/
packer.cpp
1639 lines (1333 loc) · 29.1 KB
/
packer.cpp
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// Written by Fabian "ryg" Giesen.
// I hereby place this code in the public domain.
#include "_types.hpp"
#include "packer.hpp"
#include "depacker.hpp"
#include "_startconsole.hpp"
/****************************************************************************/
void PackerBackEnd::InitPrevOffset(sInt count)
{
nPrevOffsets = count;
for(sInt i=0;i<nPrevOffsets;i++)
PrevOffset[i] = 0;
}
sInt PackerBackEnd::FindPrevOffset(sU32 offs) const
{
for(sInt i=0;i<nPrevOffsets;i++)
if(offs==PrevOffset[i])
return i;
return -1;
}
void PackerBackEnd::NewPrevOffset(sU32 offs)
{
sInt ind = FindPrevOffset(offs);
ind = (ind == -1) ? nPrevOffsets - 1 : ind;
// shift around
for(sInt i=ind;i>0;i--)
PrevOffset[i] = PrevOffset[i-1];
// add
PrevOffset[0] = offs;
}
/****************************************************************************/
PackerFrontEnd::PackerFrontEnd(PackerBackEnd *backEnd)
{
sVERIFY(backEnd != 0);
BackEnd = backEnd;
}
PackerFrontEnd::~PackerFrontEnd()
{
BackEnd = 0;
Source = 0;
SourceSize = 0;
}
PackerBackEnd *PackerFrontEnd::GetBackEnd()
{
return BackEnd;
}
sU32 PackerFrontEnd::MaxOutputSize(sU32 inSize)
{
return BackEnd->MaxOutputSize(inSize);
}
sU32 PackerFrontEnd::Pack(const sU8 *src,sU32 srcSize,sU8 *dst,PackerCallback cb,sInt relax)
{
sInt i,bestp,bestsz,sz;
sF32 profiles[17*16];
Source = src;
SourceSize = srcSize;
SourcePtr = BackEnd->EncodeStart(dst,src);
if(cb)
cb(0,srcSize,0);
DoPack(cb);
BackEnd->EncodeEnd(profiles);
sz = BackEnd->GetCurrentSize();
if(cb)
cb(srcSize,srcSize,sz);
if(relax)
{
bestp = -1;
bestsz = sz;
for(i=0;i<relax;i++)
{
SourcePtr = BackEnd->EncodeStart(dst,src,profiles+i*16);
if(cb)
cb(0,srcSize,0);
DoPack(cb);
BackEnd->EncodeEnd(profiles+(i+1)*16);
sz = BackEnd->GetCurrentSize();
if(cb)
cb(srcSize,srcSize,sz);
if(sz<bestsz)
{
bestp = i;
bestsz = sz;
}
}
if(bestp != i-1)
{
SourcePtr = BackEnd->EncodeStart(dst,src,(bestp==-1)?0:profiles+bestp*16);
if(cb)
cb(0,srcSize,0);
DoPack(cb);
BackEnd->EncodeEnd();
sz = BackEnd->GetCurrentSize();
if(cb)
cb(srcSize,srcSize,sz);
}
}
return sz;
}
/****************************************************************************/
void GoodPackerFrontEnd::FindMatch(Match &match,sU32 start,sU32 lookAhead)
{
sInt key,depth;
sU32 node,offset,matchLen,bestOffset,bestLen;
sF32 bestSize,matchSize;
const sU8 *bytes,*ptr1,*ptr2;
// todo: makes those two modifiable parameters.
