From 08446c16acbbb9a9d12fccb21e27cfa29d076e77 Mon Sep 17 00:00:00 2001 From: Tim Angus Date: Sat, 10 Dec 2005 02:56:06 +0000 Subject: * Branch upstream ioq3-r437 into trunk --- ioq3-r437/src/qcommon/huffman.c | 437 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 437 insertions(+) create mode 100644 ioq3-r437/src/qcommon/huffman.c (limited to 'ioq3-r437/src/qcommon/huffman.c') diff --git a/ioq3-r437/src/qcommon/huffman.c b/ioq3-r437/src/qcommon/huffman.c new file mode 100644 index 00000000..b230b5be --- /dev/null +++ b/ioq3-r437/src/qcommon/huffman.c @@ -0,0 +1,437 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. + +This file is part of Quake III Arena source code. + +Quake III Arena source code is free software; you can redistribute it +and/or modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of the License, +or (at your option) any later version. + +Quake III Arena source code is distributed in the hope that it will be +useful, but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Quake III Arena source code; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +=========================================================================== +*/ + +/* This is based on the Adaptive Huffman algorithm described in Sayood's Data + * Compression book. The ranks are not actually stored, but implicitly defined + * by the location of a node within a doubly-linked list */ + +#include "q_shared.h" +#include "qcommon.h" + +static int bloc = 0; + +void Huff_putBit( int bit, byte *fout, int *offset) { + bloc = *offset; + if ((bloc&7) == 0) { + fout[(bloc>>3)] = 0; + } + fout[(bloc>>3)] |= bit << (bloc&7); + bloc++; + *offset = bloc; +} + +int Huff_getBit( byte *fin, int *offset) { + int t; + bloc = *offset; + t = (fin[(bloc>>3)] >> (bloc&7)) & 0x1; + bloc++; + *offset = bloc; + return t; +} + +/* Add a bit to the output file (buffered) */ +static void add_bit (char bit, byte *fout) { + if ((bloc&7) == 0) { + fout[(bloc>>3)] = 0; + } + fout[(bloc>>3)] |= bit << (bloc&7); + bloc++; +} + +/* Receive one bit from the input file (buffered) */ +static int get_bit (byte *fin) { + int t; + t = (fin[(bloc>>3)] >> (bloc&7)) & 0x1; + bloc++; + return t; +} + +static node_t **get_ppnode(huff_t* huff) { + node_t **tppnode; + if (!huff->freelist) { + return &(huff->nodePtrs[huff->blocPtrs++]); + } else { + tppnode = huff->freelist; + huff->freelist = (node_t **)*tppnode; + return tppnode; + } +} + +static void free_ppnode(huff_t* huff, node_t **ppnode) { + *ppnode = (node_t *)huff->freelist; + huff->freelist = ppnode; +} + +/* Swap the location of these two nodes in the tree */ +static void swap (huff_t* huff, node_t *node1, node_t *node2) { + node_t *par1, *par2; + + par1 = node1->parent; + par2 = node2->parent; + + if (par1) { + if (par1->left == node1) { + par1->left = node2; + } else { + par1->right = node2; + } + } else { + huff->tree = node2; + } + + if (par2) { + if (par2->left == node2) { + par2->left = node1; + } else { + par2->right = node1; + } + } else { + huff->tree = node1; + } + + node1->parent = par2; + node2->parent = par1; +} + +/* Swap these two nodes in the linked list (update ranks) */ +static void swaplist(node_t *node1, node_t *node2) { + node_t *par1; + + par1 = node1->next; + node1->next = node2->next; + node2->next = par1; + + par1 = node1->prev; + node1->prev = node2->prev; + node2->prev = par1; + + if (node1->next == node1) { + node1->next = node2; + } + if (node2->next == node2) { + node2->next = node1; + } + if (node1->next) { + node1->next->prev = node1; + } + if (node2->next) { + node2->next->prev = node2; + } + if (node1->prev) { + node1->prev->next = node1; + } + if (node2->prev) { + node2->prev->next = node2; + } +} + +/* Do the increments */ +static void increment(huff_t* huff, node_t *node) { + node_t *lnode; + + if (!node) { + return; + } + + if (node->next != NULL && node->next->weight == node->weight) { + lnode = *node->head; + if (lnode != node->parent) { + swap(huff, lnode, node); + } + swaplist(lnode, node); + } + if (node->prev && node->prev->weight == node->weight) { + *node->head = node->prev; + } else { + *node->head = NULL; + free_ppnode(huff, node->head); + } + node->weight++; + if (node->next && node->next->weight == node->weight) { + node->head = node->next->head; + } else { + node->head = get_ppnode(huff); + *node->head = node; + } + if (node->parent) { + increment(huff, node->parent); + if (node->prev == node->parent) { + swaplist(node, node->parent); + if (*node->head == node) { + *node->head = node->parent; + } + } + } +} + +void Huff_addRef(huff_t* huff, byte ch) { + node_t *tnode, *tnode2; + if (huff->loc[ch] == NULL) { /* if this is the first transmission of this node */ + tnode = &(huff->nodeList[huff->blocNode++]); + tnode2 = &(huff->nodeList[huff->blocNode++]); + + tnode2->symbol = INTERNAL_NODE; + tnode2->weight = 1; + tnode2->next = huff->lhead->next; + if (huff->lhead->next) { + huff->lhead->next->prev = tnode2; + if (huff->lhead->next->weight == 1) { + tnode2->head = huff->lhead->next->head; + } else { + tnode2->head = get_ppnode(huff); + *tnode2->head = tnode2; + } + } else { + tnode2->head = get_ppnode(huff); + *tnode2->head = tnode2; + } + huff->lhead->next = tnode2; + tnode2->prev = huff->lhead; + + tnode->symbol = ch; + tnode->weight = 1; + tnode->next = huff->lhead->next; + if (huff->lhead->next) { + huff->lhead->next->prev = tnode; + if (huff->lhead->next->weight == 1) { + tnode->head = huff->lhead->next->head; + } else { + /* this should never happen */ + tnode->head = get_ppnode(huff); + *tnode->head = tnode2; + } + } else { + /* this should never happen */ + tnode->head = get_ppnode(huff); + *tnode->head = tnode; + } + huff->lhead->next = tnode; + tnode->prev = huff->lhead; + tnode->left = tnode->right = NULL; + + if (huff->lhead->parent) { + if (huff->lhead->parent->left == huff->lhead) { /* lhead is guaranteed to by the NYT */ + huff->lhead->parent->left = tnode2; + } else { + huff->lhead->parent->right = tnode2; + } + } else { + huff->tree = tnode2; + } + + tnode2->right = tnode; + tnode2->left = huff->lhead; + + tnode2->parent = huff->lhead->parent; + huff->lhead->parent = tnode->parent = tnode2; + + huff->loc[ch] = tnode; + + increment(huff, tnode2->parent); + } else { + increment(huff, huff->loc[ch]); + } +} + +/* Get a symbol */ +int Huff_Receive (node_t *node, int *ch, byte *fin) { + while (node && node->symbol == INTERNAL_NODE) { + if (get_bit(fin)) { + node = node->right; + } else { + node = node->left; + } + } + if (!node) { + return 0; +// Com_Error(ERR_DROP, "Illegal tree!\n"); + } + return (*ch = node->symbol); +} + +/* Get a symbol */ +void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset) { + bloc = *offset; + while (node && node->symbol == INTERNAL_NODE) { + if (get_bit(fin)) { + node = node->right; + } else { + node = node->left; + } + } + if (!node) { + *ch = 0; + return; +// Com_Error(ERR_DROP, "Illegal tree!