Merge pull request #5348 from ReinUsesLisp/astc-robustness
astc: Make the decoder more robust to invalid data
This commit is contained in:
commit
6dc1d48fd1
@ -42,21 +42,24 @@ constexpr u32 Popcnt(u32 n) {
|
||||
|
||||
class InputBitStream {
|
||||
public:
|
||||
constexpr explicit InputBitStream(const u8* ptr, std::size_t start_offset = 0)
|
||||
: cur_byte{ptr}, next_bit{start_offset % 8} {}
|
||||
constexpr explicit InputBitStream(std::span<const u8> data, size_t start_offset = 0)
|
||||
: cur_byte{data.data()}, total_bits{data.size()}, next_bit{start_offset % 8} {}
|
||||
|
||||
constexpr std::size_t GetBitsRead() const {
|
||||
constexpr size_t GetBitsRead() const {
|
||||
return bits_read;
|
||||
}
|
||||
|
||||
constexpr bool ReadBit() {
|
||||
const bool bit = (*cur_byte >> next_bit++) & 1;
|
||||
if (bits_read >= total_bits * 8) {
|
||||
return 0;
|
||||
}
|
||||
const bool bit = ((*cur_byte >> next_bit) & 1) != 0;
|
||||
++next_bit;
|
||||
while (next_bit >= 8) {
|
||||
next_bit -= 8;
|
||||
cur_byte++;
|
||||
++cur_byte;
|
||||
}
|
||||
|
||||
bits_read++;
|
||||
++bits_read;
|
||||
return bit;
|
||||
}
|
||||
|
||||
@ -79,8 +82,9 @@ public:
|
||||
|
||||
private:
|
||||
const u8* cur_byte;
|
||||
std::size_t next_bit = 0;
|
||||
std::size_t bits_read = 0;
|
||||
size_t total_bits = 0;
|
||||
size_t next_bit = 0;
|
||||
size_t bits_read = 0;
|
||||
};
|
||||
|
||||
class OutputBitStream {
|
||||
@ -193,15 +197,15 @@ struct IntegerEncodedValue {
|
||||
};
|
||||
};
|
||||
using IntegerEncodedVector = boost::container::static_vector<
|
||||
IntegerEncodedValue, 64,
|
||||
IntegerEncodedValue, 256,
|
||||
boost::container::static_vector_options<
|
||||
boost::container::inplace_alignment<alignof(IntegerEncodedValue)>,
|
||||
boost::container::throw_on_overflow<false>>::type>;
|
||||
|
||||
static void DecodeTritBlock(InputBitStream& bits, IntegerEncodedVector& result, u32 nBitsPerValue) {
|
||||
// Implement the algorithm in section C.2.12
|
||||
u32 m[5];
|
||||
u32 t[5];
|
||||
std::array<u32, 5> m;
|
||||
std::array<u32, 5> t;
|
||||
u32 T;
|
||||
|
||||
// Read the trit encoded block according to
|
||||
@ -866,7 +870,7 @@ public:
|
||||
}
|
||||
};
|
||||
|
||||
static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nPartitions,
|
||||
static void DecodeColorValues(u32* out, std::span<u8> data, const u32* modes, const u32 nPartitions,
|
||||
const u32 nBitsForColorData) {
|
||||
// First figure out how many color values we have
|
||||
u32 nValues = 0;
|
||||
@ -898,7 +902,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
|
||||
// We now have enough to decode our integer sequence.
|
||||
IntegerEncodedVector decodedColorValues;
|
||||
|
||||
InputBitStream colorStream(data);
|
||||
InputBitStream colorStream(data, 0);
|
||||
DecodeIntegerSequence(decodedColorValues, colorStream, range, nValues);
|
||||
|
||||
// Once we have the decoded values, we need to dequantize them to the 0-255 range
|
||||
@ -1441,7 +1445,7 @@ static void ComputeEndpos32s(Pixel& ep1, Pixel& ep2, const u32*& colorValues,
|
||||
|
||||
static void DecompressBlock(std::span<const u8, 16> inBuf, const u32 blockWidth,
|
||||
const u32 blockHeight, std::span<u32, 12 * 12> outBuf) {
|
||||
InputBitStream strm(inBuf.data());
|
||||
InputBitStream strm(inBuf);
|
||||
TexelWeightParams weightParams = DecodeBlockInfo(strm);
|
||||
|
||||
// Was there an error?
|
||||
@ -1619,15 +1623,16 @@ static void DecompressBlock(std::span<const u8, 16> inBuf, const u32 blockWidth,
|
||||
|
||||
// Make sure that higher non-texel bits are set to zero
|
||||
const u32 clearByteStart = (weightParams.GetPackedBitSize() >> 3) + 1;
|
||||
if (clearByteStart > 0) {
|
||||
if (clearByteStart > 0 && clearByteStart <= texelWeightData.size()) {
|
||||
texelWeightData[clearByteStart - 1] &=
|
||||
static_cast<u8>((1 << (weightParams.GetPackedBitSize() % 8)) - 1);
|
||||
std::memset(texelWeightData.data() + clearByteStart, 0,
|
||||
std::min(16U - clearByteStart, 16U));
|
||||
}
|
||||
std::memset(texelWeightData.data() + clearByteStart, 0, std::min(16U - clearByteStart, 16U));
|
||||
|
||||
IntegerEncodedVector texelWeightValues;
|
||||
|
||||
InputBitStream weightStream(texelWeightData.data());
|
||||
InputBitStream weightStream(texelWeightData);
|
||||
|
||||
DecodeIntegerSequence(texelWeightValues, weightStream, weightParams.m_MaxWeight,
|
||||
weightParams.GetNumWeightValues());
|
||||
|
Loading…
Reference in New Issue
Block a user