495 lines
18 KiB
C
495 lines
18 KiB
C
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// File: lzham_symbol_codec.h
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// See Copyright Notice and license at the end of include/lzham.h
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#pragma once
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#include "lzham_prefix_coding.h"
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namespace lzham
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{
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class symbol_codec;
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const uint cSymbolCodecArithMinLen = 0x01000000U;
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const uint cSymbolCodecArithMaxLen = 0xFFFFFFFFU;
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const uint cSymbolCodecArithProbBits = 11;
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const uint cSymbolCodecArithProbScale = 1 << cSymbolCodecArithProbBits;
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const uint cSymbolCodecArithProbHalfScale = 1 << (cSymbolCodecArithProbBits - 1);
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const uint cSymbolCodecArithProbMoveBits = 5;
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typedef uint64 bit_cost_t;
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const uint32 cBitCostScaleShift = 24;
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const uint32 cBitCostScale = (1U << cBitCostScaleShift);
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const bit_cost_t cBitCostMax = cUINT64_MAX;
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inline bit_cost_t convert_to_scaled_bitcost(uint bits) { LZHAM_ASSERT(bits <= 255); uint32 scaled_bits = bits << cBitCostScaleShift; return static_cast<bit_cost_t>(scaled_bits); }
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extern uint32 g_prob_cost[cSymbolCodecArithProbScale];
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class quasi_adaptive_huffman_data_model
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{
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public:
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quasi_adaptive_huffman_data_model(lzham_malloc_context malloc_context = NULL, bool encoding = false, uint total_syms = 0, uint max_update_interval = 0, uint adapt_rate = 0);
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quasi_adaptive_huffman_data_model(const quasi_adaptive_huffman_data_model& other);
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~quasi_adaptive_huffman_data_model();
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bool assign(const quasi_adaptive_huffman_data_model& rhs);
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quasi_adaptive_huffman_data_model& operator= (const quasi_adaptive_huffman_data_model& rhs);
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void clear();
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void set_malloc_context(lzham_malloc_context malloc_context)
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{
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m_malloc_context = malloc_context;
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m_initial_sym_freq.set_malloc_context(malloc_context);
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m_sym_freq.set_malloc_context(malloc_context);
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m_codes.set_malloc_context(malloc_context);
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m_code_sizes.set_malloc_context(malloc_context);
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}
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lzham_malloc_context get_malloc_context() const { return m_malloc_context; }
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bool init2(lzham_malloc_context context, bool encoding, uint total_syms, uint max_update_interval, uint adapt_rate, const uint16 *pInitial_sym_freq);
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bool reset();
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inline uint get_total_syms() const { return m_total_syms; }
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void rescale();
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void reset_update_rate();
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bool update_sym(uint sym);
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inline bit_cost_t get_cost(uint sym) const { return convert_to_scaled_bitcost(m_code_sizes[sym]); }
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public:
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lzham_malloc_context m_malloc_context;
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lzham::vector<uint16> m_initial_sym_freq;
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lzham::vector<uint16> m_sym_freq;
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lzham::vector<uint16> m_codes;
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lzham::vector<uint8> m_code_sizes;
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prefix_coding::decoder_tables* m_pDecode_tables;
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uint m_total_syms;
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uint m_max_cycle;
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uint m_update_cycle;
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uint m_symbols_until_update;
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uint m_total_count;
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uint8 m_decoder_table_bits;
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uint16 m_max_update_interval; // def=16, typical range 12-128, controls the max interval between table updates, higher=longer max interval (faster decode/lower ratio)
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uint16 m_adapt_rate; // def=10, 8 or higher, scaled by 8, controls the slowing of the update update freq, higher=more rapid slowing (faster decode/lower ratio)
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bool m_encoding;
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bool update_tables(int force_update_cycle = -1, bool sym_freq_all_ones = false);
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friend class symbol_codec;
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};
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class adaptive_bit_model
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{
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public:
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inline adaptive_bit_model() { clear(); }
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adaptive_bit_model(float prob0);
