mirror of
https://github.com/elasota/Aerofoil.git
synced 2025-09-23 14:53:52 +00:00
451 lines
11 KiB
C++
451 lines
11 KiB
C++
#include <limits.h>
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#include "PrefixCode.h"
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struct XADCodeTreeNode
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{
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int branches[2];
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};
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struct XADCodeTableEntry
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{
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uint32_t length;
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int32_t value;
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};
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static inline XADCodeTreeNode *NodePointer(XADPrefixCode *self, int node) { return &self->tree[node]; }
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static inline int Branch(XADPrefixCode *self, int node, int bit) { return NodePointer(self, node)->branches[bit]; }
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static inline void SetBranch(XADPrefixCode *self, int node, int bit, int nextnode) { NodePointer(self, node)->branches[bit] = nextnode; }
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static inline int LeftBranch(XADPrefixCode *self, int node) { return Branch(self, node, 0); }
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static inline int RightBranch(XADPrefixCode *self, int node) { return Branch(self, node, 1); }
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static inline void SetLeftBranch(XADPrefixCode *self, int node, int nextnode) { SetBranch(self, node, 0, nextnode); }
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static inline void SetRightBranch(XADPrefixCode *self, int node, int nextnode) { SetBranch(self, node, 1, nextnode); }
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static inline int LeafValue(XADPrefixCode *self, int node) { return LeftBranch(self, node); }
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static inline void SetLeafValue(XADPrefixCode *self, int node, int value) { SetLeftBranch(self, node, value); SetRightBranch(self, node, value); }
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static inline void SetEmptyNode(XADPrefixCode *self, int node) { SetLeftBranch(self, node, -1); SetRightBranch(self, node, -2); }
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static inline bool IsInvalidNode(XADPrefixCode *self, int node) { return node < 0; }
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static inline bool IsOpenBranch(XADPrefixCode *self, int node, int bit) { return IsInvalidNode(self, Branch(self, node, bit)); }
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static inline bool IsEmptyNode(XADPrefixCode *self, int node) { return LeftBranch(self, node) == -1 && RightBranch(self, node) == -2; }
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static inline bool IsLeafNode(XADPrefixCode *self, int node) { return LeftBranch(self, node) == RightBranch(self, node); }
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static inline int NewNode(XADPrefixCode *self)
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{
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self->tree.resize(self->numentries + 1);
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SetEmptyNode(self, self->numentries);
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return self->numentries++;
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}
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bool CSInputNextSymbolUsingCode(CSInputBuffer *buf, XADPrefixCode *code, int &outSymbol)
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{
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if (!code->table1)
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code->_makeTable();
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unsigned int bits;
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if (!CSInputPeekBitString(buf, code->tablesize, bits))
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return false;
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int length = code->table1[bits].length;
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int value = code->table1[bits].value;
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if (length < 0)
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return false;
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if (length <= code->tablesize)
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{
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if (!CSInputSkipPeekedBits(buf, length))
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return false;
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outSymbol = value;
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return true;
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}
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if (!CSInputSkipPeekedBits(buf, code->tablesize))
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return false;
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int node = value;
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while (!IsLeafNode(code, node))
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{
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unsigned int bit;
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if (!CSInputNextBit(buf, bit))
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return false;
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if (IsOpenBranch(code, node, bit))
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return false;
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node = Branch(code, node, bit);
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}
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outSymbol = LeafValue(code, node);
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return true;
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}
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bool CSInputNextSymbolUsingCodeLE(CSInputBuffer *buf, XADPrefixCode *code, int &outSymbol)
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{
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if (!code->table2)
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code->_makeTableLE();
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unsigned int bits;
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if (!CSInputPeekBitStringLE(buf, code->tablesize, bits))
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return false;
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int length = code->table2[bits].length;
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int value = code->table2[bits].value;
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if (length < 0)
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return false;
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if (length <= code->tablesize)
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{
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if (!CSInputSkipPeekedBitsLE(buf, length))
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return false;
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outSymbol = value;
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return true;
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}
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if (!CSInputSkipPeekedBitsLE(buf, code->tablesize))
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return false;
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int node = value;
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while (!IsLeafNode(code, node))
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{
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unsigned int bit;
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if (!CSInputNextBitLE(buf, bit))
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return false;
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if (IsOpenBranch(code, node, bit))
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return false;
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node = Branch(code, node, bit);
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}
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outSymbol = LeafValue(code, node);
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return true;
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}
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/*int CSInputNextSymbolUsingCode(CSInputBuffer *buf,XADPrefixCode *code)
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{
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int node=0;
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while(!IsLeafNode(code,node))
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{
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int bit=CSInputNextBit(buf);
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if(IsOpenBranch(code,node,bit)) [NSException raise:XADInvalidPrefixCodeException format:@"Invalid prefix code in bitstream"];
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node=Branch(code,node,bit);
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}
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return LeafValue(code,node);
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}
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int CSInputNextSymbolUsingCodeLE(CSInputBuffer *buf,XADPrefixCode *code)
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{
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int node=0;
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while(!IsLeafNode(code,node))
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{
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int bit=CSInputNextBitLE(buf);
