GARbro-mirror/ArcFormats/DxLib/HuffmanDecoder.cs
Sławomir Śpiewak ed0f0489d3 Update HuffmanDecoder.cs
Fix not so obvious errors.
2024-08-11 15:41:21 +02:00

369 lines
12 KiB
C#

//! \file HuffmanDecoder.cs
//! \date 2024 Aug 2
//! \brief Custom Huffman decoder for DXA archives.
//
// Copyright (C) 2017 by morkt - GetBits function
// Copyright (C) 2024 by MrSoup678
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
//Original file is Huffman.cpp. Creator: 山田 巧 Date: 2018 Dec 16
using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.CompilerServices;
using GameRes.Utility;
namespace GameRes.Formats.DxLib
{
internal class DXA8HuffmanNode
{
public UInt64 Weight;
public int bitNumber;
public byte[] bitArray; //32 bytes here
public int Index;
public int ParentNode; // index of parent node.
public int[] ChildNode; //two children nodes, -1 if not existent.
internal DXA8HuffmanNode()
{
bitArray = new byte[32];
ChildNode = new int[2];
}
}
internal sealed class HuffmanDecoder
{
byte[] m_input;
byte[] m_output;
int m_src;
byte m_bits;
int m_bit_count;
ulong m_readBytes;
byte m_readBits;
DXA8HuffmanNode[] nodes; //256+255 nodes
ulong originalSize;
ulong compressedSize;
ulong headerSize;
ulong srcSize;
//ushort token = 256;
public HuffmanDecoder (byte[] src,ulong srcSize)
{
m_input = src;
m_output = null;
this.srcSize = srcSize;
m_src = 0;
m_bit_count = 0;
m_readBytes = 0;
m_readBits = 0;
originalSize = compressedSize = headerSize = 0;
ushort[] weights = new ushort[256];
nodes = new DXA8HuffmanNode[256+255]; //256 data nodes, then 255 hierarchy nodes.
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = new DXA8HuffmanNode();
}
}
public byte[] Unpack ()
{
for (int i=0; i<nodes.Length; i++)
{
nodes[i].ParentNode = -1;
nodes[i].ChildNode[0] = -1;
nodes[i].ChildNode[1] = -1;
}
SetupWeights();
//check if compressedSize and src size match.
if (srcSize!=(compressedSize+headerSize))
{
throw new FileSizeException(String.Format("Supplied srcSize does not match with compressedSize+headerSize. Expected {0} got {1}",compressedSize+headerSize,srcSize));
}
m_output = new byte[originalSize];
CreateTree();
PopulateDataNodes();
DoUnpack();
return m_output;
}
private void DoUnpack()
{
var targetSize = originalSize;
byte[] compressedData = new byte[compressedSize];
Array.Copy(m_input, (long)headerSize, compressedData, 0, (long)(compressedSize));
int PressBitCounter=0, PressBitData=0, Index=0, NodeIndex=0;
int PressSizeCounter = 0;
ulong DestSizeCounter = 0;
int[] NodeIndexTable=new int[512];
{
ushort[] bitMask = new ushort[9];
for (int i = 0; i < 9; i++)
{
bitMask[i] = (ushort)((1<<i+1) - 1);
}
for (int i = 0; i < 512; i++)
{
NodeIndexTable[i] = -1;
for (int j = 0; j < 256 + 254; j++)
{
ushort BitArrayFirstBatch;
if (nodes[j].bitNumber > 9) continue;
BitArrayFirstBatch = (ushort)(nodes[j].bitArray[0] | (nodes[j].bitArray[1] << 8));
if ((i & bitMask[nodes[j].bitNumber - 1]) == (BitArrayFirstBatch & bitMask[nodes[j].bitNumber-1]))
{
NodeIndexTable[i] = j;
break;
}
}
}
}
PressBitData = compressedData[PressBitCounter];
for (DestSizeCounter = 0;DestSizeCounter < originalSize; DestSizeCounter++)
{
if (DestSizeCounter>= originalSize - 17)
{
NodeIndex = 510;
}
else
{
if (PressBitCounter==8)
{
PressSizeCounter++;
PressBitData = compressedData[PressSizeCounter];
PressBitCounter = 0;
}
PressBitData = (PressBitData | (compressedData[PressSizeCounter+1]<<(8-PressBitCounter))) & 0x1ff;
NodeIndex = NodeIndexTable[PressBitData];
PressBitCounter += nodes[NodeIndex].bitNumber;
if (PressBitCounter >= 16)
{
PressSizeCounter += 2;
PressBitCounter -= 16;
PressBitData = compressedData[PressSizeCounter] >> PressBitCounter;
}
else if (PressBitCounter >=8)
{
PressSizeCounter ++;
PressBitCounter -= 8;
PressBitData = compressedData[PressSizeCounter] >> PressBitCounter;
}
else
{
PressBitData >>= nodes[NodeIndex].bitNumber;
}
}
while (NodeIndex > 255)
{
if (PressBitCounter == 8)
{
PressSizeCounter++;
PressBitData = compressedData[PressSizeCounter];
PressBitCounter = 0;
}
Index = PressBitData & 1;
PressBitData >>= 1;
PressBitCounter++;
NodeIndex = nodes[NodeIndex].ChildNode[Index];
}
m_output[DestSizeCounter] = (byte)NodeIndex;
}
}
private void PopulateDataNodes()
{
//The data which is populated is path from root to target node in bits.
byte[] ScratchSpace = new byte[32];
int TempBitIndex, TempBitCount;
for (int i = 0; i < 256 + 254; i++) //root node is excluded.
