diff options
Diffstat (limited to '')
| -rw-r--r-- | encoder.cc | 89 |
1 files changed, 47 insertions, 42 deletions
@@ -36,7 +36,7 @@ Prob_prices prob_prices; bool Matchfinder::read_block() throw() { const int size = buffer_size - stream_pos; - const int rd = readblock( ides_, (char *)buffer + stream_pos, size ); + const int rd = readblock( infd_, buffer + stream_pos, size ); stream_pos += rd; if( rd < size ) at_stream_end = true; return ( rd == size || !errno ); @@ -44,13 +44,13 @@ bool Matchfinder::read_block() throw() Matchfinder::Matchfinder( const int dict_size, const int len_limit, - const int ides ) + const int infd ) : partial_data_pos( 0 ), pos( 0 ), cyclic_pos( 0 ), stream_pos( 0 ), - ides_( ides ), + infd_( infd ), match_len_limit_( len_limit ), prev_positions( new int32_t[num_prev_positions] ), at_stream_end( false ) @@ -80,7 +80,7 @@ Matchfinder::Matchfinder( const int dict_size, const int len_limit, bool Matchfinder::reset() throw() { const int size = stream_pos - pos; - std::memmove( buffer, buffer + pos, size ); + if( size > 0 ) std::memmove( buffer, buffer + pos, size ); partial_data_pos = 0; stream_pos -= pos; pos = 0; @@ -130,10 +130,11 @@ int Matchfinder::longest_match_len( int * const distances ) throw() const uint8_t * const data = buffer + pos; const int key2 = num_prev_positions4 + num_prev_positions3 + ( ( (int)data[0] << 8 ) | data[1] ); - const int tmp = crc32[data[0]] ^ data[1] ^ ( (int)data[2] << 8 ); - const int key3 = num_prev_positions4 + ( tmp & ( num_prev_positions3 - 1 ) ); - const int key4 = ( tmp ^ ( crc32[data[3]] << 5 ) ) & - ( num_prev_positions4 - 1 ); + const uint32_t tmp = crc32[data[0]] ^ data[1] ^ ( (uint32_t)data[2] << 8 ); + const int key3 = num_prev_positions4 + + (int)( tmp & ( num_prev_positions3 - 1 ) ); + const int key4 = (int)( ( tmp ^ ( crc32[data[3]] << 5 ) ) & + ( num_prev_positions4 - 1 ) ); if( distances ) { @@ -242,8 +243,8 @@ void LZ_encoder::fill_distance_prices() throw() { for( int dis_state = 0; dis_state < max_dis_states; ++dis_state ) { - int * dsp = dis_slot_prices[dis_state]; - const Bit_model * bmds = bm_dis_slot[dis_state]; + int * const dsp = dis_slot_prices[dis_state]; + const Bit_model * const bmds = bm_dis_slot[dis_state]; int slot = 0; for( ; slot < end_dis_model && slot < num_dis_slots; ++slot ) dsp[slot] = price_symbol( bmds, slot, dis_slot_bits ); @@ -251,7 +252,7 @@ void LZ_encoder::fill_distance_prices() throw() dsp[slot] = price_symbol( bmds, slot, dis_slot_bits ) + (((( slot >> 1 ) - 1 ) - dis_align_bits ) << price_shift ); - int * dp = dis_prices[dis_state]; + int * const dp = dis_prices[dis_state]; int dis = 0; for( ; dis < start_dis_model; ++dis ) dp[dis] = dsp[dis]; @@ -267,8 +268,10 @@ void LZ_encoder::fill_distance_prices() throw() } -// Return value: ( dis == -1 ) && ( len == 1 ) means literal -int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], +// Return value == number of bytes advanced (ahead). +// trials[0]..trials[retval-1] contain the steps to encode. +// ( trials[0].dis == -1 && trials[0].price == 1 ) means literal. +int LZ_encoder::sequence_optimizer( const int reps[num_rep_distances], const State & state ) { int main_len; @@ -303,15 +306,14 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], return main_len; } - trials[0].state = state; - for( int i = 0; i < num_rep_distances; ++i ) trials[0].reps[i] = reps[i]; - + { + const int pos_state = matchfinder.data_position() & pos_state_mask; const uint8_t prev_byte = matchfinder[-1]; const uint8_t cur_byte = matchfinder[0]; const uint8_t match_byte = matchfinder[-reps[0]-1]; - unsigned int position = matchfinder.data_position(); - const int pos_state = position & pos_state_mask; + trials[0].state = state; + for( int i = 0; i < num_rep_distances; ++i ) trials[0].reps[i] = reps[i]; trials[1].dis = -1; trials[1].prev_index = 0; trials[1].price = price0( bm_match[state()][pos_state] ); @@ -359,6 +361,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], trials[len].update( rep, 0, price + rep_match_len_encoder.price( len, pos_state ) ); } + } int cur = 0; int num_trials = main_len; @@ -366,7 +369,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], while( true ) { - if( ++cur >= num_trials ) + if( ++cur >= num_trials ) // no more initialized trials { backward( cur ); return cur; @@ -398,10 +401,11 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], mtf_reps( cur_trial.dis, cur_trial.reps ); } + const int pos_state = matchfinder.data_position() & pos_state_mask; const uint8_t prev_byte = matchfinder[-1]; const uint8_t cur_byte = matchfinder[0]; const uint8_t match_byte = matchfinder[-cur_trial.reps[0]-1]; - const int pos_state = ++position & pos_state_mask; + int