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adaptive_bit_model(const adaptive_bit_model& other);
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inline adaptive_bit_model& operator= (const adaptive_bit_model& rhs) { m_bit_0_prob = rhs.m_bit_0_prob; return *this; }
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inline void clear() { m_bit_0_prob = 1U << (cSymbolCodecArithProbBits - 1); }
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void set_probability_0(float prob0);
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inline void update(uint bit)
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{
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if (!bit)
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m_bit_0_prob += ((cSymbolCodecArithProbScale - m_bit_0_prob) >> cSymbolCodecArithProbMoveBits);
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else
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m_bit_0_prob -= (m_bit_0_prob >> cSymbolCodecArithProbMoveBits);
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LZHAM_ASSERT(m_bit_0_prob >= 1);
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LZHAM_ASSERT(m_bit_0_prob < cSymbolCodecArithProbScale);
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}
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inline bit_cost_t get_cost(uint bit) const { return g_prob_cost[bit ? (cSymbolCodecArithProbScale - m_bit_0_prob) : m_bit_0_prob]; }
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public:
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uint16 m_bit_0_prob;
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friend class symbol_codec;
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};
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#if LZHAM_CPU_HAS_64BIT_REGISTERS
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#define LZHAM_SYMBOL_CODEC_USE_64_BIT_BUFFER 1
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#else
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#define LZHAM_SYMBOL_CODEC_USE_64_BIT_BUFFER 0
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#endif
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class symbol_codec
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{
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LZHAM_NO_COPY_OR_ASSIGNMENT_OP(symbol_codec);
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public:
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symbol_codec(lzham_malloc_context malloc_context);
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void reset();
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// clear() is like reset(), except it also frees all memory.
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void clear();
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// Encoding
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bool start_encoding(uint expected_file_size);
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bool encode_bits(uint bits, uint num_bits);
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bool encode_arith_init();
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bool encode_align_to_byte();
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bool encode(uint sym, quasi_adaptive_huffman_data_model& model);
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bool encode(uint bit, adaptive_bit_model& model, bool update_model = true);
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inline uint encode_get_total_bits_written() const { return m_total_bits_written; }
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bool stop_encoding(bool support_arith);
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const lzham::vector<uint8>& get_encoding_buf() const { return m_output_buf; }
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lzham::vector<uint8>& get_encoding_buf() { return m_output_buf; }
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// Decoding
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typedef void (*need_bytes_func_ptr)(size_t num_bytes_consumed, void *pPrivate_data, const uint8* &pBuf, size_t &buf_size, bool &eof_flag);
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bool start_decoding(const uint8* pBuf, size_t buf_size, bool eof_flag = true, need_bytes_func_ptr pNeed_bytes_func = NULL, void *pPrivate_data = NULL);
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inline void decode_set_input_buffer(const uint8* pBuf, size_t buf_size, const uint8* pBuf_next, bool eof_flag)
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{
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m_pDecode_buf = pBuf;
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m_pDecode_buf_next = pBuf_next;
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m_decode_buf_size = buf_size;
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m_pDecode_buf_end = pBuf + buf_size;
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m_decode_buf_eof = eof_flag;
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}
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inline uint64 decode_get_bytes_consumed() const { return m_pDecode_buf_next - m_pDecode_buf; }
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inline uint64 decode_get_bits_remaining() const { return ((m_pDecode_buf_end - m_pDecode_buf_next) << 3) + m_bit_count; }
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void start_arith_decoding();
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uint decode_bits(uint num_bits);
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uint decode_peek_bits(uint num_bits);
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void decode_remove_bits(uint num_bits);
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void decode_align_to_byte();
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int decode_remove_byte_from_bit_buf();
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uint decode(quasi_adaptive_huffman_data_model& model);
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uint decode(adaptive_bit_model& model, bool update_model = true);
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uint64 stop_decoding();
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uint get_total_model_updates() const { return m_total_model_updates; }
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public:
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lzham_malloc_context m_malloc_context;
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const uint8* m_pDecode_buf;
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const uint8* m_pDecode_buf_next;
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const uint8* m_pDecode_buf_end;