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if(IsOpenBranch(code,node,bit)) [NSException raise:XADInvalidPrefixCodeException format:@"Invalid prefix code in bitstream"];
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node=Branch(code,node,bit);
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}
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return LeafValue(code,node);
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}*/
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XADPrefixCode *XADPrefixCode::prefixCode()
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{
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XADPrefixCode *self = new XADPrefixCode();
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self->init();
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return self;
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}
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XADPrefixCode *XADPrefixCode::prefixCodeWithLengths(const int *lengths, int numsymbols, int maxlength, bool zeros)
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{
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XADPrefixCode *self = prefixCode();
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if (!self->initWithLengths(lengths, numsymbols, maxlength, zeros))
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{
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delete self;
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self = nullptr;
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}
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return self;
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}
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void XADPrefixCode::init()
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{
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tree.resize(1);
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SetEmptyNode(this, 0);
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numentries = 1;
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minlength = INT_MAX;
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maxlength = INT_MIN;
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isstatic = false;
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table1 = table2 = NULL;
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}
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bool XADPrefixCode::initWithLengths(const int *lengths, int numsymbols, int maxcodelength, bool zeros)
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{
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int code = 0, symbolsleft = numsymbols;
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for (int length = 1; length <= maxcodelength; length++)
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{
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for (int i = 0; i < numsymbols; i++)
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{
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if (lengths[i] != length)
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continue;
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// Instead of reversing to get a low-bit-first code, we shift and use high-bit-first.
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if (zeros)
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{
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if (!this->addValueHighBitFirst(i, code, length))
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return false;
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}
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else
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{
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if (!this->addValueHighBitFirst(i, ~code, length))
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return false;
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}
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code++;
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if (--symbolsleft == 0)
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return true; // early exit if all codes have been handled
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}
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code <<= 1;
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}
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return true;
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}
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XADPrefixCode::XADPrefixCode()
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: numentries(0)
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, minlength(0)
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, maxlength(0)
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, isstatic(false)
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, currnode(0)
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, tablesize(0)
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, table1(nullptr)
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, table2(nullptr)
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{
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}
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XADPrefixCode::~XADPrefixCode()
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{
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delete[] table1;
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delete[] table2;
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}
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bool XADPrefixCode::addValueHighBitFirst(int value, uint32_t code, int length)
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{
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return this->addValueHighBitFirst(value, code, length, length);
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}
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bool XADPrefixCode::addValueHighBitFirst(int value, uint32_t code, int length, int repeatpos)
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{
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if (isstatic)
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return false;
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delete[] table1;
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delete[] table2;
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table1 = table2 = NULL;
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if (length > maxlength) maxlength = length;
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if (length < minlength) minlength = length;
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repeatpos = length - 1 - repeatpos;
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if (repeatpos == 0 || (repeatpos >= 0 && (((code >> (repeatpos - 1)) & 3) == 0 || ((code >> (repeatpos - 1)) & 3) == 3)))
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return false;
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int lastnode = 0;
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for (int bitpos = length - 1; bitpos >= 0; bitpos--)
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{
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int bit = (code >> bitpos) & 1;
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if (IsLeafNode(this, lastnode))
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return false;
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if (bitpos == repeatpos)
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{
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if (!IsOpenBranch(this, lastnode, bit))
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return false;
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int repeatnode = NewNode(this);
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int nextnode = NewNode(this);
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SetBranch(this, lastnode, bit, repeatnode);
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SetBranch(this, repeatnode, bit, repeatnode);
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SetBranch(this, repeatnode, bit ^ 1, nextnode);
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lastnode = nextnode;
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bitpos++; // terminating bit already handled, skip it
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}
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else
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{
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if (IsOpenBranch(this, lastnode, bit))
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SetBranch(this, lastnode, bit, NewNode(this));
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lastnode = Branch(this, lastnode, bit);
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}
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}
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if (!IsEmptyNode(this, lastnode))
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return false;
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SetLeafValue(this, lastnode, value);
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return true;
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}
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static uint32_t Reverse32(uint32_t val)
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{
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val = ((val >> 1) & 0x55555555) | ((val & 0x55555555) << 1);
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val = ((val >> 2) & 0x33333333) | ((val & 0x33333333) << 2);
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val = ((val >> 4) & 0x0F0F0F0F) | ((val & 0x0F0F0F0F) << 4);
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val = ((val >> 8) & 0x00FF00FF) | ((val & 0x00FF00FF) << 8);
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return (val >> 16) | (val << 16);
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}
