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Fixed broken bitstream parsing

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+ refactoring
This commit is contained in:
Martin Tůma 2021-11-09 23:11:45 +01:00
parent 9bfc7e8b89
commit de028cd2d4
3 changed files with 37 additions and 41 deletions
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11
src/map/IMG/bitstream.cpp
View File

@ -41,16 +41,15 @@ bool BitStream4F::flush()
return true;
}
bool BitStream4F::read(int bits, quint32 &val)
bool BitStream4F::read(quint32 bits, quint32 &val)
{
if (bits <= 32 - (int)(_used + _unused)) {
if (bits <= 32 - (_used + _unused)) {
val = bits ? (_data << _used) >> (32 - bits) : 0;
_used += bits;
return true;
}
if (_unused)
return false;
Q_ASSERT(_length && !_unused);
quint32 old = (_used < 32) ? (_data << _used) >> (32 - bits) : 0;
quint32 bytes = qMin(_length, 4U);
@ -73,7 +72,7 @@ BitStream4R::BitStream4R(const SubFile &file, SubFile::Handle &hdl,
_file.seek(_hdl, _file.pos(_hdl) - 4);
}
bool BitStream4R::readBytes(int bytes, quint32 &val)
bool BitStream4R::readBytes(quint32 bytes, quint32 &val)
{
quint32 bits = _used % 8;
quint32 b;
@ -85,7 +84,7 @@ bool BitStream4R::readBytes(int bytes, quint32 &val)
}
val = 0;
for (int i = 0; i < bytes; i++) {
for (quint32 i = 0; i < bytes; i++) {
if (!read(8, b))
return false;
val |= (b << (i * 8));

19
src/map/IMG/bitstream.h
View File

@ -10,7 +10,7 @@ public:
BitStream1(const SubFile &file, SubFile::Handle &hdl, quint32 length)
: _file(file), _hdl(hdl), _length(length), _remaining(0) {}
template<typename T> bool read(int bits, T &val);
template<typename T> bool read(quint32 bits, T &val);
bool flush();
quint64 bitsAvailable() const {return (quint64)_length * 8 + _remaining;}
@ -44,7 +44,7 @@ public:
BitStream4F(const SubFile &file, SubFile::Handle &hdl, quint32 length)
: BitStream4(file, hdl, length) {}
bool read(int bits, quint32 &val);
bool read(quint32 bits, quint32 &val);
bool flush();
};
@ -60,8 +60,8 @@ public:
BitStream4R(const SubFile &file, SubFile::Handle &hdl, quint32 length);
template<typename T> bool read(int bits, T &val);
bool readBytes(int bytes, quint32 &val);
template<typename T> bool read(quint32 bits, T &val);
bool readBytes(quint32 bytes, quint32 &val);
bool readVUInt32(quint32 &val);
bool readVuint32SM(quint32 &val1, quint32 &val2, quint32 &val2Bits);
@ -73,11 +73,11 @@ public:
template<typename T>
bool BitStream1::read(int bits, T &val)
bool BitStream1::read(quint32 bits, T &val)
{
val = 0;
for (int pos = 0; pos < bits; ) {
for (quint32 pos = 0; pos < bits; ) {
if (!_remaining) {
if (!_length || !_file.readByte(_hdl, &_data))
return false;
@ -103,16 +103,15 @@ bool BitStream1::read(int bits, T &val)
}
template<typename T>
bool BitStream4R::read(int bits, T &val)
bool BitStream4R::read(quint32 bits, T &val)
{
if (bits <= 32 - (int)(_used + _unused)) {
if (bits <= 32 - (_used + _unused)) {
val = bits ? (_data << _used) >> (32 - bits) : 0;
_used += bits;
return true;
}
if (_unused)
return false;
Q_ASSERT(_length && !_unused);
quint32 old = (_used < 32) ? (_data << _used) >> (32 - bits) : 0;
quint32 bytes = qMin(_length, 4U);

48
src/map/IMG/huffmanstream.h
View File

@ -12,7 +12,7 @@ public:
HuffmanStream(BitStream &bitstream, const HuffmanTable &table)
: _symbolDataSize(0), _symbolData(0), _bs(bitstream), _table(table) {}
bool read(int bits, quint32 &val);
bool read(quint32 bits, quint32 &val);
bool readSymbol(quint32 &symbol);
bool atEnd() const
@ -24,29 +24,35 @@ protected:
quint32 _symbolData;
private:
bool fetchData();
BitStream &_bs;
const HuffmanTable &_table;
};
template <class BitStream>
bool HuffmanStream<BitStream>::read(int bits, quint32 &val)
bool HuffmanStream<BitStream>::fetchData()
{
if (_symbolDataSize < (quint32)bits) {
quint32 next;
quint8 nextSize = qMin((quint64)(32 - _symbolDataSize),
_bs.bitsAvailable());
quint32 next;
quint8 nextSize = qMin((quint64)(32 - _symbolDataSize), _bs.bitsAvailable());
if (!_bs.read(nextSize, next))
if (!_bs.read(nextSize, next))
return false;
_symbolData = (nextSize < 32) ? (_symbolData << nextSize) | next : next;
_symbolDataSize += nextSize;
return true;
}
template <class BitStream>
bool HuffmanStream<BitStream>::read(quint32 bits, quint32 &val)
{
if (_symbolDataSize < bits)
if (!fetchData() || _symbolDataSize < bits)
return false;
_symbolData = (_symbolData << nextSize) | next;
_symbolDataSize += nextSize;
if (_symbolDataSize < (quint32)bits)
return false;
}
val = (_symbolData << (32-_symbolDataSize)) >> (32 - bits);
val = (_symbolData << (32 - _symbolDataSize)) >> (32 - bits);
_symbolDataSize -= bits;
return true;
@ -57,18 +63,10 @@ bool HuffmanStream<BitStream>::readSymbol(quint32 &symbol)
{
quint8 size;
if (_symbolDataSize < _table.symBits()) {
quint32 next;
quint8 nextSize = qMin((quint64)(32 - _symbolDataSize),
_bs.bitsAvailable());
if (!_bs.read(nextSize, next))
if (_symbolDataSize < _table.symBits())
if (!fetchData() || !_symbolDataSize)
return false;
_symbolData = (_symbolData << nextSize) | next;
_symbolDataSize += nextSize;
}
symbol = _table.symbol(_symbolData << (32 - _symbolDataSize), size);
if (size > _symbolDataSize)
return false;