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size_t m_decode_buf_size;
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bool m_decode_buf_eof;
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need_bytes_func_ptr m_pDecode_need_bytes_func;
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void* m_pDecode_private_data;
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#if LZHAM_SYMBOL_CODEC_USE_64_BIT_BUFFER
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typedef uint64 bit_buf_t;
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enum { cBitBufSize = 64 };
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#else
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typedef uint32 bit_buf_t;
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enum { cBitBufSize = 32 };
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#endif
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bit_buf_t m_bit_buf;
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int m_bit_count;
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uint m_total_model_updates;
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lzham::vector<uint8> m_output_buf;
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lzham::vector<uint8> m_arith_output_buf;
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struct output_symbol
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{
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uint m_bits;
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enum
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{
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cArithSym = -1,
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cAlignToByteSym = -2,
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cArithInit = -3
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};
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int16 m_num_bits;
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uint16 m_arith_prob0;
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};
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lzham::vector<output_symbol> m_output_syms;
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uint m_total_bits_written;
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uint m_arith_base;
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uint m_arith_value;
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uint m_arith_length;
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uint m_arith_total_bits;
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quasi_adaptive_huffman_data_model* m_pSaved_huff_model;
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void* m_pSaved_model;
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uint m_saved_node_index;
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bool put_bits_init(uint expected_size);
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bool record_put_bits(uint bits, uint num_bits);
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void arith_propagate_carry();
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bool arith_renorm_enc_interval();
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void arith_start_encoding();
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bool arith_stop_encoding();
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bool put_bits(uint bits, uint num_bits);
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bool put_bits_align_to_byte();
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bool flush_bits();
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bool assemble_output_buf();
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uint get_bits(uint num_bits);
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void remove_bits(uint num_bits);
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void decode_need_bytes();
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enum
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{
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cNull,
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cEncoding,
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cDecoding
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} m_mode;
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};
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// Optional macros for faster decompression. These macros implement the symbol_codec class's decode functionality.
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// This is hard to debug (and just plain ugly), but using these macros eliminate function calls, and they place the most important
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// member variables on the stack so they're hopefully put in registers (avoiding horrible load hit stores on some CPU's).
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// The user must define the LZHAM_DECODE_NEEDS_BYTES macro, which is invoked when the decode buffer is exhausted.
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#define LZHAM_SYMBOL_CODEC_DECODE_DECLARE(codec) \
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uint arith_value = 0; \
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uint arith_length = 0; \
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symbol_codec::bit_buf_t bit_buf = 0; \
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int bit_count = 0; \
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const uint8* pDecode_buf_next = NULL;
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#define LZHAM_SYMBOL_CODEC_DECODE_BEGIN(codec) \
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arith_value = codec.m_arith_value; \
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arith_length = codec.m_arith_length; \
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bit_buf = codec.m_bit_buf; \
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bit_count = codec.m_bit_count; \
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pDecode_buf_next = codec.m_pDecode_buf_next;
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#define LZHAM_SYMBOL_CODEC_DECODE_END(codec) \
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codec.m_arith_value = arith_value; \
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codec.m_arith_length = arith_length; \
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codec.m_bit_buf = bit_buf; \
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codec.m_bit_count = bit_count; \
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codec.m_pDecode_buf_next = pDecode_buf_next;
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// The user must declare the LZHAM_DECODE_NEEDS_BYTES macro.