next_price = cur_trial.price + price0( bm_match[cur_trial.state()][pos_state] ); if( cur_trial.state.is_char() ) next_price += literal_encoder.price_symbol( prev_byte, cur_byte ); @@ -445,7 +449,7 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], if( newlen <= len_limit && ( newlen > min_match_len || ( newlen == min_match_len && - match_distances[newlen] < modeled_distances ) ) ) + match_distances[min_match_len] < modeled_distances ) ) ) { const int normal_match_price = match_price + price0( bm_rep[cur_trial.state()] ); @@ -461,54 +465,55 @@ int LZ_encoder::best_pair_sequence( const int reps[num_rep_distances], } - // End Of Stream mark => (dis == 0xFFFFFFFF, len == min_match_len) + // End Of Stream mark => (dis == 0xFFFFFFFFU, len == min_match_len) void LZ_encoder::full_flush( const State & state ) { - const int pos_state = ( matchfinder.data_position() ) & pos_state_mask; + const int pos_state = matchfinder.data_position() & pos_state_mask; range_encoder.encode_bit( bm_match[state()][pos_state], 1 ); range_encoder.encode_bit( bm_rep[state()], 0 ); - encode_pair( 0xFFFFFFFF, min_match_len, pos_state ); + encode_pair( 0xFFFFFFFFU, min_match_len, pos_state ); range_encoder.flush(); File_trailer trailer; trailer.data_crc( crc() ); trailer.data_size( matchfinder.data_position() ); - trailer.member_size( range_encoder.member_position() + sizeof trailer ); - for( unsigned int i = 0; i < sizeof trailer; ++i ) - range_encoder.put_byte( ((uint8_t *)&trailer)[i] ); + trailer.member_size( range_encoder.member_position() + File_trailer::size() ); + for( int i = 0; i < File_trailer::size(); ++i ) + range_encoder.put_byte( trailer.data[i] ); range_encoder.flush_data(); } LZ_encoder::LZ_encoder( Matchfinder & mf, const File_header & header, - const int odes ) + const int outfd ) : longest_match_found( 0 ), - crc_( 0xFFFFFFFF ), + crc_( 0xFFFFFFFFU ), matchfinder( mf ), - range_encoder( odes ), + range_encoder( outfd ), len_encoder( matchfinder.match_len_limit() ), rep_match_len_encoder( matchfinder.match_len_limit() ), - literal_encoder(), num_dis_slots( 2 * File_header::real_bits( matchfinder.dictionary_size() - 1 ) ) { fill_align_prices(); - for( unsigned int i = 0; i < sizeof header; ++i ) - range_encoder.put_byte( ((uint8_t *)&header)[i] ); + for( int i = 0; i < File_header::size; ++i ) + range_encoder.put_byte( header.data[i] ); } bool LZ_encoder::encode_member( const long long member_size ) { - if( range_encoder.member_position() != sizeof( File_header ) ) + if( range_encoder.member_position() != File_header::size ) return false; // can be called only once - const long long member_size_limit = member_size - sizeof( File_trailer ) - 16; + const long long member_size_limit = + member_size - File_trailer::size() - max_marker_size; int fill_counter = 0; int rep_distances[num_rep_distances]; State state; for( int i = 0; i < num_rep_distances; ++i ) rep_distances[i] = 0; - if( !matchfinder.finished() ) // encode first byte + // encode first byte + if( matchfinder.data_position() == 0 && !matchfinder.finished() ) { range_encoder.encode_bit( bm_match[state()][0], 0 ); const uint8_t prev_byte = 0; @@ -523,22 +528,23 @@ bool LZ_encoder::encode_member( const long long member_size ) if( matchfinder.finished() ) { full_flush( state ); return true; } if( fill_counter <= 0 ) { fill_distance_prices(); fill_counter = 512; } - int ahead = best_pair_sequence( rep_distances, state ); + int ahead = sequence_optimizer( rep_distances, state ); if( ahead <= 0 ) return false; fill_counter -= ahead; for( int i = 0; ; ) { const int pos_state = ( matchfinder.data_position() - ahead ) & pos_state_mask; - int dis = trials[i].dis; + const int dis = trials[i].dis; const int len = trials[i].price; bool bit = ( dis < 0 && len == 1 ); range_encoder.encode_bit( bm_match[state()][pos_state], !bit ); - if( bit ) + if( bit ) // literal byte { const uint8_t prev_byte = matchfinder[-ahead-1]; const uint8_t cur_byte = matchfinder[-ahead]; + crc32.update( crc_, cur_byte ); if( state.is_char() ) literal_encoder.encode( range_encoder, prev_byte, cur_byte ); else @@ -548,8 +554,9 @@ bool LZ_encoder::encode_member( const long long member_size ) } state.set_char(); } - else + else // match or repeated match { + crc32.update( crc_, matchfinder.ptr_to_current_pos() - ahead, len ); mtf_reps( dis, rep_distances ); bit = ( dis < num_rep_distances ); range_encoder.encode_bit( bm_rep[state()], bit ); @@ -578,8 +585,6 @@ bool LZ_encoder::encode_member( const long long member_size ) state.set_match(); } } - for( int j = 0; j < len; ++j ) - crc32.update( crc_, matchfinder[j-ahead] ); ahead -= len; i += len; if( range_encoder.member_position() >= member_size_limit ) { |