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Aerofoil/unpacktool/StuffItArsenicDecompressor.cpp
2020-11-10 20:04:08 -05:00

365 lines
8.9 KiB
C++

#include "StuffItArsenicDecompressor.h"
#include "CRC.h"
#include "CSInputBuffer.h"
#include <stdlib.h>
#include <string.h>
static const uint16_t RandomizationTable[] =
{
0xee, 0x56, 0xf8, 0xc3, 0x9d, 0x9f, 0xae, 0x2c,
0xad, 0xcd, 0x24, 0x9d, 0xa6, 0x101, 0x18, 0xb9,
0xa1, 0x82, 0x75, 0xe9, 0x9f, 0x55, 0x66, 0x6a,
0x86, 0x71, 0xdc, 0x84, 0x56, 0x96, 0x56, 0xa1,
0x84, 0x78, 0xb7, 0x32, 0x6a, 0x3, 0xe3, 0x2,
0x11, 0x101, 0x8, 0x44, 0x83, 0x100, 0x43, 0xe3,
0x1c, 0xf0, 0x86, 0x6a, 0x6b, 0xf, 0x3, 0x2d,
0x86, 0x17, 0x7b, 0x10, 0xf6, 0x80, 0x78, 0x7a,
0xa1, 0xe1, 0xef, 0x8c, 0xf6, 0x87, 0x4b, 0xa7,
0xe2, 0x77, 0xfa, 0xb8, 0x81, 0xee, 0x77, 0xc0,
0x9d, 0x29, 0x20, 0x27, 0x71, 0x12, 0xe0, 0x6b,
0xd1, 0x7c, 0xa, 0x89, 0x7d, 0x87, 0xc4, 0x101,
0xc1, 0x31, 0xaf, 0x38, 0x3, 0x68, 0x1b, 0x76,
0x79, 0x3f, 0xdb, 0xc7, 0x1b, 0x36, 0x7b, 0xe2,
0x63, 0x81, 0xee, 0xc, 0x63, 0x8b, 0x78, 0x38,
0x97, 0x9b, 0xd7, 0x8f, 0xdd, 0xf2, 0xa3, 0x77,
0x8c, 0xc3, 0x39, 0x20, 0xb3, 0x12, 0x11, 0xe,
0x17, 0x42, 0x80, 0x2c, 0xc4, 0x92, 0x59, 0xc8,
0xdb, 0x40, 0x76, 0x64, 0xb4, 0x55, 0x1a, 0x9e,
0xfe, 0x5f, 0x6, 0x3c, 0x41, 0xef, 0xd4, 0xaa,
0x98, 0x29, 0xcd, 0x1f, 0x2, 0xa8, 0x87, 0xd2,
0xa0, 0x93, 0x98, 0xef, 0xc, 0x43, 0xed, 0x9d,
0xc2, 0xeb, 0x81, 0xe9, 0x64, 0x23, 0x68, 0x1e,
0x25, 0x57, 0xde, 0x9a, 0xcf, 0x7f, 0xe5, 0xba,
0x41, 0xea, 0xea, 0x36, 0x1a, 0x28, 0x79, 0x20,
0x5e, 0x18, 0x4e, 0x7c, 0x8e, 0x58, 0x7a, 0xef,
0x91, 0x2, 0x93, 0xbb, 0x56, 0xa1, 0x49, 0x1b,
0x79, 0x92, 0xf3, 0x58, 0x4f, 0x52, 0x9c, 0x2,
0x77, 0xaf, 0x2a, 0x8f, 0x49, 0xd0, 0x99, 0x4d,
0x98, 0x101, 0x60, 0x93, 0x100, 0x75, 0x31, 0xce,
0x49, 0x20, 0x56, 0x57, 0xe2, 0xf5, 0x26, 0x2b,
0x8a, 0xbf, 0xde, 0xd0, 0x83, 0x34, 0xf4, 0x17
};
// Arithmetic decoder model
void StuffItArsenicDecompressor::InitializeArithmeticModel(ArithmeticModel *model,int firstsymbol,int lastsymbol,int increment,int frequencylimit)
{
model->increment=increment;
model->frequencylimit=frequencylimit;
model->numsymbols=lastsymbol-firstsymbol+1;
for(int i=0;i<model->numsymbols;i++) model->symbols[i].symbol=i+firstsymbol;
ResetArithmeticModel(model);
}
void StuffItArsenicDecompressor::ResetArithmeticModel(ArithmeticModel *model)
{
model->totalfrequency=model->increment*model->numsymbols;
for(int i=0;i<model->numsymbols;i++) model->symbols[i].frequency=model->increment;
}
void StuffItArsenicDecompressor::IncreaseArithmeticModelFrequency(ArithmeticModel *model,int symindex)
{
model->symbols[symindex].frequency+=model->increment;
model->totalfrequency+=model->increment;
if(model->totalfrequency>model->frequencylimit)
{
model->totalfrequency=0;
for(int i=0;i<model->numsymbols;i++)
{
model->symbols[i].frequency++;
model->symbols[i].frequency>>=1;
