winamp/Src/external_dependencies/openmpt-trunk/include/ancient/src/MMCMPDecompressor.cpp

255 lines
7.2 KiB
C++

/* Copyright (C) Teemu Suutari */
#include <cstring>
#include "MMCMPDecompressor.hpp"
#include "InputStream.hpp"
#include "OutputStream.hpp"
#include "common/OverflowCheck.hpp"
#include "common/Common.hpp"
namespace ancient::internal
{
bool MMCMPDecompressor::detectHeader(uint32_t hdr) noexcept
{
return hdr==FourCC("ziRC");
}
std::shared_ptr<Decompressor> MMCMPDecompressor::create(const Buffer &packedData,bool exactSizeKnown,bool verify)
{
return std::make_shared<MMCMPDecompressor>(packedData,exactSizeKnown,verify);
}
MMCMPDecompressor::MMCMPDecompressor(const Buffer &packedData,bool exactSizeKnown,bool verify) :
_packedData(packedData)
{
if (!detectHeader(packedData.readBE32(0)) || packedData.readBE32(4U)!=FourCC("ONia") ||
packedData.readLE16(8U)!=14U || packedData.size()<24U)
throw InvalidFormatError();
_version=packedData.readLE16(10U);
_blocks=packedData.readLE16(12U);
_blocksOffset=packedData.readLE32(18U);
_rawSize=packedData.readLE32(14U);
if (OverflowCheck::sum(_blocksOffset,uint32_t(_blocks)*4U)>packedData.size())
throw InvalidFormatError();
_packedSize=0;
for (uint32_t i=0;i<_blocks;i++)
{
uint32_t blockAddr=packedData.readLE32(OverflowCheck::sum(_blocksOffset,i*4U));
if (OverflowCheck::sum(blockAddr,20U)>=packedData.size())
throw InvalidFormatError();
uint32_t blockSize=packedData.readLE32(blockAddr+4U)+uint32_t(packedData.readLE16(blockAddr+12U))*8U+20U;
_packedSize=std::max(_packedSize,OverflowCheck::sum(blockAddr,blockSize));
}
if (_packedSize>packedData.size())
throw InvalidFormatError();
}
MMCMPDecompressor::~MMCMPDecompressor()
{
// nothing needed
}
const std::string &MMCMPDecompressor::getName() const noexcept
{
static std::string name="MMCMP: Music Module Compressor";
return name;
}
size_t MMCMPDecompressor::getPackedSize() const noexcept
{
return _packedSize;
}
size_t MMCMPDecompressor::getRawSize() const noexcept
{
return _rawSize;
}
void MMCMPDecompressor::decompressImpl(Buffer &rawData,bool verify)
{
if (rawData.size()<_rawSize) throw DecompressionError();
// MMCMP allows gaps in data. Although not used in practice still we memset before decompressing to be sure
std::memset(rawData.data(),0,rawData.size());
uint8_t *rawDataPtr=rawData.data();
for (uint32_t i=0;i<_blocks;i++)
{
uint32_t blockAddr=_packedData.readLE32(_blocksOffset+i*4U);
uint32_t unpackedBlockSize=_packedData.readLE32(blockAddr);
uint32_t packedBlockSize=_packedData.readLE32(blockAddr+4U);
uint32_t fileChecksum=_packedData.readLE32(blockAddr+8U);
uint32_t subBlocks=_packedData.readLE16(blockAddr+12U);
uint16_t flags=_packedData.readLE16(blockAddr+14U);
uint32_t packTableSize=_packedData.readLE16(blockAddr+16U);
if (packTableSize>packedBlockSize)
throw DecompressionError();
uint16_t bitCount=_packedData.readLE16(blockAddr+18U);
ForwardInputStream inputStream(_packedData,OverflowCheck::sum(blockAddr,subBlocks*8U,20U,packTableSize),OverflowCheck::sum(blockAddr,subBlocks*8U,20U,packedBlockSize));
LSBBitReader<ForwardInputStream> bitReader(inputStream);
auto readBits=[&](uint32_t count)->uint32_t
{
return bitReader.readBits8(count);
};
uint32_t currentSubBlock=0;
uint32_t outputOffset=0,outputSize=0;
auto readNextSubBlock=[&]()
{
if (currentSubBlock>=subBlocks)
throw DecompressionError();
outputOffset=_packedData.readLE32(blockAddr+currentSubBlock*8U+20U);