static const sInt MaxOffset = 512*1024;
static const sInt MaxChainLen = 4096;
// update the hash chain
while(FillPtr<=start)
{
key = *(sU16 *) (Source + FillPtr);
Link[FillPtr] = Head[key];
Head[key] = FillPtr++;
}
bestOffset = 0;
bestLen = 0;
bestSize = BackEnd->MatchLen(bestOffset,bestLen);
node = Link[start];
bytes = Source;
depth = MaxChainLen;
if(lookAhead>1)
{
while(node!=~0U && depth--)
{
offset = start - node;
if(offset>MaxOffset)
break;
if(bytes[node+bestLen]==bytes[start+bestLen] || BackEnd->FindPrevOffset(offset)!=-1)
{
matchLen = 0;
ptr1 = bytes+node;
ptr2 = bytes+start;
if(lookAhead>3)
{
while(matchLen<lookAhead-3 && *(sU32 *) (ptr1+matchLen) == *(sU32 *) (ptr2+matchLen))
matchLen+=4;
}
while(matchLen<lookAhead && ptr1[matchLen]==ptr2[matchLen])
matchLen++;
if(matchLen == lookAhead)
{
bestOffset = offset;
bestLen = matchLen;
break;
}
matchSize = BackEnd->MatchLen(offset,matchLen);
if(matchSize<1e+20f && matchLen > bestLen + (matchSize-bestSize)*BackEnd->InvAvgMatchLen)
{
bestOffset = offset;
bestLen = matchLen;
bestSize = matchSize;
}
}
node = Link[node];
}
}
sVERIFY(bestOffset || !bestLen);
match.Offs = bestOffset;
match.Len = bestLen;
}
void GoodPackerFrontEnd::TryBetterAhead()
{
Match tm;
FindMatch(tm,AheadStart,Ahead);
if(tm.Len>=Ahead && BackEnd->MatchLen(tm.Offs,Ahead)<BackEnd->MatchLen(BM.Offs,Ahead))
BM = tm;
}
void GoodPackerFrontEnd::FlushAhead(sF32 bias)
{
if(Ahead)
{
if(BackEnd->LiteralLen(AheadStart,Ahead)+bias >= BackEnd->MatchLen(BM.Offs,Ahead))
BackEnd->EncodeMatch(BM.Offs,Ahead);
else
BackEnd->EncodeLiteral(AheadStart,Ahead);
Ahead = 0;
}
}
void GoodPackerFrontEnd::DoPack(PackerCallback cb)
{
sU32 lookAhead,testAhead;
Match tm; // tempmatch
sBool betterMatch;
sF32 sizec,sizet;
sU8 tick;
Head = new sU32[65536];
sSetMem(Head,0xff,sizeof(sU32)*65536);
Link = new sU32[SourceSize];
FillPtr = 0;
tick = 0;
AheadStart = 0;
Ahead = 0;
while(SourcePtr<SourceSize-1)
{
if(!++tick && cb)
cb(SourcePtr,SourceSize,BackEnd->GetCurrentSize());
lookAhead = SourceSize - SourcePtr;
FindMatch(CM,SourcePtr,lookAhead);
if(CM.Len>=2)
{
betterMatch = sFALSE;
sizec = BackEnd->MatchLen(CM.Offs,CM.Len);
// try to find a better match
if(BackEnd->FindPrevOffset(CM.Offs)==-1 || Ahead && BackEnd->MatchLen(BM.Offs,Ahead)<BackEnd->LiteralLen(AheadStart,Ahead))
{
for(testAhead=1;!betterMatch && CM.Len>testAhead && testAhead<3;testAhead++)
{
FindMatch(tm,SourcePtr+testAhead,lookAhead-testAhead);
sizet = BackEnd->MatchLen(tm.Offs,tm.Len);
if(sizet<1e+20f && CM.Len < tm.Len+(sizec-sizet)*BackEnd->InvAvgMatchLen
|| Ahead && tm.Len >= CM.Len && sizet<sizec)
betterMatch = sTRUE;
}
if(testAhead==2 && !Ahead && tm.Len<CM.Len && BackEnd->LiteralLen(SourcePtr,1)+sizet>sizec)
betterMatch = sFALSE;
}
if(!betterMatch)
{
if(Ahead)
{
TryBetterAhead();
