diff src/bzip2-1.0.6/huffman.c @ 89:8a15ff55d9af

Add bzip2, zlib, liblo, portaudio sources

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/bzip2-1.0.6/huffman.c	Wed Mar 20 13:59:52 2013 +0000
@@ -0,0 +1,205 @@
+
+/*-------------------------------------------------------------*/
+/*--- 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 <[e-mail]>
+
+   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 ---*/
+/*-------------------------------------------------------------*/