{
nodes[i].bitNumber = 0;
TempBitIndex = 0;
TempBitCount = 0;
ScratchSpace[TempBitIndex] = 0;
for (int j = i; nodes[j].ParentNode!=-1;j = nodes[j].ParentNode)
{
if (TempBitCount == 8)
{
TempBitCount = 0;
TempBitIndex++;
ScratchSpace[TempBitIndex] = 0;
}
ScratchSpace[TempBitIndex] <<= 1;
ScratchSpace[TempBitIndex] |= (byte)nodes[j].Index;
TempBitCount++;
nodes[i].bitNumber++;
}
//path is now backwards (target to root). Populate BitPath from root to target.
int BitIndex=0, BitCount=0;
nodes[i].bitArray[BitIndex] = 0;
while (TempBitIndex >= 0)
{
if (BitCount == 8)
{
BitCount = 0;
BitIndex++;
nodes[i].bitArray[BitIndex] = 0;
}
nodes[i].bitArray[BitIndex] |= (byte)((ScratchSpace[TempBitIndex] & 1) << BitCount);
ScratchSpace[TempBitIndex] >>= 1;
TempBitCount--;
if (TempBitCount == 0)
{
TempBitIndex--;
TempBitCount = 8;
}
BitCount++;
}
}
}
private void SetupWeights()
{
int sizeA, sizeB;
byte BitNum;
byte Minus;
ushort SaveData;
ushort[] weights = new ushort[256];
sizeA = (int)GetBits(6) + 1;
originalSize = GetBits(sizeA);
sizeB = (int)GetBits(6)+1;
compressedSize = GetBits(sizeB);
BitNum = (byte)(((int)GetBits(3) + 1) * 2);
Minus = (byte)GetBits(1);
SaveData = (ushort)GetBits(BitNum);
weights[0] = SaveData;
for (int i = 1; i < 256; i++)
{
BitNum = (byte)(((int)GetBits(3) + 1) * 2);
Minus = (byte)GetBits(1);
SaveData = (ushort)GetBits(BitNum);
weights[i] = (ushort)(Minus == 1 ? weights[i - 1] - SaveData : weights[i - 1] + SaveData);
}
headerSize = GetReadBytes();
for (int i = 0;i < 256; i++)
{
nodes[i].Weight = weights[i];
}
}
void CreateTree()
{
int NodeNum=256, DataNum=256;
while (DataNum > 1)
{
int MinNode1 = -1;
int MinNode2 = -1;
int NodeIndex = 0;
for (int i = 0; i < DataNum; NodeIndex++) {
//don't do anything if we already have a parent set.
if (nodes[NodeIndex].ParentNode != -1) continue;
i++;
//we need to get the two lowest numbers for parenting.
if (MinNode1 == -1 || nodes[MinNode1].Weight > nodes[NodeIndex].Weight)
{
{
MinNode2 = MinNode1;
MinNode1 = NodeIndex;
}
} else if (MinNode2 == -1 || nodes[MinNode2].Weight > nodes[NodeIndex].Weight)
{
MinNode2 = NodeIndex;
}
}
nodes[NodeNum].ParentNode = -1;
nodes[NodeNum].Weight = nodes[MinNode1].Weight + nodes[MinNode2].Weight;
nodes[NodeNum].ChildNode[0] = MinNode1;
nodes[NodeNum].ChildNode[1] = MinNode2;
nodes[MinNode1].Index = 0;
nodes[MinNode2].Index = 1;
nodes[MinNode1].ParentNode = NodeNum;
nodes[MinNode2].ParentNode = NodeNum;
NodeNum++;
DataNum--;
}
}
ulong GetBits (int count)
{
ulong bits = 0;
for (int i = 0; i < count;i++)
{
if (0 == m_bit_count)
{
m_bits = m_input[m_src];
m_src++;
m_bit_count = 8;
}
//bits are read backwards.
bits |= ((ulong)((m_bits >> (7 - m_readBits)) & 1)) <<(count-1-i);
--m_bit_count;
m_readBits++;
if (m_readBits ==8)
{
m_readBits = 0;
m_readBytes++;
}
}
return bits;
}
ulong GetReadBytes()
{
return m_readBytes + (m_readBits != 0 ? 1ul : 0ul);
}
}
}