FlushAhead(sizec - BackEnd->MatchLen(CM.Offs,CM.Len,BM.Offs));
}
if(BackEnd->LiteralLen(SourcePtr,CM.Len)<BackEnd->MatchLen(CM.Offs,CM.Len))
BackEnd->EncodeLiteral(SourcePtr,CM.Len);
else
BackEnd->EncodeMatch(CM.Offs,CM.Len);
SourcePtr += CM.Len;
}
else
{
if(!Ahead)
{
BM = CM;
AheadStart = SourcePtr;
}
Ahead++;
SourcePtr++;
}
}
else
{
if(Ahead)
Ahead++;
else
BackEnd->EncodeLiteral(SourcePtr,1);
SourcePtr++;
}
if(Ahead && Ahead==BM.Len)
{
TryBetterAhead();
FlushAhead();
}
}
FlushAhead();
if(SourcePtr!=SourceSize)
BackEnd->EncodeLiteral(SourcePtr,SourceSize-SourcePtr);
delete[] Link;
delete[] Head;
}
GoodPackerFrontEnd::GoodPackerFrontEnd(PackerBackEnd *backEnd)
: PackerFrontEnd(backEnd)
{
}
/****************************************************************************/
void BestPackerFrontEnd::DoPack(PackerCallback cb)
{
struct Token
{
sU32 DecodeSize;
sU32 Pos;
sF64 CodeSize;
};
Token *tk,*tokens;
sU32 *links;
sU32 *head,i,key,ptr,depth,bestOff,bestLen,count,maxs;
sU32 lastBestLen,lastBestOff;
sF32 sz;
const sU8 *src1,*src2;
sU8 tick;
tokens = new Token[SourceSize+1];
sSetMem(tokens,0,sizeof(Token)*(SourceSize+1));
// prepare match tables
head = new sU32[65536];
links = new sU32[SourceSize];
sSetMem(head,0xff,sizeof(sU32)*65536);
for(i=0;i<SourceSize-1;i++)
{
key = *(sU16 *) (Source + i);
links[i] = head[key];
head[key] = i;
}
links[SourceSize-1] = ~0U;
delete[] head;
// pathfinding loop
tick = 0;
lastBestLen = 0;
lastBestOff = 0;
for(i=SourceSize-1;i!=~0U;i--)
{
tk = tokens+i;
// start with literal
tk->DecodeSize = 1;
tk->Pos = i;
tk->CodeSize = BackEnd->AvgLiteralLen + tk[1].CodeSize;
ptr = links[i];
depth = 0;
if(lastBestLen && i>=lastBestOff && Source[i] == Source[i-lastBestOff])
{
// try to append to match from last iteration if possible
sz = BackEnd->MatchLen(lastBestOff,lastBestLen+1);
if(sz+tk[lastBestLen+1].CodeSize < tk->CodeSize)
{
bestLen = lastBestLen+1;
bestOff = lastBestOff;
tk->DecodeSize = bestLen;
tk->Pos = bestOff;
tk->CodeSize = sz + tk[bestLen].CodeSize;
}
}
else
{
bestOff = 0;
bestLen = 0;
}
maxs = SourceSize-i;
if(!++tick && cb)
cb(sMin(maxs,SourceSize-1),SourceSize,0);
while(ptr != ~0U)
{
src1 = Source + i;
src2 = Source + ptr;
count = 0;
if(src1[bestLen] == src2[bestLen])
{
while(count+3<maxs && *(sU32 *) (src1+count) == *(sU32 *) (src2+count))
count+=4;
while(count<maxs && src1[count]==src2[count])
count++;
if(count>1)
{
sz = BackEnd->MatchLen(i-ptr,count);
if(sz+tk[count].CodeSize < tk->CodeSize)
{
bestLen = count;
bestOff = i-ptr;
tk->DecodeSize = bestLen;
tk->Pos = bestOff;
tk->CodeSize = sz + tk[bestLen].CodeSize;
}
}
}
if(++depth == 2048)
break;
ptr = links[ptr];
}
lastBestLen = bestLen;
lastBestOff = bestOff;
}
// encoding loop
for(i=SourcePtr;i<SourceSize;i+=tokens[i].DecodeSize)
{
tk = tokens+i;
// try things we can't during pathfinding: actual literal size...