model->totalfrequency+=model->symbols[i].frequency;
}
}
}
// Arithmetic decoder
#define NumBits 26
#define One (1<<(NumBits-1))
#define Half (1<<(NumBits-2))
bool StuffItArsenicDecompressor::InitializeArithmeticDecoder(ArithmeticDecoder *decoder,CSInputBuffer *input)
{
unsigned int initialCode;
if (!CSInputNextLongBitString(input, NumBits, initialCode))
return false;
decoder->input=input;
decoder->range=One;
decoder->code = initialCode;
return true;
}
bool StuffItArsenicDecompressor::ReadNextArithmeticCode(ArithmeticDecoder *decoder,int symlow,int symsize,int symtot)
{
int renorm_factor=decoder->range/symtot;
int lowincr=renorm_factor*symlow;
decoder->code-=lowincr;
if(symlow+symsize==symtot) decoder->range-=lowincr;
else decoder->range=symsize*renorm_factor;
while(decoder->range<=Half)
{
decoder->range<<=1;
unsigned int bit;
if (!CSInputNextBit(decoder->input, bit))
return false;
decoder->code = (decoder->code << 1) | bit;
}
return true;
}
bool StuffItArsenicDecompressor::NextArithmeticSymbol(ArithmeticDecoder *decoder,ArithmeticModel *model,int &outSymbol)
{
int frequency=decoder->code/(decoder->range/model->totalfrequency);
int cumulative=0,n;
for(n=0;n<model->numsymbols-1;n++)
{
if(cumulative+model->symbols[n].frequency>frequency) break;
cumulative+=model->symbols[n].frequency;
}
if (!ReadNextArithmeticCode(decoder, cumulative, model->symbols[n].frequency, model->totalfrequency))
return false;
IncreaseArithmeticModelFrequency(model,n);
outSymbol = model->symbols[n].symbol;
return true;
}
bool StuffItArsenicDecompressor::NextArithmeticBitString(ArithmeticDecoder *decoder,ArithmeticModel *model,int bits,int &outBits)
{
int res=0;
for (int i = 0; i < bits; i++)
{
int sym;
if (!NextArithmeticSymbol(decoder, model, sym))
return false;
if (sym)
res |= 1 << i;
}
outBits = res;
return true;
}
StuffItArsenicDecompressor::StuffItArsenicDecompressor()
: block(NULL)
, transform(NULL)
{
}
StuffItArsenicDecompressor::~StuffItArsenicDecompressor()
{
delete[] block;
delete[] transform;
}
bool StuffItArsenicDecompressor::Reset(CSInputBuffer *input, size_t compressedSize, size_t decompressedSize)
{
if (!InitializeArithmeticDecoder(&decoder, input))
return false;
InitializeArithmeticModel(&initialmodel,0,1,1,256);
InitializeArithmeticModel(&selectormodel,0,10,8,1024);
InitializeArithmeticModel(&mtfmodel[0],2,3,8,1024);
InitializeArithmeticModel(&mtfmodel[1],4,7,4,1024);
InitializeArithmeticModel(&mtfmodel[2],8,15,4,1024);
InitializeArithmeticModel(&mtfmodel[3],16,31,4,1024);
InitializeArithmeticModel(&mtfmodel[4],32,63,2,1024);
InitializeArithmeticModel(&mtfmodel[5],64,127,2,1024);
InitializeArithmeticModel(&mtfmodel[6],128,255,1,1024);
int bits;
if (!NextArithmeticBitString(&decoder, &initialmodel, 8, bits) || bits != 'A')
return false;
if (!NextArithmeticBitString(&decoder, &initialmodel, 8, bits) || bits != 's')