\n"); + } + *ch = node->symbol; + *offset = bloc; +} + +/* Send the prefix code for this node */ +static void send(node_t *node, node_t *child, byte *fout) { + if (node->parent) { + send(node->parent, node, fout); + } + if (child) { + if (node->right == child) { + add_bit(1, fout); + } else { + add_bit(0, fout); + } + } +} + +/* Send a symbol */ +void Huff_transmit (huff_t *huff, int ch, byte *fout) { + int i; + if (huff->loc[ch] == NULL) { + /* node_t hasn't been transmitted, send a NYT, then the symbol */ + Huff_transmit(huff, NYT, fout); + for (i = 7; i >= 0; i--) { + add_bit((char)((ch >> i) & 0x1), fout); + } + } else { + send(huff->loc[ch], NULL, fout); + } +} + +void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset) { + bloc = *offset; + send(huff->loc[ch], NULL, fout); + *offset = bloc; +} + +void Huff_Decompress(msg_t *mbuf, int offset) { + int ch, cch, i, j, size; + byte seq[65536]; + byte* buffer; + huff_t huff; + + size = mbuf->cursize - offset; + buffer = mbuf->data + offset; + + if ( size <= 0 ) { + return; + } + + Com_Memset(&huff, 0, sizeof(huff_t)); + // Initialize the tree & list with the NYT node + huff.tree = huff.lhead = huff.ltail = huff.loc[NYT] = &(huff.nodeList[huff.blocNode++]); + huff.tree->symbol = NYT; + huff.tree->weight = 0; + huff.lhead->next = huff.lhead->prev = NULL; + huff.tree->parent = huff.tree->left = huff.tree->right = NULL; + + cch = buffer[0]*256 + buffer[1]; + // don't overflow with bad messages + if ( cch > mbuf->maxsize - offset ) { + cch = mbuf->maxsize - offset; + } + bloc = 16; + + for ( j = 0; j < cch; j++ ) { + ch = 0; + // don't overflow reading from the messages + // FIXME: would it be better to have a overflow check in get_bit ? + if ( (bloc >> 3) > size ) { + seq[j] = 0; + break; + } + Huff_Receive(huff.tree, &ch, buffer); /* Get a character */ + if ( ch == NYT ) { /* We got a NYT, get the symbol associated with it */ + ch = 0; + for ( i = 0; i < 8; i++ ) { + ch = (ch<<1) + get_bit(buffer); + } + } + + seq[j] = ch; /* Write symbol */ + + Huff_addRef(&huff, (byte)ch); /* Increment node */ + } + mbuf->cursize = cch + offset; + Com_Memcpy(mbuf->data + offset, seq, cch); +} + +extern int oldsize; + +void Huff_Compress(msg_t *mbuf, int offset) { + int i, ch, size; + byte seq[65536]; + byte* buffer; + huff_t huff; + + size = mbuf->cursize - offset; + buffer = mbuf->data+ + offset; + + if (size<=0) { + return; + } + + Com_Memset(&huff, 0, sizeof(huff_t)); + // Add the NYT (not yet transmitted) node into the tree/list */ + huff.tree = huff.lhead = huff.loc[NYT] = &(huff.nodeList[huff.blocNode++]); + huff.tree->symbol = NYT; + huff.tree->weight = 0; + huff.lhead->next = huff.lhead->prev = NULL; + huff.tree->parent = huff.tree->left = huff.tree->right = NULL; + huff.loc[NYT] = huff.tree; + + seq[0] = (size>>8); + seq[1] = size&0xff; + + bloc = 16; + + for (i=0; icursize = (bloc>>3) + offset; + Com_Memcpy(mbuf->data+offset, seq, (bloc>>3)); +} + +void Huff_Init(huffman_t *huff) { + + Com_Memset(&huff->compressor, 0, sizeof(huff_t)); + Com_Memset(&huff->decompressor, 0, sizeof(huff_t)); + + // Initialize the tree & list with the NYT node + huff->decompressor.tree = huff->decompressor.lhead = huff->decompressor.ltail = huff->decompressor.loc[NYT] = &(huff->decompressor.nodeList[huff->decompressor.blocNode++]); + huff->decompressor.tree->symbol = NYT; + huff->decompressor.tree->weight = 0; + huff->decompressor.lhead->next = huff->decompressor.lhead->prev = NULL; + huff->decompressor.tree->parent = huff->decompressor.tree->left = huff->decompressor.tree->right = NULL; + + // Add the NYT (not yet transmitted) node into the tree/list */ + huff->compressor.tree = huff->compressor.lhead = huff->compressor.loc[NYT] = &(huff->compressor.nodeList[huff->compressor.blocNode++]); + huff->compressor.tree->symbol = NYT; + huff->compressor.tree->weight = 0; + huff->compressor.lhead->next = huff->compressor.lhead->prev = NULL; + huff->compressor.tree->parent = huff->compressor.tree->left = huff->compressor.tree->right = NULL; + huff->compressor.loc[NYT] = huff->compressor.tree; +} + -- cgit