sz = BackEnd->LiteralLen(i,1);
if(sz+tk[1].CodeSize < tk->CodeSize)
{
tk->DecodeSize = 1;
tk->CodeSize = sz + tk[1].CodeSize;
}
// and previous match references
for(sInt j=0;j<BackEnd->nPrevOffsets;j++)
{
if(BackEnd->PrevOffset[j])
{
count = 0;
src1 = Source + i;
src2 = Source + i - BackEnd->PrevOffset[j];
while(i+count<SourceSize && src1[count]==src2[count])
count++;
if(count > 1)
{
sz = BackEnd->MatchLen(BackEnd->PrevOffset[j],count);
if(sz+tk[count].CodeSize < tk->CodeSize)
{
tk->DecodeSize = count;
tk->Pos = BackEnd->PrevOffset[j];
tk->CodeSize = sz + tk[count].CodeSize;
}
}
}
}
if(tk->DecodeSize == 1)
BackEnd->EncodeLiteral(i,tk->DecodeSize);
else
BackEnd->EncodeMatch(tk->Pos,tk->DecodeSize);
}
delete[] tokens;
}
BestPackerFrontEnd::BestPackerFrontEnd(PackerBackEnd *backEnd)
: PackerFrontEnd(backEnd)
{
}
/****************************************************************************/
#define sRANGETOP (1<<24)
#define sRANGEBOT (1<<16)
void RangeCoder::InitEncode(sU8 *buffer)
{
Buffer = buffer;
Bytes = Low = 0;
Range = ~0;
}
void RangeCoder::FinishEncode()
{
sInt i;
for(i=0;i<4;i++)
{
Buffer[Bytes++] = Low>>24;
Low <<= 8;
}
}
void RangeCoder::Encode(sU32 cumfreq,sU32 freq,sU32 totfreq)
{
Range /= totfreq;
Low += cumfreq * Range;
Range *= freq;
while ((Low ^ Low+Range)<sRANGETOP || Range<sRANGEBOT && ((Range = -sInt(Low) & sRANGEBOT-1),1))
{
Buffer[Bytes++] = Low>>24;
Low <<= 8;
Range <<= 8;
}
}
void RangeCoder::EncodePlain(sU32 value,sU32 max)
{
Encode(value,1,max);
}
void RangeCoder::InitDecode(sU8 *buffer)
{
sInt i;
Bytes = Low = Code = 0;
Range = ~0;
Buffer = buffer;
for(i=0;i<4;i++)
Code = (Code<<8) + Buffer[Bytes++];
}
sU32 RangeCoder::GetFreq(sU32 totfreq)
{
Range /= totfreq;
return (Code - Low) / Range;
}
void RangeCoder::Decode(sU32 cumfreq,sU32 freq)
{
Low += cumfreq * Range;
Range *= freq;
while((Low ^ Low+Range)<sRANGETOP || Range<sRANGEBOT && ((Range = -sInt(Low) & sRANGEBOT-1),1))
{
Code = (Code<<8) + Buffer[Bytes++];
Range <<= 8;
Low <<= 8;
}
}
sU32 RangeCoder::DecodePlain(sU32 max)
{
sU32 v;
v = GetFreq(max);
Decode(v,1);
return v;
}
/****************************************************************************/
void RangeModel::Init(sInt symbols,sInt thresh)
{
sInt i;
Symbols = symbols;
Freq = new sInt[symbols*2];
TotFreq = symbols;
Thresh = thresh;
BitsOut = 0.0f;
SymCount = 0;
for(i=0;i<symbols;i++)
{
Freq[i*2+0] = i;
Freq[i*2+1] = 1;
}
}
sF32 RangeModel::Encode(RangeCoder &coder,sInt symbol)
{
sF32 size;
size = GetBits(symbol);
SymCount++;
BitsOut += size;
coder.Encode(Freq[symbol*2+0],Freq[symbol*2+1],TotFreq);
Update(symbol);
return size;
}
sInt RangeModel::Decode(RangeCoder &coder)
{
sInt i,j,val;
val = coder.GetFreq(GetTotFreq());
for(i=0;i<Symbols;i++)
{
j = val-Freq[i*2+0];
if(j>=0 && j<Freq[i*2+1])
break;