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#define LZHAM_SYMBOL_CODEC_DECODE_GET_BITS(codec, result, num_bits) \
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{ \
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while (LZHAM_BUILTIN_EXPECT(bit_count < (int)(num_bits), 0)) \
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{ \
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uint r; \
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if (LZHAM_BUILTIN_EXPECT(pDecode_buf_next == codec.m_pDecode_buf_end, 0)) \
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{ \
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if (LZHAM_BUILTIN_EXPECT(!codec.m_decode_buf_eof, 1)) \
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{ \
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LZHAM_SYMBOL_CODEC_DECODE_END(codec) \
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LZHAM_DECODE_NEEDS_BYTES \
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LZHAM_SYMBOL_CODEC_DECODE_BEGIN(codec) \
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} \
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r = 0; \
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if (LZHAM_BUILTIN_EXPECT(pDecode_buf_next < codec.m_pDecode_buf_end, 1)) r = *pDecode_buf_next++; \
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} \
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else \
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r = *pDecode_buf_next++; \
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bit_count += 8; \
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bit_buf |= (static_cast<symbol_codec::bit_buf_t>(r) << (symbol_codec::cBitBufSize - bit_count)); \
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} \
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result = (num_bits) ? static_cast<uint>(bit_buf >> (symbol_codec::cBitBufSize - (num_bits))) : 0; \
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bit_buf <<= (num_bits); \
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bit_count -= (num_bits); \
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}
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#define LZHAM_SYMBOL_CODEC_DECODE_ARITH_BIT(codec, result, model) \
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{ \
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adaptive_bit_model *pModel; \
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pModel = &model; \
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while (LZHAM_BUILTIN_EXPECT(arith_length < cSymbolCodecArithMinLen, 0)) \
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{ \
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uint c; codec.m_pSaved_model = pModel; \
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LZHAM_SYMBOL_CODEC_DECODE_GET_BITS(codec, c, 8); \
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pModel = static_cast<adaptive_bit_model*>(codec.m_pSaved_model); \
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arith_value = (arith_value << 8) | c; \
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arith_length <<= 8; \
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} \
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uint x = pModel->m_bit_0_prob * (arith_length >> cSymbolCodecArithProbBits); \
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result = (arith_value >= x); \
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if (!result) \
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{ \
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pModel->m_bit_0_prob += ((cSymbolCodecArithProbScale - pModel->m_bit_0_prob) >> cSymbolCodecArithProbMoveBits); \
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arith_length = x; \
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} \
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else \
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{ \
