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
get_rl_index(const RLTable * rl,int last,int run,int level)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 */
103