}
coder.Decode(Freq[i*2+0],Freq[i*2+1]);
Update(i);
return i;
}
void RangeModel::Update(sInt symbol)
{
sInt i,j;
Freq[symbol*2+1]+=2;
TotFreq+=2;
for(i=symbol+1;i<Symbols;i++)
Freq[i*2]+=2;
if(TotFreq >= Thresh)
{
j = 0;
for(i=0;i<Symbols;i++)
{
Freq[i*2+0] = j;
Freq[i*2+1] -= Freq[i*2+1] / 2;
j += Freq[i*2+1];
}
TotFreq = j;
}
}
/****************************************************************************/
void CarryRangeCoder::InitEncode(sU8 *buffer)
{
Buffer = buffer;
Bytes = 0;
Low = 0;
Range = ~0;
FFNum = 0;
Cache = 0;
FirstByte = sTRUE;
}
void CarryRangeCoder::FinishEncode()
{
sInt i;
for(i=0;i<5;i++)
ShiftLow();
}
void CarryRangeCoder::EncodeBit(sU32 prob,sBool bit)
{
sU32 newBound = (Range >> 11) * prob;
if(!bit)
Range = newBound;
else
{
Low += newBound;
Range -= newBound;
}
while(Range < 0x01000000U)
{
Range <<= 8;
ShiftLow();
}
}
void CarryRangeCoder::ShiftLow()
{
sU32 Carry = Low >> 32;
if(Low < 0xff000000U || Carry == 1)
{
if(!FirstByte)
Buffer[Bytes++] = Cache + Carry;
else
FirstByte = sFALSE;
while(FFNum)
{
Buffer[Bytes++] = 0xff + Carry;
FFNum--;
}
Cache = (Low >> 24) & 0xff;
}
else
FFNum++;
Low = (Low << 8) & 0xffffffff;
}
/****************************************************************************/
void BitBuffer::InitEncode(sU8 *buffer)
{
Buffer = buffer;
BitPos = 7;
Bytes = 0;
Tag = 0;
}
void BitBuffer::FinishEncode()
{
if(Tag)
*Tag <<= (7 - BitPos);
}
void BitBuffer::PutBit(sBool bit)
{
if(++BitPos == 8)
{
BitPos = 0;
Tag = Buffer + Bytes++;
*Tag = 0;
}
if(bit)
*Tag = (*Tag << 1) | 1;
else
*Tag = *Tag << 1;
}
void BitBuffer::PutByte(sU8 value)
{
Buffer[Bytes++] = value;
}
/****************************************************************************/
sF32 BitModel::Cost[513];
sBool BitModel::CostInit = sFALSE;
void BitModel::Init(sInt move)
{
sInt i;
Prob = 1024;
Move = move;
if(!CostInit)
{
for(i=1;i<513;i++)
Cost[i] = -sFLog(i / 512.0f) / sFLog(2.0);
Cost[0] = 1e+20f;
}
}
sF32 BitModel::Encode(CarryRangeCoder &coder,sBool bit)
{
sF32 cost;
cost = GetBits(bit);
coder.EncodeBit(Prob,bit);
if(!bit)
Prob += (2048 - Prob) >> Move;
else
Prob -= Prob >> Move;
return cost;
}
sF32 BitModel::GetBits(sBool bit) const
{
sInt pi,ik;
sF32 t;
pi = Prob;
if(bit)
pi = 2048 - pi;
ik = pi >> 2;
t = (pi & 3) * 0.25f;
return Cost[ik] * (1.0f - t) + Cost[ik+1] * t;
}
/****************************************************************************/
void GammaModel::Init(sInt move)
{
sInt i;
for(i=0;i<256;i++)
Models[i].Init(move);
Ctx = 1;
}
sF32 GammaModel::Encode(CarryRangeCoder &coder,sInt value)
{
sF32 cbits;
cbits = Models[Ctx].Encode(coder,value >> 1);
Ctx = (Ctx * 2) + (value >> 1);
cbits += Models[Ctx].Encode(coder,value & 1);
Ctx = (Ctx * 2) + (value & 1);
if(!(value & 2))
Ctx = 1;
return cbits;
}
sF32 GammaModel::GetBits(sInt value) const
