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QuietUnrar/libunrar/unpack20.cpp

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8.4 KiB
C++
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#include "rar.hpp"
void Unpack::CopyString20(uint Length,uint Distance)
{
LastDist=OldDist[OldDistPtr++]=Distance;
OldDistPtr = OldDistPtr & 3; // Needed if RAR 1.5 file is called after RAR 2.0.
LastLength=Length;
DestUnpSize-=Length;
CopyString(Length,Distance);
}
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 uint 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};
uint Bits;
if (Suspended)
UnpPtr=WrPtr;
else
{
UnpInitData(Solid);
if (!UnpReadBuf())
return;
if ((!Solid || !TablesRead2) && !ReadTables20())
return;
--DestUnpSize;
}
while (DestUnpSize>=0)
{
UnpPtr&=MaxWinMask;
if (Inp.InAddr>ReadTop-30)
if (!UnpReadBuf())
break;
if (((WrPtr-UnpPtr) & MaxWinMask)<270 && WrPtr!=UnpPtr)
{
UnpWriteBuf20();
if (Suspended)
return;
}
if (UnpAudioBlock)
{
uint AudioNumber=DecodeNumber(Inp,&MD[UnpCurChannel]);
if (AudioNumber==256)
{
if (!ReadTables20())
break;
continue;
}
Window[UnpPtr++]=DecodeAudio((int)AudioNumber);
if (++UnpCurChannel==UnpChannels)
UnpCurChannel=0;
--DestUnpSize;
continue;
}
uint Number=DecodeNumber(Inp,&BlockTables.LD);
if (Number<256)
{
Window[UnpPtr++]=(byte)Number;
--DestUnpSize;
continue;
}
if (Number>269)
{
uint Length=LDecode[Number-=270]+3;
if ((Bits=LBits[Number])>0)
{
Length+=Inp.getbits()>>(16-Bits);
Inp.addbits(Bits);
}
uint DistNumber=DecodeNumber(Inp,&BlockTables.DD);
uint Distance=DDecode[DistNumber]+1;
if ((Bits=DBits[DistNumber])>0)
{
Distance+=Inp.getbits()>>(16-Bits);
Inp.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)
{
uint Distance=OldDist[(OldDistPtr-(Number-256)) & 3];
uint LengthNumber=DecodeNumber(Inp,&BlockTables.RD);
uint Length=LDecode[LengthNumber]+2;
if ((Bits=LBits[LengthNumber])>0)
{
Length+=Inp.getbits()>>(16-Bits);
Inp.addbits(Bits);
}
if (Distance>=0x101)
{
Length++;
if (Distance>=0x2000)
{
Length++;
if (Distance>=0x40000)
Length++;
}
}
CopyString20(Length,Distance);
continue;
}
if (Number<270)
{
uint Distance=SDDecode[Number-=261]+1;
if ((Bits=SDBits[Number])>0)
{
Distance+=Inp.getbits()>>(16-Bits);
Inp.addbits(Bits);
}
CopyString20(2,Distance);
continue;
}
}
ReadLastTables();
UnpWriteBuf20();
}
void Unpack::UnpWriteBuf20()
{
if (UnpPtr!=WrPtr)
UnpSomeRead=true;
if (UnpPtr<WrPtr)
{
UnpIO->UnpWrite(&Window[WrPtr],-(int)WrPtr & MaxWinMask);
UnpIO->UnpWrite(Window,UnpPtr);
UnpAllBuf=true;
}
else
UnpIO->UnpWrite(&Window[WrPtr],UnpPtr-WrPtr);
WrPtr=UnpPtr;
}
bool Unpack::ReadTables20()
{
byte BitLength[BC20];
byte Table[MC20*4];
if (Inp.InAddr>ReadTop-25)
if (!UnpReadBuf())
return false;
uint BitField=Inp.getbits();
UnpAudioBlock=(BitField & 0x8000)!=0;
if (!(BitField & 0x4000))
memset(UnpOldTable20,0,sizeof(UnpOldTable20));
Inp.addbits(2);
uint TableSize;
if (UnpAudioBlock)
{
UnpChannels=((BitField>>12) & 3)+1;
if (UnpCurChannel>=UnpChannels)
UnpCurChannel=0;
Inp.addbits(2);
TableSize=MC20*UnpChannels;
}
else
TableSize=NC20+DC20+RC20;
for (uint I=0;I<BC20;I++)
{
BitLength[I]=(byte)(Inp.getbits() >> 12);
Inp.addbits(4);
}
MakeDecodeTables(BitLength,&BlockTables.BD,BC20);
for (uint I=0;I<TableSize;)
{
if (Inp.InAddr>ReadTop-5)
if (!UnpReadBuf())
return false;
uint Number=DecodeNumber(Inp,&BlockTables.BD);
if (Number<16)
{
Table[I]=(Number+UnpOldTable20[I]) & 0xf;
I++;
}
else
if (Number==16)
{
uint N=(Inp.getbits() >> 14)+3;
Inp.addbits(2);
if (I==0)
return false; // We cannot have "repeat previous" code at the first position.
else
while (N-- > 0 && I<TableSize)
{
Table[I]=Table[I-1];
I++;
}
}
else
{
uint N;
if (Number==17)
{
N=(Inp.getbits() >> 13)+3;
Inp.addbits(3);
}
else
{
N=(Inp.getbits() >> 9)+11;
Inp.addbits(7);
}
while (N-- > 0 && I<TableSize)
Table[I++]=0;
}
}
TablesRead2=true;
if (Inp.InAddr>ReadTop)
return true;
if (UnpAudioBlock)
for (uint I=0;I<UnpChannels;I++)
MakeDecodeTables(&Table[I*MC20],&MD[I],MC20);
else
{
MakeDecodeTables(&Table[0],&BlockTables.LD,NC20);
MakeDecodeTables(&Table[NC20],&BlockTables.DD,DC20);
MakeDecodeTables(&Table[NC20+DC20],&BlockTables.RD,RC20);
}
memcpy(UnpOldTable20,Table,TableSize);
return true;
}
void Unpack::ReadLastTables()
{
if (ReadTop>=Inp.InAddr+5)
if (UnpAudioBlock)
{
if (DecodeNumber(Inp,&MD[UnpCurChannel])==256)
ReadTables20();
}
else
if (DecodeNumber(Inp,&BlockTables.LD)==269)
ReadTables20();
}
void Unpack::UnpInitData20(int Solid)
{
if (!Solid)
{
TablesRead2=false;
UnpAudioBlock=false;
UnpChannelDelta=0;
UnpCurChannel=0;
UnpChannels=1;
memset(AudV,0,sizeof(AudV));
memset(UnpOldTable20,0,sizeof(UnpOldTable20));
memset(MD,0,sizeof(MD));
}
}
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;
uint Ch=PCh-Delta;
int D=(signed char)Delta;
// Left shift of negative value is undefined behavior in C++,
// so we cast it to unsigned to follow the standard.
D=(uint)D<<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)
{
uint MinDif=V->Dif[0],NumMinDif=0;
V->Dif[0]=0;
for (uint I=1;I<ASIZE(V->Dif);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;
}
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