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Initial fixed huffman coding for png.

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This commit is contained in:
James Grogan 2022-11-28 10:16:04 +00:00
parent e4f9393ee7
commit 7f5009fb5e
39 changed files with 1294 additions and 440 deletions
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35
src/compression/Lz77Encoder.cpp
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@ -2,6 +2,10 @@
#include "StringUtils.h"
#include "BitStream.h"
#include "ByteUtils.h"
#include "HuffmanEncoder.h"
#include <iostream>
Lz77Encoder::Lz77Encoder(BitStream* inputStream, BitStream* outputStream)
: AbstractEncoder(inputStream, outputStream)
@ -61,8 +65,39 @@ void Lz77Encoder::lookThroughSearchBuffer(char searchChar, unsigned& hitLength,
}
}
void Lz77Encoder::setPrefixCodeGenerator(std::unique_ptr<PrefixCodeGenerator> generator)
{
mCodeGenerator = std::move(generator);
}
bool Lz77Encoder::encode()
{
if (!mCodeGenerator)
{
auto code_generator = std::make_unique<HuffmanEncoder>();
auto huffman_encoder = code_generator.get();
mCodeGenerator = std::move(code_generator);
huffman_encoder->setUseFixedCode(true);
huffman_encoder->initializeLiteralLengthTable();
}
while(auto byte = mInputStream->readNextByte())
{
const auto code = mCodeGenerator->getLiteralValue(*byte);
std::cout << "Writing value " << static_cast<int>(*byte) << " with code " << ByteUtils::toString(code.getData(), code.getLength()) << "\n";
mOutputStream->writeNBits(code.getData(), code.getLength());
}
auto eos_code = mCodeGenerator->getEndOfStreamValue();
std::cout << "Writing EOS value with code " << ByteUtils::toString(eos_code.getData(), eos_code.getLength()) << "\n";
mOutputStream->writeNBits(eos_code.getData(), eos_code.getLength());
/*
unsigned loc{0};
std::string ret;