define DEPTHOF(zz1) ((zz1) & 0x000000ff) -#define MYMAX(zz2,zz3) ((zz2) > (zz3) ? (zz2) : (zz3)) - -#define ADDWEIGHTS(zw1,zw2) \ - (WEIGHTOF(zw1)+WEIGHTOF(zw2)) | \ - (1 + MYMAX(DEPTHOF(zw1),DEPTHOF(zw2))) - -#define UPHEAP(z) \ -{ \ - Int32 zz, tmp; \ - zz = z; tmp = heap[zz]; \ - while (weight[tmp] < weight[heap[zz >> 1]]) { \ - heap[zz] = heap[zz >> 1]; \ - zz >>= 1; \ - } \ - heap[zz] = tmp; \ -} - -#define DOWNHEAP(z) \ -{ \ - Int32 zz, yy, tmp; \ - zz = z; tmp = heap[zz]; \ - while (True) { \ - yy = zz << 1; \ - if (yy > nHeap) break; \ - if (yy < nHeap && \ - weight[heap[yy+1]] < weight[heap[yy]]) \ - yy++; \ - if (weight[tmp] < weight[heap[yy]]) break; \ - heap[zz] = heap[yy]; \ - zz = yy; \ - } \ - heap[zz] = tmp; \ -} - - -/*---------------------------------------------------*/ -void BZ2_hbMakeCodeLengths ( UChar *len, - Int32 *freq, - Int32 alphaSize, - Int32 maxLen ) -{ - /*-- - Nodes and heap entries run from 1. Entry 0 - for both the heap and nodes is a sentinel. - --*/ - Int32 nNodes, nHeap, n1, n2, i, j, k; - Bool tooLong; - - Int32 heap [ BZ_MAX_ALPHA_SIZE + 2 ]; - Int32 weight [ BZ_MAX_ALPHA_SIZE * 2 ]; - Int32 parent [ BZ_MAX_ALPHA_SIZE * 2 ]; - - for (i = 0; i < alphaSize; i++) - weight[i+1] = (freq[i] == 0 ? 1 : freq[i]) << 8; - - while (True) { - - nNodes = alphaSize; - nHeap = 0; - - heap[0] = 0; - weight[0] = 0; - parent[0] = -2; - - for (i = 1; i <= alphaSize; i++) { - parent[i] = -1; - nHeap++; - heap[nHeap] = i; - UPHEAP(nHeap); - } - - AssertH( nHeap < (BZ_MAX_ALPHA_SIZE+2), 2001 ); - - while (nHeap > 1) { - n1 = heap[1]; heap[1] = heap[nHeap]; nHeap--; DOWNHEAP(1); - n2 = heap[1]; heap[1] = heap[nHeap]; nHeap--; DOWNHEAP(1); - nNodes++; - parent[n1] = parent[n2] = nNodes; - weight[nNodes] = ADDWEIGHTS(weight[n1], weight[n2]); - parent[nNodes] = -1; - nHeap++; - heap[nHeap] = nNodes; - UPHEAP(nHeap); - } - - AssertH( nNodes < (BZ_MAX_ALPHA_SIZE * 2), 2002 ); - - tooLong = False; - for (i = 1; i <= alphaSize; i++) { - j = 0; - k = i; - while (parent[k] >= 0) { k = parent[k]; j++; } - len[i-1] = j; - if (j > maxLen) tooLong = True; - } - - if (! tooLong) break; - - /* 17 Oct 04: keep-going condition for the following loop used - to be 'i < alphaSize', which missed the last element, - theoretically leading to the possibility of the compressor - looping. However, this count-scaling step is only needed if - one of the generated Huffman code words is longer than - maxLen, which up to and including version 1.0.2 was 20 bits, - which is extremely unlikely. In version 1.0.3 maxLen was - changed to 17 bits, which has minimal effect on compression - ratio, but does mean this scaling step is used from time to - time, enough to verify that it works. - - This means that bzip2-1.0.3 and later will only produce - Huffman codes with a maximum length of 17 bits. However, in - order to preserve backwards compatibility with bitstreams - produced by versions pre-1.0.3, the decompressor must still - handle lengths of up to 20. */ - - for (i = 1; i <= alphaSize; i++) { - j = weight[i] >> 8; - j = 1 + (j / 2); - weight[i] = j << 8; - } - } -} - - -/*---------------------------------------------------*/ -void BZ2_hbAssignCodes ( Int32 *code, - UChar *length, - Int32 minLen, - Int32 maxLen, - Int32 alphaSize ) -{ - Int32 n, vec, i; - - vec = 0; - for (n = minLen; n <= maxLen; n++) { - for (i = 0; i < alphaSize; i++) - if (length[i] == n) { code[i] = vec; vec++; }; - vec <<= 1; - } -} - - -/*---------------------------------------------------*/ -void BZ2_hbCreateDecodeTables ( Int32 *limit, - Int32 *base, - Int32 *perm, - UChar *length, - Int32 minLen, - Int32 maxLen, - Int32 alphaSize ) -{ - Int32 pp, i, j, vec; - - pp = 0; - for (i = minLen; i <= maxLen; i++) - for (j = 0; j < alphaSize; j++) - if (length[j] == i) { perm[pp] = j; pp++; }; - - for (i = 0; i < BZ_MAX_CODE_LEN; i++) base[i] = 0; - for (i = 0; i < alphaSize; i++) base[length[i]+1]++; - - for (i = 1; i < BZ_MAX_CODE_LEN; i++) base[i] += base[i-1]; - - for (i = 0; i < BZ_MAX_CODE_LEN; i++) limit[i] = 0; - vec = 0; - - for (i = minLen; i <= maxLen; i++) { - vec += (base[i+1] - base[i]); - limit[i] = vec-1; - vec <<= 1; - } - for (i = minLen + 1; i <= maxLen; i++) - base[i] = ((limit[i-1] + 1) << 1) - base[i]; -} - - -/*-------------------------------------------------------------*/ -/*--- end huffman.c ---*/ -/*-------------------------------------------------------------*/ |