FFmpeg
mlz.h
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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 {
41  int char_code;
42  int match_len;
43 } MLZDict;
44 
45 /** MLZ data strucure
46  */
47 typedef struct MLZ {
50  unsigned int bump_code;
51  unsigned int flush_code;
52  int next_code;
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*/
Dictionary structure for mlz decompression.
Definition: mlz.h:38
void ff_mlz_flush_dict(MLZ *dict)
Flush the dictionary.
Definition: mlz.c:35
int dic_code_bit
Definition: mlz.h:48
int ff_mlz_decompression(MLZ *mlz, GetBitContext *gb, int size, unsigned char *buff)
Run mlz decompression on the next size bits and the output will be stored in buff.
Definition: mlz.c:123
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:100
MLZDict * dict
Definition: mlz.h:54
int parent_code
Definition: mlz.h:40
unsigned int bump_code
Definition: mlz.h:50
unsigned int flush_code
Definition: mlz.h:51
int char_code
Definition: mlz.h:41
MLZ data strucure.
Definition: mlz.h:47
void ff_mlz_init_dict(void *context, MLZ *mlz)
Initialize the dictionary.
Definition: mlz.c:23
int match_len
Definition: mlz.h:42
int freeze_flag
Definition: mlz.h:53
int string_code
Definition: mlz.h:39
void * context
Definition: mlz.h:55
int current_dic_index_max
Definition: mlz.h:49
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without and describe what they for example set the foo of the bar offset is the offset of the field in your local context
int next_code
Definition: mlz.h:52