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static uint32_t ReverseN(uint32_t val, int length)
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{
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return Reverse32(val) >> (32 - length);
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}
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bool XADPrefixCode::addValueLowBitFirst(int value, uint32_t code, int length)
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{
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return this->addValueHighBitFirst(value, ReverseN(code, length), length, length);
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}
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bool XADPrefixCode::addValueLowBitFirst(int value, uint32_t code, int length, int repeatpos)
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{
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return this->addValueHighBitFirst(value, ReverseN(code, length), length, repeatpos);
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}
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void XADPrefixCode::startBuildingTree()
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{
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currnode = 0;
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stack.resize(0);
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}
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void XADPrefixCode::startZeroBranch()
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{
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int newNode = NewNode(this);
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SetBranch(this, currnode, 0, newNode);
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this->_pushNode();
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currnode = newNode;
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}
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void XADPrefixCode::startOneBranch()
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{
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int newNode = NewNode(this);
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SetBranch(this, currnode, 1, newNode);
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this->_pushNode();
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currnode = newNode;
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}
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void XADPrefixCode::finishBranches()
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{
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this->_popNode();
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}
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void XADPrefixCode::makeLeafWithValue(int value)
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{
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SetLeafValue(this, currnode, value);
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this->_popNode();
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}
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void XADPrefixCode::_pushNode()
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{
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stack.push_back(currnode);
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}
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void XADPrefixCode::_popNode()
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{
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if (stack.size() == 0) return; // the final pop will underflow the stack otherwise
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int num = stack.back();
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stack.pop_back();
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currnode = num;
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}
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static void MakeTable(XADPrefixCode *code, int node, XADCodeTableEntry *table, int depth, int maxdepth)
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{
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int currtablesize = 1 << (maxdepth - depth);
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if (IsLeafNode(code, node))
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{
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for (int i = 0; i < currtablesize; i++)
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{
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table[i].length = depth;
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table[i].value = LeafValue(code, node);
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}
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}
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else if (IsInvalidNode(code, node))
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{
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for (int i = 0; i < currtablesize; i++) table[i].length = -1;
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}
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else
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{
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if (depth == maxdepth)
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{
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table[0].length = maxdepth + 1;
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table[0].value = node;
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}
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else
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{
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MakeTable(code, LeftBranch(code, node), table, depth + 1, maxdepth);
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MakeTable(code, RightBranch(code, node), table + currtablesize / 2, depth + 1, maxdepth);
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}
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}
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}
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static void MakeTableLE(XADPrefixCode *code, int node, XADCodeTableEntry *table, int depth, int maxdepth)
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{
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int currtablesize = 1 << (maxdepth - depth);
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int currstride = 1 << depth;
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if (IsLeafNode(code, node))
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{
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for (int i = 0; i < currtablesize; i++)
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{
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table[i*currstride].length = depth;
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table[i*currstride].value = LeafValue(code, node);
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}
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}
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else if (IsInvalidNode(code, node))
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{
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for (int i = 0; i < currtablesize; i++) table[i*currstride].length = -1;
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}
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else
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{
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if (depth == maxdepth)
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{
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table[0].length = maxdepth + 1;
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table[0].value = node;
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}
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else
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{
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MakeTableLE(code, LeftBranch(code, node), table, depth + 1, maxdepth);
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MakeTableLE(code, RightBranch(code, node), table + currstride, depth + 1, maxdepth);
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}
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}
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}
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#define TableMaxSize 10
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void XADPrefixCode::_makeTable()
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{
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if (table1) return;
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if (maxlength < minlength) tablesize = TableMaxSize; // no code lengths recorded
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else if (maxlength >= TableMaxSize) tablesize = TableMaxSize;
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else tablesize = maxlength;
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table1 = new XADCodeTableEntry[1 << tablesize];
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MakeTable(this, 0, table1, 0, tablesize);
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}
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void XADPrefixCode::_makeTableLE()
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{
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if (table2) return;
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if (maxlength < minlength) tablesize = TableMaxSize; // no code lengths recorded
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else if (maxlength >= TableMaxSize) tablesize = TableMaxSize;
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else tablesize = maxlength;
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table2 = new XADCodeTableEntry[1 << tablesize];
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MakeTableLE(this, 0, table2, 0, tablesize);
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}
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