FFmpeg
rl.h
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1 /*
2  * Copyright (c) 2000-2002 Fabrice Bellard
3  * Copyright (c) 2002-2004 Michael Niedermayer
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * rl header.
25  */
26 
27 #ifndef AVCODEC_RL_H
28 #define AVCODEC_RL_H
29 
30 #include <stdint.h>
31 
32 #include "vlc.h"
33 
34 /* run length table */
35 #define MAX_RUN 64
36 #define MAX_LEVEL 64
37 
38 /** RLTable. */
39 typedef struct RLTable {
40  int n; ///< number of entries of table_vlc minus 1
41  int last; ///< number of values for last = 0
42  const uint16_t (*table_vlc)[2];
43  const int8_t *table_run;
44  const int8_t *table_level;
45  uint8_t *index_run[2]; ///< encoding only
46  int8_t *max_level[2]; ///< encoding & decoding
47  int8_t *max_run[2]; ///< encoding & decoding
48  RL_VLC_ELEM *rl_vlc[32]; ///< decoding only
49 } RLTable;
50 
51 /**
52  * Initialize index_run, max_level and max_run from n, last, table_vlc,
53  * table_run and table_level.
54  * @param static_store static uint8_t array[2][2*MAX_RUN + MAX_LEVEL + 3]
55  * to hold the level and run tables.
56  * @note This function does not touch rl_vlc at all, hence there is no need
57  * to synchronize calls to ff_rl_init() and ff_rl_init_vlc() using the
58  * same RLTable.
59  */
60 void ff_rl_init(RLTable *rl, uint8_t static_store[2][2*MAX_RUN + MAX_LEVEL + 3]);
61 
62 /**
63  * Initialize rl_vlc from n, last, table_vlc, table_run and table_level.
64  * All rl_vlc pointers to be initialized must already point to a static
65  * buffer of `static_size` RL_VLC_ELEM elements; if a pointer is NULL,
66  * initializing further VLCs stops.
67  * @note This function does not touch what ff_rl_init() initializes at all,
68  * hence there is no need to synchronize calls to ff_rl_init() and
69  * ff_rl_init_vlc() using the same RLTable.
70  */
71 void ff_rl_init_vlc(RLTable *rl, unsigned static_size);
72 
73 #define INIT_VLC_RL(rl, static_size)\
74 {\
75  static RL_VLC_ELEM rl_vlc_table[32][static_size];\
76 \
77  for (int q = 0; q < 32; q++) \
78  rl.rl_vlc[q] = rl_vlc_table[q]; \
79 \
80  ff_rl_init_vlc(&rl, static_size); \
81 }
82 
83 #define INIT_FIRST_VLC_RL(rl, static_size) \
84 do { \
85  static RL_VLC_ELEM rl_vlc_table[static_size]; \
86  \
87  rl.rl_vlc[0] = rl_vlc_table; \
88  ff_rl_init_vlc(&rl, static_size); \
89 } while (0)
90 
91 static inline int get_rl_index(const RLTable *rl, int last, int run, int level)
92 {
93  int index;
94  index = rl->index_run[last][run];
95  if (index >= rl->n)
96  return rl->n;
97  if (level > rl->max_level[last][run])
98  return rl->n;
99  return index + level - 1;
100 }
101 
102 #endif /* AVCODEC_RL_H */
level
uint8_t level
Definition: svq3.c:202
RLTable::index_run
uint8_t * index_run[2]
encoding only
Definition: rl.h:45
MAX_RUN
#define MAX_RUN
Definition: rl.h:35
index
fg index
Definition: ffmpeg_filter.c:167
RLTable
RLTable.
Definition: rl.h:39
RLTable::n
int n
number of entries of table_vlc minus 1
Definition: rl.h:40
RLTable::max_level
int8_t * max_level[2]
encoding & decoding
Definition: rl.h:46
get_rl_index
static int get_rl_index(const RLTable *rl, int last, int run, int level)
Definition: rl.h:91
run
uint8_t run
Definition: svq3.c:201
RLTable::table_vlc
const uint16_t(* table_vlc)[2]
Definition: rl.h:42
MAX_LEVEL
#define MAX_LEVEL
Definition: rl.h:36
RLTable::table_level
const int8_t * table_level
Definition: rl.h:44
RL_VLC_ELEM
Definition: vlc.h:32
ff_rl_init_vlc
void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
Initialize rl_vlc from n, last, table_vlc, table_run and table_level.
Definition: rl.c:62
RLTable::max_run
int8_t * max_run[2]
encoding & decoding
Definition: rl.h:47
RLTable::last
int last
number of values for last = 0
Definition: rl.h:41
ff_rl_init
void ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Initialize index_run, max_level and max_run from n, last, table_vlc, table_run and table_level.
Definition: rl.c:27
vlc.h
RLTable::table_run
const int8_t * table_run
Definition: rl.h:43
RLTable::rl_vlc
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48