{
sF32 cbits;
cbits = Models[Ctx].GetBits(value >> 1);
Ctx = (Ctx * 2) + (value >> 1);
cbits += Models[Ctx].GetBits(value & 1);
Ctx = (Ctx * 2) + (value & 1);
if(!(value & 2))
Ctx = 1;
return cbits;
}
/****************************************************************************/
// constants that require changes in the depacker
static const sInt MatchOffs1 = 96;
static const sInt MatchOffs2 = 2048;
sF32 CCAPackerBackEnd::RealGammaLen(sInt j,sU32 value)
{
sInt invertlen;
sU32 invert;
sF32 sz;
invertlen = 0;
invert = 0;
sz = 0.0f;
if(value<2)
return 1e+20f;
do
{
invert = (invert << 1) | (value & 1);
invertlen++;
}
while((value >>= 1) > 1);
while(--invertlen)
{
sz += GammaSize[j*4 + (invert & 1) + 2];
//sz += Gamma[j].GetBits((invert & 1) + 2);
invert >>= 1;
}
return sz + GammaSize[j*4 + (invert & 1)];
//return sz + Gamma[j].GetBits(invert & 1);*/
}
sF32 CCAPackerBackEnd::EncodeGamma(sInt j,sU32 value)
{
sInt invertlen;
sU32 invert;
sF32 sz;
invertlen = 0;
invert = 0;
sz = 0.0f;
do
{
invert = (invert << 1) | (value & 1);
invertlen++;
}
while((value >>= 1) > 1);
while(--invertlen)
{
sz += Gamma[j].Encode(Coder,(invert&1)|2);
invert >>= 1;
}
sz += Gamma[j].Encode(Coder,invert&1);
return sz;
}
sU32 CCAPackerBackEnd::MaxOutputSize(sU32 inSize)
{
return inSize + (inSize/8) + 256; // should be ok
}
DepackFunction CCAPackerBackEnd::GetDepacker()
{
return CCADepacker;
}
sF32 CCAPackerBackEnd::MatchLen(sU32 pos,sU32 len,sU32 PO)
{
sBool prev = sFALSE;
if(!PO)
prev = FindPrevOffset(pos) != -1;
else
prev = pos == PO;
if(!pos || len<2 || !prev && ((pos>=96 && len<3) || (pos>=2048 && len<4)))
return 1e+20f;
if(prev)
return GammaLen(1,len) + CodesSize[1];
else
{
if(pos>=MatchOffs1) len--;
if(pos>=MatchOffs2) len--;
pos--;
return GammaLen(0,(pos>>4)+2) + GammaLen(1,len) + CodesSize[1] + 4.0f;
}
}
sF32 CCAPackerBackEnd::LiteralLen(sU32 pos,sU32 len)
{
sF32 clen;
sInt j,ctx,bit;
clen = CodesSize[0] * len;
while(len--)
{
ctx = 1;
for(j=7;j>=0;j--)
{
bit = (Source[pos] >> j) & 1;
clen += LitBit[ctx].GetBits(bit);
ctx = (ctx * 2) + bit;
}
pos++;
}
return clen;
}
sU32 CCAPackerBackEnd::EncodeStart(sU8 *dest,const sU8 *src,sF32 *profile)
{
sInt i,j;
static sF32 defaultProfile[] =
{
1.5580f, 3.2685f, 1.8210f, 1.8699f, // gamma 0
2.0000f, 1.1142f, 2.3943f, 3.3536f, // gamma 1
0.7216f, 1.3454f, // codes
5.9170f, 7.2410f // average code lengths
};
Coder.InitEncode(dest);
Codes[0].Init(5);
Codes[1].Init(5);
Gamma[0].Init(5);
Gamma[1].Init(5);
PrevMatch.Init(5);
Source = src;
LWM = sFALSE;
InitPrevOffset(1);
if(!profile)
profile = defaultProfile;
// setup parameters from profile
GammaSize[0] = profile[ 0];
GammaSize[1] = profile[ 1];
GammaSize[2] = profile[ 2];
GammaSize[3] = profile[ 3];
GammaSize[4] = profile[ 4];
GammaSize[5] = profile[ 5];