1 /* 2 * Copyright (c) 2016 Umair Khan <omerjerk@gmail.com> 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef AVCODEC_MLZ_H 22 #define AVCODEC_MLZ_H 23 24 #include "get_bits.h" 25 26 #define CODE_UNSET -1 27 #define CODE_BIT_INIT 9 28 #define DIC_INDEX_INIT 512 // 2^9 29 #define DIC_INDEX_MAX 32768 // 2^15 30 #define FLUSH_CODE 256 31 #define FREEZE_CODE 257 32 #define FIRST_CODE 258 33 #define MAX_CODE 32767 34 #define TABLE_SIZE 35023 // TABLE_SIZE must be a prime number 35 36 /** Dictionary structure for mlz decompression 37 */ 38 typedef struct MLZDict { 39 int string_code; 40 int parent_code; 41 int char_code; 42 int match_len; 43 } MLZDict; 44 45 /** MLZ data strucure 46 */ 47 typedef struct MLZ { 48 int dic_code_bit; 49 int current_dic_index_max; 50 unsigned int bump_code; 51 unsigned int flush_code; 52 int next_code; 53 int freeze_flag; 54 MLZDict* dict; 55 void* context; 56 } MLZ; 57 58 /** Initialize the dictionary 59 */ 60 void ff_mlz_init_dict(void* context, MLZ *mlz); 61 62 /** Flush the dictionary 63 */ 64 void ff_mlz_flush_dict(MLZ *dict); 65 66 /** Run mlz decompression on the next size bits and the output will be stored in buff 67 */ 68 int ff_mlz_decompression(MLZ* mlz, GetBitContext* gb, int size, unsigned char *buff); 69 70 #endif /*AVCODEC_MLZ_H*/ 71