#include "BitStream.hpp" namespace util { const uint8_t bitmasks[] = {0, 128, 192, 224, 240, 248, 252, 254}; BitStreamReader::BitStreamReader(uint8_t *b, size_t s) : BitStream(b, s, 0, false) {} BitStreamReader::~BitStreamReader() {} void BitStreamReader::flush() { this->position = this->get_last_byte_position() * 8u; } uint8_t BitStreamReader::get_bit() { const size_t current_start_byte = this->position / 8u; if (current_start_byte >= this->get_size()) { // Prevent reading byte outside of array (-> Valgrind flagged) return 0u; } const size_t bits_taken = this->position % 8; const uint8_t value = this->buffer[current_start_byte]; this->position++; return (value & (1 << (7 - bits_taken))) != 0; } uint32_t BitStreamReader::get(size_t l) { uint32_t value = 0; for (size_t i = 0; i < l; i++) { const uint32_t v = this->get_bit(); value |= v << (l - i - 1); //printf("%s %d pos %d i %d v %d value %x\n", __func__, __LINE__, position, i, v, value); } return value; } //////////////////////////////////////////////////////////////////////////////////// BitStreamWriter::BitStreamWriter(size_t s) : BitStream(util::allocArray(s), s, 0, true) { //printf("Allocated buffer of size: %d\n", s); } BitStreamWriter::BitStreamWriter(uint8_t *b, size_t s) : BitStream(b, s, 0, false) {} BitStreamWriter::~BitStreamWriter() {} void BitStreamWriter::flush() { if (this->position % 8 != 0) { this->buffer[this->position / 8] &= bitmasks[this->position % 8]; this->position += 8 - (this->position % 8); } } void BitStreamWriter::put_bit(int8_t value) { const size_t bits_taken = this->position % 8; if (value) { this->buffer[this->position / 8] |= 1 << (7 - bits_taken); } else { this->buffer[this->position / 8] &= ~(1 << (7 - bits_taken)); } this->position++; } void BitStreamWriter::put(size_t length, uint32_t value) { for (size_t p = 0; p < length; p++) { put_bit(1 & (value >> (length - 1 - p))); } } void write(FILE *f, const BitStreamWriter &b) { const size_t position = b.get_position(); const uint8_t *buffer = b.get_buffer(); fwrite(buffer, 1, position / 8, f); if (position % 8 != 0) { fwrite(buffer + position / 8, 1, 1, f); } } void write(std::ofstream &fs, const BitStreamWriter &b) { const size_t position = b.get_position(); const uint8_t *buffer = b.get_buffer(); fs.write(reinterpret_cast(buffer), position / 8); if (position % 8 != 0) { fs.write(reinterpret_cast(buffer + position / 8), 1); } } }