outputSize=_packedData.readLE32(blockAddr+currentSubBlock*8U+24U);
if (OverflowCheck::sum(outputOffset,outputSize)>_rawSize)
throw DecompressionError();
currentSubBlock++;
};
uint32_t checksum=0,checksumPartial=0,checksumRot=0;
auto writeByte=[&](uint8_t value,bool allowOverrun=false)
{
while (!outputSize)
{
if (allowOverrun && currentSubBlock>=subBlocks) return;
readNextSubBlock();
}
outputSize--;
rawDataPtr[outputOffset++]=value;
if (verify)
{
if (_version>=0x1310)
{
checksum^=value;
checksum=(checksum<<1)|(checksum>>31);
} else {
checksumPartial|=((uint32_t)value)<<checksumRot;
checksumRot+=8U;
if (checksumRot==32U)
{
checksum^=checksumPartial;
checksumPartial=0;
checksumRot=0;
}
}
}
};
// flags are
// 0 = compressed
// 1 = delta mode
// 2 = 16 bit mode
// 8 = stereo
// 9 = abs16
// 10 = endian
// flags do not combine nicely
// no compress - no other flags
// compressed 8 bit - only delta (and presumably stereo matters)
// compressed 16 bit - all flags matter
if (!(flags&0x1U))
{
// not compressed
for (uint32_t j=0;j<packedBlockSize;j++)
writeByte(inputStream.readByte());
} else if (!(flags&0x4U)) {
// 8 bit compression
// in case the bit-count is not enough to store a value, symbol at the end
// of the codemap is created and this marks as a new bitCount
static const uint8_t valueThresholds[16]={0x1U, 0x3U, 0x7U, 0xfU,0x1eU,0x3cU,0x78U,0xf8U};
static const uint8_t extraBits[8]={3,3,3,3, 2,1,0,0};
if (bitCount>=8)
throw DecompressionError();
uint8_t oldValue[2]={0,0};
uint32_t chIndex=0;
const uint8_t *tablePtr=&_packedData[blockAddr+subBlocks*8U+20U];
for (uint32_t j=0;j<unpackedBlockSize;)
{
uint8_t value=readBits(bitCount+1);
if (value>=valueThresholds[bitCount])
{
uint32_t newBitCount=readBits(extraBits[bitCount])+((value-valueThresholds[bitCount])<<extraBits[bitCount]);
if (bitCount!=newBitCount)
{
bitCount=newBitCount&0x7U;
continue;
}
value=0xf8U+readBits(3U);
if (value==0xffU && readBits(1U)) break;
}
if (value>=packTableSize)
throw DecompressionError();
value=tablePtr[value];
if (flags&0x2U)
{
// delta
value+=oldValue[chIndex];
oldValue[chIndex]=value;
if (flags&0x100U) chIndex^=1U; // stereo
}
writeByte(value);
j++;
}
} else {
// 16 bit compression
// shameless copy-paste from 8-bit variant, with minor changes
static const uint16_t valueThresholds[16]={
0x1U, 0x3U, 0x7U, 0xfU, 0x1eU, 0x3cU, 0x78U, 0xf0U,
0x1f0U, 0x3f0U, 0x7f0U, 0xff0U,0x1ff0U,0x3ff0U,0x7ff0U,0xfff0U
};
static const uint8_t extraBits[16]={4,4,4,4, 3,2,1,0, 0,0,0,0, 0,0,0,0};
if (bitCount>=16)
throw DecompressionError();
int16_t oldValue[2]={0,0};
uint32_t chIndex=0;
for (uint32_t j=0;j<unpackedBlockSize;)
{
int32_t value=readBits(bitCount+1);
if (value>=valueThresholds[bitCount])
{
uint32_t newBitCount=readBits(extraBits[bitCount])+((value-valueThresholds[bitCount])<<extraBits[bitCount]);
if (bitCount!=newBitCount)
{
bitCount=newBitCount&0xfU;
continue;
}
value=0xfff0U+readBits(4U);
if (value==0xffffU && readBits(1U)) break;
}
if (value&1U) value=-value-1;
value>>=1;
if (flags&0x2U)
{
// delta
value+=oldValue[chIndex];
oldValue[chIndex]=value;
if (flags&0x100U) chIndex^=1U; // stereo
} else if (!(flags&0x200U)) value^=0x8000U; // abs16
if (flags&0x400U)
{
// big ending
writeByte(value>>8U);
writeByte(value,true);
} else {
// little endian
writeByte(value);
writeByte(value>>8U,true);
}
j+=2;
}
}
if (verify && checksum!=fileChecksum)
throw VerificationError();
}
}
}