blob: c3df52c9b4f193e11a5eff06a0ab753c525c741b
| 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 |