Raster Data Packet RLE decoding to levels

This commit is contained in:
Dan Paulat 2022-04-09 21:03:49 -05:00
parent 0b761185a0
commit 5b32118626
2 changed files with 31 additions and 1 deletions

View file

@ -37,6 +37,8 @@ public:
uint16_t number_of_rows() const;
uint16_t packaging_descriptor() const;
const std::vector<uint8_t>& level(uint16_t r) const;
size_t data_size() const override;
bool Parse(std::istream& is) override;

View file

@ -22,8 +22,9 @@ public:
{
uint16_t numberOfBytes_;
std::vector<uint8_t> data_;
std::vector<uint8_t> level_;
Row() : numberOfBytes_ {0}, data_ {} {}
Row() : numberOfBytes_ {0}, data_ {}, level_ {} {}
};
explicit RasterDataPacketImpl() :
@ -120,6 +121,11 @@ uint16_t RasterDataPacket::packaging_descriptor() const
return p->packagingDescriptor_;
}
const std::vector<uint8_t>& RasterDataPacket::level(uint16_t r) const
{
return p->row_[r].level_;
}
size_t RasterDataPacket::data_size() const
{
return p->dataSize_;
@ -212,6 +218,28 @@ bool RasterDataPacket::Parse(std::istream& is)
{
row.data_.pop_back();
}
// Unpack the levels from the Run Length Encoded data
uint16_t binCount =
std::accumulate(row.data_.cbegin(),
row.data_.cend(),
0,
[](const uint16_t& a, const uint8_t& b) -> uint16_t
{ return a + (b >> 4); });
row.level_.resize(binCount);
uint16_t b = 0;
for (auto it = row.data_.cbegin(); it != row.data_.cend(); it++)
{
uint8_t run = *it >> 4;
uint8_t level = *it & 0x0f;
for (int i = 0; i < run && b < binCount; i++)
{
row.level_[b++] = level;
}
}
}
}