#include "rar.hpp"void Unpack::CopyString20(unsigned int Length,unsigned int Distance){  LastDist=OldDist[OldDistPtr++ & 3]=Distance;  LastLength=Length;  DestUnpSize-=Length;  unsigned int DestPtr=UnpPtr-Distance;  if (DestPtr<MAXWINSIZE-300 && UnpPtr<MAXWINSIZE-300)  {    Window[UnpPtr++]=Window[DestPtr++];    Window[UnpPtr++]=Window[DestPtr++];    while (Length>2)    {      Length--;      Window[UnpPtr++]=Window[DestPtr++];    }  }  else    while (Length--)    {      Window[UnpPtr]=Window[DestPtr++ & MAXWINMASK];      UnpPtr=(UnpPtr+1) & MAXWINMASK;    }}void Unpack::Unpack20(bool Solid){  static unsigned char LDecode[]={0,1,2,3,4,5,6,7,8,10,12,14,16,20,24,28,32,40,48,56,64,80,96,112,128,160,192,224};  static unsigned char LBits[]=  {0,0,0,0,0,0,0,0,1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4,  4,  5,  5,  5,  5};  static int DDecode[]={0,1,2,3,4,6,8,12,16,24,32,48,64,96,128,192,256,384,512,768,1024,1536,2048,3072,4096,6144,8192,12288,16384,24576,32768U,49152U,65536,98304,131072,196608,262144,327680,393216,458752,524288,589824,655360,720896,786432,851968,917504,983040};  static unsigned char DBits[]=  {0,0,0,0,1,1,2, 2, 3, 3, 4, 4, 5, 5,  6,  6,  7,  7,  8,  8,   9,   9,  10,  10,  11,  11,  12,   12,   13,   13,    14,    14,   15,   15,    16,    16,    16,    16,    16,    16,    16,    16,    16,    16,    16,    16,    16,    16};  static unsigned char SDDecode[]={0,4,8,16,32,64,128,192};  static unsigned char SDBits[]=  {2,2,3, 4, 5, 6,  6,  6};  unsigned int Bits;  if (Suspended)    UnpPtr=WrPtr;  else  {    UnpInitData(Solid);    if (!UnpReadBuf())      return;    if (!Solid)      if (!ReadTables20())        return;    --DestUnpSize;  }  while (is64plus(DestUnpSize))  {    UnpPtr&=MAXWINMASK;    if (InAddr>ReadTop-30)      if (!UnpReadBuf())        break;    if (((WrPtr-UnpPtr) & MAXWINMASK)<270 && WrPtr!=UnpPtr)    {      OldUnpWriteBuf();      if (Suspended)        return;    }    if (UnpAudioBlock)    {      int AudioNumber=DecodeNumber((struct Decode *)&MD[UnpCurChannel]);      if (AudioNumber==256)      {        if (!ReadTables20())          break;        continue;      }      Window[UnpPtr++]=DecodeAudio(AudioNumber);      if (++UnpCurChannel==UnpChannels)        UnpCurChannel=0;      --DestUnpSize;      continue;    }    int Number=DecodeNumber((struct Decode *)&LD);    if (Number<256)    {      Window[UnpPtr++]=(byte)Number;      --DestUnpSize;      continue;    }    if (Number>269)    {      int Length=LDecode[Number-=270]+3;      if ((Bits=LBits[Number])>0)      {        Length+=getbits()>>(16-Bits);        addbits(Bits);      }      int DistNumber=DecodeNumber((struct Decode *)&DD);      unsigned int Distance=DDecode[DistNumber]+1;      if ((Bits=DBits[DistNumber])>0)      {        Distance+=getbits()>>(16-Bits);        addbits(Bits);      }      if (Distance>=0x2000)      {        Length++;        if (Distance>=0x40000L)          Length++;      }      CopyString20(Length,Distance);      continue;    }    if (Number==269)    {      if (!ReadTables20())        break;      continue;    }    if (Number==256)    {      CopyString20(LastLength,LastDist);      continue;    }    if (Number<261)    {      unsigned int Distance=OldDist[(OldDistPtr-(Number-256)) & 3];      int LengthNumber=DecodeNumber((struct Decode *)&RD);      int Length=LDecode[LengthNumber]+2;      if ((Bits=LBits[LengthNumber])>0)      {        Length+=getbits()>>(16-Bits);        addbits(Bits);      }      if (Distance>=0x101)      {        Length++;        if (Distance>=0x2000)        {          Length++;          if (Distance>=0x40000)            Length++;        }      }      CopyString20(Length,Distance);      continue;    }    if (Number<270)    {      unsigned int Distance=SDDecode[Number-=261]+1;      if ((Bits=SDBits[Number])>0)      {        Distance+=getbits()>>(16-Bits);        addbits(Bits);      }      CopyString20(2,Distance);      continue;   }  }  ReadLastTables();  OldUnpWriteBuf();}bool Unpack::ReadTables20(){  byte BitLength[BC20];  unsigned char Table[MC20*4];  int TableSize,N,I;  if (InAddr>ReadTop-25)    if (!UnpReadBuf())      return(false);  unsigned int BitField=getbits();  UnpAudioBlock=(BitField & 0x8000);  if (!