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pModel->m_bit_0_prob -= (pModel->m_bit_0_prob >> cSymbolCodecArithProbMoveBits); \
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arith_value -= x; \
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arith_length -= x; \
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} \
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}
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#if LZHAM_SYMBOL_CODEC_USE_64_BIT_BUFFER
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#define LZHAM_SYMBOL_CODEC_DECODE_ADAPTIVE_HUFFMAN(codec, result, model) \
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{ \
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quasi_adaptive_huffman_data_model* pModel; const prefix_coding::decoder_tables* pTables; \
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pModel = &model; pTables = model.m_pDecode_tables; \
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if (LZHAM_BUILTIN_EXPECT(bit_count < 24, 0)) \
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{ \
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uint c; \
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pDecode_buf_next += sizeof(uint32); \
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if (LZHAM_BUILTIN_EXPECT(pDecode_buf_next >= codec.m_pDecode_buf_end, 0)) \
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{ \
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pDecode_buf_next -= sizeof(uint32); \
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while (bit_count < 24) \
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{ \
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if (!codec.m_decode_buf_eof) \
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{ \
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codec.m_pSaved_huff_model = pModel; \
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LZHAM_SYMBOL_CODEC_DECODE_END(codec) \
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LZHAM_DECODE_NEEDS_BYTES \
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LZHAM_SYMBOL_CODEC_DECODE_BEGIN(codec) \
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pModel = codec.m_pSaved_huff_model; pTables = pModel->m_pDecode_tables; \
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} \
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c = 0; if (pDecode_buf_next < codec.m_pDecode_buf_end) c = *pDecode_buf_next++; \
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bit_count += 8; \
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bit_buf |= (static_cast<symbol_codec::bit_buf_t>(c) << (symbol_codec::cBitBufSize - bit_count)); \
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} \
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} \
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else \
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{ \
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c = LZHAM_READ_BIG_ENDIAN_UINT32(pDecode_buf_next - sizeof(uint32)); \
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bit_count += 32; \
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bit_buf |= (static_cast<symbol_codec::bit_buf_t>(c) << (symbol_codec::cBitBufSize - bit_count)); \
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} \
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} \
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uint k = static_cast<uint>((bit_buf >> (symbol_codec::cBitBufSize - 16)) + 1); \
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uint len; \
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if (LZHAM_BUILTIN_EXPECT(k <= pTables->m_table_max_code, 1)) \
|
||
|
{ \
|
||
|
uint32 t = pTables->m_lookup[bit_buf >> (symbol_codec::cBitBufSize - pTables->m_table_bits)]; \
|
||
|
result = t & cUINT16_MAX; \
|
||
|
len = t >> 16; \
|
||
|
} \
|
||
|
else \
|
||
|
{ \
|
||
|
len = pTables->m_decode_start_code_size; \
|
||
|
for ( ; ; ) \
|
||
|
{ \
|
||
|
if (LZHAM_BUILTIN_EXPECT(k <= pTables->m_max_codes[len - 1], 0)) \
