diff options
Diffstat (limited to 'decoder.cc')
| -rw-r--r-- | decoder.cc | 56 |
1 files changed, 24 insertions, 32 deletions
@@ -1,5 +1,5 @@ /* Lziprecover - Data recovery tool for the lzip format - Copyright (C) 2009-2016 Antonio Diaz Diaz. + Copyright (C) 2009-2017 Antonio Diaz Diaz. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -181,7 +181,7 @@ bool LZ_decoder::verify_trailer( const Pretty_print & pp ) const ( 8.0 * member_size ) / data_size, 100.0 * ( 1.0 - ( (double)member_size / data_size ) ) ); if( !error && verbosity >= 4 ) - std::fprintf( stderr, "data CRC %08X, data size %9llu, member size %8llu. ", + std::fprintf( stderr, "CRC %08X, decompressed %9llu, compressed %8llu. ", crc(), data_size, member_size ); if( rdec.get_code() != 0 && !error && verbosity >= 1 ) { // corruption in the last 4 bytes of the EOS marker @@ -204,7 +204,7 @@ int LZ_decoder::decode_member( const Pretty_print & pp ) Bit_model bm_rep2[State::states]; Bit_model bm_len[State::states][pos_states]; Bit_model bm_dis_slot[len_states][1<<dis_slot_bits]; - Bit_model bm_dis[modeled_distances-end_dis_model]; + Bit_model bm_dis[modeled_distances-end_dis_model+1]; Bit_model bm_align[dis_align_size]; Len_model match_len_model; Len_model rep_len_model; @@ -220,25 +220,23 @@ int LZ_decoder::decode_member( const Pretty_print & pp ) const int pos_state = data_position() & pos_state_mask; if( rdec.decode_bit( bm_match[state()][pos_state] ) == 0 ) // 1st bit { - const uint8_t prev_byte = peek_prev(); - if( state.is_char() ) - { - state.set_char1(); - put_byte( rdec.decode_tree8( bm_literal[get_lit_state(prev_byte)] ) ); - } + Bit_model * const bm = bm_literal[get_lit_state(peek_prev())]; + if( state.is_char_set_char() ) + put_byte( rdec.decode_tree8( bm ) ); else - { - state.set_char2(); - put_byte( rdec.decode_matched( bm_literal[get_lit_state(prev_byte)], - peek( rep0 ) ) ); - } + put_byte( rdec.decode_matched( bm, peek( rep0 ) ) ); } else // match or repeated match { int len; if( rdec.decode_bit( bm_rep[state()] ) != 0 ) // 2nd bit { - if( rdec.decode_bit( bm_rep0[state()] ) != 0 ) // 3rd bit + if( rdec.decode_bit( bm_rep0[state()] ) == 0 ) // 3rd bit + { + if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit + { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; } + } + else { unsigned distance; if( rdec.decode_bit( bm_rep1[state()] ) == 0 ) // 4th bit @@ -254,34 +252,28 @@ int LZ_decoder::decode_member( const Pretty_print & pp ) rep1 = rep0; rep0 = distance; } - else - { - if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit - { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; } - } state.set_rep(); len = min_match_len + rdec.decode_len( rep_len_model, pos_state ); } else // match { - const unsigned rep0_saved = rep0; len = min_match_len + rdec.decode_len( match_len_model, pos_state ); - const int dis_slot = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] ); - if( dis_slot < start_dis_model ) rep0 = dis_slot; - else + unsigned distance = rdec.decode_tree6( bm_dis_slot[get_len_state(len)] ); + if( distance >= start_dis_model ) { + const unsigned dis_slot = distance; const int direct_bits = ( dis_slot >> 1 ) - 1; - rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits; + distance = ( 2 | ( dis_slot & 1 ) ) << direct_bits; if( dis_slot < end_dis_model ) - rep0 += rdec.decode_tree_reversed( bm_dis + rep0 - dis_slot - 1, - direct_bits ); + distance += rdec.decode_tree_reversed( + bm_dis + ( distance - dis_slot ), direct_bits ); else { - rep0 += rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits; - rep0 += rdec.decode_tree_reversed4( bm_align ); - if( rep0 == 0xFFFFFFFFU ) // marker found + distance += + rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits; + distance += rdec.decode_tree_reversed4( bm_align ); + if( distance == 0xFFFFFFFFU ) // marker found { - rep0 = rep0_saved; rdec.normalize(); flush_data(); if( len == min_match_len ) // End Of Stream marker @@ -301,7 +293,7 @@ int LZ_decoder::decode_member( const Pretty_print & pp ) } } } - rep3 = rep2; rep2 = rep1; rep1 = rep0_saved; + rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance; state.set_match(); if( rep0 >= dictionary_size || ( rep0 >= pos && !pos_wrapped ) ) { flush_data(); return 1; } |