(BitField & 0x4000))    memset(UnpOldTable20,0,sizeof(UnpOldTable20));  addbits(2);  if (UnpAudioBlock)  {    UnpChannels=((BitField>>12) & 3)+1;    if (UnpCurChannel>=UnpChannels)      UnpCurChannel=0;    addbits(2);    TableSize=MC20*UnpChannels;  }  else    TableSize=NC20+DC20+RC20;  for (I=0;I<BC20;I++)  {    BitLength[I]=(byte)(getbits() >> 12);    addbits(4);  }  MakeDecodeTables(BitLength,(struct Decode *)&BD,BC20);  I=0;  while (I<TableSize)  {    if (InAddr>ReadTop-5)      if (!UnpReadBuf())        return(false);    int Number=DecodeNumber((struct Decode *)&BD);    if (Number<16)    {      Table[I]=(Number+UnpOldTable20[I]) & 0xf;      I++;    }    else      if (Number==16)      {        N=(getbits() >> 14)+3;        addbits(2);        while (N-- > 0 && I<TableSize)        {          Table[I]=Table[I-1];          I++;        }      }      else      {        if (Number==17)        {          N=(getbits() >> 13)+3;          addbits(3);        }        else        {          N=(getbits() >> 9)+11;          addbits(7);        }        while (N-- > 0 && I<TableSize)          Table[I++]=0;      }  }  if (InAddr>ReadTop)    return(true);  if (UnpAudioBlock)    for (I=0;I<UnpChannels;I++)      MakeDecodeTables(&Table[I*MC20],(struct Decode *)&MD[I],MC20);  else  {    MakeDecodeTables(&Table[0],(struct Decode *)&LD,NC20);    MakeDecodeTables(&Table[NC20],(struct Decode *)&DD,DC20);    MakeDecodeTables(&Table[NC20+DC20],(struct Decode *)&RD,RC20);  }  memcpy(UnpOldTable20,Table,sizeof(UnpOldTable20));  return(true);}void Unpack::ReadLastTables(){  if (ReadTop>=InAddr+5)    if (UnpAudioBlock)    {      if (DecodeNumber((struct Decode *)&MD[UnpCurChannel])==256)        ReadTables20();    }    else      if (DecodeNumber((struct Decode *)&LD)==269)        ReadTables20();}void Unpack::UnpInitData20(int Solid){  if (!Solid)  {    UnpChannelDelta=UnpCurChannel=0;    UnpChannels=1;    memset(AudV,0,sizeof(AudV));    memset(UnpOldTable20,0,sizeof(UnpOldTable20));  }}byte Unpack::DecodeAudio(int Delta){  struct AudioVariables *V=&AudV[UnpCurChannel];  V->ByteCount++;  V->D4=V->D3;  V->D3=V->D2;  V->D2=V->LastDelta-V->D1;  V->D1=V->LastDelta;  int PCh=8*V->LastChar+V->K1*V->D1+V->K2*V->D2+V->K3*V->D3+V->K4*V->D4+V->K5*UnpChannelDelta;  PCh=(PCh>>3) & 0xFF;  unsigned int Ch=PCh-Delta;  int D=((signed char)Delta)<<3;  V->Dif[0]+=abs(D);  V->Dif[1]+=abs(D-V->D1);  V->Dif[2]+=abs(D+V->D1);  V->Dif[3]+=abs(D-V->D2);  V->Dif[4]+=abs(D+V->D2);  V->Dif[5]+=abs(D-V->D3);  V->Dif[6]+=abs(D+V->D3);  V->Dif[7]+=abs(D-V->D4);  V->Dif[8]+=abs(D+V->D4);  V->Dif[9]+=abs(D-UnpChannelDelta);  V->Dif[10]+=abs(D+UnpChannelDelta);  UnpChannelDelta=V->LastDelta=(signed char)(Ch-V->LastChar);  V->LastChar=Ch;  if ((V->ByteCount & 0x1F)==0)  {    unsigned int MinDif=V->Dif[0],NumMinDif=0;    V->Dif[0]=0;    for (int I=1;I<sizeof(V->Dif)/sizeof(V->Dif[0]);I++)    {      if (V->Dif[I]<MinDif)      {        MinDif=V->Dif[I];        NumMinDif=I;      }      V->Dif[I]=0;    }    switch(NumMinDif)    {      case 1:        if (V->K1>=-16)          V->K1--;        break;      case 2:        if (V->K1<16)          V->K1++;        break;      case 3:        if (V->K2>=-16)          V->K2--;        break;      case 4:        if (V->K2<16)          V->K2++;        break;      case 5:        if (V->K3>=-16)          V->K3--;        break;      case 6:        if (V->K3<16)          V->K3++;        break;      case 7:        if (V->K4>=-16)          V->K4--;        break;      case 8:        if (V->K4<16)          V->K4++;        break;      case 9:        if (V->K5>=-16)          V->K5--;        break;      case 10:        if (V->K5<16)          V->K5++;        break;    }  }  return((byte)Ch);}