|
||
|
break; \
|
||
|
len++; \
|
||
|
} \
|
||
|
int val_ptr = pTables->m_val_ptrs[len - 1] + static_cast<int>(bit_buf >> (symbol_codec::cBitBufSize - len)); \
|
||
|
if (((uint)val_ptr >= pModel->m_total_syms)) val_ptr = 0; \
|
||
|
result = pTables->m_sorted_symbol_order[val_ptr]; \
|
||
|
} \
|
||
|
bit_buf <<= len; \
|
||
|
bit_count -= len; \
|
||
|
uint freq = pModel->m_sym_freq[result]; \
|
||
|
freq++; \
|
||
|
pModel->m_sym_freq[result] = static_cast<uint16>(freq); \
|
||
|
LZHAM_ASSERT(freq <= cUINT16_MAX); \
|
||
|
if (LZHAM_BUILTIN_EXPECT(--pModel->m_symbols_until_update == 0, 0)) \
|
||
|
{ \
|
||
|
pModel->update_tables(); \
|
||
|
} \
|
||
|
}
|
||
|
#else
|
||
|
#define LZHAM_SYMBOL_CODEC_DECODE_ADAPTIVE_HUFFMAN(codec, result, model) \
|
||
|
{ \
|
||
|
quasi_adaptive_huffman_data_model* pModel; const prefix_coding::decoder_tables* pTables; \
|
||
|
pModel = &model; pTables = model.m_pDecode_tables; \
|
||
|
while (LZHAM_BUILTIN_EXPECT(bit_count < (symbol_codec::cBitBufSize - 8), 1)) \
|
||
|
{ \
|
||
|
uint c; \
|
||
|
if (LZHAM_BUILTIN_EXPECT(pDecode_buf_next == codec.m_pDecode_buf_end, 0)) \
|
||
|
{ \
|
||
|
if (LZHAM_BUILTIN_EXPECT(!codec.m_decode_buf_eof, 1)) \
|
||
|
{ \
|
||
|
codec.m_pSaved_huff_model = pModel; \
|
||
|
LZHAM_SYMBOL_CODEC_DECODE_END(codec) \
|
||
|
LZHAM_DECODE_NEEDS_BYTES \
|
||
|
LZHAM_SYMBOL_CODEC_DECODE_BEGIN(codec) \
|
||
|
pModel = codec.m_pSaved_huff_model; pTables = pModel->m_pDecode_tables; \
|
||
|
} \
|
||
|
c = 0; if (LZHAM_BUILTIN_EXPECT(pDecode_buf_next < codec.m_pDecode_buf_end, 1)) c = *pDecode_buf_next++; \
|
||
|
} \
|
||
|
else \
|
||
|
c = *pDecode_buf_next++; \
|
||
|
bit_count += 8; \
|
||
|
bit_buf |= (static_cast<symbol_codec::bit_buf_t>(c) << (symbol_codec::cBitBufSize - bit_count)); \
|
||
|
} \
|
||
|
uint k = static_cast<uint>((bit_buf >> (symbol_codec::cBitBufSize - 16)) + 1); \
|
||
|
uint len; \
|
||
|
if (LZHAM_BUILTIN_EXPECT(k <= pTables->m_table_max_code, 1)) \
|
||
|
{ \
|
||
|
uint32 t = pTables->m_lookup[bit_buf >> (symbol_codec::cBitBufSize - pTables->m_table_bits)]; \
|
||
|
result = t & cUINT16_MAX; \
|
||
|
len = t >> 16; \
|
||
|
} \
|
||
|
else \
|
||
|
{ \
|
||
|
len = pTables->m_decode_start_code_size; \
|
||
|
for ( ; ; ) \
|
||
|
{ \
|
||
|
if (LZHAM_BUILTIN_EXPECT(k <= pTables->m_max_codes[len - 1], 0)) \
|
||
|
break; \
|
||
|
len++; \
|
||
|
} \
|
||
|
int val_ptr = pTables->m_val_ptrs[len - 1] + static_cast<int>(bit_buf >> (symbol_codec::cBitBufSize - len)); \
|
||
|
if (LZHAM_BUILTIN_EXPECT(((uint)val_ptr >= pModel->m_total_syms), 0)) val_ptr = 0; \
|
||
|
result = pTables->m_sorted_symbol_order[val_ptr]; \
|
||
|
} \
|
||
|
bit_buf <<= len; \
|
||
|
bit_count -= len; \
|
||
|
uint freq = pModel->m_sym_freq[result]; \
|
||
|
freq++; \
|
||
|
pModel->m_sym_freq[result] = static_cast<uint16>(freq); \
|
||
|
LZHAM_ASSERT(freq <= cUINT16_MAX); \
|
||
|
if (LZHAM_BUILTIN_EXPECT(--pModel->m_symbols_until_update == 0, 0)) \
|
||
|
{ \
|
||
|
pModel->update_tables(); \
|
||
|
} \
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
#define LZHAM_SYMBOL_CODEC_DECODE_ALIGN_TO_BYTE(codec) if (bit_count & 7) { int dummy_result; LZHAM_NOTE_UNUSED(dummy_result); LZHAM_SYMBOL_CODEC_DECODE_GET_BITS(codec, dummy_result, bit_count & 7); }
|
||
|
|
||
|
#define LZHAM_SYMBOL_CODEC_DECODE_REMOVE_BYTE_FROM_BIT_BUF(codec, result) \
|
||
|
{ \
|
||
|
result = -1; \
|
||
|
if (bit_count >= 8) \
|
||
|
{ \
|
||
|
result = static_cast<int>(bit_buf >> (symbol_codec::cBitBufSize - 8)); \
|
||
|
bit_buf <<= 8; \
|
||
|
bit_count -= 8; \
|
||
|
} \
|
||
|
}
|
||
|
|
||
|
#define LZHAM_SYMBOL_CODEC_DECODE_ARITH_START(codec) \
|
||
|
{ \
|
||
|
for ( arith_value = 0, arith_length = 0; arith_length < 4; ++arith_length ) \
|
||
|
{ \
|
||
|
uint val; LZHAM_SYMBOL_CODEC_DECODE_GET_BITS(codec, val, 8); \
|
||
|
arith_value = (arith_value << 8) | val; \
|
||
|
} \
|
||
|
arith_length = cSymbolCodecArithMaxLen; \
|
||
|
}
|
||
|
|
||
|
} // namespace lzham
|