return false;
if (!NextArithmeticBitString(&decoder, &initialmodel, 4, blockbits))
return false;
blockbits+=9;
blocksize=1<<blockbits;
numbytes=bytecount=0;
repeat=0;
delete[] block;
block=new uint8_t[blocksize];
crc=0xffffffff;
compcrc=0;
// check first end marker
int eobsym;
if (!NextArithmeticSymbol(&decoder, &initialmodel, eobsym))
return false;
endofblocks = (eobsym != 0);
return true;
}
bool StuffItArsenicDecompressor::ReadBlock()
{
ResetMTFDecoder(&mtf);
if (!NextArithmeticSymbol(&decoder, &initialmodel, randomized))
return false;
if (!NextArithmeticBitString(&decoder, &initialmodel, blockbits, transformindex))
return false;
numbytes=0;
for(;;)
{
int sel;
if (!NextArithmeticSymbol(&decoder, &selectormodel, sel))
return false;
if(sel==0||sel==1) // zero counting
{
int zerostate=1,zerocount=0;
while(sel<2)
{
if(sel==0) zerocount+=zerostate;
else if(sel==1) zerocount+=2*zerostate;
zerostate*=2;
if (!NextArithmeticSymbol(&decoder, &selectormodel, sel))
return false;
}
if (numbytes + zerocount > blocksize)
return false;
memset(&block[numbytes],DecodeMTF(&mtf,0),zerocount);
numbytes+=zerocount;
}
int symbol;
if(sel==10)
break;
else if(sel==2)
symbol=1;
else
{
if (!NextArithmeticSymbol(&decoder, &mtfmodel[sel - 3], symbol))
return false;
}
if (numbytes >= blocksize)
return false;
block[numbytes++] = DecodeMTF(&mtf, symbol);
}
if (transformindex >= numbytes)
return false;
ResetArithmeticModel(&selectormodel);
for(int i=0;i<7;i++) ResetArithmeticModel(&mtfmodel[i]);
int endMarkerSym;
if (!NextArithmeticSymbol(&decoder, &initialmodel, endMarkerSym))
return false;
if(endMarkerSym) // end marker
{
int compcrcsym;
if (!NextArithmeticBitString(&decoder, &initialmodel, 32, compcrcsym))
return false;
compcrc = compcrcsym;
endofblocks=true;
}
free(transform);
transform = new uint32_t[numbytes];
CalculateInverseBWT(transform,block,numbytes);
return true;
}
bool StuffItArsenicDecompressor::ReadBytes(void *dest, size_t numBytes)
{
while (numBytes)
{
uint8_t outbyte;
if (repeat)
{
repeat--;
outbyte = last;
}
else
{
retry:
if (bytecount >= numbytes)
{
if (endofblocks)
return false;
if (!this->ReadBlock())
return false;
bytecount = 0;
count = 0;
last = 0;
randindex = 0;
randcount = RandomizationTable[0];
}
transformindex = transform[transformindex];
int byte = block[transformindex];
if (randomized&&randcount == bytecount)
{
byte ^= 1;
randindex = (randindex + 1) & 255;
randcount += RandomizationTable[randindex];
}
bytecount++;
if (count == 4)
{
count = 0;
if (byte == 0) goto retry;
repeat = byte - 1;
outbyte = last;
}
else
{
if (byte == last) count++;
else { count = 1; last = byte; }
outbyte = byte;
}
}
crc = XADCRC(crc, outbyte, XADCRCTable_edb88320);
uint8_t *destBytes = static_cast<uint8_t*>(dest);
destBytes[0] = outbyte;
numBytes--;
dest = destBytes + 1;
}
return true;
}